Spectrum Pharmaceuticals (SPPI) 10-K 28 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 21, 2019	Jun. 29, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	SPPI
Entity Registrant Name	SPECTRUM PHARMACEUTICALS INC
Entity Central Index Key	831,547
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		111,049,989
Entity Public Float			$ 1,786,580,557

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 157,480	$ 227,323
Marketable securities	46,508	248
Accounts receivable, net of allowance for doubtful accounts of $67 and $71, respectively	29,873	32,260
Other receivables	3,698	2,133
Inventories	3,550	5,715
Prepaid expenses and other assets	9,579	10,067
Total current assets	250,688	277,746
Property and equipment, net of accumulated depreciation	385	589
Intangible assets, net of accumulated amortization	111,594	137,159
Goodwill	18,061	18,162
Other assets	10,158	53,783
Total assets	390,886	487,439
Current liabilities:
Accounts payable and other accrued liabilities	69,460	58,117
Accrued payroll and benefits	9,853	9,261
Contract liabilities	4,850
Deferred revenue	0	3,872
FOLOTYN development liability	2,311	275
Convertible senior notes	0	38,224
Total current liabilities	86,474	109,749
FOLOTYN development liability, less current portion	9,686	12,111
Deferred revenue, less current portion	0	315
Acquisition-related contingent obligations	4,345	6,272
Deferred tax liabilities	1,469	1,438
Other long-term liabilities	5,650	6,215
Total liabilities	107,624	136,100
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.001 par value; 300,000,000 shares authorized; 110,525,141 and 100,742,735 issued and outstanding at December 31, 2018 and 2017, respectively	110	100
Additional paid-in capital	886,740	837,347
Accumulated other comprehensive (loss) income	(3,702)	15,999
Accumulated deficit	(599,886)	(502,107)
Total stockholders’ equity	283,262	351,339
Total liabilities and stockholders’ equity	$ 390,886	$ 487,439

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 67	$ 71
Preferred stock, par value ($ per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (shares)	5,000,000	5,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value ($ per share)	$ 0.001	$ 0.001
Common stock, shares authorized (shares)	300,000,000	300,000,000
Common stock, shares issued (shares)	110,525,141	100,742,735
Common stock, shares outstanding (shares)	110,525,141	100,742,735

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Total revenues	$ 109,333	$ 128,367	$ 146,444
Operating costs and expenses:
Selling, general and administrative	90,700	84,267	88,418
Research and development	94,956	65,895	59,123
Amortization of intangible assets	28,098	27,647	25,946
Total operating costs and expenses	240,510	225,027	209,330
Loss from operations	(131,177)	(96,660)	(62,886)
Other income (expense):
Interest expense, net	(340)	(6,798)	(9,435)
Change in fair value of contingent consideration related to acquisitions	1,927	(4,957)	(649)
Other income, net	9,580	389	887
Total other income (expenses)	11,167	(11,366)	(9,197)
Loss before income taxes	(120,010)	(108,026)	(72,083)
(Provision) benefit for income taxes	(1)	16,778	2,313
Net loss	$ (120,011)	$ (91,248)	$ (69,770)
Net loss per share:
Basic ($ per share)	$ (1.16)	$ (1.07)	$ (0.96)
Diluted ($ per share)	$ (1.16)	$ (1.07)	$ (0.96)
Weighted average shares outstanding:
Basic (shares)	103,305,911	85,115,592	72,824,070
Diluted (shares)	103,305,911	85,115,592	72,824,070
Product [Member]
Revenues:
Total revenues	$ 104,466	$ 116,178	$ 128,596
Operating costs and expenses:
Cost of sales (excludes amortization of intangible assets)	26,756	42,859	27,953
License and Service [Member]
Revenues:
Total revenues	4,867	12,189	17,848
Service [Member]
Operating costs and expenses:
Cost of service revenue	$ 0	$ 4,359	$ 7,890

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (120,011)	$ (91,248)	$ (69,770)
Other comprehensive (loss) income :
Unrealized loss on available-for-sale securities, net of income tax expense of $0, $2.2 million and $0 for the years ended December 31, 2018, 2017, and 2016, respectively	0	16,039	4,185
Foreign currency translation adjustments	(2,490)	1,539	(445)
Other comprehensive (loss) income	(2,490)	17,578	3,740
Total comprehensive loss	$ (122,501)	$ (73,670)	$ (66,030)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Unrealized gain (loss) on available-for-sale securities, tax	$ 0	$ 9.7	$ 2.2

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Total Stockholders Equity [Member]	ROLONTIS [Member]Common Stock [Member]	ROLONTIS [Member]Additional Paid-In Capital [Member]	ROLONTIS [Member]Total Stockholders Equity [Member]	QAPZOLA [Member]Common Stock [Member]	QAPZOLA [Member]Additional Paid-In Capital [Member]	QAPZOLA [Member]Total Stockholders Equity [Member]
Beginning Balance at Dec. 31, 2015		$ 123	$ 68	$ 559,068	$ (5,319)	$ (341,083)	$ 212,857
Beginning Balance, (shares) at Dec. 31, 2015		20	68,228,935
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (69,770)					(69,770)	(69,770)
Other comprehensive income (loss), net	$ 3,740				3,740		3,740
Issuance of common stock to 401(k) plan				953			953
Issuance of common stock to 401(k) plan, (shares)			172,650
Issuance of common stock for ESPP				668			668
Issuance of common stock for ESPP, (shares)			150,303
Issuance of common stock upon exercise of stock options				202			202
Issuance of common stock upon exercise of stock options, (shares)	39,010		39,010
RSA and stock option issuances and forfeitures for terminations, net	$ 1			12,717			12,718
RSA and stock option issuances and forfeitures for terminations, net, (shares)			868,032
Repurchase/retirement of RSAs to satisfy employee tax withholding				(1,397)			(1,397)
Repurchase/retirement of RSAs to satisfy employee tax withholding (shares)			(266,860)
Common stock issued under an at-the-market sales agreement (Note 7)			$ 11	73,858			73,869
Common stock issued under an at-the-market sales agreement (Note 7) (shares)	10,890,915		10,890,915
Issuance of common stock for milestone achievement									$ 2,308	$ 2,308		$ 111	$ 111
Issuance of common stock for milestone achievement, (shares)								318,750			25,000
Conversion hedge unwind in connection with open market purchases of 2018 Convertible Notes (Note 15)				(227)			(227)
Conversion of preferred shares into common stock (Note 7)		$ (123)		123			0
Conversion of preferred shares into common stock (Note 7) (shares)		(20)	40,000
Dividend paid on preferred shares (Note 7)	$ (6)					(6)
Ending Balance at Dec. 31, 2016		$ 0	$ 80	648,384	(1,579)	(410,859)	236,026
Ending Balance, (shares) at Dec. 31, 2016		0	80,466,735
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(91,248)					(91,248)	(91,248)
Other comprehensive income (loss), net	$ 17,578				17,578		17,578
Issuance of common stock to 401(k) plan				912			912
Issuance of common stock to 401(k) plan, (shares)			102,874
Issuance of common stock for ESPP				1,010			1,010
Issuance of common stock for ESPP, (shares)			203,229
Issuance of common stock upon exercise of stock options			$ 1	5,477			5,478
Issuance of common stock upon exercise of stock options, (shares)	937,482		864,897
RSA and stock option issuances and forfeitures for terminations, net				13,197			13,197
RSA and stock option issuances and forfeitures for terminations, net, (shares)			548,394
Repurchase/retirement of RSAs to satisfy employee tax withholding				(4,331)			(4,331)
Repurchase/retirement of RSAs to satisfy employee tax withholding (shares)			(373,822)
Issuance of common stock upon vesting of RSUs				1,030			1,030
Common stock issued under an at-the-market sales agreement (Note 7)			$ 14	128,258			128,272
Common stock issued under an at-the-market sales agreement (Note 7) (shares)			13,558,132
Conversion hedge unwind in connection with open market purchases of 2018 Convertible Notes (Note 15)			$ 5	43,410			43,415
Conversion hedge unwind in connection with open market purchases of 2018 Convertible Notes (Note 15) (shares)			5,372,296
Ending Balance at Dec. 31, 2017	$ 351,339	$ 0	$ 100	837,347	15,999	(502,107)	351,339
Ending Balance, (shares) at Dec. 31, 2017	100,742,735	0	100,742,735
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment of adopting ASUs | Accounting Standards Update 2016-01 [Member]					(17,200)	17,200
Net loss	$ (120,011)					(120,011)	(120,011)
Other comprehensive income (loss), net	$ (2,490)				(2,490)		(2,490)
Issuance of common stock to 401(k) plan				1,175			1,175
Issuance of common stock to 401(k) plan, (shares)			70,379
Issuance of common stock for ESPP				1,122			1,122
Issuance of common stock for ESPP, (shares)			97,804
Issuance of common stock upon exercise of stock options			$ 8	52,977			52,985
Issuance of common stock upon exercise of stock options, (shares)	7,858,141		7,858,141
RSA and stock option issuances and forfeitures for terminations, net			$ 1	14,113			14,114
RSA and stock option issuances and forfeitures for terminations, net, (shares)			874,532
Repurchase/retirement of RSAs to satisfy employee tax withholding			$ (3)	(62,541)			(62,544)
Repurchase/retirement of RSAs to satisfy employee tax withholding (shares)			(3,463,873)
Issuance of common stock upon vesting of RSUs	$ 2,196			2,196
Issuance of common stock upon vesting of RSUs (shares)			200,652
Issuance of common stock upon exercise of warrants	0
Issuance of common stock upon exercise of warrants (shares)			292,575
Conversion hedge unwind in connection with open market purchases of 2018 Convertible Notes (Note 15)			$ 4	40,351			40,355
Conversion hedge unwind in connection with open market purchases of 2018 Convertible Notes (Note 15) (shares)			3,852,196
Ending Balance at Dec. 31, 2018	$ 283,262	$ 0	$ 110	$ 886,740	$ (3,702)	$ (599,886)	$ 283,262
Ending Balance, (shares) at Dec. 31, 2018	110,525,141	0	110,525,141

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows From Operating Activities:
Net loss	$ (120,011)	$ (91,248)	$ (69,770)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	28,409	27,972	26,492
Stock-based compensation	17,483	15,139	13,670
Accretion of debt discount on 2018 Convertible Notes, recorded to interest expense (Note 15)	1,931	4,890	5,710
Amortization of deferred financing costs on 2018 Convertible Notes, recorded to interest expense (Note 15)	220	567	696
Bad debt expense (recovery)	12	(17)	57
Unrealized loss (gains) from transactions denominated in foreign currency	10	(23)	(153)
Loss on 2018 Convertible Note purchase (Note 15)	0	845	25
Change in cash surrender value of corporate-owned life insurance policy	(5)	(418)	(137)
Deferred tax liabilities	31	(5,237)	(104)
Income tax recognition on unrealized gain for available-for-sale securities	0	(9,651)	(2,217)
Unrealized gains on marketable securities (Note 3(a))	(10,458)	0	0
Change in fair value of contingent consideration related to the Talon and EVOMELA acquisitions (Note 10)	(1,927)	4,957	649
Research and development expense recognized for the value of common stock issued in connection with QAPZOLA (Note 17(b)(x)) and ROLONTIS (Note 17(b)(xiii)) milestone achievements	0	0	2,419
Changes in operating assets and liabilities:
Accounts receivable, net	2,844	7,694	(9,494)
Other receivables	(1,571)	3,663	6,895
Inventories	3,390	4,318	(5,800)
Prepaid expenses	(3,642)	(6,137)	(423)
Other assets	5,010	1,573	(2,043)
Accounts payable and other accrued obligations	11,382	5,518	(4,033)
Accrued payroll and benefits	592	280	790
FOLOTYN development liability	(389)	(744)	(1,556)
Acquisition-related contingent obligations	0	0	(1,300)
Contract liabilities	4,850
Deferred revenue	0	593	(2,985)
Other long-term liabilities	(564)	(3,389)	2,153
Net cash used in operating activities	(62,403)	(38,855)	(40,459)
Cash Flows From Investing Activities:
Proceeds from redemption of corporate-owned life insurance policy	4,130	0	0
Payment for corporate-owned life insurance premiums	0	(601)	(601)
Purchases of property and equipment	(107)	(465)	(78)
Cash paid for KHAPZORY distribution rights (Note 3(g))	(2,650)	0	0
Purchase of equity securities (Note 11)	0	(15)	0
Net cash provided by (used in) investing activities	1,373	(1,081)	(679)
Cash Flows From Financing Activities:
Proceeds from employees for exercises of stock options, net	13,475	5,477	203
Proceeds from sale of stock under our employee stock purchase plan	1,122	1,010	668
Proceeds from employees, for our remittance to tax authorities, upon vesting of restricted stock	4,645	0	0
Payments to tax authorities upon employees' surrender of restricted stock at vesting and exercises of stock options	(27,679)	(4,331)	(1,397)
Payment of principal upon the maturity of the 2018 Convertible Notes (Note 15)	(20)	0	0
Payment of contingent consideration related to EVOMELA acquisition (Note 10(b))	0	0	(4,700)
Purchase of 2018 Convertible Notes (Note 15)	0	(27,500)	(9,014)
Purchase of warrants related to the conversion hedge of 2018 Convertible Notes (Note 15)	0	(27,189)	(330)
Proceeds from sale of call options related to the conversion hedge of 2018 Convertible Notes (Note 15)	0	32,982	351
Proceeds from sale of common stock under an at-the-market sales agreement (Note 7)	0	128,272	73,869
Dividends paid upon conversion of Series E Convertible Voting Preferred Stock (Note 7)	0	0	(6)
Net cash (used in) provided by financing activities	(8,457)	108,721	59,644
Effect of exchange rates on cash and equivalents	(356)	316	(25)
Net (decrease) increase in cash and cash equivalents	(69,843)	69,101	18,481
Cash and cash equivalents — beginning of year	227,323	158,222	139,741
Cash and cash equivalents — end of year	157,480	227,323	158,222
Supplemental Disclosure of Cash Flow Information:
Cash paid for income taxes	45	17	11
Cash paid for interest	$ 1,031	$ 2,692	$ 3,300

Description of Business, Basis

Description of Business, Basis of Presentation, and Operating Segment	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Description of Business, Basis of Presentation, and Operating Segment	DESCRIPTION OF BUSINESS, BASIS OF PRESENTATION, AND OPERATING SEGMENT (a) Description of Business Spectrum Pharmaceuticals, Inc. (“Spectrum,” the “Company,” “we,” “our,” or “us”) is a biopharma company, with a primary strategy comprised of acquiring, developing, and commercializing a broad and diverse pipeline of clinical and commercial products. We have an in-house clinical development organization with regulatory and data management capabilities, in addition to commercial infrastructure and a field-based sales force for our marketed products. Currently, we have seven approved oncology/hematology products (FUSILEV, KHAPZORY, FOLOTYN, ZEVALIN, MARQIBO, BELEODAQ, and EVOMELA) that target different types of non-Hodgkin's lymphoma ("NHL"), advanced metastatic colorectal cancer ("mCRC"), acute lymphoblastic leukemia ("ALL"), and multiple myeloma ("MM"). We also have two drugs in late-stage development: • Poziotinib, a novel pan-HER inhibitor under investigation for non-small cell lung cancer ("NSCLC") tumors with either EGFR or HER2 exon-20 insertion mutations; and • ROLONTIS, a novel long-acting granulocyte colony-stimulating factor ("G-CSF"), analog for chemotherapy-induced neutropenia. On January 17, 2019, we entered into a definitive asset purchase agreement for the sale of our FDA-approved product portfolio of FUSILEV, KHAPZORY, FOLOTYN, ZEVALIN, MARQIBO, BELEODAQ, and EVOMELA to Acrotech Biopharma L.L.C. ("Acrotech"), a New Jersey-based wholly-owned subsidiary of Aurobindo Pharma USA Inc. (the "Acrotech Transaction"). Upon the closing of the Acrotech Transaction, we are entitled to receive up to $160 million in an upfront cash payment (of which $4 million will be held in escrow for six months ). In addition, we expect a purchase price adjustment for certain ongoing research and development activities of the commercialized product portfolio. We are also entitled to receive an aggregate $140 million upon Acrotech's achievement of certain regulatory and sales-based milestones relating to this product portfolio. We plan to reduce our staff by approximately 90 employees, the majority of which we expect to transition to Acrotech. The accounting recognition and financial reporting for the disposal of this commercial component of our business will be reflected in our financial statements in the period corresponding with its closing. (b) Basis of Presentation Principles of Consolidation The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") and with the rules and regulations of the Securities and Exchange Commission ("SEC"). These financial statements include the financial position, results of operations, and cash flows of Spectrum and its subsidiaries, all of which are wholly-owned (except for Spectrum Pharma Canada ("SPC")), as discussed below. All inter-company accounts and transactions among these legal entities have been eliminated in consolidation. Variable Interest Entity We own fifty -percent of SPC, a legal entity organized in Quebec, Canada in January 2008. Some of our clinical studies are conducted through this “variable interest entity” (as defined under applicable GAAP). We fund all of SPC’s operating costs, and since we assume all risks and rewards for this entity, we meet the criteria as being its “primary beneficiary” (as defined under applicable GAAP). Accordingly, SPC’s balance sheets and statements of operations are included in our Consolidated Financial Statements as if it were a wholly-owned subsidiary for all periods presented. (c) Operating Segment We operate in one reportable operating segment that is focused exclusively on developing and marketing oncology and hematology drug products. For the years ended December 31, 2018 , 2017 , and 2016 , all of our revenue and related expenses were solely attributable to these activities. Substantially all of our assets (excluding our cash held in certain foreign bank accounts and our ZEVALIN distribution rights for the ex-U.S. territories - see Note 3(g) ) are held in the U.S.

Balance Sheet Account Detail

Balance Sheet Account Detail	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Account Detail	BALANCE SHEET ACCOUNT DETAIL The composition of selected financial statement captions that comprise the accompanying Consolidated Balance Sheets are summarized below: (a) Cash and Cash Equivalents and Marketable Securities As of December 31, 2018 and December 31, 2017 , our “cash and cash equivalents” were held with major financial institutions. Our “marketable securities” primarily relate to our equity holdings in CASI Pharmaceuticals, Inc. (“CASI”), as defined below. We maintain cash balances in excess of federally insured limits with reputable financial institutions. To a limited degree, the Federal Deposit Insurance Corporation and other third parties insure these investments. However, these investments are not insured against the possibility of a complete loss of earnings or principal and are inherently subject to the credit risk related to the continued credit worthiness of the underlying issuer and general credit market risks. We manage such risks in our portfolio by investing in highly liquid, highly-rated instruments, and limit investing in long-term maturity instruments. Our investment policy requires that purchased investments in marketable securities may only be in highly-rated instruments, which are primarily U.S. treasury bills or treasury-backed securities, and also limits our investments in securities of any single issuer (excluding any debt or equity securities received from our strategic partners in connection with an out-license arrangement, as discussed in Note 11 ). The carrying amount of our equity securities, money market funds, and Bank CDs approximates their fair value (utilizing “ Level 1” or “ Level 2” inputs - see Note 2(xiii) ) because of our ability to immediately convert these instruments into cash with minimal expected change in value. The following is a summary of our presented “cash and cash equivalents” and “marketable securities”: Cost Foreign Currency Translation Gross Estimated Cash and Marketable Securities Current December 31, 2018 Equity securities* (see Note 3(h) and Note 10 ) $ 8,710 $ (2,168 ) $ 39,880 $ 46,422 $ — $ 46,422 Bank deposits 14,735 — — 14,735 14,735 — Money market funds 142,745 — — 142,745 142,745 — Bank certificates of deposits 86 — — 86 — 86 Total cash and cash equivalents and marketable securities $ 166,276 $ (2,168 ) $ 39,880 $ 203,988 $ 157,480 $ 46,508 December 31, 2017 Bank deposits $ 10,965 $ — $ — $ 10,965 $ 10,965 $ — Money market funds 216,358 — — 216,358 216,358 — Bank certificates of deposits 248 — — 248 — 248 Total cash and cash equivalents and marketable securities $ 227,571 $ — $ — $ 227,571 $ 227,323 $ 248 * Beginning January 1, 2018, under the new requirements of ASU 2016-01, Recognition and Measurement of Financial Assets and Liabilities , the unrealized (loss) gains on our CASI Pharmaceuticals, Inc. (NASDAQ: CASI) (“CASI”) equity securities are recognized as a (decrease) increase to “other income, net” on the Consolidated Statements of Operations (rather than through “other comprehensive (loss) income” on the Consolidated Statements of Comprehensive Loss). Our adoption of ASU 2016-01 on January 1, 2018, resulted in a $17.2 million cumulative-effect adjustment, net of income tax, recorded as a decrease to “accumulated other comprehensive (loss) income” and a decrease to “accumulated deficit” on the accompanying Consolidated Balance Sheets. Our recognized unrealized gain on these equity securities for the year ended December 31, 2018 was $10.5 million , as reported in “other income, net” on the accompanying Consolidated Statements of Operations. As of December 31, 2018 , none of these securities had been in a continuous unrealized loss position longer than one year. (b) Property and Equipment, net of Accumulated Depreciation “Property and equipment, net of accumulated depreciation” consists of the following: December 31, 2018 2017 Computers hardware and software $ 3,079 $ 2,994 Laboratory equipment 635 630 Office furniture 212 218 Leasehold improvements 2,957 2,938 Property and equipment, at cost 6,883 6,780 (Less): Accumulated depreciation (6,498 ) (6,191 ) Property and equipment, net of accumulated depreciation $ 385 $ 589 Depreciation expense (included within “total operating costs and expenses” in the accompanying Consolidated Statements of Operations) for the years ended December 31, 2018 , 2017 , and 2016 was $0.3 million , $0.3 million , and $0.5 million , respectively. (c) Inventories “Inventories” consists of the following: December 31, 2018 2017 Raw materials $ 2,024 $ 1,077 Work-in-process 2,209 2,551 Finished goods 1,193 5,187 (Less:) Non-current portion of inventories included within "other assets" * (1,876 ) (3,100 ) Inventories $ 3,550 $ 5,715 * The “non-current” portion of inventories is presented within "other assets" in the accompanying Consolidated Balance Sheets at December 31, 2018 and 2017 , respectively. This value of $1.9 million at December 31, 2018 represents product that we expect to sell beyond December 31, 2019 , and the value at December 31, 2017 represented product that we expected to sell beyond December 31, 2018 . (d) Accounts receivable, net of Allowance for Doubtful Accounts “Accounts receivable, net of allowance for doubtful accounts” consists of trade receivables from our customers. We are exposed to credit risk associated with trade receivables that result from these product sales. We do not require collateral or deposits from our customers due to our assessment of their creditworthiness and our long-standing relationship with them. We maintain reserves for potential bad debt, though credit losses have historically been nominal and within management’s expectations. A summary of our customers that represent 10% or more of our accounts receivables as of December 31, 2018 and 2017 , are as follows: December 31, 2018 2017 AmerisourceBergen Corporation, and its affiliates $ 10,448 35.0 % $ 7,175 22.2 % Cardinal Health, Inc. and its affiliates 8,228 27.5 % 9,514 29.5 % McKesson Corporation and its affiliates 7,615 25.5 % 11,186 34.7 % All other customers 3,582 12.0 % 4,385 13.6 % Accounts receivable, net $ 29,873 100.0 % $ 32,260 100.0 % (e) Prepaid Expenses and Other Assets “Prepaid expenses and other assets” consists of the following: December 31, 2018 2017 Other miscellaneous prepaid operating expenses $ 8,186 $ 3,389 Prepaid insurance 782 645 Research and development supplies 611 1,883 Key employee life insurance – cash surrender value — 4,150 Prepaid expenses and other assets $ 9,579 $ 10,067 (f) Other Receivables “Other receivables” consists of the following: December 31, 2018 2017 CASI note - short term ( Note 11 ) $ 1,525 $ — Other miscellaneous receivables (including Medicaid rebate credits and royalty receivables) 1,189 1,152 Insurance receivable 206 53 Income tax receivable 643 665 Reimbursements due from development partners for incurred research and development expenses 135 263 Other receivables $ 3,698 $ 2,133 (g) Intangible Assets and Goodwill “Intangible assets, net of accumulated amortization” consists of the following: December 31, 2018 Historical Accumulated Foreign Impairment Net Amount Full Remaining MARQIBO IPR&D (NHL and other novel indications) $ 17,600 $ — $ — $ — $ 17,600 n/a n/a EVOMELA distribution rights 7,700 (1,629 ) — — 6,071 156 123 KHAPZORY distribution rights (1) 2,650 (379 ) — — 2,271 14 12 BELEODAQ distribution rights 25,000 (8,438 ) — — 16,562 160 106 MARQIBO distribution rights 26,900 (21,501 ) — — 5,399 81 18 FOLOTYN distribution rights 118,400 (67,187 ) — — 51,213 152 47 ZEVALIN distribution rights – U.S. 41,900 (41,031 ) — — 869 123 3 ZEVALIN distribution rights – Ex-U.S. 23,490 (18,071 ) (3,409 ) — 2,010 96 15 FUSILEV distribution rights (2) 16,778 (9,618 ) — (7,160 ) — 56 0 FOLOTYN out-license (3) 27,900 (17,278 ) — (1,023 ) 9,599 110 43 Total intangible assets (4) $ 308,318 $ (185,132 ) $ (3,409 ) $ (8,183 ) $ 111,594 December 31, 2017 Historical Cost Accumulated Amortization Foreign Currency Translation Impairment Net Amount MARQIBO IPR&D (NHL and other novel indications) $ 17,600 $ — $ — $ — $ 17,600 EVOMELA distribution rights 7,700 (1,037 ) — — 6,663 BELEODAQ distribution rights 25,000 (6,563 ) — — 18,437 MARQIBO distribution rights 26,900 (17,182 ) — — 9,718 FOLOTYN distribution rights 118,400 (54,111 ) — — 64,289 ZEVALIN distribution rights – U.S. 41,900 (37,557 ) — — 4,343 ZEVALIN distribution rights – Ex-U.S. 23,490 (17,232 ) (2,471 ) — 3,787 FUSILEV distribution rights (2) 16,778 (9,618 ) — (7,160 ) — FOLOTYN out-license (3) 27,900 (14,555 ) — (1,023 ) 12,322 Total intangible assets (4) $ 305,668 $ (157,855 ) $ (2,471 ) $ (8,183 ) $ 137,159 (1) In November 2018, we made a $2.7 million payment to Medac related to the FDA approval of KHAPZORY for its commercial sale. This amount was capitalized to "KHAPZORY distribution rights" during the fourth quarter of 2018 and will be amortized through December 31, 2019 (see Note 17(b)(xvi) ). (2) On February 20, 2015, the U.S. District Court for the District of Nevada found the patent covering FUSILEV to be invalid, which was upheld on appeal. On April 24, 2015, Sandoz began to commercialize a generic version of FUSILEV. This represented a “triggering event” under applicable GAAP in evaluating the value of our FUSILEV distribution rights as of March 31, 2015, resulting in a $7.2 million impairment charge (non-cash) in the first quarter of 2015. We accelerated amortization expense recognition for the remaining net book value of FUSILEV distribution rights. Effective December 2018, FUSILEV has been discontinued and we are no longer selling this product. We have since transitioned to marketing KHAPZORY for the same indications as FUSILEV. (3) On May 29, 2013, we amended our FOLOTYN collaboration agreement with Mundipharma. As a result of the amendment, Europe and Turkey were excluded from Mundipharma’s commercialization territory, and their royalty rates and milestone payments to us were modified. This constituted a change under which we originally valued the FOLOTYN out-license as part of business combination accounting, resulting in an impairment charge (non-cash) of $1.0 million resulted from this amendment. (4) See Note 1(a) for a discussion of the Acrotech Transaction, relating to our pending sale of these intangible assets. Our annual impairment evaluation (as of October 1st) of our indefinite-lived intangible assets was completed by our management, with no resulting impairment. Intangible asset amortization expense recognized in 2018 , 2017 , and 2016 , was $28.1 million , $27.6 million , and $25.9 million , respectively. Estimated intangible asset amortization expense for the five succeeding years and thereafter is as follows (without consideration of the completion of the Acrotech Transaction - see Note 1(a) ): Years Ending December 31, 2019 $ 27,333 2020 19,748 2021 18,266 2022 15,882 2023 2,467 2024 and thereafter 10,298 $ 93,994 “Goodwill” consists of the following: December 31, 2018 2017 Acquisition of Talon (MARQIBO rights) $ 10,526 $ 10,526 Acquisition of ZEVALIN Ex-U.S. distribution rights 2,525 2,525 Acquisition of Allos (FOLOTYN rights) 5,346 5,346 Foreign currency exchange translation effects (336 ) (235 ) Goodwill $ 18,061 $ 18,162 (h) Other Assets “Other assets” consists of the following: December 31, 2018 2017 Key employee life insurance – cash surrender value $ 6,274 $ 10,737 Inventories - non-current portion 1,876 3,100 Research & development supplies and other 1,340 231 Income tax receivable* 668 668 Equity securities (see Note 11 )** — 37,530 CASI note - long term (see Note 11 ) — 1,517 Other assets $ 10,158 $ 53,783 * This value represents the non-current portion of the refundable alternative minimum tax credit that is expected to be received over the next few years (see Note 18 ). ** As of March 31, 2018, we reclassified our presentation of these equity securities from this account caption to “marketable securities” on our accompanying Consolidated Balance Sheets - ( see Note 3(a) ). (i) Accounts Payable and Other Accrued Liabilities "Accounts payable and other accrued liabilities" consists of the following: December 31, 2018 2017 Trade accounts payable and other accrued liabilities $ 44,919 $ 33,648 Accrued rebates 8,371 7,990 Accrued product royalty 4,337 4,339 Allowance for returns 5,171 4,045 Accrued data and distribution fees 3,248 4,305 Accrued GPO administrative fees 296 296 Accrued inventory management fee 388 1,126 Allowance for chargebacks 2,730 2,368 Accounts payable and other accrued liabilities $ 69,460 $ 58,117 Amounts presented within “accounts payable and other accrued liabilities” in the accompanying Consolidated Balance Sheets for GTN estimates (see Note 2(i) ) were as follows: Description Rebates and Data and Returns Balance as of December 31, 2016 $ 9,817 $ 5,146 $ 2,309 Add: provisions 106,647 20,104 2,807 (Less): credits or actual allowances (106,106 ) (19,523 ) (1,071 ) Balance as of December 31, 2017 10,358 5,727 4,045 Add: provisions 65,751 13,962 1,700 (Less): credits or actual allowances (65,008 ) (15,757 ) (574 ) Balance as of December 31, 2018 $ 11,101 $ 3,932 $ 5,171 (j) Contract Liabilities "Contract liabilities" consists of the following: December 31, 2018 2017 Deposit made by licensee for EVOMELA supply in China territory $ 4,850 $ — Contract liabilities $ 4,850 $ — (k) Deferred revenue Deferred revenue (current and non-current) consists of the following: December 31, 2018 2017 EVOMELA deferred revenue $ — $ 3,819 ZEVALIN out-license in India territory (see Note 17(b)(iii) ) — 368 Deferred revenue* $ — $ 4,187 * On January 1, 2018, we reclassified the deferred revenue related to our EVOMELA product sales and our ZEVALIN out-license in the India territory of $3.8 million and $0.4 million , respectively. These amounts were included in the $4.7 million aggregate decrease to “accumulated deficit” on January 1, 2018, in accordance with the adoption of Topic 606 (see Note 2(i) ). (l) Other Long-Term Liabilities "Other long-term liabilities" consists of the following: December 31, 2018 2017 Accrued executive deferred compensation $ 5,474 $ 5,928 Deferred rent (non-current portion) — 52 Clinical study holdback costs, non-current — 59 Other tax liabilities 176 176 Other long-term liabilities $ 5,650 $ 6,215

Summary of Significant Accounti

Summary of Significant Accounting Policies and Use of Estimates	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Use of Estimates	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND USE OF ESTIMATES The preparation of financial statements in conformity with GAAP requires our management to make informed estimates and assumptions that affect our reported amounts of assets, liabilities, revenues, and expenses. These amounts may materially differ from the amounts ultimately realized and reported due to the inherent uncertainty of any estimate or assumption. On an on-going basis, our management evaluates its most critical estimates and assumptions, including those related to: (i) gross-to-net revenue adjustments; (ii) the timing of revenue recognition; (iii) the collectability of customer accounts; (iv) whether the cost of our inventories can be recovered; (v) the recoverability of our reported goodwill and intangible assets; (vi) the realization of our tax assets and estimates of our tax liabilities; (vii) the likelihood of payment and value of contingent liabilities; (viii) the fair value of our investments; (ix) the valuation of our stock options and the periodic expense recognition of stock-based compensation; and (x) the potential outcome of our ongoing or threatened litigation. Our accounting policies and estimates that most significantly impact the presented amounts within these Consolidated Financial Statements are further described below: (i) Revenue Recognition Impact of the Adoption of the New Revenue Recognition Standard : ASU No. 2014-09 , Revenue from Contracts with Customers ( “Topic 606” ), became effective for us on January 1, 2018. Our disclosure within the below sections to this footnote reflects our updated accounting policies that are affected by this new standard. We applied the “modified retrospective” transition method for open contracts for the implementation of Topic 606; this resulted in the recognition of an aggregate $4.7 million , net of tax, decrease to our January 1, 2018 “accumulated deficit” on our accompanying Consolidated Balance Sheets for the cumulative impact of applying this new standard. We made no adjustments to our previously-reported total revenues, as those periods continue to be presented in accordance with our historical accounting practices under Topic 605, Revenue Recognition (“Topic 605”) . See Notes 4, 5, and 20 for additional quantitative and qualitative revenue disclosures in accordance with Topic 606. Required Elements of Our Revenue Recognition : Revenue from our (a) product sales, (b) out-license arrangements, and (c) service arrangements is recognized under Topic 606 in a manner that reasonably reflects the delivery of our goods and/or services to customers in return for expected consideration and includes the following elements: (1) we ensure that we have an executed contract(s) with our customer that we believe is legally enforceable; (2) we identify the “performance obligations” in the respective contract; (3) we determine the “transaction price” for each performance obligation in the respective contract; (4) we allocate the transaction price to each performance obligation; and (5) we recognize revenue only when we satisfy each performance obligation. These five elements, as applied to each of our revenue categories, are summarized below: (a) Product Sales : We sell our products to pharmaceutical wholesalers/distributors (i.e., our customers), except for our U.S. sales of ZEVALIN, and limited sales of EVOMELA, in which case the end-user (i.e., clinic or hospital) is our customer. Our wholesalers/distributors in turn sell our products directly to clinics, hospitals, and private oncology-based practices. Revenue from our product sales is recognized as physical delivery of product occurs (when our customer obtains control of the product), in return for agreed-upon consideration. Our gross product sales (i.e., delivered units multiplied by the contractual price per unit) are reduced by our corresponding gross-to-net (“GTN”) estimates using the “expected value” method, resulting in our reported “product sales, net” in the accompanying Consolidated Statements of Operations, reflecting the amount we ultimately expect to realize in net cash proceeds, taking into account our current period gross sales and related cash receipts, and the subsequent cash disbursements on these sales that we estimate for the various GTN categories discussed below. These estimates are based upon information received from external sources (such as written or oral information obtained from our customers with respect to their period-end inventory levels and sales to end-users during the period), in combination with management’s informed judgments. Due to the inherent uncertainty of these estimates, the actual amount incurred (of some, or all) of product returns, government chargebacks, prompt pay discounts, commercial rebates, Medicaid rebates, and distribution, data, and GPO administrative fees may be materially above or below the amount estimated, then requiring prospective adjustments to our reported net product sales. These GTN estimate categories are each discussed below: Product Returns Allowances : Our FUSILEV, MARQIBO, and BELEODAQ customers are contractually permitted to return purchased products beginning at its expiration date and within six months thereafter. Our EVOMELA customers are permitted to return purchased product beginning at six months prior to its expiration date, and within 12 months thereafter (as well as for overstock inventory, as determined by end-users). ZEVALIN and FOLOTYN returns for expiry are not contractually permitted. Returns outside of this aforementioned criteria are not customarily allowed. We estimate expected product returns for our allowance based on our historical return rates. Returned product is typically destroyed, since substantially all returns are due to expiry and cannot be resold. Government Chargebacks : Our products are subject to pricing limits under certain federal government programs (e.g., Medicare and 340B Drug Pricing Program). Qualifying entities (i.e., end-users) purchase products from our customers at their qualifying discounted price. The chargeback amount we incur represents the difference between our contractual sales price to our customer, and the end-user’s applicable discounted purchase price under the government program. There may be significant lag time between our reported net product sales and our receipt of the corresponding government chargeback claims from our customers. Prompt Pay Discounts : Discounts for prompt payment are estimated at the time of sale, based on our eligible customers’ prompt payment history and the contractual discount percentage. Commercial Rebates : Commercial rebates are based on (i) our estimates of end-user purchases through a group purchasing organization (“GPO”), (ii) the corresponding contractual rebate percentage tier we expect each GPO to achieve, and (iii) our estimates of the impact of any prospective rebate program changes made by us. Medicaid Rebates : Our products are subject to state government-managed Medicaid programs, whereby rebates are issued to participating state governments. These rebates arise when a patient treated with our product is covered under Medicaid, resulting in a discounted price for our product under the applicable Medicaid program. Our Medicaid rebate accrual calculations require us to project the magnitude of our sales, by state, that will be subject to these rebates. There is a significant time lag in us receiving rebate notices from each state (generally several months or longer after our sale is recognized). Our estimates are based on our historical claim levels by state, as supplemented by management’s judgment. Distribution, Data, and GPO Administrative Fees : Distribution, data, and GPO administrative fees are paid to authorized wholesalers/distributors of our products (except for U.S. sales of ZEVALIN) for various commercial services including: contract administration, inventory management, delivery of end-user sales data, and product returns processing. These fees are based on a contractually-determined percentage of our applicable sales. (b) License Fees : Our out-license arrangements allow licensees to market our product(s) in certain territories for a specific term (representing the out-license of “functional intellectual property”). These arrangements may include one or more of the following forms of consideration: (i) upfront license fees, (ii) sales royalties, (iii) sales milestone-achievement fees, and (iv) regulatory milestone-achievement fees. We recognize revenue for each based on the contractual terms that establish our right to collect payment once the performance obligation is achieved, as follows: (1) Upfront License Fees: We determine whether upfront license fees are earned at the time of contract execution (i.e., when rights transfer to the customer) or over the actual (or implied) contractual period of the out-license. As part of this determination, we evaluate whether we have any other requirements to provide substantive services that are inseparable from the performance obligation of the license transfer. Our customers’ “distinct” rights to licensed “functional intellectual property” at the time of contract execution results in concurrent revenue recognition of all upfront license fees (assuming that there are no other performance obligations at contract execution that are inseparable from this license transfer). (2) Royalties : Under the “sales-or-usage-based royalty exception” we recognize revenue in the same period that our licensees complete product sales in their territory for which we are contractually entitled to a percentage-based royalty receipt. (3) Sales Milestones : Under the “sales-or-usage-based royalty exception” we recognize revenue in full within the period that our licensees achieve annual or aggregate product sales levels in their territories for which we are contractually entitled to a specified lump-sum receipt. (4) Regulatory Milestones : Under the terms of the respective out-license, regulatory achievements may either be our responsibility, or that of our licensee. • When our licensee is responsible for the achievement of the regulatory milestone, we recognize revenue in full (for the contractual amount due from our licensee) in the period that the approval occurs (i.e., when the “performance obligation” is satisfied by our customer) under the “most likely amount” method. This revenue recognition remains “constrained” (i.e., not recognized) until regulatory approval occurs, given its inherent uncertainty and the requirement of a significant revenue reversal not being probable if achievement does not occur. At each reporting period, we re-evaluate the probability of milestone achievement and the associated revenue constraint; any resulting adjustments would be recorded on a cumulative catch-up basis, thus reflected in our financial statements in the period of adjustment. • When we are responsible for the achievement of a regulatory milestone, the “relative selling price method” is applied for purposes of allocating the transaction price to our performance obligations. In such case, we consider (i) the extent of our effort to achieve the milestone and/or the enhancement of the value of the delivered item(s) as a result of milestone achievement and (ii) if the milestone payment is reasonable relative to all of the deliverables and payment terms (including other potential milestone consideration) within the arrangement. We have historically assessed the contractual value of these milestones upon their achievement to be identical to the allocation of value of our performance obligations and thus representing the “transaction price” for each milestone at contract inception. We recognize this revenue in the period that the regulatory approval occurs (i.e., when we complete the “performance obligation”) under the “most likely amount” method, and revenue recognition is otherwise “constrained” until regulatory approval occurs, given its inherent uncertainty and the requirement of a significant revenue reversal not being probable if achievement does not occur. At each reporting period, we re-evaluate the probability of milestone achievement and the associated revenue constraint; any resulting adjustments would be recorded on a cumulative catch-up basis, thus reflected in our financial statements in the period of adjustment. (c) Service Revenue : We receive fees under certain arrangements for (i) sales and marketing services, (ii) supply chain services, (iii) research and development services, and (iv) clinical trial management services. Our rights to receive payment for these services may be established by (1) a fixed-fee schedule that covers the term of the arrangement, so long as we meet ongoing performance obligations, (2) our completion of product delivery in our capacity as a procurement agent, (3) the successful completion of a phase of drug development, (4) favorable results from a clinical trial, and/or (5) regulatory approval events. We consider whether revenue associated with these service arrangements is reportable each period, based on our completed services or deliverables (i.e., satisfied “performance obligations”) during the reporting period, and the terms of the arrangement that contractually result in fixed payments due to us. The promised service(s) within these arrangements are distinct and explicitly stated within each contract, and our customer benefits from the separable service(s) delivery/completion. Further, the nature of the promise to our customer as stated within the respective contract is to deliver each named service individually (not a transfer of combined items to which the promised goods or services are inputs), and thus are separable for revenue recognition. (ii) Cash and Cash Equivalents Cash and cash equivalents consist of bank deposits and highly liquid investments with maturities of three months or less from the purchase date. (iii) Marketable Securities Our marketable securities consist of our holdings in equity securities (beginning January 1, 2018 - see Note 3(a) ), mutual funds, and bank certificates of deposit (“Bank CDs”). Beginning January 1, 2018, our realized and unrealized (loss) gains on marketable securities are included in “other income, net” on the accompanying Consolidated Statements of Operations. Prior to January 1, 2018, our unrealized (loss) gains were included in “other comprehensive (loss) income” on our accompanying Consolidated Statements of Comprehensive Loss. (iv) Accounts Receivable Our accounts receivable are derived from our product sales and license fees, and do not bear interest. The allowance for doubtful accounts is management’s best estimate of the amount of probable credit losses in our existing accounts receivable. Account balances are charged off against the allowance after appropriate collection efforts are exhausted. (v) Inventories We value our inventory at the lower of (i) the actual cost of its purchase or manufacture, or (ii) its net realizable value. Inventory cost is determined on the first-in, first-out method. We regularly review our inventory quantities in process of manufacture and on hand. When appropriate, we record a provision for obsolete and excess inventory to derive its new cost basis, which takes into account our sales forecast by product and corresponding expiry dates of each product lot. Manufacturing costs of drug products that are pending U.S. Food and Drug Administration ("FDA") approval are fully expensed through “research and development,” on the accompanying Consolidated Statements of Operations. (vi) Property and Equipment Our property and equipment is stated at historical cost, and is depreciated on a straight-line basis over an estimated useful life that corresponds with its designated asset category. We evaluate the recoverability of “long-lived assets” (which includes property and equipment) whenever events or changes in circumstances in our business indicate that the asset’s carrying amount may not be recoverable through our on-going operations. (vii) Goodwill and Intangible Assets Our goodwill represents the excess of our business acquisition cost over the estimated fair value of the net assets acquired in the corresponding transaction. Goodwill has an indefinite accounting life and is therefore not amortized. Instead, goodwill is evaluated for impairment on an annual basis (as of each October 1st), unless we identify impairment indicators that would require earlier testing. We evaluate the recoverability of indefinite-lived intangible assets at least annually, or whenever events or changes in our business indicate that an intangible asset’s (whether indefinite or definite-lived) carrying amount may not be recoverable. Such circumstances could include, but are not limited to the following: (a) a significant decrease in the market value of an asset; (b) a significant adverse change in the extent or manner in which an asset is used; or (c) an accumulation of costs significantly in excess of the amount originally expected for the acquisition of an asset. Intangible assets with finite useful lives are amortized over their estimated useful lives on a straight-line basis. We review these assets for potential impairment if/when facts or circumstances suggest that the carrying value of these assets may not be recoverable. (viii) Stock-Based Compensation Stock-based compensation expense for equity awards granted to our employees and members of our Board of Directors is recognized on a straight-line basis over each award’s vesting period. Recognized compensation expense is net of an estimated forfeiture rate, representing the percentage of awards that are expected to be forfeited prior to vesting, though is ultimately adjusted for actual forfeitures. We use the Black-Scholes option pricing model to determine the fair value of stock options (as of the date of grant) that have service conditions for vesting. We use the Monte Carlo valuation model to value equity awards (as of the date of grant) that have combined market conditions and service conditions for vesting. The recognition of stock-based compensation expense and the initial calculation of stock option fair value requires uncertain assumptions, including (a) the pre-vesting forfeiture rate of the award, (b) the expected term that the stock option will remain outstanding, (c) our stock price volatility over the expected term (and that of our designated peer group with respect to certain market-based awards), and (d) the prevailing risk-free interest rate for the period matching the expected term. With regard to (a)-(d): We estimate forfeiture rates based on our employees’ overall forfeiture history, which we believe will be representative of future results. We estimate the expected term of stock options granted based on our employees’ historical exercise patterns, which we believe will be representative of their future behavior. We estimate the volatility of our common stock on the date of grant based on the historical volatility of our common stock for a look-back period that corresponds with the expected term. We estimate the risk-free interest rate based upon the U.S. Department of the Treasury yields in effect at award grant, for a period equaling the expected term of the stock option. (ix) Foreign Currency Translation Our foreign subsidiaries’ separate financial statements are stated in their functional currencies (i.e., local operating currencies). To create the accompanying Consolidated Financial Statements, we translate the assets and liabilities of our subsidiaries to U.S. dollars at the rates of exchange in effect at the reported balance sheet date; revenues and expenses are translated using the monthly average exchange rates during the reported period. Unrealized gains and losses from these translations are included in “accumulated other comprehensive (loss) income” in the accompanying Consolidated Balance Sheets. We record foreign currency-based transactions (i.e., when not denominated in the functional currency of our transacting legal entity) at the prevailing exchange rate on the date of the transaction. Resulting unrealized foreign exchange gains and losses from these unsettled transactions are included in “accumulated other comprehensive (loss) income” in the accompanying Consolidated Balance Sheets. All unrealized foreign exchange gains and losses associated with our intercompany loans are included in “accumulated other comprehensive (loss) income” in the accompanying Consolidated Balance Sheets, as these loans with our foreign subsidiaries are not expected to be settled in the “foreseeable future.” (x) Basic and Diluted Net Loss per Share We calculate basic and diluted net loss per share using the weighted average number of common shares outstanding during the periods presented. In periods of a net loss, basic and diluted loss per share are the same. For the diluted earnings per share calculation, we adjust the weighted average number of common shares outstanding to include only dilutive stock options, warrants, and other common stock equivalents outstanding during the period. (xi) Income Taxes Deferred tax assets and liabilities are recorded based on the estimated future tax effects of temporary differences between the tax basis of assets and liabilities and amounts reported in the financial statements, as well as operating losses and tax credit carry forwards using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Realization of deferred tax assets is dependent upon future earnings, the timing and amount of which are uncertain. We have recorded a valuation allowance to reduce our deferred tax assets, because we believe that, based upon a weighting of positive and negative factors, it is more likely than not that these deferred tax assets will not be realized. If/when we were to determine that our deferred tax assets are realizable, an adjustment to the corresponding valuation allowance would increase our net income in the period that such determination was made. In the event that we are assessed interest and/or penalties from taxing authorities that have not been previously accrued, such amounts would be included in “(provision) benefit for income taxes” within the Consolidated Statements of Operations in the period the notice was received. (xii) Research and Development Costs Our research and development costs are expensed as incurred (see Note 17(c) ), or as certain milestone payments become contractually due to our licensors, as triggered by the achievement of clinical or regulatory events. (xiii) Fair Value Measurements We determine measurement-date fair value based on the proceeds that would be received through the sale of the asset, or that we would pay to settle or transfer the liability, in an orderly transaction between market participants. We utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. Fair value measurements are based on a three-tier hierarchy that prioritizes the inputs used to measure fair value. These tiers include the following: Level 1: Quoted prices (unadjusted) in active markets for identical assets or liabilities that are publicly accessible at the measurement date. Level 2: Observable prices that are based on inputs not quoted on active markets, but that are corroborated by market data. These inputs may include quoted prices for similar assets or liabilities or quoted market prices in markets that are not active to the general public. Level 3: Unobservable inputs are used when little or no market data is available.

Gross-to-Net Product Sales and

Gross-to-Net Product Sales and Significant Customers	12 Months Ended
	Dec. 31, 2018
Revenues [Abstract]
Gross-to-Net Product Sales and Significant Customers	GROSS-TO-NET PRODUCT SALES AND SIGNIFICANT CUSTOMERS The below table presents a GTN revenue (see Note 2(i) ) product sales reconciliation for the accompanying Consolidated Statement of Operations: Year Ended December 31, 2018 2017 2016 Gross product sales $ 190,825 $ 245,797 $ 244,770 Commercial rebates and government chargebacks (68,976 ) (36.1 )% (105,148 ) (42.8 )% (98,317 ) (40.2 )% Data and distribution fees, GPO fees, and inventory management fees (14,048 ) (7.4 )% (20,083 ) (8.2 )% (14,979 ) (6.1 )% Prompt pay discounts (1,553 ) (0.8 )% (1,610 ) (0.7 )% (755 ) (0.3 )% Product returns (1,782 ) (0.9 )% (2,778 ) (1.1 )% (2,123 ) (0.9 )% Product sales, net $ 104,466 54.7 % $ 116,178 47.3 % $ 128,596 52.5 % The below table presents the customers that represent 10% or more of our gross product sales in 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 McKesson Corporation and its affiliates 69,320 36.3 % 76,363 31.1 % 75,952 31.0 % AmerisourceBergen Corporation, and its affiliates $ 55,576 29.1 % $ 79,362 32.3 % $ 93,951 38.4 % Cardinal Health, Inc. and its affiliates 42,074 22.0 % 64,634 26.3 % 58,780 24.0 % All other customers 23,855 12.5 % 25,438 10.3 % 16,087 6.6 % Gross product sales $ 190,825 100.0 % $ 245,797 100.0 % $ 244,770 100.0 %

Composition of Total Revenue

Composition of Total Revenue	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Composition of Total Revenue	COMPOSITION OF TOTAL REVENUE The below table presents our net product sales by geography for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 United States $ 91,822 87.9 % $ 107,135 92.2 % $ 125,074 97.3 % International: Europe/Canada 11,220 10.7 % 7,727 6.7 % 3,522 2.7 % Asia Pacific 1,424 1.4 % 1,316 1.1 % — — % Total International 12,644 12.1 % 9,043 7.8 % 3,522 2.7 % Product sales, net $ 104,466 100.0 % $ 116,178 100.0 % $ 128,596 100.0 % The below table presents our net sales by product for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 FOLOTYN $ 47,981 45.9 % $ 43,015 37.0 % $ 46,245 36.0 % EVOMELA 28,292 27.1 % 35,178 30.3 % 16,169 12.6 % BELEODAQ 12,328 11.8 % 12,353 10.6 % 13,368 10.4 % ZEVALIN 7,044 6.7 % 11,759 10.1 % 10,730 8.3 % MARQIBO 5,502 5.3 % 6,573 5.7 % 7,245 5.6 % FUSILEV* 2,437 2.3 % 7,300 6.3 % 34,839 27.1 % KHAPZORY 882 0.8 % — — % — — % Product sales, net** $ 104,466 100.0 % $ 116,178 100.0 % $ 128,596 100.0 % * Effective December 2018, FUSILEV has been discontinued and we are no longer selling this product. We have since transitioned to marketing KHAPZORY for identical indications as FUSILEV. ** See Note 2(i) for a discussion of our adoption of Topic 606 effective beginning on January 1, 2018. The below table presents our license fees and service revenue by source for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Out-license of ZEVALIN: recognition of milestone achievement, upfront cash receipt and subsequent royalties for Asia and certain other territories, excluding China ( Note 12 ) $ 2,001 41.1 % $ 1,245 10.2 % $ 1,756 9.8 % Out-license of FOLOTYN in all countries except the United States, Canada, Europe, and Turkey: royalties ( Note 16 ) 1,860 38.2 % 5,848 48.0 % 927 5.2 % Out-license of ZEVALIN, FOLOTYN, BELEODAQ, MARQIBO: upfront cash receipt and subsequent royalties for the Canada territory ( Note 17(b)(xv) ) 1,006 20.7 % 5 — % 6,000 33.6 % Out-license of ZEVALIN: amortization of upfront cash receipt related to India territory ( Note17(b)(iii) ) and other — — % 50 0.4 % 69 0.4 % Sales and marketing contracted services ( Note 14 ) — — % 4,747 38.9 % 9,096 51.0 % Regulatory services provided to licensee — — % 294 2.4 % — — % License fees and service revenues $ 4,867 100.0 % $ 12,189 100.0 % $ 17,848 100.0 %

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION 2018 Long-Term Incentive Plan Overview We have one active stockholder-approved stock-based compensation plan, the 2018 Long- Term Incentive Plan (the “2018 Plan”), which replaced our former 2009 Incentive Award Plan (the "2009 Plan") in June 2018. Under the 2018 Plan we may grant incentive stock options, non-qualified stock options, restricted stock awards, restricted stock units, performance awards, stock appreciation rights and other stock-based awards. The maximum number of shares of our common stock available for issuance under the 2018 Plan at inception was 9.5 million shares. The number of shares of common stock that may be issued under the 2018 Plan may not exceed 9.5 million shares, plus any shares that become eligible for issuance under the 2018 Plan because of awards under the 2009 Plan that are terminated, forfeited, cancelled or expire unexercised. As of December 31, 2018 , 17.6 million shares were available for grant, inclusive of aforementioned rollovers from our 2009 Plan. It is our policy that before stock is issued through the exercise of stock options, we must first receive all required cash payment for such shares (whether through an upfront cash exercise or net-settlement exercise). Stock-based awards are governed by agreements between us and the recipients. Incentive stock options and nonqualified stock options may be granted under the 2018 Plan at an exercise price of not less than 100% of the fair market value of our common stock on the respective date of grant, and in some cases may not be less than 110% of such fair market value with respect to Incentive Stock Options ("ISOs"). The grant date is generally the date the terms of the award are approved by the Compensation Committee of the Board of Directors. Stock-based awards generally vest at 25% to 33% on the first anniversary following the date of grant, or for new hires, the first anniversary of their initial date of employment. Awards generally vest annually thereafter on a straight-line basis over three to four years. Stock options must generally be exercised, if at all, no later than 10 years from the date of grant. Upon termination of employment, vested stock options may generally be exercised based on the option termination rules including the following: six months after the date of termination upon retirement; twelve months after the date of termination upon disability or death; ninety days after the date of termination for all other terminations (though whether vested or unvested, stock options of the employee recipient are immediately forfeited upon termination for "Cause", as defined in the 2018 Plan). Employee Stock Purchase Plan Under the terms of our 2009 Employee Stock Purchase Plan (the “ESPP”), eligible employees can purchase common stock through payroll deductions. The purchase price is equal to the closing price of our common stock on the first or last day of the offering period (whichever is less), minus a 15% discount. We use the Black-Scholes option-pricing model, in combination with the discounted employee price, in determining the value of ESPP expense to be recognized during each offering period. A participant may purchase a maximum of 50,000 shares of common stock during a six -month offering period, not to exceed $25,000 worth of stock on the offering date during each plan year. As of December 31, 2018 , a total of 8.9 million shares of common stock are authorized and remain available for issuance under the ESPP. Beginning on January 1, 2010, and each January 1st thereafter, the number of shares of common stock available for issuance under the ESPP shall automatically increase by an amount equal to the lesser of (i) one million shares or (ii) an amount determined by the ESPP administrator. However, in no event shall the number of shares of common stock available for future sale under the ESPP exceed 10 million shares, subject to capitalization adjustments occurring due to dividends, splits, dissolution, liquidation, mergers, or changes in control. Stock-Based Compensation Expense Summary We report our stock-based compensation expense (inclusive of our incentive stock plan, employee stock purchase plan, and 401(k) contribution matching program) in the accompanying Consolidated Statements of Operations, based on the assigned department of the recipient. Stock-based compensation expense included within “total operating costs and expenses” for the years ended December 31, 2018 , 2017 , and 2016 , was as follows: Year Ended December 31, 2018 2017 2016 Cost of sales $ 298 $ 203 $ 135 Selling, general and administrative 14,010 12,904 11,480 Research and development 3,175 2,032 2,055 Total stock-based compensation $ 17,483 $ 15,139 $ 13,670 Employee stock-based compensation expense for the years ended December 31, 2018 , 2017 , and 2016 was recognized (reduced for estimated forfeitures) on a straight-line basis over the vesting period. Forfeitures are estimated at the time of grant and prospectively revised if actual forfeitures differ from those estimates. We estimate forfeitures of stock options using the historical exercise behavior of our employees. For purposes of this estimate, we have applied an estimated forfeiture rate of 15% , 14% , and 11% for the years ended December 31, 2018 , 2017 , and 2016 , respectively. Valuation Assumptions – Restricted Stock and Stock Options The grant-date fair value per share for restricted stock awards was based upon the closing market price of our common stock on the award grant-date. The fair value of stock options granted was estimated at the date of grant using the Black-Scholes option-pricing model. The following assumptions were used to determine fair value for the stock awards granted in the applicable year: Year Ended December 31, 2018 2017 2016 Expected option life (in years) (a) 4.73 4.84 5.02 Risk-free interest rate (b) 1.81% - 2.75% 0.82% - 1.90% 1.07% - 1.90% Volatility (c) 50.0% - 56.2% 49.3% - 61.4% 48.9% - 50.6% Dividend yield (d) —% —% —% Weighted-average grant-date fair value per stock option $8.64 $2.89 $2.80 (a) Determined by the historical stock option exercise behavior of our employees (maximum term is 10 years). (b) Based upon the U.S. Treasury yields in effect during the period which the options were granted (for a period equaling the stock options’ expected term). (c) Measured using our historical stock price for a period equal to stock options’ expected term. (d) We do not expect to declare any cash dividends in the foreseeable future. Stock Option Activity Stock option activity during the years ended December 31, 2018 , 2017 , and 2016 was as follows: Number of Weighted- Weighted- Aggregate Outstanding — December 31, 2015 13,836,851 $ 6.97 Granted 1,435,550 5.94 Exercised (39,010 ) 5.18 $ 50 (1 ) Forfeited (379,268 ) 7.21 Expired (513,541 ) 7.26 Outstanding — December 31, 2016 14,340,582 6.86 Granted 1,223,483 6.51 Exercised (937,482 ) 6.40 $ 6,813 (1 ) Forfeited (244,793 ) 6.26 Expired (524,577 ) 6.27 Outstanding — December 31, 2017 13,857,213 6.89 Granted 1,094,358 18.87 Exercised (7,858,141 ) 6.74 $ 84,758 (1 ) Forfeited (214,464 ) 6.54 Expired (35,381 ) 6.94 Outstanding — December 31, 2018 6,843,585 $ 8.98 6.39 $ 11,095 (2 ) Vested (exercisable) — December 31, 2018 4,955,073 $ 7.87 5.62 $ 8,422 (2 ) Unvested (unexercisable) — December 31, 2018 1,888,512 $ 11.91 8.38 $ 2,673 (2 ) (1) Represents the total difference between our closing stock price at the time of exercise and the stock option exercise price, multiplied by the number of options exercised. (2) Represents the total difference between our closing stock price on the last trading day of 2018 and the stock option exercise price, multiplied by the number of in-the-money options as of December 31, 2018 . The amount of intrinsic value will change based on the fair market value of our stock. The following table summarizes information with respect to stock option grants as of December 31, 2018 : Outstanding Exercisable Exercise Price Granted Stock Weighted- Weighted- Granted Weighted- $1.03 - 3.16 7,250 0.23 $ 1.76 7,250 $ 1.76 $3.17 - 4.96 212,880 4.27 4.22 168,409 4.16 $4.97 - 6.91 2,938,104 6.98 5.97 2,029,420 5.90 $6.92 - 9.00 1,914,493 5.00 7.75 1,856,327 7.77 $9.01 - 22.64 1,770,858 7.18 15.92 893,667 13.27 6,843,585 6.39 $ 8.98 4,955,073 $ 7.87 As of December 31, 2018 , there was unrecognized compensation expense of $7.7 million related to unvested stock options, which we expect to recognize over a weighted average period of 2.3 years . Restricted Stock Award Activity A summary of restricted stock award activity is as follows: Number of Weighted Average Unvested — December 31, 2015 2,173,982 $ 6.58 Granted 1,203,675 5.93 Vested (889,857 ) 6.49 Forfeited (335,643 ) 6.33 Unvested — December 31, 2016 2,152,157 6.29 Granted 927,306 6.22 Vested (1,137,555 ) 6.38 Forfeited (378,990 ) 5.95 Unvested — December 31, 2017 1,562,918 6.27 Granted 1,092,534 17.35 Vested (635,320 ) 6.51 Forfeited (218,002 ) 7.56 Unvested — December 31, 2018 1,802,130 $ 12.75 Year Ended December 31, 2018 2017 2016 Restricted stock award expense $ 7,652 $ 6,821 $ 6,518 As of December 31, 2018 , there was approximately $16.9 million of unrecorded expense related to issued restricted stock awards that will be recognized over an estimated weighted average period of 2.2 years . These unvested shares are included in our reported issued and outstanding common stock as of December 31, 2018 . Restricted Stock Unit Activity Our outstanding restricted stock units substantially relate to awards that contain "market-based" vesting conditions that are issued to certain of our executive officers. These conditions result in a variable number of shares ultimately issued at the assessment date designated by our Compensation Committee. A summary of restricted stock unit activity is as follows: Number of Weighted Average Outstanding — December 31, 2016 — $ — Granted 217,206 6.49 Outstanding — December 31, 2017 217,206 6.49 Granted 138,334 28.31 Market-based achievement adjustment at vesting 100,326 6.49 Share issuance upon approved achievement date (200,652 ) 6.49 Outstanding — December 31, 2018 255,214 $ 17.91 2018 2017 2016 Restricted stock unit expense $ 2,301 $ 1,030 $ — 401(k) Plan – Stock Matching Contribution We issued shares of common stock to our employees in connection with our 401(k) program, partially matching our employees’ annual 401(k) contributions, as summarized below: Year Ended December 31, 2018 2017 2016 Shares of common stock issued 70,379 102,874 172,650 Match contribution value $ 1,175 $ 912 $ 953

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY Authorized Stock In June 2018, our stockholders approved an amendment and restatement of our Certificate of Incorporation to reflect an increase in the number of authorized shares of our common stock from 175 million shares to 300 million shares. In addition to the increase in the authorized number of shares of common stock, the amendment eliminates designated series of preferred stock that are obsolete and are no longer outstanding or issuable, including Series B Junior Participating Preferred Stock and Series E Convertible Voting Preferred Stock. As of December 31, 2018 , we had five million shares of preferred stock authorized. The amendment was filed with the Delaware Secretary of State in June 2018. Stockholder Rights Agreement On November 29, 2010, our Board of Directors approved a stockholder rights agreement (the "Stockholder Rights Agreement"), effective December 13, 2010 . A stockholder rights agreement is designed to deter coercive, unfair, or inadequate takeovers and other abusive tactics that might be used in an attempt to gain control of our company. A stockholder rights agreement will not prevent takeovers at a full and fair price, but rather is designed to deter coercive takeover tactics and to encourage anyone attempting to acquire our company to first negotiate with our Board of Directors. On March 27, 2018, we entered into a Second Amendment to Rights Agreement which had the effect of suspending the Stockholders Rights Agreement as of March 30, 2018, though it will expire under its terms on December 13, 2020. Common Stock Issuable As of December 31, 2018 , 5.0 million shares of our common stock were issuable upon the exercise of granted stock options (regardless of whether in or out-of-the-money). Warrant Activity We typically issue warrants to purchase shares of our common stock to investors as part of a financing transaction or in connection with services rendered by placement agents or consultants. During 2018, our previously outstanding warrants were exercised, and therefore no outstanding warrants remained as of December 31, 2018 . A summary of warrant activity is as follows: Number of Weighted Outstanding — December 31, 2016 445,000 $ 6.78 Granted — — Outstanding — December 31, 2017 445,000 $ 6.78 Granted — — Exercised (445,000 ) $ 6.78 Outstanding — December 31, 2018 — — Exercisable — December 31, 2018 — $ — Sale of Common Stock Under ATM Agreements In December 2015, and August 2017, we entered into a collective at-market-issuance sales agreement with FBR Capital Markets & Co., MLV & Co. LLC, and H.C. Wainwright & Co., LLC. (“December 2015 ATM Agreement” and the "August 2017 ATM Agreement", respectively). These agreements allowed us to raise aggregate gross proceeds through these brokers of up to $250 million from the sale of our common stock on the public market. Through December 31, 2018, we had raised gross net proceeds of $202.1 million through these at-market sales, of which $128.3 million was raised during the year ended December 31, 2017. We are using these proceeds to continue to develop our product pipeline and to provide additional capital structure flexibility. We sold and issued shares of our common stock under both the December 2015 and August 2017 ATM Agreements, summarized as follows: No. of Common Shares Issued Proceeds Received (Net of Broker Commissions and Fees ) Common shares issued pursuant to the December 2015 ATM Agreement during the year ended December 31, 2016 10,890,915 $ 73,869 Common shares issued pursuant to the December 2015 ATM Agreement between July 1, 2017 and July 31, 2017 3,243,882 $ 23,745 Common shares issued pursuant to the August 2017 ATM Agreement between August 1, 2017 and December 31, 2017 10,314,250 $ 104,527 There were no sales of our common stock under the August 2017 ATM Agreement during the year ended December 31, 2018 .

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	NET LOSS PER SHARE Net loss per share was computed by dividing net loss by the weighted average number of common shares outstanding for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Net loss $ (120,011 ) $ (91,248 ) $ (69,770 ) Weighted average shares—basic 103,305,911 85,115,592 72,824,070 Net loss per share—basic $ (1.16 ) $ (1.07 ) $ (0.96 ) Weighted average shares—diluted 103,305,911 85,115,592 72,824,070 Net loss per share—diluted $ (1.16 ) $ (1.07 ) $ (0.96 ) The below outstanding securities were excluded from the above calculation of net loss per share because their impact under the "treasury stock method" and "if-converted method" would have been anti-dilutive due to our net loss per share for the years ended December 31, 2018 , 2017 , and 2016 , as summarized below: Year Ended December 31, 2018 2017 2016 Common stock options 4,407,765 3,668,662 1,294,594 Restricted stock awards 1,802,130 1,562,918 2,147,157 Restricted stock units 255,214 217,206 — 2018 Convertible Notes — 3,854,959 10,454,799 Common stock warrants — 138,277 — Total 6,465,109 9,442,022 13,896,550

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The table below summarizes certain asset and liability fair values that are included within our accompanying Consolidated Balance Sheets, and their designations among the three fair value measurement categories (see Note 2(xiii) ): December 31, 2018 Level 1 Level 2 Level 3 Total Assets: Bank certificates of deposits $ — $ 86 $ — $ 86 Money market funds — 142,745 — 142,745 Equity securities ( Note 11 ) 46,422 — — 46,422 Mutual funds — 78 — 78 Deferred compensation investments (life insurance cash surrender value - Note 3(h) ) — 6,274 — 6,274 * $ 46,422 $ 149,183 $ — $ 195,605 Liabilities: Deferred executive compensation liability ( Note 17(f) ) — 6,167 — 6,167 * FOLOTYN development liability ( Note 16 ) — — 11,997 11,997 Talon CVR ( Note 10 (a) ) — — 4,345 4,345 $ — $ 6,167 $ 16,342 $ 22,509 December 31, 2017 Level 1 Level 2 Level 3 Total Assets: Bank certificates of deposits $ — $ 248 $ — $ 248 Money market funds — 216,358 — 216,358 Equity securities (Note 11) 37,530 — — 37,530 Mutual funds — 59 — 59 Deferred compensation investments (life insurance cash surrender value - Note 3(h)) — 14,887 — 14,887 * $ 37,530 $ 231,552 $ — $ 269,082 Liabilities: Deferred executive compensation liability (Note 17(f)) — 11,038 — 11,038 * FOLOTYN development liability (Note 16) — — 12,386 12,386 Talon CVR (Note 10 (a)) — — 6,210 6,210 Corixa Liability (Note 17(b)(i)) — — 62 62 $ — $ 11,038 $ 18,658 $ 29,696 * The reported amount of “deferred compensation investments” is based on the cash surrender value of employee life insurance policies at period-end, while the reported amount of “deferred executive compensation liability” is based on the period-end market value of investments selected by plan participants. We did not have any transfers between “Level 1” and “Level 2” (see Note 2(xiii) ) measurement categories for any periods presented. The table below summarizes the 2017 and 2018 activity of our liabilities that are valued with unobservable inputs: Fair Value Measurements of Level 3 ) Balance at December 31, 2016 $ 14,445 FOLOTYN development liability ( Note 16 ) (744 ) Talon CVR fair value adjustment - MARQIBO ( Note 10(a) ) 4,957 Balance at December 31, 2017 $ 18,658 FOLOTYN development liability ( Note 16 ) (389 ) Talon CVR fair value adjustment - MARQIBO ( Note 10(a) ) (1,865 ) Corixa Liability ( Note 17(b)(i) ) (62 ) Balance at December 31, 2018 $ 16,342 Our carrying amounts of financial instruments such as cash equivalents, accounts receivable, prepaid expenses, accounts payable, and accrued liabilities, excluding acquisition-related contingent obligations, approximate their related fair values due to their short-term nature.

Business Combinations and Conti

Business Combinations and Contingent Consideration	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Combinations and Contingent Consideration	BUSINESS COMBINATIONS AND CONTINGENT CONSIDERATION (a) Acquisition of Talon Therapeutics, Inc. Overview of Talon Acquisition On July 17, 2013 , we purchased all of the outstanding shares of common stock of Talon Therapeutics, Inc. (“Talon”). Through the acquisition of Talon, we gained worldwide rights to MARQIBO. The Talon purchase consideration consisted of (i) an aggregate upfront cash amount of $11.3 million , (ii) issuance of 3 million shares of our common stock, then equivalent to $26.3 million (based on a closing price of $8.77 per share on July 17, 2013), and (iii) the issuance of a contingent value right (“CVR”) initially valued at $6.5 million . The CVR was valued using a valuation model that probability-weights expected outcomes (ranging from 50% to 100% ) and discounts those amounts to their present value, using an appropriate discount rate (these represent unobservable inputs and are therefore classified as Level 3 inputs – see Note 2 (xiii) ). The CVR has a maximum payout of $195 million if all sales and regulatory approval milestones are achieved, as summarized below: • $5 million upon the achievement of net sales of MARQIBO in excess of $30 million in any calendar year • $10 million upon the achievement of net sales of MARQIBO in excess of $60 million in any calendar year • $25 million upon the achievement of net sales of MARQIBO in excess of $100 million in any calendar year • $50 million upon the achievement of net sales of MARQIBO in excess of $200 million in any calendar year • $100 million upon the achievement of net sales of MARQIBO in excess of $400 million in any calendar year • $5 million upon receipt of marketing authorization from the FDA regarding Menadione Topical Lotion Talon CVR Fair Value as of December 31, 2018 and December 31, 2017 The CVR fair value will continue to be evaluated on a quarterly basis. Current and future changes in its fair value results from the likelihood and timing of milestone achievement and/or the corresponding discount rate applied thereon. Adjustments to the CVR fair value are recognized within “change in fair value of contingent consideration related to acquisitions” in the accompanying Consolidated Statements of Operations. Fair Value December 31, 2017 $ 6,210 Fair value adjustment for the year ended December 31, 2018 (1,865 ) December 31, 2018 $ 4,345 (b) Acquisition of Rights to EVOMELA and Related Contingent Consideration Overview of Acquisition of Rights to EVOMELA In March 2013, we completed the acquisition of exclusive global development and commercialization rights to Captisol-enabled®, propylene glycol-free MELPHALAN (which we market as “EVOMELA”) for use as a conditioning treatment prior to autologous stem cell transplant for patients with MM. We acquired these rights from CyDex, a wholly-owned subsidiary of Ligand, for an initial license fee of $3 million , and assumed responsibility for EVOMELA's then-ongoing clinical and regulatory development program. We accounted for this transaction as a business combination, which required that assets acquired and liabilities assumed be recognized on the balance sheet at their fair values as of the transaction date. We are required to pay Ligand additional amounts up to an aggregate $60 million , upon the achievement of annual net sales thresholds (exclusive of the $6 million milestone payment triggered in March 2016, as discussed below), however, we do not expect to achieve these sales thresholds based on our estimated market size for this product and our projected market share at the time of the acquisition and to date. We also must pay Ligand royalties of 20% on our net sales of EVOMELA in all territories. Our EVOMELA royalty obligation and sales-based milestones are jointly treated as part of an "executory contract" (as defined under GAAP) that is connected with an at-market supply agreement for Captisol that was executed concurrently with this acquisition (requiring the continuing involvement of CyDex). As a result, our royalty and sales-based milestone arrangements are treated as separate transactions, distinct from the consideration for the EVOMELA rights. Our royalty expenses are reported through "cost of sales" on our Consolidated Statement of Operations in the same period of our recognized revenue for the product sale. Consideration Transferred The acquisition-date fair value of the consideration transferred consisted of the following: Cash consideration $ 3,000 Ligand Contingent Consideration 4,700 Total purchase consideration $ 7,700 Fair Value Estimate of Asset Acquired and Liability Assumed The total purchase consideration is allocated to the acquisition of the net tangible and intangible assets based on their estimated fair values as of the transaction date. The allocation of the total purchase price to the net assets acquired is as follows: EVOMELA IPR&D rights $ 7,700 We estimated the fair value of the in-process research and development using the income approach. The income approach uses valuation techniques to convert future net cash flows to a single present value (discounted) amount. We applied our net cash flow projections for EVOMELA over 10 years and a discount rate of 25% , taking into account our estimates of future incremental earnings that may be achieved upon regulatory approval and commercialization of the product(s). The fair value of the Ligand Contingent Consideration (as defined below) liability was determined using the probability of success and the discounted cash flow method of the income approach (representing unobservable " Level 3" inputs (see Note 2(xiii) ) for regulatory and sales-based milestones due to Ligand upon achievement). In March 2016, the FDA approved EVOMELA, triggering a $6 million milestone payment to Ligand ("Ligand Contingent Consideration") that was paid in April 2016. "EVOMELA IPR&D" of $7.7 million was reclassified in April 2016 to "EVOMELA" distribution rights" that is reported within "Intangible assets, net of accumulated amortization" in the accompanying Consolidated Balance Sheets as of December 31, 2018 (see Note 3(g) ). Amortization related to this intangible asset commenced on April 1, 2016. Ligand Contingent Consideration Fair Value as of December 31, 2016 The fair value of the Ligand Contingent Consideration immediately prior to its payment was the full $6 million payment due upon EVOMELA's FDA approval. Accordingly, in the first quarter of 2016, we recorded a $0.8 million adjustment to the “change in fair value of the contingent consideration related to acquisitions” in the accompanying Consolidated Statements of Operations. We have no further contingent consideration obligations as part of this transaction. Fair Value of December 31, 2015 $ 5,227 Fair value adjustment for the three months ended March 31, 2016 773 Payment to Ligand in April 2016 for FDA approval milestone achievement (6,000 ) December 31, 2016 $ — (c) Allos Acquisition We acquired Allos Therapeutics, Inc. ("Allos") in September 2012 for cash consideration of $205.2 million and assumed its FOLOTYN distribution rights (see Note 16 ). We accounted for this transaction as a business combination, which required that assets acquired and liabilities assumed be reported on our balance sheet at their fair values as of the transaction date. We have no ongoing contingent consideration obligations from this transaction.

Out-License of MARQIBO, ZEVALIN

Out-License of MARQIBO, ZEVALIN, & EVOMELA in China Territory	12 Months Ended
	Dec. 31, 2018
Other Commitments [Abstract]
Out-License of MARQIBO, ZEVALIN, & EVOMELA in China Territory	OUT-LICENSE OF MARQIBO, ZEVALIN, & EVOMELA IN CHINA TERRITORY Overview of CASI Out-License In September 2014, we executed three perpetual out-license agreements for ZEVALIN, MARQIBO, and EVOMELA (“CASI Out-Licensed Products”) with CASI, a publicly-traded biopharmaceutical company (NASDAQ: CASI) with a primary focus on the China market (collectively, the “CASI Out-License”). Under the CASI Out-License, we received CASI common stock and a secured promissory note; CASI gained the exclusive rights to distribute these drug products in greater China (which includes Taiwan, Hong Kong and Macau). CASI is responsible for the development and commercialization of these drugs, including the submission of import drug registration applications to regulatory authorities and conducting any confirmatory clinical studies in greater China. We will provide CASI with future commercial supply of the CASI Out-Licensed Products under typical market terms. CASI Ownership at December 31, 2018 Under certain conditions that expired in December 2017, we had a right to purchase additional shares of CASI common stock in order to maintain our post-investment ownership percentage. During 2017 and 2016, we acquired an additional 1.5 million and 4.6 million CASI common shares at par value, respectively. Our aggregate holding of 11.5 million common shares as of December 31, 2018 , represented an approximate 12.1% ownership in CASI, with a fair market value of $46.4 million (see Note 3(a) ). Proceeds Received in 2014 The proceeds we received in 2014, and its fair value on the CASI Out-License execution date, consisted of the following: CASI common stock (5.4 million shares) $ 8,649 (a) CASI secured promissory note, net of fair value discount ($1.5 million face value and 0.5% annual coupon) 1,310 (b) Total consideration received, net of fair value discount $ 9,959 (c) (a) Value determined based on the September 17, 2014 closing price of 5.4 million shares of CASI common stock on the NASDAQ Capital Market of $1.60 per share. (b) Value estimated using the terms of the $1.5 million promissory note, the application of a synthetic debt rating based on CASI’s publicly-available financial information, and the prevailing interest yields on similar public debt securities as of September 17, 2014. This promissory note has been reclassified in the accompanying Consolidated Balance Sheets as of December 31, 2018 to "other receivables" (presented within current assets) from "other assets" (presented within non-current assets) due to its maturity date (as amended) of September 17, 2019. (c) Presented within “license fees and service revenue” in the accompanying Consolidated Statements of Operations for the year ended December 31, 2015 (see below). In addition, CASI will be responsible for paying any royalties or milestones that we are obligated to pay to our third-party licensors resulting from the achievement of certain milestones and/or sales of CASI Out-Licensed Products, but only to the extent of the greater China portion of such royalties or milestones. License Fee Revenue Recognized in 2015 The $9.7 million value of the upfront proceeds (undiscounted, and net of certain foreign exchange adjustments) from CASI were recognized in 2015 within “license fees and service revenue.” The delayed timing of this revenue recognition corresponded with the execution of certain supply agreements with CASI for ZEVALIN, MARQIBO, and EVOMELA. These agreements allow CASI to procure CASI Out-Licensed Products directly from approved third parties, and in such case, do not require our future involvement for its commercial supply.

Out-License of ZEVALIN in Certa

Out-License of ZEVALIN in Certain Ex-U.S. Territories	12 Months Ended
	Dec. 31, 2018
Other Commitments [Line Items]
Out-License of ZEVALIN in Certain Ex-U.S. Territories	OUT-LICENSE OF MARQIBO, ZEVALIN, & EVOMELA IN CHINA TERRITORY Overview of CASI Out-License In September 2014, we executed three perpetual out-license agreements for ZEVALIN, MARQIBO, and EVOMELA (“CASI Out-Licensed Products”) with CASI, a publicly-traded biopharmaceutical company (NASDAQ: CASI) with a primary focus on the China market (collectively, the “CASI Out-License”). Under the CASI Out-License, we received CASI common stock and a secured promissory note; CASI gained the exclusive rights to distribute these drug products in greater China (which includes Taiwan, Hong Kong and Macau). CASI is responsible for the development and commercialization of these drugs, including the submission of import drug registration applications to regulatory authorities and conducting any confirmatory clinical studies in greater China. We will provide CASI with future commercial supply of the CASI Out-Licensed Products under typical market terms. CASI Ownership at December 31, 2018 Under certain conditions that expired in December 2017, we had a right to purchase additional shares of CASI common stock in order to maintain our post-investment ownership percentage. During 2017 and 2016, we acquired an additional 1.5 million and 4.6 million CASI common shares at par value, respectively. Our aggregate holding of 11.5 million common shares as of December 31, 2018 , represented an approximate 12.1% ownership in CASI, with a fair market value of $46.4 million (see Note 3(a) ). Proceeds Received in 2014 The proceeds we received in 2014, and its fair value on the CASI Out-License execution date, consisted of the following: CASI common stock (5.4 million shares) $ 8,649 (a) CASI secured promissory note, net of fair value discount ($1.5 million face value and 0.5% annual coupon) 1,310 (b) Total consideration received, net of fair value discount $ 9,959 (c) (a) Value determined based on the September 17, 2014 closing price of 5.4 million shares of CASI common stock on the NASDAQ Capital Market of $1.60 per share. (b) Value estimated using the terms of the $1.5 million promissory note, the application of a synthetic debt rating based on CASI’s publicly-available financial information, and the prevailing interest yields on similar public debt securities as of September 17, 2014. This promissory note has been reclassified in the accompanying Consolidated Balance Sheets as of December 31, 2018 to "other receivables" (presented within current assets) from "other assets" (presented within non-current assets) due to its maturity date (as amended) of September 17, 2019. (c) Presented within “license fees and service revenue” in the accompanying Consolidated Statements of Operations for the year ended December 31, 2015 (see below). In addition, CASI will be responsible for paying any royalties or milestones that we are obligated to pay to our third-party licensors resulting from the achievement of certain milestones and/or sales of CASI Out-Licensed Products, but only to the extent of the greater China portion of such royalties or milestones. License Fee Revenue Recognized in 2015 The $9.7 million value of the upfront proceeds (undiscounted, and net of certain foreign exchange adjustments) from CASI were recognized in 2015 within “license fees and service revenue.” The delayed timing of this revenue recognition corresponded with the execution of certain supply agreements with CASI for ZEVALIN, MARQIBO, and EVOMELA. These agreements allow CASI to procure CASI Out-Licensed Products directly from approved third parties, and in such case, do not require our future involvement for its commercial supply.
Mundipharma [Member]
Other Commitments [Line Items]
Out-License of ZEVALIN in Certain Ex-U.S. Territories	OUT-LICENSE OF ZEVALIN IN CERTAIN EX-U.S. TERRITORIES In November 2015, we entered into an out-license agreement with Mundipharma AG ("Mundipharma") for its commercialization of ZEVALIN in Asia (excluding India and Greater China), Australia, New Zealand, Africa, the Middle East, and Latin America (including the Caribbean). In return, we received $18 million (comprised of $15 million received in December 2015 and $3 million received in January 2016). Of these proceeds, $15 million was recognized and reported within "license fees and service revenue" in the fourth quarter of 2015, and the remaining $3 million payment was recognized in full by June 30, 2017. In April 2018, we received $2 million due to Mundipharma’s achievement of a specified sales milestone which was recognized in the first quarter of 2018 and reported within “license fees and service revenue” on our accompanying Consolidated Statements of Operations for the year ended December 31, 2018 (see Note 5 ). Mundipharma is required to reimburse us for our payment of royalties due to Bayer Pharma AG (“Bayer”) from its ZEVALIN sales - see Note 17(b)(ii) .

Out-License of ZEVALIN, FOLOTYN

Out-License of ZEVALIN, FOLOTYN, BELEDAQ, and MARQIBO in Canada Territory	12 Months Ended
	Dec. 31, 2018
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Out-License of ZEVALIN, FOLOTYN, BELEDAQ, and MARQIBO in Canada Territory	OUT-LICENSE OF MARQIBO, ZEVALIN, & EVOMELA IN CHINA TERRITORY Overview of CASI Out-License In September 2014, we executed three perpetual out-license agreements for ZEVALIN, MARQIBO, and EVOMELA (“CASI Out-Licensed Products”) with CASI, a publicly-traded biopharmaceutical company (NASDAQ: CASI) with a primary focus on the China market (collectively, the “CASI Out-License”). Under the CASI Out-License, we received CASI common stock and a secured promissory note; CASI gained the exclusive rights to distribute these drug products in greater China (which includes Taiwan, Hong Kong and Macau). CASI is responsible for the development and commercialization of these drugs, including the submission of import drug registration applications to regulatory authorities and conducting any confirmatory clinical studies in greater China. We will provide CASI with future commercial supply of the CASI Out-Licensed Products under typical market terms. CASI Ownership at December 31, 2018 Under certain conditions that expired in December 2017, we had a right to purchase additional shares of CASI common stock in order to maintain our post-investment ownership percentage. During 2017 and 2016, we acquired an additional 1.5 million and 4.6 million CASI common shares at par value, respectively. Our aggregate holding of 11.5 million common shares as of December 31, 2018 , represented an approximate 12.1% ownership in CASI, with a fair market value of $46.4 million (see Note 3(a) ). Proceeds Received in 2014 The proceeds we received in 2014, and its fair value on the CASI Out-License execution date, consisted of the following: CASI common stock (5.4 million shares) $ 8,649 (a) CASI secured promissory note, net of fair value discount ($1.5 million face value and 0.5% annual coupon) 1,310 (b) Total consideration received, net of fair value discount $ 9,959 (c) (a) Value determined based on the September 17, 2014 closing price of 5.4 million shares of CASI common stock on the NASDAQ Capital Market of $1.60 per share. (b) Value estimated using the terms of the $1.5 million promissory note, the application of a synthetic debt rating based on CASI’s publicly-available financial information, and the prevailing interest yields on similar public debt securities as of September 17, 2014. This promissory note has been reclassified in the accompanying Consolidated Balance Sheets as of December 31, 2018 to "other receivables" (presented within current assets) from "other assets" (presented within non-current assets) due to its maturity date (as amended) of September 17, 2019. (c) Presented within “license fees and service revenue” in the accompanying Consolidated Statements of Operations for the year ended December 31, 2015 (see below). In addition, CASI will be responsible for paying any royalties or milestones that we are obligated to pay to our third-party licensors resulting from the achievement of certain milestones and/or sales of CASI Out-Licensed Products, but only to the extent of the greater China portion of such royalties or milestones. License Fee Revenue Recognized in 2015 The $9.7 million value of the upfront proceeds (undiscounted, and net of certain foreign exchange adjustments) from CASI were recognized in 2015 within “license fees and service revenue.” The delayed timing of this revenue recognition corresponded with the execution of certain supply agreements with CASI for ZEVALIN, MARQIBO, and EVOMELA. These agreements allow CASI to procure CASI Out-Licensed Products directly from approved third parties, and in such case, do not require our future involvement for its commercial supply.
Servier Canada [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Out-License of ZEVALIN, FOLOTYN, BELEDAQ, and MARQIBO in Canada Territory	OUT-LICENSE OF ZEVALIN, FOLOTYN, BELEODAQ, AND MARQIBO IN CANADA TERRITORY On January 8, 2016, we entered into a strategic partnership with Servier Canada, Inc. ("Servier") for the out-licenses of ZEVALIN, FOLOTYN, BELEODAQ, and MARQIBO. We received $6 million in upfront payments in the first quarter of 2016 which was recognized within "license fees and service revenue" in the accompanying Consolidated Statements of Operations for the year ended December 31, 2016. In November 2018, we received a $1 million milestone receipt from Servier upon the approval of FOLOTYN in Canada (see Note 17(b)(xv) ). We will also receive additional development milestone payments if/when achieved, and a high single-digit royalty on their sales of these products.

Co-Promotion Arrangement With E

Co-Promotion Arrangement With Eagle Pharmaceuticals	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Co-promotion Arrangement With Eagle Pharmaceuticals	CO-PROMOTION ARRANGEMENT WITH EAGLE PHARMACEUTICALS In November 2015, we executed an agreement with Eagle Pharmaceuticals, Inc. ("Eagle") whereby designated members of our sales force concurrently marketed up to six of Eagle's products (along with our products). This arrangement was in return for fixed monthly payments (aggregating $12.8 million ), and variable sales-based milestones from Eagle over an 18 month contract term from January 1, 2016 through June 30, 2017 (the "Eagle Agreement"). On July 1, 2017 our sales force ceased marketing Eagle products and the Eagle Agreement expired under its terms. The fixed receipts from Eagle for our sales activities, as well as reimbursements of third-party marketing services, are recognized within "license fees and service revenue" on our accompanying Consolidated Statements of Operations, and was $0 , $4.7 million , and $9.1 million , for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , respectively. No sales-based milestones were achieved in the current or prior periods. An allocation of costs of our sales personnel that were dedicated to the Eagle Agreement are reported within "cost of service revenue" on our accompanying Consolidated Statement of Operations, as are reimbursed costs for Eagle marketing activities; these were an aggregate of $0 , $4.2 million , and $7.9 million for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , respectively.

Convertible Senior Notes

Convertible Senior Notes	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Convertible Senior Notes	CONVERTIBLE SENIOR NOTES Overview of 2013 Convertible Notes On December 17, 2013, we entered into an agreement for the sale of $120 million aggregate principal amount of 2.75% Convertible Senior Notes (equaling 120,000 notes, denominated in $1,000 principal units). the "2013 Convertible Notes." As of December 31, 2018 and December 31, 2017 , $0 and $38.2 million of debt principal was outstanding, respectively. Maturity of the 2013 Convertible Notes occurred on December 15, 2018, and substantially all of these notes were converted into our common stock at a rate of 95 shares per $1,000 principal units, with an in-the-money conversion price of $10.53 per common share. Proceeds and Conversion Hedge We received net proceeds of $115.4 million in December 2013 for the sale of the 2013 Convertible Notes, after deducting banker and professional fees of $4.6 million . We used a portion of these net proceeds to simultaneously enter into “bought call” and “sold warrant” transactions with Royal Bank of Canada (collectively, the "Conversion Hedge"). We recorded the Conversion Hedge on a net cost basis of $13.1 million , as a reduction to “additional paid-in capital” within our Consolidated Balance Sheets, and under applicable GAAP, were not marked-to-market through earnings or comprehensive income. We entered into these Conversion Hedge transactions to reduce the potential dilution to our stockholders and/or offset any cash payments that we would be required to make in excess of the principal amount, upon the conversion of the 2013 Convertible Notes (in the event that the market price of our common stock was greater than the conversion price). The strike price of the “bought call” was equal to the conversion price and conversion rate of the 2013 Convertible Notes (at such time, it matched the 11.4 million common shares into which the holders could convert the 2013 Convertible Notes); the strike price of our “sold warrant” is $14.03 per share of our common stock, and was also for 11.4 million common shares (reduced by partial unwinding of these instruments in 2016 and 2017, as discussed below). Open Market Purchases of 2013 Convertible Notes and Conversion Hedge Unwind in December 2016 and October 2017 In December 2016, we completed two open market purchases of our 2013 Convertible Notes, aggregating 9,963 note units (equivalent to $10 million principal value) for $9 million . We recognized an aggregate book loss of $25 thousand on the retirement of these 2013 Convertible Notes (based on its carrying value under GAAP), which is included in "other (expense) income, net" on the Consolidated Statements of Operations for the year ended December 31, 2016. Concurrent with these two open market purchases in December 2016, we concurrently unwound a portion of our previously sold warrants and previously purchased call options (that were part of our Conversion Hedge described below) for aggregate net proceeds of $21 thousand . We recorded a corresponding net increase to "additional paid-in capital" in the Consolidated Balance Sheets as of December 31, 2016. In October 2017, we completed an additional open market purchase of our 2013 Convertible Notes, aggregating 69,472 note units (equivalent to $69.5 million principal value) for $27.3 million in cash and 5.4 million newly-issued shares of our common stock, then worth $73 million . We recognized a book loss of $0.8 million on the retirement of these 2013 Convertible Notes (based on its carrying value under GAAP), which was included in "other (expense) income, net" on the Consolidated Statements of Operations for the year ended December 31, 2017. Concurrent with this open market purchase in October 2017, we also unwound a portion of the previously sold warrants and previously purchased call options that were part of our Conversion Hedge for aggregate net proceeds of $5.8 million . We recorded a corresponding net increase to "additional paid-in capital" in the Consolidated Balance Sheets as of December 31, 2017. Carrying Value and Fair Value of 2013 Convertible Notes at December 31, 2017 The carrying value of the 2013 Convertible Notes as of December 31, 2017, is summarized as follows: Year Ended December 31, 2017 Principal amount $ 40,565 (Less): Unamortized debt discount (amortized through December 2018) (2,101 ) (Less): Debt issuance costs (240 ) Carrying value $ 38,224 As of December 31, 2017 , the estimated aggregate fair value of the 2018 Convertible Notes is $74.3 million . These estimated fair values represent a Level 2 measurement (see Note 2(xiii) ), based upon the 2018 Convertible Notes quoted bid price at each date in a thinly-traded market. Maturity of the 2013 Convertible Notes occurred on December 15, 2018, and converted at a rate of 95 shares per $1,000 principal units, with an in-the-money conversion price of $10.53 per common share. Components of Interest Expense on 2013 Convertible Notes The following table sets forth the components of interest expense recognized in the accompanying Consolidated Statements of Operations for the 2013 Convertible Notes for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Contractual coupon interest expense $ 981 $ 2,615 $ 3,288 Amortization of debt issuance costs 220 567 696 Accretion of debt discount 1,931 4,890 5,710 Total $ 3,132 $ 8,072 $ 9,694 Effective interest rate 8.41 % 8.41 % 8.65 %

FOLOTYN License Agreement and D

FOLOTYN License Agreement and Development Liability	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
FOLOTYN License Agreement and Development Liability	FOLOTYN LICENSE AGREEMENT AND DEVELOPMENT LIABILITY As a result of our acquisition of Allos on September 5, 2012 (see Note 10(c) ), we assumed a strategic collaboration agreement with Mundipharma (as amended and/or restated, the “Mundipharma Collaboration Agreement”), as well as certain FOLOTYN clinical development obligations (the "FOLOTYN Development Liability"). Overview of Mundipharma Collaboration Agreement Under the Mundipharma Collaboration Agreement, we retained full commercialization rights for FOLOTYN in the United States and Canada, with Mundipharma having exclusive rights to commercialize FOLOTYN in all other countries in the world. On May 29, 2013, the Mundipharma Collaboration Agreement was amended and restated, in order to modify: (i) the scope of the licensed territory, (ii) milestone payments, (iii) royalty rates, and (iv) drug development obligations. In connection with the amendment and restatement of the Mundipharma Collaboration Agreement, we received a one-time $7 million payment from Mundipharma for certain research and development activities to be performed by us. As a result of the amendment and restatement of the Mundipharma Collaboration Agreement, (a) Europe and Turkey were excluded from Mundipharma’s commercialization territory, (b) we may receive regulatory milestone payments of up to $16 million , and commercial progress and sales-dependent milestone payments of up to $107 million (see Note 17(b)(vii) for July 2017 achievement), (c) we will receive tiered double-digit royalties based on net sales of FOLOTYN within Mundipharma’s licensed territories, and (d) we and Mundipharma will each bear our own FOLOTYN development costs. Effective as of May 1, 2015, we modified the Mundipharma Collaboration Agreement to revise the conditions for our exercise of the option to gain commercialization rights in Switzerland from Mundipharma, as well as royalties payable to us (in the tiered double-digits) on Mundipharma's net sales in Switzerland. FOLOTYN Development Liability The fair value of the FOLOTYN Development Liability within the accompanying Consolidated Balance Sheets was estimated using the discounted cash flow model. The unobservable inputs (i.e., " Level 3" inputs - see Note 2(xiii) ) in this valuation model that have the most significant effect on these liabilities include (i) estimates of research and development personnel costs needed to perform the research and development services contractually required, (ii) estimates of expected cash outflows to third parties for these clinical services and supplies during the expected period of performance through 2031, and (iii) an appropriate discount rate for these expenditures. These inputs are reviewed by management on a quarterly basis for continued applicability. We adjust this liability at each quarter-end, with corresponding adjustments for incurred costs recorded as credits to “research and development” expense in our accompanying Consolidated Statements of Operations. FOLOTYN FOLOTYN FOLOTYN Balance at December 31, 2017 $ 275 $ 12,111 $ 12,386 Transfer from long-term to current in 2018 2,425 (2,425 ) — (Less): Expenses incurred in 2018 (389 ) — (389 ) Balance at December 31, 2018 $ 2,311 $ 9,686 $ 11,997

Financial Commitments and Conti

Financial Commitments and Contingencies and License Agreements	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Financial Commitments and Contingencies and License Agreements	FINANCIAL COMMITMENTS & CONTINGENCIES AND LICENSE AGREEMENTS (a) Facility Leases We lease our principal executive office in Henderson, Nevada under a non-cancelable operating lease expiring October 31, 2021 . We also lease our research and development facility in Irvine, California under a non-cancelable operating lease expiring July 31, 2022 , in addition to several other administrative office leases. Each lease agreement contains scheduled rent increases which are accounted for on a straight-line basis. Our total rental expense in 2018 , 2017 , and 2016 was $1.6 million , $1.6 million , and $1.5 million , respectively. Adoption of New Lease Accounting Standard, Effective January 1, 2019 In February 2016, the FASB issued ASU 2016-02 , which amends the FASB Accounting Standards Codification and creates Topic 842 , Leases ( “Topic 842” ). Topic 842 will become effective for us beginning January 1, 2019, and requires us (as a lessee) to recognize a "right-of-use asset" and a "lease liability" on our balance sheet for all leases (with the exception of leases less than 12 months) at the lease commencement date. The lease liability will be measured as the present value of the unpaid lease payments and the right-of-use asset will be derived from the calculation of the lease liability, adjusted for any prepayments or incentives. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842) Targeted Improvements , amending certain aspects of this new accounting standard. The amendment allows an additional optional transition method whereby an entity records a cumulative effect adjustment to the opening retained earnings balance in the year of adoption, without restating prior periods. We plan to elect the package of practical expedients available under the transition provisions of the new guidance, including (i) not reassessing whether expired or existing contracts contain leases, (ii) lease classification, and (iii) not revaluing initial direct costs for existing leases. Additionally, we plan to elect the practical expedient which allows for the aggregation of lease and non-lease components of underlying asset classes, as well as the short-term lease exemption. We will elect the optional transition approach to not apply the new lease standard in the comparative periods presented and the package of practical expedients available under the transition provisions in ASU 2018-11 . Under the new lease classification criterion, we currently do not have any finance or embedded leases. Our operating leases solely relate to (1) our executive, administrative, and research and development office facilities and (2) certain office equipment. Our January 1, 2019 adoption of Topic 842 will result in the initial reporting of "right-of-use assets" and "lease liabilities" on our Consolidated Balance Sheets of approximately $4.4 million and $4.4 million , respectively. Our future minimum operating lease payments are as follows: Year ending December 31, Operating Lease 2019 $ 1,486 2020 1,441 2021 1,465 2022 828 2023 and thereafter 87 $ 5,308 (b) In/Out Licensing Agreements and Co-Development Arrangements The in-license agreements for our commercialized and development-stage drug products provide us with territory-specific rights to their manufacture and distribution (including further sub-licensing/out-licensing rights). We are generally responsible for all related clinical development costs, patent filings and maintenance costs, marketing costs, and liability insurance costs. We are also obligated to make specified milestone payments to our licensors upon the achievement of certain regulatory and sales milestones, and to pay royalties based on our net sales of all in-licensed products. We also enter into out-license agreements for territory-specific rights to our drug products which include one or more of: upfront license fees, royalties from our licensees’ sales, and/or milestone payments from our licensees’ sales or regulatory achievements. For certain development-stage drug products, we may enter into cost-sharing arrangements with our licensees and licensors. Our most significant of these agreements, and the key financial terms and our accounting for each, are summarized below: (i) ZEVALIN U.S.: In-Licensing and development in the U.S. In December 2008, we acquired rights to commercialize and develop ZEVALIN in the United States as the result of a transaction with Cell Therapeutics, Inc. (“CTI”) through our wholly-owned subsidiary, RIT Oncology LLC (“RIT”). In accordance with the terms of assumed contracts, we were required to meet specified payment obligations, including a milestone payment to Corixa Corporation of $5 million based on ZEVALIN sales in the United States. As of December 31, 2018 all the patents licensed from Corixa had expired under the terms of the agreement. Under the terms of the agreement, we are no longer obligated to pay United States net sales-based royalties in the low to mid-single digits to Genentech, Inc. and mid-teens to Biogen Inc. (ii) ZEVALIN Ex-U.S.: In-License and Asset Purchase Agreement with Bayer Pharma In April 2012, through our wholly-owned subsidiary, Spectrum Pharmaceuticals Cayman, L.P., we completed a €19 million acquisition of licensing rights to market ZEVALIN outside of the United States from Bayer. ZEVALIN is currently approved in approximately 40 countries outside the United States for the treatment of B-cell NHL, including countries in Europe, Latin America, and Asia. We amended the agreement in February 2016, which adjusted our tiered royalty to Bayer from the single-digits to 20% . The term of the agreement, as amended, continues until the expiration of the last-to-expire ZEVALIN patent in the relevant country, or 15 years from the date of the first commercial sale of ZEVALIN in such country, whichever is longer. (iii) ZEVALIN Ex-U.S.: Out-License Agreement with Dr. Reddy’s In June 2014, we executed an exclusive License Agreement with Dr. Reddy’s Laboratories Ltd. (“Dr. Reddy’s”) for ZEVALIN distribution rights within India. The agreement term is 15 years from the receipt of pending approval of ZEVALIN from the Drug Controller General of India. In December 2014, upon our execution of a drug supply agreement, an upfront and non-refundable payment of $0.5 million was triggered and paid to us in February 2015. The recognition of the applicable portion of this upfront receipt is no longer reported on a straight line basis, within “license fees and service revenue” on our accompanying Consolidated Statements of Operations, due to the adoption of Topic 606 as of January 1, 2018 (see Note 2(i) ). Additionally, sales and regulatory milestones, each aggregating $1.5 million (for a total of $3 million if both are achieved), are due to us upon Dr. Reddy’s achievement of such milestones, as well as a 20% royalty on its net sales of ZEVALIN in India. (iv) ZEVALIN Ex-U.S.: Out-License Agreement with Mundipharma In November 2015, we entered into an out-license agreement with Mundipharma for its commercialization of ZEVALIN in Asia (excluding India and Greater China), Australia, New Zealand, Africa, the Middle East, and Latin America (including the Caribbean). In return, we received $18 million (comprised of $15 million received in December 2015 and $3 million received in January 2016). Of these proceeds, $15 million was recognized within "license fees and service revenue" in the fourth quarter of 2015, and the remaining $3 million payment was recognized in full by June 30, 2017. Mundipharma is required to reimburse us for our payment of royalties due to Bayer from its Zevalin sales (see Note 17(b)(ii) ). In March 2018, Mundipharma achieved a specified sales milestone, resulting in a receipt of $2 million recorded within "license fees and service revenue" on our accompanying Consolidated Statements of Operations for the year ended December 31, 2018 (see Note 5 ). (v) FUSILEV: In-License Agreement with Merck & Cie AG In May 2006, we amended and restated a license agreement with Merck & Cie AG (“Merck”), which we assumed in connection with our March 2006 acquisition of the assets of Targent, Inc. This provided us with an exclusive license to use regulatory filings related to FUSILEV, and a non-exclusive license under certain patents and know-how to develop, manufacture, and sell FUSILEV in the field of oncology in North America. The contractual royalty percentage on our FUSILEV net sales due to Merck is set at the mid-single digits; however, in September 2017, we paid Merck $2.6 million in full settlement of all royalty obligations under the agreement. As a result, we are no longer contractually obligated to pay any royalties or milestones for our net sales of FUSILEV. (vi) FOLOTYN: In-License Agreement with Sloan-Kettering Institute, SRI International and Southern Research Institute In December 2002, Allos entered into an in-license agreement for the drug now marketed as FOLOTYN with Sloan-Kettering Institute for Cancer Research, SRI International (SRI), and Southern Research Institute. We assumed this agreement when we acquired Allos in September 2012. The agreement provides for our exclusive worldwide rights to a portfolio of patents and patent applications related to FOLOTYN, though we are required to fund certain drug development programs. In addition, we pay graduated royalties to our licensors based on our worldwide annual net sales of FOLOTYN (including our sub-licensees). These royalties are 8% of annual worldwide net sales up to $150 million ; 9% of annual worldwide net sales of $150 million through $300 million ; and 11% of annual worldwide net sales in excess of $300 million . We are also obligated to remit a $3.5 million payment to SRI upon approval of FOLOTYN by the European Medicines Agency (“EMA”) approval of FOLOTYN. This regulatory milestone has not been met, and no amounts have been accrued in our accompanying Consolidated Balance Sheets for its potential achievement. (vii) FOLOTYN: Out-License Agreement with Mundipharma As a result of our acquisition of Allos (see Note 10(c) ), we assumed “the Mundipharma Collaboration Agreement” as well as certain FOLOTYN clinical development obligations. Under the Mundipharma Collaboration Agreement, (see Note 16 ), we retained full commercialization rights for FOLOTYN in the United States and Canada, with Mundipharma having exclusive rights to commercialize FOLOTYN in all other countries in the world, except in Europe and Turkey. We are contractually entitled to receive regulatory and sales milestone payments from Mundipharma upon its achievement of such milestones, which aggregate $16 million and $107 million , respectively, as well as tiered double-digit royalties on Mundipharma's net sales. In July 2017, FOLOTYN was approved in Japan for the treatment of adult patients with relapsed or refractory peripheral T-cell lymphoma ("PTCL"). Consequently, we received $3 million from Mundipharma in August 2017 for this milestone achievement. This amount was recognized within "license fees and service revenue" on our accompanying Consolidated Statements of Operations for the year ended December 31, 2017. In August 2017, FOLOTYN was commercially launched in Japan. This triggered a contractual milestone of $2 million from Mundipharma. This amount was recorded within "license fees and service revenue" on our accompanying Consolidated Statements of Operations for the year ended December 31, 2017. (viii) EVOMELA: In-License Agreement with Cydex Pharmaceuticals, Inc. In March 2013, we completed the acquisition of exclusive global development rights to EVOMELA from CyDex, a wholly-owned subsidiary of Ligand (see Note 10(b) ), and assumed responsibility for its then-ongoing clinical and regulatory development program. We filed a New Drug Application ("NDA") with the FDA in December 2015 for its use as a conditioning treatment prior to autologous stem cell transplant for patients with MM, and in March 2016, the FDA communicated its approval. Consequently, we made a $6 million contractual milestone payment to Ligand in April 2016. We reclassified $7.7 million from "EVOMELA IPR&D rights" to "EVOMELA distribution rights" which is presented within "intangible assets, net of accumulated amortization" (see Note 3(g) ) within our accompanying Consolidated Balance Sheets as of December 31, 2018 . We are required to pay Ligand amounts of up to $60 million (exclusive of the $6 million milestone paid in April 2016), upon our achievement of specified net sales thresholds. We are also responsible to pay Ligand royalties of 20% on our net sales of EVOMELA in all territories. (ix) MARQIBO: Acquisition of Talon Therapeutics, Inc. and Related Contingent Consideration Agreement In July 2013, we completed the acquisition of Talon, through which we obtained exclusive global development and commercialization rights to MARQIBO (see Note 10(a) ). As part of this acquisition, the former Talon stockholders have contingent financial rights that we have valued and presented on our accompanying Consolidated Balance Sheets as a $4.3 million and $6.2 million liability within “acquisition-related contingent obligations” as of December 31, 2018 and December 31, 2017 , respectively. The maximum payout value of these contingent financial rights to the former Talon shareholders is $195 million , assuming we achieve all sales and regulatory approval milestones. In addition, we are contractually obligated to pay royalties in the single digits on our net sales of MARQIBO and a portion of sublicensing revenue may be due upon our receipt of such revenue for MARQIBO. (x) QAPZOLA : License Agreements with Allergan, Inc. and NDDO Research Foundation In October 2008, we entered into an exclusive development and commercialization collaboration agreement with Allergan, Inc. ("Allergan") for QAPZOLA pursuant to which Allergan paid us an up-front non-refundable fee of $41.5 million at execution (which we have recognized in full within “license fees and service revenue” by December 31, 2013). Concurrently we also entered into a letter agreement with NDDO Research Foundation (“NDDO”), pursuant to which we agreed to pay NDDO the following in relation to QAPZOLA milestones: (a) upon FDA acceptance of our NDA, the issuance of 25,000 of our common shares (which occurred in March 2016 and the $0.1 million value of these shares was included in "research and development" expense for the year ended December 31, 2016), and (b) upon FDA approval, a one-time payment of $0.3 million (which has not yet been met, and no amounts have been accrued in our accompanying Consolidated Balance Sheets for its potential achievement). In January 2013, we entered into a second amendment to the license, development, supply, and distribution agreement with Allergan. This amendment relieved Allergan of its development and commercialization obligations and resulted in our acquisition of its rights in the United States, Europe, and other territories, in exchange for our agreement to pay a tiered single-digit royalty on our sales of certain products containing QAPZOLA. (xi) QAPZOLA: Collaboration Agreement with Nippon Kayaku Co. LTD. In November 2009, we entered into a collaboration agreement with Nippon Kayaku Co., LTD. (“Nippon Kayaku”) for the development and commercialization of QAPZOLA in Asia, except North and South Korea (the “Nippon Kayaku Territory”). In addition, Nippon Kayaku received exclusive rights to QAPZOLA for the treatment of Non-Muscle Invasive Bladder Cancer in the Nippon Kayaku Territory, including Japan and China. Nippon Kayaku will conduct QAPZOLA clinical trials in the Nippon Kayaku Territory pursuant to a development plan. Further, Nippon Kayaku will be responsible for all expenses relating to the development and commercialization of QAPZOLA in the Nippon Kayaku Territory. Under the terms of this agreement, Nippon Kayaku paid us an upfront fee of $15 million (which we recognized within “license fees and service revenue” in full by December 31, 2013). Under the terms of the agreement, we are entitled to receive $10 million and $126 million from Nippon Kayaku upon the achievement of certain regulatory and commercialization milestones, respectively (some of which are our responsibility to achieve). Nippon Kayaku is also obligated to pay us royalties on its net sales of QAPZOLA in the mid-teen digits. (xii) BELEODAQ: In-License and Collaboration Agreement with Onxeo In February 2010, we entered into an in-license and collaboration agreement with TopoTarget A/S (now Onxeo DK) (“Onxeo”), for the development and commercialization of BELEODAQ, as amended in October 2013. We paid Onxeo an upfront fee of $30 million (and agreed to additional payments described below) for rights in North America and India, with an option for China. We are contractually obligated to pay royalties in the mid-teen digits on our net sales of BELEODAQ. All development and studies of BELEODAQ are conducted under a joint development plan (of which we fund 70% and Onxeo funds 30% ). We have the final decision-making authority for all developmental activities in North America and India (and China upon exercise of our option). Onxeo has final decision-making authority for all developmental activities in all other jurisdictions. In February 2014, upon FDA acceptance of our NDA, we were contractually obligated to issue Onxeo one million shares of our common stock and to make a $10 million milestone payment. The aggregate value of this milestone at achievement was $17.8 million , and was recognized within “research and development” expense in the first quarter of 2014. In July 2014, we received approval from the FDA for BELEODAQ’s use for injection and treatment of relapsed or refractory PTCL. As a result, we made a second milestone payment to Onxeo of $25 million in November 2014. This amount was capitalized as "BELEODAQ distribution rights" and is presented within "intangible assets, net of accumulated amortization" (see Note 3(g) ). We are also contractually obligated to pay Onxeo upon our achievements of other regulatory events and sales thresholds, up to $88 million and $190 million , respectively. These milestone amounts are not included within “total liabilities” in our accompanying Consolidated Balance Sheets. (xiii) ROLONTIS: Co-Development and Commercialization Agreement with Hanmi Pharmaceutical Co. Ltd In October 2014, we exercised our option under a License Option and Research Collaboration Agreement dated January 2012 (as amended) with Hanmi Pharmaceutical Co. Ltd., or Hanmi, for ROLONTIS (formerly known as “LAPS-G-CSF" or "SPI-2012”), a drug based on Hanmi’s proprietary LAPSCOVERY™ technology for the treatment of chemotherapy induced neutropenia. Under the terms of this agreement, as amended, we have primary financial responsibility for the ROLONTIS development plan and hold its worldwide rights (except for Korea, China, and Japan). We are contractually obligated to pay Hanmi tiered royalties that range from the low double-digits to mid-teens on our net sales of ROLONTIS. In January 2016, the first patient was dosed with ROLONTIS in a clinical trial. This triggered our contractual milestone payment to Hanmi, and in April 2016, we (i) issued Hanmi 318,750 shares of our common stock, then valued at $2.3 million , and (ii) remitted a $0.4 million payment to the Internal Revenue Service (IRS) on their behalf for related tax obligations. This aggregate $2.7 million was recognized within "research and development" expense in our accompanying Consolidated Statements of Operations for the year ended December 31, 2016. We are responsible for further contractual payments upon our achievement of regulatory and sales milestones, up to $13 million and $225 million , respectively. These amounts are not included within “total liabilities” in our accompanying Consolidated Balance Sheets. (xiv) Poziotinib: In-License Agreement with Hanmi and Exclusive Patent and Technology License Agreement with MD Anderson In February 2015, we executed an in-license agreement with Hanmi for poziotinib, a pan-HER inhibitor in Phase 2 clinical trials (which has also shown single agent activity in the treatment of various cancer types during Phase 1 studies, including breast, gastric, colorectal, and lung cancers), and made an upfront payment for these rights. Under the terms of this agreement, we received the exclusive rights to commercialize poziotinib, excluding Korea and China. Hanmi and its development partners are fully responsible for the completion of on-going Phase 2 trials in Korea. We are financially responsible for all other clinical studies. We are contractually obligated to make payments to Hanmi upon our achievement of certain regulatory and sales milestones, aggregating $33 million and $325 million , respectively, which are not included within “total liabilities” in our accompanying Consolidated Balance Sheets. We will pay Hanmi royalties in the low to mid-teen digits on our net sales of poziotinib, potentially reduced by royalties due to other third parties. These amounts are not included within “total liabilities” in our accompanying Consolidated Balance Sheets. In April 2018, we executed an exclusive patent and technology agreement for poziotinib’s use in treating patients with EGFR and HER2 exon 20 mutations in cancer and HER2 exon 19 mutations in cancer with The University of Texas M.D. Anderson Cancer Center (“MD Anderson”) that had discovered its use in treating these patient-types (“Exon 19/20 Patients”). We made an upfront payment of $0.5 million upon this agreement’s execution that was recognized within “research and development” expense in the accompanying Consolidated Statements of Operations for the year ended December 31, 2018 . We will also pay MD Anderson royalties in the low single-digits on our net sales of poziotinib that relate to the treatment of Exon 19/20 Patients. We are contractually obligated to make fixed payments to MD Anderson upon our achievement of certain regulatory and sales milestones, aggregating $11 million and $23 million , respectively, which are not included within “total liabilities” in our accompanying Consolidated Balance Sheets. (xv) ZEVALIN, FOLOTYN, BELEODAQ, and MARQIBO: Out-License Agreement with Servier in Canada In January 2016, we out-licensed ZEVALIN, FOLOTYN, BELEODAQ, and MARQIBO to Servier (see Note 13 ). We received an aggregate $6 million of upfront proceeds in the first quarter of 2016, which was recognized within "license fees and service revenue" in our accompanying Consolidated Statements of Operations for the year ended December 31, 2016. In November 2018, we received a $1 million milestone receipt from Servier upon the approval of FOLOTYN in Canada (see Note 13 ). We are entitled to additional milestone receipts (aggregating $1.0 million ) upon Servier's achievement of specific regulatory approvals, and a high single-digit royalty on its sales of these products. (xvi) KHAPZORY: Data Sharing License Agreement with Medac Pharma, Inc. In March 2013, we executed a Data Sharing License Agreement with Medac Pharma, Inc, ("Medac") for certain data relating to the manufacture, testing and use of KHAPZORY (previously referred to as sodium levoleucovorin) and levofolinic acid for pharmaceutical applications. Our access to Medac's data will be used to obtain regulatory approval, and commercialize our products containing sodium levoleucovorin in the United States and Canada. In March 2015, we entered into a first amendment to the data sharing license agreement with Medac. We filed an NDA with the FDA for KHAPZORY and the FDA communicated its approval in October 2018. Consequently, we made milestone payments to Medac including (i) $0.3 million upon FDA acceptance of our NDA filing, which was recognized within "research and development" expense in our Consolidated Statements of Operations for the year ended December 31, 2017, and (ii) $2.7 million upon FDA approval for commercial sale of KHAPZORY. We capitalized the $2.7 million to "KHAPZORY distribution rights" which is presented within "intangible assets, net of accumulated amortization" (see Note 3(g) ) within our accompanying Consolidated Balance Sheets as of December 31, 2018 . (c) Service Agreements for our Research and Development Activities We have entered into various contracts with numerous third-party service providers for the execution of our research and development initiatives (to which we assign discreet project codes in order to compile and monitor such expenses). These vendors include raw material suppliers and contract manufacturers for drug products not yet FDA approved, clinical trial sites, clinical research organizations, and data monitoring centers, among others. The financial terms of these agreements are varied and generally obligate us to pay in stages, depending on the achievement of certain events specified in the agreements - such as contract execution, progress of service completion, delivery of drug supply, and the dosing of patients in clinical studies. We recognize these “research and development” expenses and corresponding “accounts payable and other accrued liabilities” in the accompanying financial statements based on estimates of our vendors’ progress of performed services, patient enrollments and dosing, completion of clinical studies, and other events. Should we decide to discontinue and/or slow-down the work on any project, the associated costs for those projects would typically be limited to the extent of the work completed, as we are generally able to terminate these contracts with adequate notice. (d) Supply and Service Agreements for our Commercial Products We have entered into various supply and service agreements, and/or have issued purchase orders, which obligate us to complete agreed-upon raw material purchases from certain vendors for the production of our commercialized drug products through designated contract manufacturers. These commitments do not exceed our planned commercial requirements, and the contracted prices do not exceed current fair market value. (e) Employment Agreement We previously entered into an employment agreement with our former Chief Executive Officer, Rajesh C. Shrotriya, M.D., under which cash compensation and benefits would become payable to him in the event of termination by us for any reason other than cause, his resignation for good reason, or upon a change in control of our Company. Effective December 17, 2017, Dr. Shrotriya’s employment was terminated without cause. As of December 31, 2017, we accrued for all contractual cash amounts due and unpaid to him within “accrued payroll and benefits” on the accompanying Consolidated Balance Sheets. We entered into new employment agreements with each of our named executive officers (chief executive officer, chief operating officer, chief financial officer, and chief legal officer) in April and June 2018, which supersede any prior Change in Control Severance Agreements with such individuals. These new agreements provide for the payment of certain benefits to each executive upon his separation of employment under specified circumstances. These arrangements are designed to encourage each to act in the best interests of our stockholders at all times during the course of a change in control event or other significant transaction. (f) Deferred Compensation Plan The Spectrum Pharmaceuticals, Inc. Deferred Compensation Plan (the “DC Plan”) is administered by the Compensation Committee of our Board of Directors and is intended to comply with the requirements of Section 409A of the Internal Revenue Code of 1986, as amended. The DC Plan is maintained to provide deferred compensation benefits for a select group of our employees (the “DC Participants”). DC Participants make annual elections to defer a portion of their eligible cash compensation which is then placed into their DC Plan accounts. We match a fixed percentage of these deferrals, and may make additional discretionary contributions. At December 31, 2018 and December 31, 2017 , the aggregate value of this DC Plan liability totaled $6.2 million and $11.0 million , respectively, and is included within “accounts payable and other accrued liabilities” and "other long-term liabilities" in the accompanying Consolidated Balance Sheets. (g) Litigation We are involved from time-to-time with various legal matters arising in the ordinary course of business. These claims and legal proceedings are of a nature we believe are normal and incidental to a pharmaceutical business, and may include product liability, intellectual property, employment matters, and other general claims. We may also be subject to derivative lawsuits from time to time. We make provisions for liabilities when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Such provisions are assessed at least quarterly and adjusted to reflect the impact of any settlement negotiations, judicial and administrative rulings, advice of legal counsel, and other information and events pertaining to a particular case. Litigation is inherently unpredictable. Although the ultimate resolution of these various matters cannot be determined at this time, we do not believe that such matters, individually or in the aggregate, will have a material adverse effect on our consolidated results of operations, cash flows, or financial condition. Shareholder Litigation Olutayo Ayeni v. Spectrum Pharmaceuticals, Inc., et al. (Filed September 21, 2016 in the United States District Court, Central District of California; Case No. 2:16-cv-07074) (the “Ayeni Action”) and Glen Hartsock v. Spectrum Pharmaceuticals, Inc., et al. (Filed September 28, 2016 in the United States District Court, District Court of Nevada Case; No. 2:16-cv-02279-RFB-GWF) (the “Hartsock Action”). On November 15, 2016, the Ayeni Action was transferred to the United States District Court for the District of Nevada. The parties have stipulated to a consolidation of the Ayeni Action with the Hartsock Action. These class action lawsuits allege that we and certain of our executive officers made false or misleading statements and failed to disclose material facts about our business and the prospects of approval for our NDA to the FDA for QAPZOLA in violation of Section 10(b) (and Rule 10b-5 promulgated thereunder) and 20(a) of the Securities Exchange Act of 1934, as amended. The plaintiffs seek damages, interest, costs, attorneys’ fees, and other unspecified equitable relief. We believe that these claims are without merit, and intend to vigorously defend against these claims. Furthermore, as of December 31, 2018 , the value of a potential settlement cannot be reasonably estimated given its highly uncertain nature. EVOMELA Litigation We obtained global development and commercialization rights to EVOMELA from CyDex Pharmaceuticals, Inc., a wholly-owned subsidiary of Ligand Pharmaceuticals Incorporated, or CyDex, in March 2013. We thereafter assumed responsibility for completing its clinical trials and were responsible for filing the New Drug Application. Under our license agreement with CyDex, CyDex received a license fee and is eligible to receive milestone payments and royalties. On December 20, 2017, CyDex filed an action against Teva Pharmaceuticals USA, Inc., TEVA Pharmaceuticals Industries Ltd., and Actavis, LLC, together Teva, in the U.S. District Court for the District of Delaware, alleging patent infringement with respect to a paragraph IV certification, or an Abbreviated New Drug Application (“ANDA”), filed with the FDA seeking approval to market a generic version of EVOMELA. CyDex brought suit against Teva to protect its intellectual property rights, for which we have a direct financial interest by virtue of our distribution rights for EVOMELA. Intellectual Property Litigation We and Onxeo received a Paragraph IV Notice Letter dated August 21, 2018, notifying us that Fresenius Kabi USA, LLC (“Fresenius”) has submitted to the FDA, an ANDA seeking approval from the FDA to manufacture and market a generic version of BELEODAQ (belinostat) for injection in the U.S. On October 3, 2018, we and Onxeo have filed a patent infringement lawsuit in the U.S. District Court for the District of Delaware, alleging patent infringement with respect to a paragraph IV certification, or an Abbreviated New Drug Application ("ANDA"), against Fresenius which triggered an automatic stay of this ANDA for 30 months . In addition, BELOEDAQ is protected from competition in the U.S. by an Orphan Drug Exclusivity indication until July 3, 2021.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The components of loss before (provision) benefit for income taxes are as follows: For the Years Ended 2018 2017 2016 United States $ (125,177 ) $ (109,678 ) $ (69,976 ) Foreign 5,167 1,652 (2,107 ) Total $ (120,010 ) $ (108,026 ) $ (72,083 ) The provision (benefit) for income taxes consist of the following: For the Years Ended 2018 2017 2016 Current: Federal $ (11 ) $ (10,608 ) $ (2,001 ) State (19 ) (940 ) (216 ) Foreign — 7 8 $ (30 ) $ (11,541 ) $ (2,209 ) Deferred: Federal 12 (5,256 ) (93 ) State 19 19 (11 ) Foreign — — — 31 (5,237 ) (104 ) Total income tax provision (benefit) $ 1 $ (16,778 ) $ (2,313 ) The income tax provision (benefit) differs from that computed using the applicable federal statutory rate, as applied to income before taxes in each year as follows: For the Years Ended 2018 2017 2016 Tax provision computed at the federal statutory rate $ (25,202 ) $ (37,809 ) $ (25,217 ) State tax, net of federal benefit (4,827 ) (1,849 ) (307 ) Research credits (4,884 ) (1,176 ) (3,232 ) Change in tax credit carryforwards (3,056 ) 386 11,042 Officers compensation 600 (9,292 ) 1,196 Stock based compensation (12,610 ) (2,735 ) 588 Permanent items and other (116 ) 1,450 12 Tax differential on foreign earnings (32 ) 33 15 Change in tax rate (1,329 ) 37,769 (744 ) Refundable ATM credit — (1,336 ) — Uncertain tax positions — (561 ) — Change in prior year deferred taxes 6,595 (1,218 ) — Valuation allowance 44,862 (440 ) 14,334 Income tax provision (benefit) $ 1 $ (16,778 ) $ (2,313 ) Significant components of our deferred tax assets and liabilities as of December 31, 2018 and 2017 are presented below. A valuation allowance has been recognized to offset the net deferred tax assets as realization of such deferred tax assets did not meet the “more-likely-than-not” threshold under GAAP. December 31, 2018 2017 Deferred tax assets: Net operating loss carry forwards $ 106,446 $ 60,771 Research credits 21,618 14,255 Stock based compensation 5,057 10,046 Deferred revenue — 1,017 Development costs 3,938 4,143 Returns and allowances 1,976 1,636 Other, net (5,066 ) — Total deferred tax assets before valuation allowance 133,969 91,868 Valuation allowance (131,042 ) (86,021 ) Total deferred tax assets 2,927 5,847 Deferred tax liabilities: Basis difference in debt — (28 ) Depreciation and amortization differences (4,396 ) (6,836 ) Other, net — (421 ) Net deferred tax liabilities $ (1,469 ) $ (1,438 ) At December 31, 2018 and 2017 , we recorded a valuation allowance of $131.0 million and $86.0 million , respectively. The valuation allowance increased by $45.0 million and $0.8 million during 2018 and 2017 , respectively. The increase in the valuation allowance in 2018 and 2017 was due to an increase in net operating loss carryforwards. We had federal and state net operating loss carryforwards of approximately $452.0 million and $241.6 million , at December 31, 2018 , respectively. We have approximately $4.5 million of foreign loss carryforwards that will begin to expire in 2022 . The federal and state loss carry forwards began to expire in 2018 and 2017, respectively, unless previously utilized. At December 31, 2018 , we had federal and state tax credits of approximately $15.2 million and $8.2 million , respectively. The federal tax credit carryovers begin to expire in 2027 unless previously utilized. The state research and development credit carryforwards have an indefinite carryover period. As a result of the prior ownership changes, the utilization of certain net operating loss and research and development tax credit carryforwards including those acquired in connection with the acquisition of Allos and Talon are subject to annual limitations under Sections 382 and 383 of the Internal Revenue Code of 1986 and similar state provisions. Any net operating losses or credits that would expire unutilized as a result of Section 382 and 383 limitations have been removed from the table of deferred tax assets and the accompanying disclosures of net operating loss and research and development carryforwards. Accounting guidance clarifies the accounting for uncertain tax positions and prescribes a recognition threshold and measurement process for recording in the financial statements uncertain tax positions taken or expected to be taken in a tax return. Additionally, the authoritative guidance addresses the de-recognition, classification, accounting in interim periods and disclosure requirements for uncertain tax positions. Only tax positions that meet the more-likely-than-not recognition threshold at the effective date may be recognized. The following tabular reconciliation summarizes activity related to unrecognized tax benefits: For the Years Ended 2018 2017 2016 Balance at beginning of year $ 2,715 $ 3,271 $ 4,498 Adjustments related to prior year tax positions (551 ) (39 ) (1,638 ) Increases related to current year tax positions 1,084 374 411 Decreases due to expiration of tax statutes — (891 ) — Balance at end of year $ 3,248 $ 2,715 $ 3,271 We continue to believe that our tax positions meet the more-likely-than-not standard required under the recognition phase of the authoritative guidance. However, we consider the amounts and probabilities of the outcomes that can be realized upon ultimate settlement with the tax authorities and determined unrecognized tax benefits primarily related to credits should be established as noted in the summary rollforward above. Approximately $0.2 million , $0.2 million , and $0.7 million of the total unrecognized tax benefits as of December 31, 2018 , 2017 , and 2016 , respectively, would reduce our annual effective tax rate if recognized. Additional amounts in the summary rollforward could impact our effective tax rate if we did not maintain a full valuation allowance on our net deferred tax assets. We do not expect our unrecognized tax benefits to change significantly over the next 12 months . With a few exceptions, we are no longer subject to U.S. federal, state and local income tax examinations for years before 2014. Our policy is to recognize interest and/or penalties related to unrecognized tax benefits in income tax expense in the consolidated statements of operations. On January 1, 2017, we adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, on a prospective basis. Under ASU 2016-09 , differences between the tax deduction for share based awards and the related compensation expenses recognized under ASC 718 are now accounted for as a component of the provision for income taxes. In addition, ASU 2016-09 eliminated the requirement that excess tax benefits from share based compensation reduce taxes payable prior to being recognized in the financial statements. As of December 31, 2016, we had cumulative excess benefits related to share based compensation of $2.7 million which had not been reflected as a deferred tax asset. As a result of the adoption of ASU 2016-09, the excess benefits were reclassified to our net operating loss carryover resulting in an increase in our deferred tax assets and valuation allowance of $2.7 million as of January 1, 2017. There is no impact to retained earnings as a result of the adoption of ASU 2016-09 on January 1, 2017. On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act, or the Tax Act. Changes include, but are not limited to, a corporate tax rate decrease from 35% to 21% effective for tax years beginning in 2018, the transition of U.S international taxation from a worldwide tax system to a territorial system, which includes a new federal tax on global intangible low-taxed income (Global Minimum Tax or GMT), and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017. The Company calculated its best estimate of the impact of the Tax Act in its 2017 income tax provision in accordance with its understanding of the Tax Act and guidance available as of the date of the 10-K filing for the year ended December 31, 2017. In addition, the SEC Staff issued SAB 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. The provisional amounts were subject to revisions as the Company completed its analysis of the Tax Act, collected and prepared necessary data, and interpreted any additional guidance issued by the U.S. Treasury Department, Internal Revenue Service, or IRS, FASB, and other standard-setting and regulatory bodies. The measurement period expired as of December 31, 2018 and the Company's accounting for the Tax Act is complete. The changes in 2018 to provisional amounts recorded in 2017 for the effects of the Tax Act were not material.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) Selected quarterly financial data (unaudited) for the year ended December 31, 2018 and 2017 is presented below: Quarter Ended (Unaudited) March 31, June 30, September 30, December 31, 2018 Total revenues* $ 30,495 $ 24,168 $ 25,268 $ 29,402 Loss from Operations $ (25,264 ) $ (34,311 ) $ (29,024 ) $ (42,578 ) Net (loss) income $ (15,816 ) $ 13,744 $ (68,718 ) $ (49,221 ) Net loss per share, basic and diluted $ (0.16 ) $ 0.13 $ (0.66 ) $ (0.47 ) * See Note 2(i) for a discussion of our adoption of Topic 606 effective beginning on January 1, 2018. Quarter Ended (Unaudited) March 31, June 30, September 30, December 31, 2017 Total revenues $ 29,101 $ 34,301 $ 36,395 $ 28,570 Loss from Operations $ (21,909 ) $ (18,609 ) $ (15,054 ) $ (41,088 ) Net loss $ (23,547 ) $ (20,852 ) $ (18,293 ) $ (28,556 ) Net loss per share, basic and diluted $ (0.30 ) $ (0.27 ) $ (0.22 ) $ (0.29 ) Net loss per basic and diluted shares are computed independently for each of the quarters presented based on basic and diluted shares outstanding per quarter and, therefore, may not sum to the totals for the year.

New Revenue Recognition Standar

New Revenue Recognition Standard	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
New Revenue Recognition Standard	NEW REVENUE RECOGNITION STANDARD As discussed in Note 2(i) , Topic 606 became effective for us on January 1, 2018. We applied the “modified retrospective” transition method for the accounting of open contracts at implementation. This resulted in the recognition of an aggregate $4.7 million increase to our January 1, 2018 retained earnings (for the tax-effected cumulative impact of initially applying this new standard, with no adjustments to our prior period financial statements). Our prior periods continue to be presented in accordance with our historical revenue accounting practices under Topic 605 . Had we continued to apply Topic 605 for our revenue recognition for the year ended December 31, 2018 , the impact to our Consolidated Statements of Operations is presented in the table below: Year Ended December 31, 2018 As Reported Under Topic 606 Adjustments If Reported Under Topic 605 Revenue: Product sales, net $ 104,466 $ 906 $ 105,372 License fees and service revenue 4,867 179 5,046 Total revenues $ 109,333 $ 1,085 $ 110,418 Loss from operations (131,177 ) 1,085 (130,092 ) Loss before income taxes (120,010 ) 1,085 (118,925 ) Net loss $ (120,011 ) $ 1,085 $ (118,926 ) Net loss per share: Basic $ (1.16 ) $ 0.01 $ (1.15 ) Diluted $ (1.16 ) $ 0.01 $ (1.15 ) Weighted average shares outstanding: Basic $ 103,305,911 $ 103,305,911 $ 103,305,911 Diluted $ 103,305,911 $ 103,305,911 $ 103,305,911 Had we continued to apply Topic 605 for our revenue recognition for the year ended December 31, 2018 , the impact to our Consolidated Balance Sheets is presented in the table below: December 31, 2018 As Reported Under Topic 606 Adjustments If Reported Under Topic 605 Current assets: Accounts receivable, net of allowance for doubtful accounts $ 29,873 $ 127 $ 30,000 Total current assets 250,688 127 250,815 Total assets $ 390,886 $ 127 $ 391,013 Current liabilities: Deferred revenue — 2,963 2,963 Total current liabilities 86,474 2,963 89,437 Deferred revenue, less current portion — 251 251 Total liabilities 107,624 3,214 110,838 Stockholders’ equity: Accumulated deficit (599,886 ) (3,087 ) (602,973 ) Total stockholders’ equity 283,262 (3,087 ) 280,175 Total liabilities and stockholders’ equity $ 390,886 $ 127 $ 391,013 Had we continued to apply Topic 605 for our revenue recognition for the year ended December 31, 2018 , the impact to our Consolidated Statements of Cash Flows for the year ended December 31, 2018 is presented in the table below: December 31, 2018 As Reported Under Topic 606 Adjustments If Reported Under Topic 605 Net loss $ (120,011 ) $ 1,085 $ (118,926 ) Changes in operating assets and liabilities: Accounts receivable, net 2,844 (127 ) 2,717 Deferred revenue — (958 ) (958 )

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT Sale of Commercial Portfolio Distribution Rights for Proceeds Up to $300 million On January 17, 2019, we entered into a definitive asset purchase agreement for the sale of our FDA-approved product portfolio of FUSILEV, KHAPZORY, FOLOTYN, ZEVALIN, MARQIBO, BELEODAQ, and EVOMELA to Acrotech. Upon the closing of the Acrotech Transaction, we are entitled to receive up to $160 million in an upfront cash payment (of which $4 million will be held in escrow for six months ). In addition, we expect a purchase price adjustment for certain ongoing research and development activities of the commercialized product portfolio. We are also entitled to receive an aggregate $140 million upon Acrotech's achievement of certain regulatory and sales-based milestones relating to this product portfolio. We plan to reduce our staff by approximately 90 employees, the majority of which we expect to transition to Acrotech. The accounting recognition and financial reporting for the disposal of this commercial component of our business will be reflected in our financial statements in the period corresponding with its closing.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS Years Ended December 31, 2018 , 2017 , and 2016 Additions ($ in thousands) Description Balance at Additions Charged Deductions (1) Balance at (in thousands) December 31, 2018 Allowance for doubtful accounts $ 71 $ 12 $ — $ (16 ) $ 67 December 31, 2017 Allowance for doubtful accounts $ 88 $ (17 ) $ — $ — $ 71 December 31, 2016 Allowance for doubtful accounts $ 120 $ 57 $ — $ (89 ) $ 88 (1) Deductions represent the actual write-off of accounts receivable balances.

Description of Business, Basi_2

Description of Business, Basis of Presentation, and Operating Segment (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Description of Business	Description of Business Spectrum Pharmaceuticals, Inc. (“Spectrum,” the “Company,” “we,” “our,” or “us”) is a biopharma company, with a primary strategy comprised of acquiring, developing, and commercializing a broad and diverse pipeline of clinical and commercial products. We have an in-house clinical development organization with regulatory and data management capabilities, in addition to commercial infrastructure and a field-based sales force for our marketed products. Currently, we have seven approved oncology/hematology products (FUSILEV, KHAPZORY, FOLOTYN, ZEVALIN, MARQIBO, BELEODAQ, and EVOMELA) that target different types of non-Hodgkin's lymphoma ("NHL"), advanced metastatic colorectal cancer ("mCRC"), acute lymphoblastic leukemia ("ALL"), and multiple myeloma ("MM"). We also have two drugs in late-stage development: • Poziotinib, a novel pan-HER inhibitor under investigation for non-small cell lung cancer ("NSCLC") tumors with either EGFR or HER2 exon-20 insertion mutations; and •
Basis of Presentation	Basis of Presentation Principles of Consolidation The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") and with the rules and regulations of the Securities and Exchange Commission ("SEC"). These financial statements include the financial position, results of operations, and cash flows of Spectrum and its subsidiaries, all of which are wholly-owned (except for Spectrum Pharma Canada ("SPC")), as discussed below. All inter-company accounts and transactions among these legal entities have been eliminated in consolidation. Variable Interest Entity We own fifty -percent of SPC, a legal entity organized in Quebec, Canada in January 2008. Some of our clinical studies are conducted through this “variable interest entity” (as defined under applicable GAAP). We fund all of SPC’s operating costs, and since we assume all risks and rewards for this entity, we meet the criteria as being its “primary beneficiary” (as defined under applicable GAAP). Accordingly, SPC’s balance sheets and statements of operations are included in our Consolidated Financial Statements as if it were a wholly-owned subsidiary for all periods presented.
Operating Segment	Operating Segment We operate in one reportable operating segment that is focused exclusively on developing and marketing oncology and hematology drug products. For the years ended December 31, 2018 , 2017 , and 2016 , all of our revenue and related expenses were solely attributable to these activities. Substantially all of our assets (excluding our cash held in certain foreign bank accounts and our ZEVALIN distribution rights for the ex-U.S. territories - see Note 3(g) ) are held in the U.S.
Revenue Recognition	Revenue Recognition Impact of the Adoption of the New Revenue Recognition Standard : ASU No. 2014-09 , Revenue from Contracts with Customers ( “Topic 606” ), became effective for us on January 1, 2018. Our disclosure within the below sections to this footnote reflects our updated accounting policies that are affected by this new standard. We applied the “modified retrospective” transition method for open contracts for the implementation of Topic 606; this resulted in the recognition of an aggregate $4.7 million , net of tax, decrease to our January 1, 2018 “accumulated deficit” on our accompanying Consolidated Balance Sheets for the cumulative impact of applying this new standard. We made no adjustments to our previously-reported total revenues, as those periods continue to be presented in accordance with our historical accounting practices under Topic 605, Revenue Recognition (“Topic 605”) . See Notes 4, 5, and 20 for additional quantitative and qualitative revenue disclosures in accordance with Topic 606. Required Elements of Our Revenue Recognition : Revenue from our (a) product sales, (b) out-license arrangements, and (c) service arrangements is recognized under Topic 606 in a manner that reasonably reflects the delivery of our goods and/or services to customers in return for expected consideration and includes the following elements: (1) we ensure that we have an executed contract(s) with our customer that we believe is legally enforceable; (2) we identify the “performance obligations” in the respective contract; (3) we determine the “transaction price” for each performance obligation in the respective contract; (4) we allocate the transaction price to each performance obligation; and (5) we recognize revenue only when we satisfy each performance obligation. These five elements, as applied to each of our revenue categories, are summarized below: (a) Product Sales : We sell our products to pharmaceutical wholesalers/distributors (i.e., our customers), except for our U.S. sales of ZEVALIN, and limited sales of EVOMELA, in which case the end-user (i.e., clinic or hospital) is our customer. Our wholesalers/distributors in turn sell our products directly to clinics, hospitals, and private oncology-based practices. Revenue from our product sales is recognized as physical delivery of product occurs (when our customer obtains control of the product), in return for agreed-upon consideration. Our gross product sales (i.e., delivered units multiplied by the contractual price per unit) are reduced by our corresponding gross-to-net (“GTN”) estimates using the “expected value” method, resulting in our reported “product sales, net” in the accompanying Consolidated Statements of Operations, reflecting the amount we ultimately expect to realize in net cash proceeds, taking into account our current period gross sales and related cash receipts, and the subsequent cash disbursements on these sales that we estimate for the various GTN categories discussed below. These estimates are based upon information received from external sources (such as written or oral information obtained from our customers with respect to their period-end inventory levels and sales to end-users during the period), in combination with management’s informed judgments. Due to the inherent uncertainty of these estimates, the actual amount incurred (of some, or all) of product returns, government chargebacks, prompt pay discounts, commercial rebates, Medicaid rebates, and distribution, data, and GPO administrative fees may be materially above or below the amount estimated, then requiring prospective adjustments to our reported net product sales. These GTN estimate categories are each discussed below: Product Returns Allowances : Our FUSILEV, MARQIBO, and BELEODAQ customers are contractually permitted to return purchased products beginning at its expiration date and within six months thereafter. Our EVOMELA customers are permitted to return purchased product beginning at six months prior to its expiration date, and within 12 months thereafter (as well as for overstock inventory, as determined by end-users). ZEVALIN and FOLOTYN returns for expiry are not contractually permitted. Returns outside of this aforementioned criteria are not customarily allowed. We estimate expected product returns for our allowance based on our historical return rates. Returned product is typically destroyed, since substantially all returns are due to expiry and cannot be resold. Government Chargebacks : Our products are subject to pricing limits under certain federal government programs (e.g., Medicare and 340B Drug Pricing Program). Qualifying entities (i.e., end-users) purchase products from our customers at their qualifying discounted price. The chargeback amount we incur represents the difference between our contractual sales price to our customer, and the end-user’s applicable discounted purchase price under the government program. There may be significant lag time between our reported net product sales and our receipt of the corresponding government chargeback claims from our customers. Prompt Pay Discounts : Discounts for prompt payment are estimated at the time of sale, based on our eligible customers’ prompt payment history and the contractual discount percentage. Commercial Rebates : Commercial rebates are based on (i) our estimates of end-user purchases through a group purchasing organization (“GPO”), (ii) the corresponding contractual rebate percentage tier we expect each GPO to achieve, and (iii) our estimates of the impact of any prospective rebate program changes made by us. Medicaid Rebates : Our products are subject to state government-managed Medicaid programs, whereby rebates are issued to participating state governments. These rebates arise when a patient treated with our product is covered under Medicaid, resulting in a discounted price for our product under the applicable Medicaid program. Our Medicaid rebate accrual calculations require us to project the magnitude of our sales, by state, that will be subject to these rebates. There is a significant time lag in us receiving rebate notices from each state (generally several months or longer after our sale is recognized). Our estimates are based on our historical claim levels by state, as supplemented by management’s judgment. Distribution, Data, and GPO Administrative Fees : Distribution, data, and GPO administrative fees are paid to authorized wholesalers/distributors of our products (except for U.S. sales of ZEVALIN) for various commercial services including: contract administration, inventory management, delivery of end-user sales data, and product returns processing. These fees are based on a contractually-determined percentage of our applicable sales. (b) License Fees : Our out-license arrangements allow licensees to market our product(s) in certain territories for a specific term (representing the out-license of “functional intellectual property”). These arrangements may include one or more of the following forms of consideration: (i) upfront license fees, (ii) sales royalties, (iii) sales milestone-achievement fees, and (iv) regulatory milestone-achievement fees. We recognize revenue for each based on the contractual terms that establish our right to collect payment once the performance obligation is achieved, as follows: (1) Upfront License Fees: We determine whether upfront license fees are earned at the time of contract execution (i.e., when rights transfer to the customer) or over the actual (or implied) contractual period of the out-license. As part of this determination, we evaluate whether we have any other requirements to provide substantive services that are inseparable from the performance obligation of the license transfer. Our customers’ “distinct” rights to licensed “functional intellectual property” at the time of contract execution results in concurrent revenue recognition of all upfront license fees (assuming that there are no other performance obligations at contract execution that are inseparable from this license transfer). (2) Royalties : Under the “sales-or-usage-based royalty exception” we recognize revenue in the same period that our licensees complete product sales in their territory for which we are contractually entitled to a percentage-based royalty receipt. (3) Sales Milestones : Under the “sales-or-usage-based royalty exception” we recognize revenue in full within the period that our licensees achieve annual or aggregate product sales levels in their territories for which we are contractually entitled to a specified lump-sum receipt. (4) Regulatory Milestones : Under the terms of the respective out-license, regulatory achievements may either be our responsibility, or that of our licensee. • When our licensee is responsible for the achievement of the regulatory milestone, we recognize revenue in full (for the contractual amount due from our licensee) in the period that the approval occurs (i.e., when the “performance obligation” is satisfied by our customer) under the “most likely amount” method. This revenue recognition remains “constrained” (i.e., not recognized) until regulatory approval occurs, given its inherent uncertainty and the requirement of a significant revenue reversal not being probable if achievement does not occur. At each reporting period, we re-evaluate the probability of milestone achievement and the associated revenue constraint; any resulting adjustments would be recorded on a cumulative catch-up basis, thus reflected in our financial statements in the period of adjustment. • When we are responsible for the achievement of a regulatory milestone, the “relative selling price method” is applied for purposes of allocating the transaction price to our performance obligations. In such case, we consider (i) the extent of our effort to achieve the milestone and/or the enhancement of the value of the delivered item(s) as a result of milestone achievement and (ii) if the milestone payment is reasonable relative to all of the deliverables and payment terms (including other potential milestone consideration) within the arrangement. We have historically assessed the contractual value of these milestones upon their achievement to be identical to the allocation of value of our performance obligations and thus representing the “transaction price” for each milestone at contract inception. We recognize this revenue in the period that the regulatory approval occurs (i.e., when we complete the “performance obligation”) under the “most likely amount” method, and revenue recognition is otherwise “constrained” until regulatory approval occurs, given its inherent uncertainty and the requirement of a significant revenue reversal not being probable if achievement does not occur. At each reporting period, we re-evaluate the probability of milestone achievement and the associated revenue constraint; any resulting adjustments would be recorded on a cumulative catch-up basis, thus reflected in our financial statements in the period of adjustment. (c) Service Revenue : We receive fees under certain arrangements for (i) sales and marketing services, (ii) supply chain services, (iii) research and development services, and (iv) clinical trial management services. Our rights to receive payment for these services may be established by (1) a fixed-fee schedule that covers the term of the arrangement, so long as we meet ongoing performance obligations, (2) our completion of product delivery in our capacity as a procurement agent, (3) the successful completion of a phase of drug development, (4) favorable results from a clinical trial, and/or (5) regulatory approval events. We consider whether revenue associated with these service arrangements is reportable each period, based on our completed services or deliverables (i.e., satisfied “performance obligations”) during the reporting period, and the terms of the arrangement that contractually result in fixed payments due to us. The promised service(s) within these arrangements are distinct and explicitly stated within each contract, and our customer benefits from the separable service(s) delivery/completion. Further, the nature of the promise to our customer as stated within the respective contract is to deliver each named service individually (not a transfer of combined items to which the promised goods or services are inputs), and thus are separable for revenue recognition.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of bank deposits and highly liquid investments with maturities of three months or less from the purchase date.
Marketable Securities	Marketable Securities Our marketable securities consist of our holdings in equity securities (beginning January 1, 2018 - see Note 3(a) ), mutual funds, and bank certificates of deposit (“Bank CDs”). Beginning January 1, 2018, our realized and unrealized (loss) gains on marketable securities are included in “other income, net” on the accompanying Consolidated Statements of Operations. Prior to January 1, 2018, our unrealized (loss) gains were included in “other comprehensive (loss) income” on our accompanying Consolidated Statements of Comprehensive Loss.
Accounts Receivable	Accounts Receivable Our accounts receivable are derived from our product sales and license fees, and do not bear interest. The allowance for doubtful accounts is management’s best estimate of the amount of probable credit losses in our existing accounts receivable. Account balances are charged off against the allowance after appropriate collection efforts are exhausted.
Inventories	Inventories We value our inventory at the lower of (i) the actual cost of its purchase or manufacture, or (ii) its net realizable value. Inventory cost is determined on the first-in, first-out method. We regularly review our inventory quantities in process of manufacture and on hand. When appropriate, we record a provision for obsolete and excess inventory to derive its new cost basis, which takes into account our sales forecast by product and corresponding expiry dates of each product lot. Manufacturing costs of drug products that are pending U.S. Food and Drug Administration ("FDA") approval are fully expensed through “research and development,” on the accompanying Consolidated Statements of Operations.
Property and Equipment	Property and Equipment Our property and equipment is stated at historical cost, and is depreciated on a straight-line basis over an estimated useful life that corresponds with its designated asset category. We evaluate the recoverability of “long-lived assets” (which includes property and equipment) whenever events or changes in circumstances in our business indicate that the asset’s carrying amount may not be recoverable through our on-going operations.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Our goodwill represents the excess of our business acquisition cost over the estimated fair value of the net assets acquired in the corresponding transaction. Goodwill has an indefinite accounting life and is therefore not amortized. Instead, goodwill is evaluated for impairment on an annual basis (as of each October 1st), unless we identify impairment indicators that would require earlier testing. We evaluate the recoverability of indefinite-lived intangible assets at least annually, or whenever events or changes in our business indicate that an intangible asset’s (whether indefinite or definite-lived) carrying amount may not be recoverable. Such circumstances could include, but are not limited to the following: (a) a significant decrease in the market value of an asset; (b) a significant adverse change in the extent or manner in which an asset is used; or (c) an accumulation of costs significantly in excess of the amount originally expected for the acquisition of an asset. Intangible assets with finite useful lives are amortized over their estimated useful lives on a straight-line basis. We review these assets for potential impairment if/when facts or circumstances suggest that the carrying value of these assets may not be recoverable.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense for equity awards granted to our employees and members of our Board of Directors is recognized on a straight-line basis over each award’s vesting period. Recognized compensation expense is net of an estimated forfeiture rate, representing the percentage of awards that are expected to be forfeited prior to vesting, though is ultimately adjusted for actual forfeitures. We use the Black-Scholes option pricing model to determine the fair value of stock options (as of the date of grant) that have service conditions for vesting. We use the Monte Carlo valuation model to value equity awards (as of the date of grant) that have combined market conditions and service conditions for vesting. The recognition of stock-based compensation expense and the initial calculation of stock option fair value requires uncertain assumptions, including (a) the pre-vesting forfeiture rate of the award, (b) the expected term that the stock option will remain outstanding, (c) our stock price volatility over the expected term (and that of our designated peer group with respect to certain market-based awards), and (d) the prevailing risk-free interest rate for the period matching the expected term. With regard to (a)-(d): We estimate forfeiture rates based on our employees’ overall forfeiture history, which we believe will be representative of future results. We estimate the expected term of stock options granted based on our employees’ historical exercise patterns, which we believe will be representative of their future behavior. We estimate the volatility of our common stock on the date of grant based on the historical volatility of our common stock for a look-back period that corresponds with the expected term. We estimate the risk-free interest rate based upon the U.S. Department of the Treasury yields in effect at award grant, for a period equaling the expected term of the stock option.
Foreign Currency Translation	Foreign Currency Translation Our foreign subsidiaries’ separate financial statements are stated in their functional currencies (i.e., local operating currencies). To create the accompanying Consolidated Financial Statements, we translate the assets and liabilities of our subsidiaries to U.S. dollars at the rates of exchange in effect at the reported balance sheet date; revenues and expenses are translated using the monthly average exchange rates during the reported period. Unrealized gains and losses from these translations are included in “accumulated other comprehensive (loss) income” in the accompanying Consolidated Balance Sheets. We record foreign currency-based transactions (i.e., when not denominated in the functional currency of our transacting legal entity) at the prevailing exchange rate on the date of the transaction. Resulting unrealized foreign exchange gains and losses from these unsettled transactions are included in “accumulated other comprehensive (loss) income” in the accompanying Consolidated Balance Sheets. All unrealized foreign exchange gains and losses associated with our intercompany loans are included in “accumulated other comprehensive (loss) income” in the accompanying Consolidated Balance Sheets, as these loans with our foreign subsidiaries are not expected to be settled in the “foreseeable future.”
Basic and Diluted Net Loss per Share	Basic and Diluted Net Loss per Share We calculate basic and diluted net loss per share using the weighted average number of common shares outstanding during the periods presented. In periods of a net loss, basic and diluted loss per share are the same. For the diluted earnings per share calculation, we adjust the weighted average number of common shares outstanding to include only dilutive stock options, warrants, and other common stock equivalents outstanding during the period.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recorded based on the estimated future tax effects of temporary differences between the tax basis of assets and liabilities and amounts reported in the financial statements, as well as operating losses and tax credit carry forwards using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Realization of deferred tax assets is dependent upon future earnings, the timing and amount of which are uncertain. We have recorded a valuation allowance to reduce our deferred tax assets, because we believe that, based upon a weighting of positive and negative factors, it is more likely than not that these deferred tax assets will not be realized. If/when we were to determine that our deferred tax assets are realizable, an adjustment to the corresponding valuation allowance would increase our net income in the period that such determination was made. In the event that we are assessed interest and/or penalties from taxing authorities that have not been previously accrued, such amounts would be included in “(provision) benefit for income taxes” within the Consolidated Statements of Operations in the period the notice was received.
Research and Development Costs	Research and Development Costs Our research and development costs are expensed as incurred (see Note 17(c) ), or as certain milestone payments become contractually due to our licensors, as triggered by the achievement of clinical or regulatory events.
Fair Value Measurements	Fair Value Measurements We determine measurement-date fair value based on the proceeds that would be received through the sale of the asset, or that we would pay to settle or transfer the liability, in an orderly transaction between market participants. We utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. Fair value measurements are based on a three-tier hierarchy that prioritizes the inputs used to measure fair value. These tiers include the following: Level 1: Quoted prices (unadjusted) in active markets for identical assets or liabilities that are publicly accessible at the measurement date. Level 2: Observable prices that are based on inputs not quoted on active markets, but that are corroborated by market data. These inputs may include quoted prices for similar assets or liabilities or quoted market prices in markets that are not active to the general public. Level 3: Unobservable inputs are used when little or no market data is available.

Balance Sheet Account Detail (T

Balance Sheet Account Detail (Tables)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Cash and Cash Equivalents and Marketable Securities	The following is a summary of our presented “cash and cash equivalents” and “marketable securities”: Cost Foreign Currency Translation Gross Estimated Cash and Marketable Securities Current December 31, 2018 Equity securities* (see Note 3(h) and Note 10 ) $ 8,710 $ (2,168 ) $ 39,880 $ 46,422 $ — $ 46,422 Bank deposits 14,735 — — 14,735 14,735 — Money market funds 142,745 — — 142,745 142,745 — Bank certificates of deposits 86 — — 86 — 86 Total cash and cash equivalents and marketable securities $ 166,276 $ (2,168 ) $ 39,880 $ 203,988 $ 157,480 $ 46,508 December 31, 2017 Bank deposits $ 10,965 $ — $ — $ 10,965 $ 10,965 $ — Money market funds 216,358 — — 216,358 216,358 — Bank certificates of deposits 248 — — 248 — 248 Total cash and cash equivalents and marketable securities $ 227,571 $ — $ — $ 227,571 $ 227,323 $ 248 * Beginning January 1, 2018, under the new requirements of ASU 2016-01, Recognition and Measurement of Financial Assets and Liabilities , the unrealized (loss) gains on our CASI Pharmaceuticals, Inc. (NASDAQ: CASI) (“CASI”) equity securities are recognized as a (decrease) increase to “other income, net” on the Consolidated Statements of Operations (rather than through “other comprehensive (loss) income” on the Consolidated Statements of Comprehensive Loss). Our adoption of ASU 2016-01 on January 1, 2018, resulted in a $17.2 million cumulative-effect adjustment, net of income tax, recorded as a decrease to “accumulated other comprehensive (loss) income” and a decrease to “accumulated deficit” on the accompanying Consolidated Balance Sheets. Our recognized unrealized gain on these equity securities for the year ended December 31, 2018 was $10.5 million , as reported in “other income, net” on the accompanying Consolidated Statements of Operations.
Schedule of Property and Equipment Net of Accumulated Depreciation	“Property and equipment, net of accumulated depreciation” consists of the following: December 31, 2018 2017 Computers hardware and software $ 3,079 $ 2,994 Laboratory equipment 635 630 Office furniture 212 218 Leasehold improvements 2,957 2,938 Property and equipment, at cost 6,883 6,780 (Less): Accumulated depreciation (6,498 ) (6,191 ) Property and equipment, net of accumulated depreciation $ 385 $ 589
Components of Inventories	“Inventories” consists of the following: December 31, 2018 2017 Raw materials $ 2,024 $ 1,077 Work-in-process 2,209 2,551 Finished goods 1,193 5,187 (Less:) Non-current portion of inventories included within "other assets" * (1,876 ) (3,100 ) Inventories $ 3,550 $ 5,715 * The “non-current” portion of inventories is presented within "other assets" in the accompanying Consolidated Balance Sheets at December 31, 2018 and 2017 , respectively. This value of $1.9 million at December 31, 2018 represents product that we expect to sell beyond December 31, 2019 , and the value at December 31, 2017 represented product that we expected to sell beyond December 31, 2018 .
Summary of Customers Representing 10% or More of Accounts Receivables	A summary of our customers that represent 10% or more of our accounts receivables as of December 31, 2018 and 2017 , are as follows: December 31, 2018 2017 AmerisourceBergen Corporation, and its affiliates $ 10,448 35.0 % $ 7,175 22.2 % Cardinal Health, Inc. and its affiliates 8,228 27.5 % 9,514 29.5 % McKesson Corporation and its affiliates 7,615 25.5 % 11,186 34.7 % All other customers 3,582 12.0 % 4,385 13.6 % Accounts receivable, net $ 29,873 100.0 % $ 32,260 100.0 %
Schedule of Prepaid Expenses and Other Assets	“Prepaid expenses and other assets” consists of the following: December 31, 2018 2017 Other miscellaneous prepaid operating expenses $ 8,186 $ 3,389 Prepaid insurance 782 645 Research and development supplies 611 1,883 Key employee life insurance – cash surrender value — 4,150 Prepaid expenses and other assets $ 9,579 $ 10,067
Schedule of Other Receivables	“Other receivables” consists of the following: December 31, 2018 2017 CASI note - short term ( Note 11 ) $ 1,525 $ — Other miscellaneous receivables (including Medicaid rebate credits and royalty receivables) 1,189 1,152 Insurance receivable 206 53 Income tax receivable 643 665 Reimbursements due from development partners for incurred research and development expenses 135 263 Other receivables $ 3,698 $ 2,133
Components of Intangible Assets Net of Accumulated Amortization	“Intangible assets, net of accumulated amortization” consists of the following: December 31, 2018 Historical Accumulated Foreign Impairment Net Amount Full Remaining MARQIBO IPR&D (NHL and other novel indications) $ 17,600 $ — $ — $ — $ 17,600 n/a n/a EVOMELA distribution rights 7,700 (1,629 ) — — 6,071 156 123 KHAPZORY distribution rights (1) 2,650 (379 ) — — 2,271 14 12 BELEODAQ distribution rights 25,000 (8,438 ) — — 16,562 160 106 MARQIBO distribution rights 26,900 (21,501 ) — — 5,399 81 18 FOLOTYN distribution rights 118,400 (67,187 ) — — 51,213 152 47 ZEVALIN distribution rights – U.S. 41,900 (41,031 ) — — 869 123 3 ZEVALIN distribution rights – Ex-U.S. 23,490 (18,071 ) (3,409 ) — 2,010 96 15 FUSILEV distribution rights (2) 16,778 (9,618 ) — (7,160 ) — 56 0 FOLOTYN out-license (3) 27,900 (17,278 ) — (1,023 ) 9,599 110 43 Total intangible assets (4) $ 308,318 $ (185,132 ) $ (3,409 ) $ (8,183 ) $ 111,594 December 31, 2017 Historical Cost Accumulated Amortization Foreign Currency Translation Impairment Net Amount MARQIBO IPR&D (NHL and other novel indications) $ 17,600 $ — $ — $ — $ 17,600 EVOMELA distribution rights 7,700 (1,037 ) — — 6,663 BELEODAQ distribution rights 25,000 (6,563 ) — — 18,437 MARQIBO distribution rights 26,900 (17,182 ) — — 9,718 FOLOTYN distribution rights 118,400 (54,111 ) — — 64,289 ZEVALIN distribution rights – U.S. 41,900 (37,557 ) — — 4,343 ZEVALIN distribution rights – Ex-U.S. 23,490 (17,232 ) (2,471 ) — 3,787 FUSILEV distribution rights (2) 16,778 (9,618 ) — (7,160 ) — FOLOTYN out-license (3) 27,900 (14,555 ) — (1,023 ) 12,322 Total intangible assets (4) $ 305,668 $ (157,855 ) $ (2,471 ) $ (8,183 ) $ 137,159 (1) In November 2018, we made a $2.7 million payment to Medac related to the FDA approval of KHAPZORY for its commercial sale. This amount was capitalized to "KHAPZORY distribution rights" during the fourth quarter of 2018 and will be amortized through December 31, 2019 (see Note 17(b)(xvi) ). (2) On February 20, 2015, the U.S. District Court for the District of Nevada found the patent covering FUSILEV to be invalid, which was upheld on appeal. On April 24, 2015, Sandoz began to commercialize a generic version of FUSILEV. This represented a “triggering event” under applicable GAAP in evaluating the value of our FUSILEV distribution rights as of March 31, 2015, resulting in a $7.2 million impairment charge (non-cash) in the first quarter of 2015. We accelerated amortization expense recognition for the remaining net book value of FUSILEV distribution rights. Effective December 2018, FUSILEV has been discontinued and we are no longer selling this product. We have since transitioned to marketing KHAPZORY for the same indications as FUSILEV. (3) On May 29, 2013, we amended our FOLOTYN collaboration agreement with Mundipharma. As a result of the amendment, Europe and Turkey were excluded from Mundipharma’s commercialization territory, and their royalty rates and milestone payments to us were modified. This constituted a change under which we originally valued the FOLOTYN out-license as part of business combination accounting, resulting in an impairment charge (non-cash) of $1.0 million resulted from this amendment. (4) See Note 1(a) for a discussion of the Acrotech Transaction, relating to our pending sale of these intangible assets.
Estimated Intangible Asset Amortization Expense	Estimated intangible asset amortization expense for the five succeeding years and thereafter is as follows (without consideration of the completion of the Acrotech Transaction - see Note 1(a) ): Years Ending December 31, 2019 $ 27,333 2020 19,748 2021 18,266 2022 15,882 2023 2,467 2024 and thereafter 10,298 $ 93,994
Schedule of Goodwill	“Goodwill” consists of the following: December 31, 2018 2017 Acquisition of Talon (MARQIBO rights) $ 10,526 $ 10,526 Acquisition of ZEVALIN Ex-U.S. distribution rights 2,525 2,525 Acquisition of Allos (FOLOTYN rights) 5,346 5,346 Foreign currency exchange translation effects (336 ) (235 ) Goodwill $ 18,061 $ 18,162
Summary of Other Assets	“Other assets” consists of the following: December 31, 2018 2017 Key employee life insurance – cash surrender value $ 6,274 $ 10,737 Inventories - non-current portion 1,876 3,100 Research & development supplies and other 1,340 231 Income tax receivable* 668 668 Equity securities (see Note 11 )** — 37,530 CASI note - long term (see Note 11 ) — 1,517 Other assets $ 10,158 $ 53,783 * This value represents the non-current portion of the refundable alternative minimum tax credit that is expected to be received over the next few years (see Note 18 ). ** As of March 31, 2018, we reclassified our presentation of these equity securities from this account caption to “marketable securities” on our accompanying Consolidated Balance Sheets - ( see Note 3(a) ).
Schedule of Accounts Payable and Other Accrued Obligations	"Accounts payable and other accrued liabilities" consists of the following: December 31, 2018 2017 Trade accounts payable and other accrued liabilities $ 44,919 $ 33,648 Accrued rebates 8,371 7,990 Accrued product royalty 4,337 4,339 Allowance for returns 5,171 4,045 Accrued data and distribution fees 3,248 4,305 Accrued GPO administrative fees 296 296 Accrued inventory management fee 388 1,126 Allowance for chargebacks 2,730 2,368 Accounts payable and other accrued liabilities $ 69,460 $ 58,117
Schedule of Amounts Presented in Accounts Payable and Other Accrued Obligations	Amounts presented within “accounts payable and other accrued liabilities” in the accompanying Consolidated Balance Sheets for GTN estimates (see Note 2(i) ) were as follows: Description Rebates and Data and Returns Balance as of December 31, 2016 $ 9,817 $ 5,146 $ 2,309 Add: provisions 106,647 20,104 2,807 (Less): credits or actual allowances (106,106 ) (19,523 ) (1,071 ) Balance as of December 31, 2017 10,358 5,727 4,045 Add: provisions 65,751 13,962 1,700 (Less): credits or actual allowances (65,008 ) (15,757 ) (574 ) Balance as of December 31, 2018 $ 11,101 $ 3,932 $ 5,171
Deferred Revenue	Contract liabilities" consists of the following: December 31, 2018 2017 Deposit made by licensee for EVOMELA supply in China territory $ 4,850 $ — Contract liabilities $ 4,850 $ —
Deferred Revenue, by Arrangement, Disclosure	Deferred revenue (current and non-current) consists of the following: December 31, 2018 2017 EVOMELA deferred revenue $ — $ 3,819 ZEVALIN out-license in India territory (see Note 17(b)(iii) ) — 368 Deferred revenue* $ — $ 4,187 * On January 1, 2018, we reclassified the deferred revenue related to our EVOMELA product sales and our ZEVALIN out-license in the India territory of $3.8 million and $0.4 million , respectively. These amounts were included in the $4.7 million aggregate decrease to “accumulated deficit” on January 1, 2018, in accordance with the adoption of Topic 606 (see Note 2(i) ).
Summary of Other Long-Term Liabilities	"Other long-term liabilities" consists of the following: December 31, 2018 2017 Accrued executive deferred compensation $ 5,474 $ 5,928 Deferred rent (non-current portion) — 52 Clinical study holdback costs, non-current — 59 Other tax liabilities 176 176 Other long-term liabilities $ 5,650 $ 6,215

Gross-to-Net Product Sales an_2

Gross-to-Net Product Sales and Significant Customers (Tables)	12 Months Ended
	Dec. 31, 2018
Revenues [Abstract]
Reconciliation of Gross to Net Product Sales	The below table presents a GTN revenue (see Note 2(i) ) product sales reconciliation for the accompanying Consolidated Statement of Operations: Year Ended December 31, 2018 2017 2016 Gross product sales $ 190,825 $ 245,797 $ 244,770 Commercial rebates and government chargebacks (68,976 ) (36.1 )% (105,148 ) (42.8 )% (98,317 ) (40.2 )% Data and distribution fees, GPO fees, and inventory management fees (14,048 ) (7.4 )% (20,083 ) (8.2 )% (14,979 ) (6.1 )% Prompt pay discounts (1,553 ) (0.8 )% (1,610 ) (0.7 )% (755 ) (0.3 )% Product returns (1,782 ) (0.9 )% (2,778 ) (1.1 )% (2,123 ) (0.9 )% Product sales, net $ 104,466 54.7 % $ 116,178 47.3 % $ 128,596 52.5 %
Schedule of Revenue by Major Customers by Reporting Segments	The below table presents the customers that represent 10% or more of our gross product sales in 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 McKesson Corporation and its affiliates 69,320 36.3 % 76,363 31.1 % 75,952 31.0 % AmerisourceBergen Corporation, and its affiliates $ 55,576 29.1 % $ 79,362 32.3 % $ 93,951 38.4 % Cardinal Health, Inc. and its affiliates 42,074 22.0 % 64,634 26.3 % 58,780 24.0 % All other customers 23,855 12.5 % 25,438 10.3 % 16,087 6.6 % Gross product sales $ 190,825 100.0 % $ 245,797 100.0 % $ 244,770 100.0 % The below table presents our license fees and service revenue by source for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Out-license of ZEVALIN: recognition of milestone achievement, upfront cash receipt and subsequent royalties for Asia and certain other territories, excluding China ( Note 12 ) $ 2,001 41.1 % $ 1,245 10.2 % $ 1,756 9.8 % Out-license of FOLOTYN in all countries except the United States, Canada, Europe, and Turkey: royalties ( Note 16 ) 1,860 38.2 % 5,848 48.0 % 927 5.2 % Out-license of ZEVALIN, FOLOTYN, BELEODAQ, MARQIBO: upfront cash receipt and subsequent royalties for the Canada territory ( Note 17(b)(xv) ) 1,006 20.7 % 5 — % 6,000 33.6 % Out-license of ZEVALIN: amortization of upfront cash receipt related to India territory ( Note17(b)(iii) ) and other — — % 50 0.4 % 69 0.4 % Sales and marketing contracted services ( Note 14 ) — — % 4,747 38.9 % 9,096 51.0 % Regulatory services provided to licensee — — % 294 2.4 % — — % License fees and service revenues $ 4,867 100.0 % $ 12,189 100.0 % $ 17,848 100.0 %

Composition of Total Revenue (T

Composition of Total Revenue (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Schedule of Net Product Sales by Geography	The below table presents our net product sales by geography for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 United States $ 91,822 87.9 % $ 107,135 92.2 % $ 125,074 97.3 % International: Europe/Canada 11,220 10.7 % 7,727 6.7 % 3,522 2.7 % Asia Pacific 1,424 1.4 % 1,316 1.1 % — — % Total International 12,644 12.1 % 9,043 7.8 % 3,522 2.7 % Product sales, net $ 104,466 100.0 % $ 116,178 100.0 % $ 128,596 100.0 %
Schedule of Net Product Sales by Product Line	The below table presents our net sales by product for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 FOLOTYN $ 47,981 45.9 % $ 43,015 37.0 % $ 46,245 36.0 % EVOMELA 28,292 27.1 % 35,178 30.3 % 16,169 12.6 % BELEODAQ 12,328 11.8 % 12,353 10.6 % 13,368 10.4 % ZEVALIN 7,044 6.7 % 11,759 10.1 % 10,730 8.3 % MARQIBO 5,502 5.3 % 6,573 5.7 % 7,245 5.6 % FUSILEV* 2,437 2.3 % 7,300 6.3 % 34,839 27.1 % KHAPZORY 882 0.8 % — — % — — % Product sales, net** $ 104,466 100.0 % $ 116,178 100.0 % $ 128,596 100.0 % * Effective December 2018, FUSILEV has been discontinued and we are no longer selling this product. We have since transitioned to marketing KHAPZORY for identical indications as FUSILEV. ** See Note 2(i) for a discussion of our adoption of Topic 606 effective beginning on January 1, 2018.
Summary of Customers Representing 10% or More of Gross Product Sales	The below table presents the customers that represent 10% or more of our gross product sales in 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 McKesson Corporation and its affiliates 69,320 36.3 % 76,363 31.1 % 75,952 31.0 % AmerisourceBergen Corporation, and its affiliates $ 55,576 29.1 % $ 79,362 32.3 % $ 93,951 38.4 % Cardinal Health, Inc. and its affiliates 42,074 22.0 % 64,634 26.3 % 58,780 24.0 % All other customers 23,855 12.5 % 25,438 10.3 % 16,087 6.6 % Gross product sales $ 190,825 100.0 % $ 245,797 100.0 % $ 244,770 100.0 % The below table presents our license fees and service revenue by source for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Out-license of ZEVALIN: recognition of milestone achievement, upfront cash receipt and subsequent royalties for Asia and certain other territories, excluding China ( Note 12 ) $ 2,001 41.1 % $ 1,245 10.2 % $ 1,756 9.8 % Out-license of FOLOTYN in all countries except the United States, Canada, Europe, and Turkey: royalties ( Note 16 ) 1,860 38.2 % 5,848 48.0 % 927 5.2 % Out-license of ZEVALIN, FOLOTYN, BELEODAQ, MARQIBO: upfront cash receipt and subsequent royalties for the Canada territory ( Note 17(b)(xv) ) 1,006 20.7 % 5 — % 6,000 33.6 % Out-license of ZEVALIN: amortization of upfront cash receipt related to India territory ( Note17(b)(iii) ) and other — — % 50 0.4 % 69 0.4 % Sales and marketing contracted services ( Note 14 ) — — % 4,747 38.9 % 9,096 51.0 % Regulatory services provided to licensee — — % 294 2.4 % — — % License fees and service revenues $ 4,867 100.0 % $ 12,189 100.0 % $ 17,848 100.0 %

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock-Based Compensation Expense	Stock-based compensation expense included within “total operating costs and expenses” for the years ended December 31, 2018 , 2017 , and 2016 , was as follows: Year Ended December 31, 2018 2017 2016 Cost of sales $ 298 $ 203 $ 135 Selling, general and administrative 14,010 12,904 11,480 Research and development 3,175 2,032 2,055 Total stock-based compensation $ 17,483 $ 15,139 $ 13,670
Fair Value of Stock Options Granted Using Black-Scholes Option Pricing Model	The fair value of stock options granted was estimated at the date of grant using the Black-Scholes option-pricing model. The following assumptions were used to determine fair value for the stock awards granted in the applicable year: Year Ended December 31, 2018 2017 2016 Expected option life (in years) (a) 4.73 4.84 5.02 Risk-free interest rate (b) 1.81% - 2.75% 0.82% - 1.90% 1.07% - 1.90% Volatility (c) 50.0% - 56.2% 49.3% - 61.4% 48.9% - 50.6% Dividend yield (d) —% —% —% Weighted-average grant-date fair value per stock option $8.64 $2.89 $2.80 (a) Determined by the historical stock option exercise behavior of our employees (maximum term is 10 years). (b) Based upon the U.S. Treasury yields in effect during the period which the options were granted (for a period equaling the stock options’ expected term). (c) Measured using our historical stock price for a period equal to stock options’ expected term. (d) We do not expect to declare any cash dividends in the foreseeable future.
Summary of Stock Option Activity	Stock option activity during the years ended December 31, 2018 , 2017 , and 2016 was as follows: Number of Weighted- Weighted- Aggregate Outstanding — December 31, 2015 13,836,851 $ 6.97 Granted 1,435,550 5.94 Exercised (39,010 ) 5.18 $ 50 (1 ) Forfeited (379,268 ) 7.21 Expired (513,541 ) 7.26 Outstanding — December 31, 2016 14,340,582 6.86 Granted 1,223,483 6.51 Exercised (937,482 ) 6.40 $ 6,813 (1 ) Forfeited (244,793 ) 6.26 Expired (524,577 ) 6.27 Outstanding — December 31, 2017 13,857,213 6.89 Granted 1,094,358 18.87 Exercised (7,858,141 ) 6.74 $ 84,758 (1 ) Forfeited (214,464 ) 6.54 Expired (35,381 ) 6.94 Outstanding — December 31, 2018 6,843,585 $ 8.98 6.39 $ 11,095 (2 ) Vested (exercisable) — December 31, 2018 4,955,073 $ 7.87 5.62 $ 8,422 (2 ) Unvested (unexercisable) — December 31, 2018 1,888,512 $ 11.91 8.38 $ 2,673 (2 ) (1) Represents the total difference between our closing stock price at the time of exercise and the stock option exercise price, multiplied by the number of options exercised. (2) Represents the total difference between our closing stock price on the last trading day of 2018 and the stock option exercise price, multiplied by the number of in-the-money options as of December 31, 2018 . The amount of intrinsic value will change based on the fair market value of our stock.
Summary of Stock Option Grants	The following table summarizes information with respect to stock option grants as of December 31, 2018 : Outstanding Exercisable Exercise Price Granted Stock Weighted- Weighted- Granted Weighted- $1.03 - 3.16 7,250 0.23 $ 1.76 7,250 $ 1.76 $3.17 - 4.96 212,880 4.27 4.22 168,409 4.16 $4.97 - 6.91 2,938,104 6.98 5.97 2,029,420 5.90 $6.92 - 9.00 1,914,493 5.00 7.75 1,856,327 7.77 $9.01 - 22.64 1,770,858 7.18 15.92 893,667 13.27 6,843,585 6.39 $ 8.98 4,955,073 $ 7.87
Summary of Restricted Stock Award and Restricted Stock Units Activity	A summary of restricted stock unit activity is as follows: Number of Weighted Average Outstanding — December 31, 2016 — $ — Granted 217,206 6.49 Outstanding — December 31, 2017 217,206 6.49 Granted 138,334 28.31 Market-based achievement adjustment at vesting 100,326 6.49 Share issuance upon approved achievement date (200,652 ) 6.49 Outstanding — December 31, 2018 255,214 $ 17.91 A summary of restricted stock award activity is as follows: Number of Weighted Average Unvested — December 31, 2015 2,173,982 $ 6.58 Granted 1,203,675 5.93 Vested (889,857 ) 6.49 Forfeited (335,643 ) 6.33 Unvested — December 31, 2016 2,152,157 6.29 Granted 927,306 6.22 Vested (1,137,555 ) 6.38 Forfeited (378,990 ) 5.95 Unvested — December 31, 2017 1,562,918 6.27 Granted 1,092,534 17.35 Vested (635,320 ) 6.51 Forfeited (218,002 ) 7.56 Unvested — December 31, 2018 1,802,130 $ 12.75
Fair Value of Restricted Stock and Restricted Stock Units Awards	Year Ended December 31, 2018 2017 2016 Restricted stock award expense $ 7,652 $ 6,821 $ 6,518 2018 2017 2016 Restricted stock unit expense $ 2,301 $ 1,030 $ —
Issued Shares of Common Stock	We issued shares of common stock to our employees in connection with our 401(k) program, partially matching our employees’ annual 401(k) contributions, as summarized below: Year Ended December 31, 2018 2017 2016 Shares of common stock issued 70,379 102,874 172,650 Match contribution value $ 1,175 $ 912 $ 953

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Summary of Warrant Activity	A summary of warrant activity is as follows: Number of Weighted Outstanding — December 31, 2016 445,000 $ 6.78 Granted — — Outstanding — December 31, 2017 445,000 $ 6.78 Granted — — Exercised (445,000 ) $ 6.78 Outstanding — December 31, 2018 — — Exercisable — December 31, 2018 — $ —
Schedule of Stock by Class	We sold and issued shares of our common stock under both the December 2015 and August 2017 ATM Agreements, summarized as follows: No. of Common Shares Issued Proceeds Received (Net of Broker Commissions and Fees ) Common shares issued pursuant to the December 2015 ATM Agreement during the year ended December 31, 2016 10,890,915 $ 73,869 Common shares issued pursuant to the December 2015 ATM Agreement between July 1, 2017 and July 31, 2017 3,243,882 $ 23,745 Common shares issued pursuant to the August 2017 ATM Agreement between August 1, 2017 and December 31, 2017 10,314,250 $ 104,527

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Computation of Net (Loss) Income Per Share	Net loss per share was computed by dividing net loss by the weighted average number of common shares outstanding for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Net loss $ (120,011 ) $ (91,248 ) $ (69,770 ) Weighted average shares—basic 103,305,911 85,115,592 72,824,070 Net loss per share—basic $ (1.16 ) $ (1.07 ) $ (0.96 ) Weighted average shares—diluted 103,305,911 85,115,592 72,824,070 Net loss per share—diluted $ (1.16 ) $ (1.07 ) $ (0.96 )
Schedule of Securities Excluded from Calculation of Net (Loss) per Share	The below outstanding securities were excluded from the above calculation of net loss per share because their impact under the "treasury stock method" and "if-converted method" would have been anti-dilutive due to our net loss per share for the years ended December 31, 2018 , 2017 , and 2016 , as summarized below: Year Ended December 31, 2018 2017 2016 Common stock options 4,407,765 3,668,662 1,294,594 Restricted stock awards 1,802,130 1,562,918 2,147,157 Restricted stock units 255,214 217,206 — 2018 Convertible Notes — 3,854,959 10,454,799 Common stock warrants — 138,277 — Total 6,465,109 9,442,022 13,896,550

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Summary of Asset and Liability Fair Values	The table below summarizes certain asset and liability fair values that are included within our accompanying Consolidated Balance Sheets, and their designations among the three fair value measurement categories (see Note 2(xiii) ): December 31, 2018 Level 1 Level 2 Level 3 Total Assets: Bank certificates of deposits $ — $ 86 $ — $ 86 Money market funds — 142,745 — 142,745 Equity securities ( Note 11 ) 46,422 — — 46,422 Mutual funds — 78 — 78 Deferred compensation investments (life insurance cash surrender value - Note 3(h) ) — 6,274 — 6,274 * $ 46,422 $ 149,183 $ — $ 195,605 Liabilities: Deferred executive compensation liability ( Note 17(f) ) — 6,167 — 6,167 * FOLOTYN development liability ( Note 16 ) — — 11,997 11,997 Talon CVR ( Note 10 (a) ) — — 4,345 4,345 $ — $ 6,167 $ 16,342 $ 22,509 December 31, 2017 Level 1 Level 2 Level 3 Total Assets: Bank certificates of deposits $ — $ 248 $ — $ 248 Money market funds — 216,358 — 216,358 Equity securities (Note 11) 37,530 — — 37,530 Mutual funds — 59 — 59 Deferred compensation investments (life insurance cash surrender value - Note 3(h)) — 14,887 — 14,887 * $ 37,530 $ 231,552 $ — $ 269,082 Liabilities: Deferred executive compensation liability (Note 17(f)) — 11,038 — 11,038 * FOLOTYN development liability (Note 16) — — 12,386 12,386 Talon CVR (Note 10 (a)) — — 6,210 6,210 Corixa Liability (Note 17(b)(i)) — — 62 62 $ — $ 11,038 $ 18,658 $ 29,696 * The reported amount of “deferred compensation investments” is based on the cash surrender value of employee life insurance policies at period-end, while the reported amount of “deferred executive compensation liability” is based on the period-end market value of investments selected by plan participants.
Activity of Level 3 Inputs Measured on Recurring Basis	The table below summarizes the 2017 and 2018 activity of our liabilities that are valued with unobservable inputs: Fair Value Measurements of Level 3 ) Balance at December 31, 2016 $ 14,445 FOLOTYN development liability ( Note 16 ) (744 ) Talon CVR fair value adjustment - MARQIBO ( Note 10(a) ) 4,957 Balance at December 31, 2017 $ 18,658 FOLOTYN development liability ( Note 16 ) (389 ) Talon CVR fair value adjustment - MARQIBO ( Note 10(a) ) (1,865 ) Corixa Liability ( Note 17(b)(i) ) (62 ) Balance at December 31, 2018 $ 16,342

Business Combinations and Con_2

Business Combinations and Contingent Consideration (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Change in Fair Value of Contingent Consideration Related to Acquisition	Fair Value December 31, 2017 $ 6,210 Fair value adjustment for the year ended December 31, 2018 (1,865 ) December 31, 2018 $ 4,345 Fair Value of December 31, 2015 $ 5,227 Fair value adjustment for the three months ended March 31, 2016 773 Payment to Ligand in April 2016 for FDA approval milestone achievement (6,000 ) December 31, 2016 $ —
Acquisition-Date Fair Value of Consideration Transferred	The acquisition-date fair value of the consideration transferred consisted of the following: Cash consideration $ 3,000 Ligand Contingent Consideration 4,700 Total purchase consideration $ 7,700
Summary of Allocation of Total Purchase Price to Net Assets Acquired	The allocation of the total purchase price to the net assets acquired is as follows: EVOMELA IPR&D rights $ 7,700

Out-License of MARQIBO, ZEVAL_2

Out-License of MARQIBO, ZEVALIN, & EVOMELA in China Territory (Tables)	12 Months Ended
	Dec. 31, 2018
Other Commitments [Abstract]
Schedule of Proceeds Received and Fair Value on CASI Out-License Execution Date	The proceeds we received in 2014, and its fair value on the CASI Out-License execution date, consisted of the following: CASI common stock (5.4 million shares) $ 8,649 (a) CASI secured promissory note, net of fair value discount ($1.5 million face value and 0.5% annual coupon) 1,310 (b) Total consideration received, net of fair value discount $ 9,959 (c) (a) Value determined based on the September 17, 2014 closing price of 5.4 million shares of CASI common stock on the NASDAQ Capital Market of $1.60 per share. (b) Value estimated using the terms of the $1.5 million promissory note, the application of a synthetic debt rating based on CASI’s publicly-available financial information, and the prevailing interest yields on similar public debt securities as of September 17, 2014. This promissory note has been reclassified in the accompanying Consolidated Balance Sheets as of December 31, 2018 to "other receivables" (presented within current assets) from "other assets" (presented within non-current assets) due to its maturity date (as amended) of September 17, 2019. (c) Presented within “license fees and service revenue” in the accompanying Consolidated Statements of Operations for the year ended December 31, 2015 (see below).

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Carrying Value of 2018 Convertible Notes	The carrying value of the 2013 Convertible Notes as of December 31, 2017, is summarized as follows: Year Ended December 31, 2017 Principal amount $ 40,565 (Less): Unamortized debt discount (amortized through December 2018) (2,101 ) (Less): Debt issuance costs (240 ) Carrying value $ 38,224
Components of Total Interest Expense, Net Recognized	The following table sets forth the components of interest expense recognized in the accompanying Consolidated Statements of Operations for the 2013 Convertible Notes for the years ended December 31, 2018 , 2017 , and 2016 : Year Ended December 31, 2018 2017 2016 Contractual coupon interest expense $ 981 $ 2,615 $ 3,288 Amortization of debt issuance costs 220 567 696 Accretion of debt discount 1,931 4,890 5,710 Total $ 3,132 $ 8,072 $ 9,694 Effective interest rate 8.41 % 8.41 % 8.65 %

FOLOTYN License Agreement and_2

FOLOTYN License Agreement and Development Liability (Tables)	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Schedule of Drug Development Liability Adjustments	FOLOTYN FOLOTYN FOLOTYN Balance at December 31, 2017 $ 275 $ 12,111 $ 12,386 Transfer from long-term to current in 2018 2,425 (2,425 ) — (Less): Expenses incurred in 2018 (389 ) — (389 ) Balance at December 31, 2018 $ 2,311 $ 9,686 $ 11,997

Financial Commitments and Con_2

Financial Commitments and Contingencies and License Agreements (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments	Our future minimum operating lease payments are as follows: Year ending December 31, Operating Lease 2019 $ 1,486 2020 1,441 2021 1,465 2022 828 2023 and thereafter 87 $ 5,308

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of (Loss) Income before (Provision) Benefit for Income Taxes	The components of loss before (provision) benefit for income taxes are as follows: For the Years Ended 2018 2017 2016 United States $ (125,177 ) $ (109,678 ) $ (69,976 ) Foreign 5,167 1,652 (2,107 ) Total $ (120,010 ) $ (108,026 ) $ (72,083 )
Provision (Benefit) for Income Taxes	The provision (benefit) for income taxes consist of the following: For the Years Ended 2018 2017 2016 Current: Federal $ (11 ) $ (10,608 ) $ (2,001 ) State (19 ) (940 ) (216 ) Foreign — 7 8 $ (30 ) $ (11,541 ) $ (2,209 ) Deferred: Federal 12 (5,256 ) (93 ) State 19 19 (11 ) Foreign — — — 31 (5,237 ) (104 ) Total income tax provision (benefit) $ 1 $ (16,778 ) $ (2,313 )
Income Tax Provision (Benefit) Differs from Computed Using Federal Statutory Rate Applied to Income before Taxes	The income tax provision (benefit) differs from that computed using the applicable federal statutory rate, as applied to income before taxes in each year as follows: For the Years Ended 2018 2017 2016 Tax provision computed at the federal statutory rate $ (25,202 ) $ (37,809 ) $ (25,217 ) State tax, net of federal benefit (4,827 ) (1,849 ) (307 ) Research credits (4,884 ) (1,176 ) (3,232 ) Change in tax credit carryforwards (3,056 ) 386 11,042 Officers compensation 600 (9,292 ) 1,196 Stock based compensation (12,610 ) (2,735 ) 588 Permanent items and other (116 ) 1,450 12 Tax differential on foreign earnings (32 ) 33 15 Change in tax rate (1,329 ) 37,769 (744 ) Refundable ATM credit — (1,336 ) — Uncertain tax positions — (561 ) — Change in prior year deferred taxes 6,595 (1,218 ) — Valuation allowance 44,862 (440 ) 14,334 Income tax provision (benefit) $ 1 $ (16,778 ) $ (2,313 )
Components of Company's Deferred Tax Assets	Significant components of our deferred tax assets and liabilities as of December 31, 2018 and 2017 are presented below. A valuation allowance has been recognized to offset the net deferred tax assets as realization of such deferred tax assets did not meet the “more-likely-than-not” threshold under GAAP. December 31, 2018 2017 Deferred tax assets: Net operating loss carry forwards $ 106,446 $ 60,771 Research credits 21,618 14,255 Stock based compensation 5,057 10,046 Deferred revenue — 1,017 Development costs 3,938 4,143 Returns and allowances 1,976 1,636 Other, net (5,066 ) — Total deferred tax assets before valuation allowance 133,969 91,868 Valuation allowance (131,042 ) (86,021 ) Total deferred tax assets 2,927 5,847 Deferred tax liabilities: Basis difference in debt — (28 ) Depreciation and amortization differences (4,396 ) (6,836 ) Other, net — (421 ) Net deferred tax liabilities $ (1,469 ) $ (1,438 )
Summary of Unrecognized Tax Benefits	The following tabular reconciliation summarizes activity related to unrecognized tax benefits: For the Years Ended 2018 2017 2016 Balance at beginning of year $ 2,715 $ 3,271 $ 4,498 Adjustments related to prior year tax positions (551 ) (39 ) (1,638 ) Increases related to current year tax positions 1,084 374 411 Decreases due to expiration of tax statutes — (891 ) — Balance at end of year $ 3,248 $ 2,715 $ 3,271

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Summary of Selected Quarterly Financial Data	Selected quarterly financial data (unaudited) for the year ended December 31, 2018 and 2017 is presented below: Quarter Ended (Unaudited) March 31, June 30, September 30, December 31, 2018 Total revenues* $ 30,495 $ 24,168 $ 25,268 $ 29,402 Loss from Operations $ (25,264 ) $ (34,311 ) $ (29,024 ) $ (42,578 ) Net (loss) income $ (15,816 ) $ 13,744 $ (68,718 ) $ (49,221 ) Net loss per share, basic and diluted $ (0.16 ) $ 0.13 $ (0.66 ) $ (0.47 ) * See Note 2(i) for a discussion of our adoption of Topic 606 effective beginning on January 1, 2018. Quarter Ended (Unaudited) March 31, June 30, September 30, December 31, 2017 Total revenues $ 29,101 $ 34,301 $ 36,395 $ 28,570 Loss from Operations $ (21,909 ) $ (18,609 ) $ (15,054 ) $ (41,088 ) Net loss $ (23,547 ) $ (20,852 ) $ (18,293 ) $ (28,556 ) Net loss per share, basic and diluted $ (0.30 ) $ (0.27 ) $ (0.22 ) $ (0.29 )

New Revenue Recognition Stand_2

New Revenue Recognition Standard (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	Had we continued to apply Topic 605 for our revenue recognition for the year ended December 31, 2018 , the impact to our Consolidated Statements of Operations is presented in the table below: Year Ended December 31, 2018 As Reported Under Topic 606 Adjustments If Reported Under Topic 605 Revenue: Product sales, net $ 104,466 $ 906 $ 105,372 License fees and service revenue 4,867 179 5,046 Total revenues $ 109,333 $ 1,085 $ 110,418 Loss from operations (131,177 ) 1,085 (130,092 ) Loss before income taxes (120,010 ) 1,085 (118,925 ) Net loss $ (120,011 ) $ 1,085 $ (118,926 ) Net loss per share: Basic $ (1.16 ) $ 0.01 $ (1.15 ) Diluted $ (1.16 ) $ 0.01 $ (1.15 ) Weighted average shares outstanding: Basic $ 103,305,911 $ 103,305,911 $ 103,305,911 Diluted $ 103,305,911 $ 103,305,911 $ 103,305,911 Had we continued to apply Topic 605 for our revenue recognition for the year ended December 31, 2018 , the impact to our Consolidated Balance Sheets is presented in the table below: December 31, 2018 As Reported Under Topic 606 Adjustments If Reported Under Topic 605 Current assets: Accounts receivable, net of allowance for doubtful accounts $ 29,873 $ 127 $ 30,000 Total current assets 250,688 127 250,815 Total assets $ 390,886 $ 127 $ 391,013 Current liabilities: Deferred revenue — 2,963 2,963 Total current liabilities 86,474 2,963 89,437 Deferred revenue, less current portion — 251 251 Total liabilities 107,624 3,214 110,838 Stockholders’ equity: Accumulated deficit (599,886 ) (3,087 ) (602,973 ) Total stockholders’ equity 283,262 (3,087 ) 280,175 Total liabilities and stockholders’ equity $ 390,886 $ 127 $ 391,013 Had we continued to apply Topic 605 for our revenue recognition for the year ended December 31, 2018 , the impact to our Consolidated Statements of Cash Flows for the year ended December 31, 2018 is presented in the table below: December 31, 2018 As Reported Under Topic 606 Adjustments If Reported Under Topic 605 Net loss $ (120,011 ) $ 1,085 $ (118,926 ) Changes in operating assets and liabilities: Accounts receivable, net 2,844 (127 ) 2,717 Deferred revenue — (958 ) (958 )

Description of Business, Basi_3

Description of Business, Basis of Presentation, and Operating Segment - Additional Information (Details) $ in Millions	Jan. 17, 2019USD ($)employee	Dec. 31, 2018Segmentproduct
Accounting Policies [Abstract]
Number of products | product		7
Number of late stage development drugs | product		2
Number of reportable operating segment | Segment		1
Spectrum Pharma Canada [Member]
Segment Reporting Information [Line Items]
Ownership interest, percentage		5000.00%
Subsequent Event [Member] | FUSILEV, FOLOTYN, ZEVALIN, MARQIBO, BELEODAQ, EVOMELA, and KHAPZORY [Member] | Acrotech Biopharma LLC [Member]
Segment Reporting Information [Line Items]
Upfront payment expected to be received	$ 160
Consideration held in escrow for six months	$ 4
Period consideration is held in escrow	6 months
Payment receivable on achievement of regulatory milestones	$ 140
Reduction in employees, number of employees | employee	90

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Use of Estimates - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in retained earnings due to revenue recognition	$ (599,886)		$ (502,107)
Cash and equivalents maturities period	3 months
FUSILEV, MARQIBO, and BELEODAQ [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of months after expiration customers are allowed to return products	6 months
EVOMELA [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of months after expiration customers are allowed to return products	12 months
Number of months prior to product expiration during which customer can return product	6 months
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in retained earnings due to revenue recognition	$ (3,087)	$ 4,700

Balance Sheet Account Detail -

Balance Sheet Account Detail - Summary of Cash and Cash Equivalents and Marketable Securities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Cost of equity securities	$ 8,710
Foreign Currency Translation	(2,168)
Gross unrealized gain on equity securities	39,880
Equity securities	46,422
Available-for-sale securities, amortized cost			$ 227,571
Available-for-sale securities, gross unrealized gain			0
Cash, cash equivalents and short-term investments, amortized cost	166,276
Cash, cash equivalents, and short-term investments	203,988		227,571
Equity securities, unrealized gain (loss)	10,500
Accounting Standards Update 2016-01 [Member]
Schedule of Investments [Line Items]
Cumulative effect of new accounting principle in period of adoption		$ 0
Retained Earnings [Member] | Accounting Standards Update 2016-01 [Member]
Schedule of Investments [Line Items]
Cumulative effect of new accounting principle in period of adoption		17,211	17,200
AOCI Attributable to Parent [Member]
Schedule of Investments [Line Items]
Cumulative effect of new accounting principle in period of adoption		$ (17,211)
AOCI Attributable to Parent [Member] | Accounting Standards Update 2016-01 [Member]
Schedule of Investments [Line Items]
Cumulative effect of new accounting principle in period of adoption			(17,200)
Bank Deposits [Member]
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	14,735
Available-for-sale, debt securities, estimated fair value	14,735
Available-for-sale securities, amortized cost			10,965
Available-for-sale securities, gross unrealized gain			0
Available-for-sale securities			10,965
Money market funds [Member]
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	142,745
Available-for-sale, debt securities, estimated fair value	142,745
Available-for-sale securities, amortized cost			216,358
Available-for-sale securities, gross unrealized gain			0
Available-for-sale securities			216,358
Bank certificates of deposit [Member]
Schedule of Investments [Line Items]
Available-for-sale, debt securities, amortized cost	86
Available-for-sale, debt securities, estimated fair value	86
Available-for-sale securities, amortized cost			248
Available-for-sale securities, gross unrealized gain			0
Available-for-sale securities			248
Cash and Cash Equivalents [Member]
Schedule of Investments [Line Items]
Cash, cash equivalents, and short-term investments	157,480		227,323
Cash and Cash Equivalents [Member] | Bank Deposits [Member]
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	14,735
Available-for-sale securities			10,965
Cash and Cash Equivalents [Member] | Money market funds [Member]
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	142,745
Available-for-sale securities			216,358
Marketable Securities [Member]
Schedule of Investments [Line Items]
Equity securities	46,422
Cash, cash equivalents, and short-term investments	46,508		248
Marketable Securities [Member] | Bank certificates of deposit [Member]
Schedule of Investments [Line Items]
Available-for-sale, debt securities, estimated fair value	$ 86
Available-for-sale securities			$ 248

Balance Sheet Account Detail _2

Balance Sheet Account Detail - Schedule of Property and Equipment Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 6,883	$ 6,780
(Less): Accumulated depreciation	(6,498)	(6,191)
Property and equipment, net of accumulated depreciation	385	589
Computer hardware and software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	3,079	2,994
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	635	630
Office furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	212	218
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 2,957	$ 2,938

Balance Sheet Account Detail _3

Balance Sheet Account Detail - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation expense	$ 300	$ 300	$ 500
Amortization of intangible assets	$ 28,098	$ 27,647	$ 25,946

Balance Sheet Account Detail _4

Balance Sheet Account Detail - Components of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 2,024	$ 1,077
Work-in-process	2,209	2,551
Finished goods	1,193	5,187
(Less:) Non-current portion of inventories included within other assets	(1,876)	(3,100)
Inventories	$ 3,550	$ 5,715

Balance Sheet Account Detail _5

Balance Sheet Account Detail - Summary of Customers Representing 10% or More of Accounts Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 29,873	$ 32,260
AmerisourceBergen Corporation, and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	10,448	7,175
Cardinal Health, Inc. and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	8,228	9,514
McKesson Corporation and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	7,615	11,186
All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	$ 3,582	$ 4,385
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	100.00%	100.00%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | AmerisourceBergen Corporation, and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	35.00%	22.20%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Cardinal Health, Inc. and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	27.50%	29.50%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | McKesson Corporation and its affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	25.50%	34.70%
Customer Concentration Risk [Member] | Accounts Receivable [Member] | All Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of accounts receivable, net	12.00%	13.60%

Balance Sheet Account Detail _6

Balance Sheet Account Detail - Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other miscellaneous prepaid operating expenses	$ 8,186	$ 3,389
Prepaid insurance	782	645
Research and development supplies	611	1,883
Key employee life insurance – cash surrender value	0	4,150
Prepaid expenses and other assets	$ 9,579	$ 10,067

Balance Sheet Account Detail _7

Balance Sheet Account Detail - Schedule of Other Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
CASI note - short term (Note 11)	$ 1,525	$ 0
Other miscellaneous receivables (including Medicaid rebate credits and royalty receivables)	1,189	1,152
Insurance receivable	206	53
Income tax receivable	643	665
Reimbursements due from development partners for incurred research and development expenses	135	263
Other receivables	$ 3,698	$ 2,133

Balance Sheet Account Detail _8

Balance Sheet Account Detail - Components of Intangible Assets Net of Accumulated Amortization (Details) - USD ($) $ in Thousands	May 29, 2013	Nov. 30, 2018	Mar. 31, 2015	Dec. 31, 2018	Dec. 31, 2017
Product Rights [Line Items]
Historical Cost				$ 308,318	$ 305,668
Accumulated Amortization				(185,132)	(157,855)
Foreign Currency Translation				(3,409)	(2,471)
Impairment				(8,183)	(8,183)
Net Amount				111,594	137,159
MARQIBO IPR&D (NHL and further ALL indications) [Member]
Product Rights [Line Items]
Historical Cost				17,600	17,600
Accumulated Amortization				0	0
Foreign Currency Translation				0	0
Impairment				0	0
Net Amount				17,600	17,600
EVOMELA Distribution Rights [Member]
Product Rights [Line Items]
Historical Cost				7,700	7,700
Accumulated Amortization				(1,629)	(1,037)
Foreign Currency Translation				0	0
Impairment				0	0
Net Amount				$ 6,071	6,663
Full Amortization Period (months)				156 months
Remaining Amortization Period (months)				123 months
KHAPZORY Distribution Rights [Member]
Product Rights [Line Items]
Historical Cost				$ 2,650
Accumulated Amortization				(379)
Foreign Currency Translation				0
Impairment				0
Net Amount				$ 2,271
Full Amortization Period (months)				14 months
Remaining Amortization Period (months)				12 months
BELEODAQ distribution rights [Member]
Product Rights [Line Items]
Historical Cost				$ 25,000	25,000
Accumulated Amortization				(8,438)	(6,563)
Foreign Currency Translation				0	0
Impairment				0	0
Net Amount				$ 16,562	18,437
Full Amortization Period (months)				160 months
Remaining Amortization Period (months)				106 months
MARQIBO distribution rights [Member]
Product Rights [Line Items]
Historical Cost				$ 26,900	26,900
Accumulated Amortization				(21,501)	(17,182)
Foreign Currency Translation				0	0
Impairment				0	0
Net Amount				$ 5,399	9,718
Full Amortization Period (months)				81 months
Remaining Amortization Period (months)				18 months
FOLOTYN distribution rights [Member]
Product Rights [Line Items]
Historical Cost				$ 118,400	118,400
Accumulated Amortization				(67,187)	(54,111)
Foreign Currency Translation				0	0
Impairment	$ (1,000)			0	0
Net Amount				$ 51,213	64,289
Full Amortization Period (months)				152 months
Remaining Amortization Period (months)				47 months
ZEVALIN distribution rights [Member] | United States [Member]
Product Rights [Line Items]
Historical Cost				$ 41,900	41,900
Accumulated Amortization				(41,031)	(37,557)
Foreign Currency Translation				0	0
Impairment				0	0
Net Amount				$ 869	4,343
Full Amortization Period (months)				123 months
Remaining Amortization Period (months)				3 months
ZEVALIN distribution rights [Member] | Ex-U.S. [Member]
Product Rights [Line Items]
Historical Cost				$ 23,490	23,490
Accumulated Amortization				(18,071)	(17,232)
Foreign Currency Translation				(3,409)	(2,471)
Impairment				0	0
Net Amount				$ 2,010	3,787
Full Amortization Period (months)				96 months
Remaining Amortization Period (months)				15 months
FUSILEV distribution rights [Member]
Product Rights [Line Items]
Historical Cost				$ 16,778	16,778
Accumulated Amortization				(9,618)	(9,618)
Foreign Currency Translation				0	0
Impairment				(7,160)	(7,160)
Net Amount				$ 0	0
Full Amortization Period (months)				56 months
Remaining Amortization Period (months)				0 months
FOLOTYN out-License [Member]
Product Rights [Line Items]
Historical Cost				$ 27,900	27,900
Accumulated Amortization				(17,278)	(14,555)
Foreign Currency Translation				0	0
Impairment				(1,023)	(1,023)
Net Amount				$ 9,599	$ 12,322
Full Amortization Period (months)				110 months
Remaining Amortization Period (months)				43 months
KHAPZORY [Member]
Product Rights [Line Items]
Milestone payments		$ 2,700
Fusilev [Member]
Product Rights [Line Items]
Impairment			$ (7,200)

Balance Sheet Account Detail _9

Balance Sheet Account Detail - Estimated Intangible Asset Amortization Expense (Details) $ in Thousands	Dec. 31, 2018USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
2,019	$ 27,333
2,020	19,748
2,021	18,266
2,022	15,882
2,023	2,467
2024 and thereafter	10,298
Total	$ 93,994

Balance Sheet Account Detail_10

Balance Sheet Account Detail - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Foreign currency exchange translation effects	$ (336)	$ (235)
Goodwill	18,061	18,162
ZEVALIN Ex-U.S. Distribution Rights [Member]
Goodwill [Line Items]
Acquisition	2,525	2,525
Allos Therapeutics, Inc. [Member]
Goodwill [Line Items]
Acquisition	5,346	5,346
Talon [Member]
Goodwill [Line Items]
Acquisition	$ 10,526	$ 10,526

Balance Sheet Account Detail_11

Balance Sheet Account Detail - Summary of Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Key employee life insurance – cash surrender value	$ 6,274	$ 10,737
Inventories - non-current portion	1,876	3,100
Research & development supplies and other	1,340	231
Income tax receivable	668	668
Equity securities (see Note 11)	0
Equity securities (see Note 11)		37,530
CASI note - long term (see Note 11)	0	1,517
Other assets	$ 10,158	$ 53,783

Balance Sheet Account Detail_12

Balance Sheet Account Detail - Schedule of Accounts Payable and Other Accrued Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Trade accounts payable and other accrued liabilities	$ 44,919	$ 33,648
Accrued rebates	8,371	7,990
Accrued product royalty	4,337	4,339
Allowance for returns	5,171	4,045
Accrued data and distribution fees	3,248	4,305
Accrued GPO administrative fees	296	296
Accrued inventory management fee	388	1,126
Allowance for chargebacks	2,730	2,368
Accounts payable and other accrued liabilities	$ 69,460	$ 58,117

Balance Sheet Account Detail_13

Balance Sheet Account Detail - Schedule of Amounts Presented in Accounts Payable and Other Accrued Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Rebates and Chargebacks [Member]
Accounts Payable and Other Accrued Liabilities [Roll Forward]
Beginning balance	$ 10,358	$ 9,817
Add: provisions	65,751	106,647
(Less): credits or actual allowances	(65,008)	(106,106)
Ending balance	11,101	10,358
Data and Distribution, GPO Fees, and Inventory Management Fees [Member]
Accounts Payable and Other Accrued Liabilities [Roll Forward]
Beginning balance	5,727	5,146
Add: provisions	13,962	20,104
(Less): credits or actual allowances	(15,757)	(19,523)
Ending balance	3,932	5,727
Returns [Member]
Accounts Payable and Other Accrued Liabilities [Roll Forward]
Beginning balance	4,045	2,309
Add: provisions	1,700	2,807
(Less): credits or actual allowances	(574)	(1,071)
Ending balance	$ 5,171	$ 4,045

Balance Sheet Account Detail_14

Balance Sheet Account Detail - Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 4,850
Deferred revenue			$ 4,187
Increase (decrease) in retained earnings due to revenue recognition	(599,886)		(502,107)
EVOMELA Out-License in China Territory [Member]
Disaggregation of Revenue [Line Items]
Deferred revenue	4,850
EVOMELA [Member]
Disaggregation of Revenue [Line Items]
Deferred revenue			3,800
Deferred revenue			3,819
ZEVALIN, in India Territory [Member]
Disaggregation of Revenue [Line Items]
Deferred revenue			400
Deferred revenue			$ 368
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Disaggregation of Revenue [Line Items]
Increase (decrease) in retained earnings due to revenue recognition	$ (3,087)	$ 4,700

Balance Sheet Account Detail_15

Balance Sheet Account Detail - Summary of Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued executive deferred compensation	$ 5,474	$ 5,928
Deferred rent (non-current portion)	0	52
Clinical study holdback costs, non-current	0	59
Other tax liabilities	176	176
Other long-term liabilities	$ 5,650	$ 6,215

Gross-to-Net Product Sales an_3

Gross-to-Net Product Sales and Significant Customers - Reconciliation of Gross-to-Net Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Product sales, net	$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101	$ 109,333	$ 128,367	$ 146,444
Product [Member]
Disaggregation of Revenue [Line Items]
Gross product sales									190,825	245,797	244,770
Commercial rebates and government chargebacks									(68,976)	(105,148)	(98,317)
Data and distribution fees, GPO fees, and inventory management fees									(14,048)	(20,083)	(14,979)
Prompt pay discounts									(1,553)	(1,610)	(755)
Product returns									(1,782)	(2,778)	(2,123)
Product sales, net									$ 104,466	$ 116,178	$ 128,596
Gross product sales, percentage of net revenue
Commercial rebates and government chargebacks, percentage of net revenue									(36.10%)	(42.80%)	(40.20%)
Data and distribution fees, GPO fees, and inventory management fees, percentage of net revenue									(7.40%)	(8.20%)	(6.10%)
Prompt pay discounts, percentage of net revenue									(0.80%)	(0.70%)	(0.30%)
Product returns, percentage of net revenue									(0.90%)	(1.10%)	(0.90%)
Product sales, net, percentage of net revenue									54.70%	47.30%	52.50%

Gross-to-Net Product Sales an_4

Gross-to-Net Product Sales and Significant Customers - Summary of Customers Representing 10% or More of Gross Product Sales (Details) - Product [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Major Customer [Line Items]
Gross product sales	$ 190,825	$ 245,797	$ 244,770
McKesson Corporation and its affiliates [Member]
Revenue, Major Customer [Line Items]
Gross product sales	69,320	76,363	75,952
AmerisourceBergen Corporation, and its affiliates [Member]
Revenue, Major Customer [Line Items]
Gross product sales	55,576	79,362	93,951
Cardinal Health, Inc. and its affiliates [Member]
Revenue, Major Customer [Line Items]
Gross product sales	42,074	64,634	58,780
All Other Customers [Member]
Revenue, Major Customer [Line Items]
Gross product sales	$ 23,855	$ 25,438	$ 16,087
Customer Concentration Risk [Member] | Gross Product Sales [Member]
Revenue, Major Customer [Line Items]
Percentage of sales	100.00%	100.00%	100.00%
Customer Concentration Risk [Member] | Gross Product Sales [Member] | McKesson Corporation and its affiliates [Member]
Revenue, Major Customer [Line Items]
Percentage of sales	36.30%	31.10%	31.00%
Customer Concentration Risk [Member] | Gross Product Sales [Member] | AmerisourceBergen Corporation, and its affiliates [Member]
Revenue, Major Customer [Line Items]
Percentage of sales	29.10%	32.30%	38.40%
Customer Concentration Risk [Member] | Gross Product Sales [Member] | Cardinal Health, Inc. and its affiliates [Member]
Revenue, Major Customer [Line Items]
Percentage of sales	22.00%	26.30%	24.00%
Customer Concentration Risk [Member] | Gross Product Sales [Member] | All Other Customers [Member]
Revenue, Major Customer [Line Items]
Percentage of sales	12.50%	10.30%	6.60%

Composition of Total Revenue -

Composition of Total Revenue - Schedule of Net Product Sales by Geography (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenues	$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101	$ 109,333	$ 128,367	$ 146,444
Product [Member]
Segment Reporting Information [Line Items]
Total revenues									104,466	116,178	128,596
United States [Member] | Product [Member]
Segment Reporting Information [Line Items]
Total revenues									91,822	107,135	125,074
Total International [Member] | Product [Member]
Segment Reporting Information [Line Items]
Total revenues									12,644	9,043	3,522
Total International [Member] | Europe [Member] | Product [Member]
Segment Reporting Information [Line Items]
Total revenues									11,220	7,727	3,522
Total International [Member] | Asia Pacific [Member] | Product [Member]
Segment Reporting Information [Line Items]
Total revenues									$ 1,424	$ 1,316	$ 0
Geographic Concentration Risk [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Percentage of sales									100.00%	100.00%	100.00%
Geographic Concentration Risk [Member] | Sales [Member] | United States [Member]
Segment Reporting Information [Line Items]
Percentage of sales									87.90%	92.20%	97.30%
Geographic Concentration Risk [Member] | Sales [Member] | Total International [Member]
Segment Reporting Information [Line Items]
Percentage of sales									12.10%	7.80%	2.70%
Geographic Concentration Risk [Member] | Sales [Member] | Total International [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Percentage of sales									10.70%	6.70%	2.70%
Geographic Concentration Risk [Member] | Sales [Member] | Total International [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Percentage of sales									1.40%	1.10%	0.00%

Composition of Total Revenue _2

Composition of Total Revenue - Schedule of Net Product Sales by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenues	$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101	$ 109,333	$ 128,367	$ 146,444
Product [Member]
Segment Reporting Information [Line Items]
Total revenues									104,466	116,178	128,596
FOLOTYN [Member]
Segment Reporting Information [Line Items]
Total revenues									47,981	43,015	46,245
EVOMELA [Member]
Segment Reporting Information [Line Items]
Total revenues									28,292	35,178	16,169
Beleodaq [Member]
Segment Reporting Information [Line Items]
Total revenues									12,328	12,353	13,368
ZEVALIN [Member]
Segment Reporting Information [Line Items]
Total revenues									7,044	11,759	10,730
MARQIBO [Member]
Segment Reporting Information [Line Items]
Total revenues									5,502	6,573	7,245
Fusilev [Member]
Segment Reporting Information [Line Items]
Total revenues									2,437	7,300	34,839
KHAPZORY [Member]
Segment Reporting Information [Line Items]
Total revenues									$ 882	$ 0	$ 0
Product Concentration Risk [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Percentage of sales									100.00%	100.00%	100.00%
Product Concentration Risk [Member] | Sales [Member] | FOLOTYN [Member]
Segment Reporting Information [Line Items]
Percentage of sales									45.90%	37.00%	36.00%
Product Concentration Risk [Member] | Sales [Member] | EVOMELA [Member]
Segment Reporting Information [Line Items]
Percentage of sales									27.10%	30.30%	12.60%
Product Concentration Risk [Member] | Sales [Member] | Beleodaq [Member]
Segment Reporting Information [Line Items]
Percentage of sales									11.80%	10.60%	10.40%
Product Concentration Risk [Member] | Sales [Member] | ZEVALIN [Member]
Segment Reporting Information [Line Items]
Percentage of sales									6.70%	10.10%	8.30%
Product Concentration Risk [Member] | Sales [Member] | MARQIBO [Member]
Segment Reporting Information [Line Items]
Percentage of sales									5.30%	5.70%	5.60%
Product Concentration Risk [Member] | Sales [Member] | Fusilev [Member]
Segment Reporting Information [Line Items]
Percentage of sales									2.30%	6.30%	27.10%
Product Concentration Risk [Member] | Sales [Member] | KHAPZORY [Member]
Segment Reporting Information [Line Items]
Percentage of sales									0.80%	0.00%	0.00%

Composition of Total Revenue _3

Composition of Total Revenue - Schedule of Net Product Sales by Source (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Major Customer [Line Items]
License fees and service revenue	$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101	$ 109,333	$ 128,367	$ 146,444
Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									100.00%	100.00%	100.00%
License and Service [Member]
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 4,867	$ 12,189	$ 17,848
ZEVALIN, in Asia and Certain Other Territories, Excluding China [Member]
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 2,001	$ 1,245	$ 1,756
ZEVALIN, in Asia and Certain Other Territories, Excluding China [Member] | Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									41.10%	10.20%	9.80%
FOLOTYN in all Countries Except the U.S., Canada, Europe, and Turkey [Member]
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 1,860	$ 5,848	$ 927
FOLOTYN in all Countries Except the U.S., Canada, Europe, and Turkey [Member] | Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									38.20%	48.00%	5.20%
ZEVALIN, FOLOTYN, BELEODAQ, MARQIBO, In Canada Territory
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 1,006	$ 5	$ 6,000
ZEVALIN, FOLOTYN, BELEODAQ, MARQIBO, In Canada Territory | Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									20.70%	0.00%	33.60%
ZEVALIN, in India Territory [Member]
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 0	$ 50	$ 69
ZEVALIN, in India Territory [Member] | Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									0.00%	0.40%	0.40%
Sales and Marketing Contracted Services [Member]
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 0	$ 4,747	$ 9,096
Sales and Marketing Contracted Services [Member] | Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									0.00%	38.90%	51.00%
Regulatory Services Provided to Licensee [Member]
Revenue, Major Customer [Line Items]
License fees and service revenue									$ 0	$ 294	$ 0
Regulatory Services Provided to Licensee [Member] | Sales Revenue, Services, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of sales									0.00%	2.40%	0.00%

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)Plansshares	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock incentive plans | Plans	1
Estimated forfeiture rate	15.00%	14.00%	11.00%
Exercise of Issued Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense | $	$ 7,700,000
Weighted average period to recognize compensation expense	2 years 3 months 20 days
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense | $	$ 16,900,000
Weighted average period to recognize compensation expense	2 years 2 months 10 days
Two Thousand Eighteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for issuance under incentive plan (shares)	9,500,000
Incentive awards available for grant (shares)	17,600,000
Exercise price fair value	100.00%
Two Thousand Eighteen Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based award vest	25.00%
Restricted stock vesting period	3 years
Two Thousand Eighteen Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price fair value	110.00%
Stock based award vest	33.00%
Restricted stock vesting period	4 years
Term of award	P10Y
Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized for issuance under incentive plan (shares)	8,900,000
Incentive awards available for grant (shares)	10,000,000
Percentage of common stock purchase price	15.00%
Maximum number of common stock shares available for purchase per participant (shares)	50,000
Purchase plan offering period	6 months
Maximum number of common stock value available for purchase per participant | $	$ 25,000
Increase in number of shares of common stock available for issuance under the purchase plan (shares)	1,000,000
Upon Termination of Retirement [Member] | Two Thousand Eighteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock exercised period	6 months
In the Event of Termination Upon Disability or Death [Member] | Two Thousand Eighteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock exercised period	12 months
In the Event of Termination for all Other Terminations [Member] | Two Thousand Eighteen Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock exercised period	90 days

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 17,483	$ 15,139	$ 13,670
Cost of product sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	298	203	135
Selling, general and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	14,010	12,904	11,480
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 3,175	$ 2,032	$ 2,055

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value of Stock Options Granted Using Black-Scholes Option Pricing Model (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option life (in years)	4 years 8 months 23 days	4 years 10 months 2 days	5 years 8 days
Risk-free interest rate, Minimum	1.81%	0.82%	1.07%
Risk-free interest rate, Maximum	2.75%	1.90%	1.90%
Volatility, Minimum	50.00%	49.30%	48.90%
Volatility, Maximum	56.20%	61.40%	50.60%
Dividend yield	0.00%	0.00%	0.00%
Weighted-average grant-date fair value per stock option ($ per share)	$ 8.64	$ 2.89	$ 2.80
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected option life (in years)	10 years	10 years	10 years

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Shares
Outstanding, beginning (shares)	13,857,213	14,340,582	13,836,851
Granted (shares)	1,094,358	1,223,483	1,435,550
Exercised (shares)	(7,858,141)	(937,482)	(39,010)
Forfeited (shares)	(214,464)	(244,793)	(379,268)
Expired (shares)	(35,381)	(524,577)	(513,541)
Outstanding, ending (shares)	6,843,585	13,857,213	14,340,582
Vested (exercisable) (shares)	4,955,073
Unvested (unexercisable) (shares)	1,888,512
Weighted- Average Exercise Price/Share
Outstanding, beginning ($ per share)	$ 6.89	$ 6.86	$ 6.97
Granted ($ per share)	18.87	6.51	5.94
Exercised ($ per share)	6.74	6.40	5.18
Forfeited ($ per share)	6.54	6.26	7.21
Expired ($ per share)	6.94	6.27	7.26
Outstanding, ending ($ per share)	8.98	$ 6.89	$ 6.86
Vested (exercisable) ($ per share)	7.87
Unvested (unexercisable) ($ per share)	$ 11.91
Weighted-Average Remaining Contractual Term (years), outstanding	6 years 4 months 20 days
Weighted-Average Remaining Contractual Term (years), vested (exercisable)	5 years 7 months 13 days
Weighted-Average Remaining Contractual Term (years), unvested (unexercisable)	8 years 4 months 17 days
Exercised, Aggregate Intrinsic Value	$ 84,758	$ 6,813	$ 50
Outstanding, Aggregate Intrinsic Value	11,095
Aggregate Intrinsic Value, vested (exercisable)	8,422
Aggregate Intrinsic Value, unvested (unexercisable)	$ 2,673

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Stock Option Grants (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Granted Stock Options Outstanding (shares) | shares	6,843,585
Weighted- Average Remaining Contractual Life (Years)	6 years 4 months 20 days
Weighted-Average Exercise Price ($ per share)	$ 8.98
Granted Stock Options Exercisable (shares) | shares	4,955,073
Weighted-Average Exercise Price ($ per share)	$ 7.87
$1.03 - 3.16 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, range lower limit	1.03
Exercise price, range upper limit	$ 3.16
Granted Stock Options Outstanding (shares) | shares	7,250
Weighted- Average Remaining Contractual Life (Years)	2 months 23 days
Weighted-Average Exercise Price ($ per share)	$ 1.76
Granted Stock Options Exercisable (shares) | shares	7,250
Weighted-Average Exercise Price ($ per share)	$ 1.76
$3.17 - 4.96 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, range lower limit	3.17
Exercise price, range upper limit	$ 4.96
Granted Stock Options Outstanding (shares) | shares	212,880
Weighted- Average Remaining Contractual Life (Years)	4 years 3 months 8 days
Weighted-Average Exercise Price ($ per share)	$ 4.22
Granted Stock Options Exercisable (shares) | shares	168,409
Weighted-Average Exercise Price ($ per share)	$ 4.16
$4.97 - 6.91 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, range lower limit	4.97
Exercise price, range upper limit	$ 6.91
Granted Stock Options Outstanding (shares) | shares	2,938,104
Weighted- Average Remaining Contractual Life (Years)	6 years 11 months 23 days
Weighted-Average Exercise Price ($ per share)	$ 5.97
Granted Stock Options Exercisable (shares) | shares	2,029,420
Weighted-Average Exercise Price ($ per share)	$ 5.90
$6.92 - 9.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, range lower limit	6.92
Exercise price, range upper limit	$ 9
Granted Stock Options Outstanding (shares) | shares	1,914,493
Weighted- Average Remaining Contractual Life (Years)	5 years
Weighted-Average Exercise Price ($ per share)	$ 7.75
Granted Stock Options Exercisable (shares) | shares	1,856,327
Weighted-Average Exercise Price ($ per share)	$ 7.77
$9.01 - 22.64 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, range lower limit	9.01
Exercise price, range upper limit	$ 22.64
Granted Stock Options Outstanding (shares) | shares	1,770,858
Weighted- Average Remaining Contractual Life (Years)	7 years 2 months 5 days
Weighted-Average Exercise Price ($ per share)	$ 15.92
Granted Stock Options Exercisable (shares) | shares	893,667
Weighted-Average Exercise Price ($ per share)	$ 13.27

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Restricted Stock and Restricted Stock Unit Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock [Member]
Number of Restricted Stock Awards
Unvested, Beginning Balance (shares)	1,562,918	2,152,157	2,173,982
Granted (shares)	1,092,534	927,306	1,203,675
Share issuance upon approved achievement date (shares)	(635,320)	(1,137,555)	(889,857)
Forfeited (shares)	(218,002)	(378,990)	(335,643)
Unvested, Ending Balance (shares)	1,802,130	1,562,918	2,152,157
Weighted Average Fair Value per Share at Grant Date
Beginning Balance ($ per share)	$ 6.27	$ 6.29	$ 6.58
Granted ($ per share)	17.35	6.22	5.93
Share issuance upon approved achievement date ($ per share)	6.51	6.38	6.49
Forfeited ($ per share)	7.56	5.95	6.33
Ending Balance ($ per share)	$ 12.75	$ 6.27	$ 6.29
Restricted Stock Units (RSUs) [Member]
Number of Restricted Stock Awards
Unvested, Beginning Balance (shares)	217,206	0
Granted (shares)	138,334	217,206
Market-based achievement adjustment at vesting (shares)	100,326
Share issuance upon approved achievement date (shares)	(200,652)
Unvested, Ending Balance (shares)	255,214	217,206	0
Weighted Average Fair Value per Share at Grant Date
Beginning Balance ($ per share)	$ 6.49	$ 0
Granted ($ per share)	28.31	6.49
Market-based achievement adjustment at vesting ($ per share)	6.49
Share issuance upon approved achievement date ($ per share)	6.49
Ending Balance ($ per share)	$ 17.91	$ 6.49	$ 0

Stock-Based Compensation - Fa_2

Stock-Based Compensation - Fair Value of Restricted Stock and Restricted Stock Unit Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock award expense	$ 7,652	$ 6,821	$ 6,518
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock award expense	$ 2,301	$ 1,030	$ 0

Stock-Based Compensation - Issu

Stock-Based Compensation - Issued Shares of Common Stock (Details) - 401(k) Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock issued (shares)	70,379	102,874	172,650
Match contribution value	$ 1,175	$ 912	$ 953

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	21 Months Ended	25 Months Ended	37 Months Ended
	Aug. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	May 31, 2018	Jun. 30, 2016
Equity [Abstract]
Number of common shares authorized (shares)		300,000,000	300,000,000	175,000,000	300,000,000
Preferred stock, shares authorized (shares)		5,000,000	5,000,000
Shares of common stock issuable upon conversion or exercise of rights granted (shares)			5,000,000
Maximum proceeds to be raised	$ 250,000,000	$ 128,300,000	$ 202,100,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Warrant Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Weighted Average Exercise Price, Beginning balance ($ per share)	$ 6.78	$ 6.78
Weighted Average Exercise Price, Granted ($ per share)	0	0
Weighted Average Exercise Price, Exercised ($ per share)	6.78
Weighted Average Exercise Price, Ending balance ($ per share)	0	$ 6.78
Weighted Average Exercise Price, Exercisable ($ per share)	$ 0
Exercise of Issued Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number of shares, outstanding beginning (shares)	445,000	445,000
Number of shares, granted (shares)	0	0
Number of shares, exercised (shares)	(445,000)
Number of shares, outstanding ending balance (shares)	0	445,000
Number of shares, exercisable (shares)	0

Stockholders' Equity - Sales Ag

Stockholders' Equity - Sales Agreement (Details) - USD ($) $ in Thousands	1 Months Ended	5 Months Ended	12 Months Ended
	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Stock issued (shares)	3,243,882	10,314,250			10,890,915
Proceeds from sale of common stock under an at-the-market sales agreement (Note 7)	$ 23,745	$ 104,527	$ 0	$ 128,272	$ 73,869

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Net (Loss) Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net loss	$ (49,221)	$ (68,718)	$ 13,744	$ (15,816)	$ (28,556)	$ (18,293)	$ (20,852)	$ (23,547)	$ (120,011)	$ (91,248)	$ (69,770)
Weighted average shares-basic (shares)									103,305,911	85,115,592	72,824,070
Net loss per share-basic ($ per share)									$ (1.16)	$ (1.07)	$ (0.96)
Weighted average shares-diluted (shares)									103,305,911	85,115,592	72,824,070
Net loss per share-diluted ($ per share)									$ (1.16)	$ (1.07)	$ (0.96)

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Securities Excluded from Calculation of Net (Loss) per Share (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive excluded from computation of earnings per share amount (shares)	6,465,109	9,442,022	13,896,550
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive excluded from computation of earnings per share amount (shares)	0	138,277	0
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive excluded from computation of earnings per share amount (shares)	4,407,765	3,668,662	1,294,594
Restricted Stock Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive excluded from computation of earnings per share amount (shares)	1,802,130	1,562,918	2,147,157
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive excluded from computation of earnings per share amount (shares)	255,214	217,206	0
2018 Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive excluded from computation of earnings per share amount (shares)	0	3,854,959	10,454,799

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Asset and Liability Fair Values (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Equity securities (Note 11)	$ 46,422
Equity securities (Note 11)		$ 37,530
Deferred compensation investments (life insurance cash surrender value - Note 3(h))	6,274	14,887
Total Assets	195,605	269,082
Liabilities:
Deferred executive compensation liability (Note 17(f))	6,167	11,038
FOLOTYN development liability (Note 16)	11,997	12,386
Talon CVR (Note 10 (a))	4,345	6,210
Corixa Liability (Note 17(b)(i))		62
Total Liabilities	22,509	29,696
Level 1 [Member]
Assets:
Equity securities (Note 11)	46,422
Equity securities (Note 11)		37,530
Deferred compensation investments (life insurance cash surrender value - Note 3(h))	0	0
Total Assets	46,422	37,530
Liabilities:
Deferred executive compensation liability (Note 17(f))	0	0
FOLOTYN development liability (Note 16)	0	0
Talon CVR (Note 10 (a))	0	0
Corixa Liability (Note 17(b)(i))		0
Total Liabilities	0	0
Level 2 [Member]
Assets:
Equity securities (Note 11)	0
Equity securities (Note 11)		0
Deferred compensation investments (life insurance cash surrender value - Note 3(h))	6,274	14,887
Total Assets	149,183	231,552
Liabilities:
Deferred executive compensation liability (Note 17(f))	6,167	11,038
FOLOTYN development liability (Note 16)	0	0
Talon CVR (Note 10 (a))	0	0
Corixa Liability (Note 17(b)(i))		0
Total Liabilities	6,167	11,038
Level 3 [Member]
Assets:
Equity securities (Note 11)	0
Equity securities (Note 11)		0
Deferred compensation investments (life insurance cash surrender value - Note 3(h))	0	0
Total Assets	0	0
Liabilities:
Deferred executive compensation liability (Note 17(f))	0	0
FOLOTYN development liability (Note 16)	11,997	12,386
Talon CVR (Note 10 (a))	4,345	6,210
Corixa Liability (Note 17(b)(i))		62
Total Liabilities	16,342	18,658
Bank certificates of deposit [Member]
Assets:
Cash and cash equivalents	86	248
Bank certificates of deposit [Member] | Level 1 [Member]
Assets:
Cash and cash equivalents	0	0
Bank certificates of deposit [Member] | Level 2 [Member]
Assets:
Cash and cash equivalents	86	248
Bank certificates of deposit [Member] | Level 3 [Member]
Assets:
Cash and cash equivalents	0	0
Money market funds [Member]
Assets:
Cash and cash equivalents	142,745	216,358
Money market funds [Member] | Level 1 [Member]
Assets:
Cash and cash equivalents	0	0
Money market funds [Member] | Level 2 [Member]
Assets:
Cash and cash equivalents	142,745	216,358
Money market funds [Member] | Level 3 [Member]
Assets:
Cash and cash equivalents	0	0
Mutual Funds [Member]
Assets:
Cash and cash equivalents	78	59
Mutual Funds [Member] | Level 1 [Member]
Assets:
Cash and cash equivalents	0	0
Mutual Funds [Member] | Level 2 [Member]
Assets:
Cash and cash equivalents	78	59
Mutual Funds [Member] | Level 3 [Member]
Assets:
Cash and cash equivalents	$ 0	$ 0

Fair Value Measurements - Activ

Fair Value Measurements - Activity of Level 3 Inputs Measured on Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning	$ 18,658	$ 14,445
Transfers in (out) of Level 3	(389)
Ending	16,342	18,658
Deferred Development Costs [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers in (out) of Level 3		(744)
Talon CVR [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers in (out) of Level 3	(1,865)	$ 4,957
Corixa Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Transfers in (out) of Level 3	$ (62)

Business Combinations and Con_3

Business Combinations and Contingent Consideration - Additional Information (Details) - USD ($)	Jul. 17, 2013	Apr. 30, 2016	Mar. 31, 2016	Mar. 31, 2013	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2012
Business Acquisition [Line Items]
Revenue milestone threshold					$ 29,402,000	$ 25,268,000	$ 24,168,000	$ 30,495,000	$ 28,570,000	$ 36,395,000	$ 34,301,000	$ 29,101,000		$ 109,333,000	$ 128,367,000	$ 146,444,000
License fees received				$ 3,000,000
Royalties payout percentage on our future net sales of licensed products					20.00%									20.00%
Acquisition-related contingent obligations														$ 0	$ 0	$ (1,300,000)
IPR&D [Member]
Business Acquisition [Line Items]
Estimated cash flow period														10 years
Estimated cash flow discount rate					25.00%									25.00%
Milestone Payments [Member]
Business Acquisition [Line Items]
Milestone net sales achievement	$ 5,000,000													$ 60,000,000
Revenue milestone threshold	30,000,000
Ligand Contingent Consideration		$ 7,700,000	$ 6,000,000										$ 6,000,000
Milestone Payment One [Member]
Business Acquisition [Line Items]
Milestone net sales achievement	10,000,000
Revenue milestone threshold	60,000,000
Milestone Payment Two [Member]
Business Acquisition [Line Items]
Milestone net sales achievement	25,000,000
Revenue milestone threshold	100,000,000
Milestone Payment Three [Member]
Business Acquisition [Line Items]
Milestone net sales achievement	50,000,000
Revenue milestone threshold	200,000,000
Milestone Payment Four [Member]
Business Acquisition [Line Items]
Milestone net sales achievement	100,000,000
Revenue milestone threshold	400,000,000
Menadione Topical Lotion [Member]
Business Acquisition [Line Items]
Milestone net sales achievement	5,000,000
Talon Therapeutics, Inc. [Member]
Business Acquisition [Line Items]
Cash consideration	$ 11,300,000
Shares issued in acquisition (shares)	3,000,000
Common stock value assigned	$ 26,300,000
Common stock value, per share ($ per share)	$ 8.77
Estimated fair value of acquisition	$ 6,500,000
Contingent value rights future cash payments	$ 195,000,000				$ 195,000,000									195,000,000
Talon Therapeutics, Inc. [Member] | Minimum [Member]
Business Acquisition [Line Items]
Contingent value rights expected rate	50.00%
Talon Therapeutics, Inc. [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent value rights expected rate	100.00%
Ligand Pharmaceuticals Inc [Member]
Business Acquisition [Line Items]
Ligand Contingent Consideration			6,000,000										6,000,000
Acquisition-related contingent obligations													$ 800,000
Allos Therapeutics, Inc. [Member]
Business Acquisition [Line Items]
Ligand Contingent Consideration					$ 0									$ 0
Total purchase consideration																	$ 205,200,000
Ligand Pharmaceuticals Inc [Member]
Business Acquisition [Line Items]
Milestone net sales achievement		$ 6,000,000	$ 6,000,000

Business Combinations and Con_4

Business Combinations and Contingent Consideration - Change in Fair Value of Contingent Consideration Related to Acquisitions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016
Change in Fair Value of Contingent Consideration [Roll Forward]
Beginning	$ 18,658
Ending	16,342	$ 14,445
Talon Therapeutics, Inc. [Member]
Change in Fair Value of Contingent Consideration [Roll Forward]
Beginning	6,210
Fair value adjustment for the three months ended March 31, 2016	(1,865)
Ending	$ 4,345
Contingent Consideration [Member] | Ligand Pharmaceuticals Inc [Member]
Change in Fair Value of Contingent Consideration [Roll Forward]
Beginning		5,227
Fair value adjustment for the three months ended March 31, 2016		773
Payment to Ligand in April 2016 for FDA approval milestone achievement		(6,000)
Ending		$ 0

Business Combinations and Con_5

Business Combinations and Contingent Consideration - Acquisition-Date Fair Value of Consideration Transferred (Detail) - Captisol-enabled, propylene glycol-free melphalan rights [Member] $ in Thousands	1 Months Ended
	Mar. 31, 2013USD ($)
Business Acquisition [Line Items]
Cash consideration	$ 3,000
Ligand Contingent Consideration	4,700
Total purchase consideration	$ 7,700

Business Combinations and Con_6

Business Combinations and Contingent Consideration - Summary of Allocation of Total Purchase Price to Net Assets Acquired (Detail) - Captisol-enabled, propylene glycol-free melphalan rights [Member] $ in Thousands	Mar. 31, 2013USD ($)
Business Acquisition [Line Items]
Total purchase consideration	$ 7,700
IPR&D [Member]
Business Acquisition [Line Items]
Total purchase consideration	$ 7,700

Out-License of MARQIBO, ZEVAL_3

Out-License of MARQIBO, ZEVALIN, & EVOMELA in China Territory - Additional Information (Details) $ in Thousands, shares in Millions	Sep. 17, 2014shares	Sep. 30, 2014agreement	Dec. 31, 2018USD ($)shares	Dec. 31, 2017shares	Dec. 31, 2016shares	Dec. 31, 2015USD ($)
Other Commitments [Line Items]
Equity securities (Note 11)			$ 46,422
CASI Out License [Member]
Other Commitments [Line Items]
Number of agreements | agreement		3
Shares received (shares) | shares	5.4			1.5	4.6
Number of shares held in investment (shares) | shares			11.5
Percentage of ownership			12.10%
Equity securities (Note 11)			$ 46,400
Undiscounted proceeds						$ 9,700

Out-License of MARQIBO, ZEVAL_4

Out-License of MARQIBO, ZEVALIN, & EVOMELA in China Territory - Schedule of Proceeds Received and Fair Value on CASI Out-License Execution Date (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	Sep. 17, 2014	Dec. 31, 2017	Dec. 31, 2016
Secured Promissory Note [Member]
Other Commitments [Line Items]
Debt instrument face value	$ 1,500
CASI Out License [Member]
Other Commitments [Line Items]
Total consideration received	$ 9,959
Shares received (shares)	5.4	1.5	4.6
Stock price on the NASDAQ Capital Market ($ per share)	$ 1.6
CASI Out License [Member] | Secured Promissory Note [Member]
Other Commitments [Line Items]
Total consideration received	$ 1,310
Debt instrument coupon rate	0.50%
CASI Out License [Member] | Common Stock [Member]
Other Commitments [Line Items]
Total consideration received	$ 8,649

Out-License of ZEVALIN in Cer_2

Out-License of ZEVALIN in Certain Ex-U.S. Territories (Details) - ZEVALIN Ex-U.S. Distribution Rights [Member] - USD ($) $ in Millions	Jun. 30, 2017	Apr. 30, 2018	Jan. 31, 2016	Dec. 31, 2015	Jan. 31, 2016	Dec. 31, 2015
Payment One [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Total consideration received				$ 15
Payment Two [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Total consideration received			$ 3
Total Consideration [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Total consideration received					$ 18
License and Service [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License fees and service revenue		$ 2
License and Service [Member] | Payment Two [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License fees and service revenue	$ 3
License and Service [Member] | Total Consideration [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License fees and service revenue						$ 15

Out-License of ZEVALIN, FOLOT_2

Out-License of ZEVALIN, FOLOTYN, BELEDAQ, and MARQIBO in Canada Territory (Details) - USD ($) $ in Thousands

1 Months Ended

3 Months Ended

12 Months Ended

Nov. 30, 2018

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Mar. 31, 2016

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Other Significant Noncash Transactions [Line Items]

License fees and service revenue

$ 29,402

$ 25,268

$ 24,168

$ 30,495

$ 28,570

$ 36,395

$ 34,301

$ 29,101

$ 109,333

$ 128,367

$ 146,444

License and Service [Member]

Other Significant Noncash Transactions [Line Items]

License fees and service revenue

$ 4,867

$ 12,189

$ 17,848

License and Service [Member] | ZEVALIN, FOLOTYN, BELEODAQ, And MARQIBO [Member]

Other Significant Noncash Transactions [Line Items]

License fees and service revenue

$ 6,000

License and Service [Member] | FOLOTYN in Canada [Member]

Other Significant Noncash Transactions [Line Items]

License fees and service revenue

$ 1,000

Co-Promotion Arrangement With_2

Co-Promotion Arrangement With Eagle Pharmaceuticals (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 2015USD ($)product	Dec. 31, 2018USD ($)product	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of products | product		7
Term of arrangement	18 months
Collaborative Arrangement, Co-promotion [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of products | product	6
Value of agreement	$ 12,800,000
License and Service [Member] | Collaborative Arrangement, Co-promotion [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 0	$ 4,700,000	$ 9,100,000
Product [Member] | Collaborative Arrangement, Co-promotion [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized			0
Reimbursable Expenses [Member] | Collaborative Arrangement, Co-promotion [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cost of reimbursable expenses		$ 0	$ 4,200,000	$ 7,900,000

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Details)	Dec. 17, 2013USD ($)shares	Oct. 31, 2017USD ($)shares	Jul. 31, 2017shares	Dec. 31, 2016USD ($)open_market_purchaseshares	Dec. 31, 2013USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares
Debt Instrument [Line Items]
Common stock, shares issued (shares) | shares						100,742,735	110,525,141	100,742,735
Payments for repurchase							$ 0	$ 27,500,000	$ 9,014,000
Stock issued (shares) | shares			3,243,882			10,314,250			10,890,915
2018 Convertible Notes [Member]
Debt Instrument [Line Items]
Debt instrument face value						$ 74,300,000		74,300,000
Conversion rate (shares) | shares							95
Conversion rate, price per $1,000 | $ / shares							$ 1,000
Money conversion price per share ($ per share) | $ / shares							$ 10.53
Long-term debt, gross						40,565,000		40,565,000
2.75% Convertible Senior Notes Due 2018 [Member]
Debt Instrument [Line Items]
Sale of convertible notes, principal amount	$ 120,000,000
Interest rate	2.75%
Debt conversion, converted instrument, securities converted (in shares) | shares	120,000
Debt instrument face value						$ 38,200,000	$ 0	38,200,000
Common shares converted value (shares) | shares		69,472		9,963	11,400,000
Conversion rate (shares) | shares							95
Conversion rate, price per $1,000 | $ / shares							$ 1,000
Money conversion price per share ($ per share) | $ / shares							$ 10.53
Net proceeds from convertible notes					$ 115,400,000
Professional fee					4,600,000
Additional paid-in capital					$ 13,100,000
Strike price per share ($ per share) | $ / shares					$ 14.03
Common stock, shares issued (shares) | shares					11,400,000
Number Of open market purchases | open_market_purchase				2
Repurchase of principal		$ 69,500,000		$ 10,000,000
Payments for repurchase		$ 27,300,000		$ 9,000,000
Loss on 2018 Convertible Note purchase								800,000	$ 25,000
Proceeds from unwinding								$ 5,800,000	$ 21,000
Stock issued (shares) | shares		5,400,000
Common stock issued, value		$ 73,000,000

Convertible Senior Notes - Carr

Convertible Senior Notes - Carrying Value of 2018 Convertible Notes (Details) - 2018 Convertible Notes [Member] $ in Thousands	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Principal amount	$ 40,565
(Less): Unamortized debt discount (amortized through December 2018)	(2,101)
(Less): Debt issuance costs	(240)
Carrying value	$ 38,224

Convertible Senior Notes - Comp

Convertible Senior Notes - Components of Total Interest Expense, Net Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Contractual coupon interest expense	$ 981	$ 2,615	$ 3,288
Amortization of debt issuance costs	220	567	696
Accretion of debt discount	1,931	4,890	5,710
Total	$ 3,132	$ 8,072	$ 9,694
Effective interest rate	8.41%	8.41%	8.65%

FOLOTYN License Agreement and_3

FOLOTYN License Agreement and Development Liability - Additional Information (Details) - USD ($) $ in Thousands	May 29, 2013	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total operating costs and expenses		$ 240,510	$ 225,027	$ 209,330
Maximum [Member] | Regulatory [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments		16,000
Maximum [Member] | Commercial progress and sales-dependent [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments		$ 107,000
Mundipharma [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total operating costs and expenses	$ 7,000

FOLOTYN License Agreement and_4

FOLOTYN License Agreement and Development Liability - Schedule of Drug Development Liability Adjustments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2017	$ 275
Balance at December 31, 2018	2,311
FOLOTYN [Member]
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2017	12,386
Transfer from long-term to current in 2018	0
(Less): Expenses incurred in 2018	(389)
Balance at December 31, 2018	11,997
FOLOTYN [Member] | FOLOTYN Development Liability, Current [Member]
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2017	275
Transfer from long-term to current in 2018	2,425
(Less): Expenses incurred in 2018	(389)
Balance at December 31, 2018	2,311
FOLOTYN [Member] | FOLOTYN Development Liability, Long Term [Member]
Accrued Drug Development Expenses [Roll Forward]
Balance at December 31, 2017	12,111
Transfer from long-term to current in 2018	(2,425)
(Less): Expenses incurred in 2018	0
Balance at December 31, 2018	$ 9,686

Financial Commitments and Con_3

Financial Commitments and Contingencies and License Agreements - Additional Information (Details) $ in Thousands, € in Millions	Oct. 03, 2018	Nov. 30, 2018USD ($)	Apr. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Aug. 31, 2017USD ($)	Jul. 31, 2017USD ($)shares	Jun. 30, 2017USD ($)	Apr. 30, 2016USD ($)shares	Mar. 31, 2016USD ($)	Feb. 29, 2016	Jan. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Feb. 28, 2015USD ($)	Jun. 30, 2014	Feb. 28, 2014USD ($)	Apr. 30, 2012EUR (€)	Feb. 28, 2010USD ($)	Nov. 30, 2009USD ($)	Oct. 31, 2008USD ($)shares	Jan. 31, 2016USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2017USD ($)shares	Dec. 31, 2018USD ($)Country	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)shares	Jan. 01, 2019USD ($)	Nov. 30, 2014USD ($)	Jul. 17, 2013USD ($)
Long-term Purchase Commitment [Line Items]
Rental expense																																	$ 1,600	$ 1,600	$ 1,500
Total revenues																					$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101					$ 109,333	128,367	$ 146,444
Payment of all royalty obligations				$ 2,600
Percentage of royalty on annual worldwide sales under condition one																					20.00%												20.00%
Intangible assets, gross																					$ 308,318				305,668							$ 305,668	$ 308,318	305,668
Additional license fees																																	$ 60,000
Percentage of royalties on net sale of licensed products																																	20.00%
Acquisition-related contingent obligations																					4,345				6,272							$ 6,272	$ 4,345	6,272
Stock issued (shares) | shares						3,243,882																										10,314,250			10,890,915
Consideration paid under agreement (shares)															$ 1,000
Proceeds from stock						$ 23,745																										$ 104,527	0	128,272	$ 73,869
Cash paid for income taxes																																	45	17	11
Deferred compensation liability, current																					6,200				11,000							11,000	6,200	11,000
Allergan [Member]
Long-term Purchase Commitment [Line Items]
Up-front non-refundable payment																			$ 41,500
Nippon Kayaku [Member]
Long-term Purchase Commitment [Line Items]
Upfront fee																		$ 15,000
Payment receivable on achievement of regulatory milestones																																	10,000
Payment on achievement of commercialization milestones																																	126,000
TopoTarget [Member]
Long-term Purchase Commitment [Line Items]
Payments receivable on achievement of potential sales milestones																					$ 190,000												190,000
Payment of all royalty obligations																	$ 30,000
Payment receivable on achievement of regulatory milestones																																	88,000
Percentage of development cost																	70.00%
Percentage of development cost that is funded by TopoTarget for joint development plan																	30.00%
Additional payments based on the achievement of certain development															$ 10,000
Aggregate payout value																															$ 17,800
Second milestone payment																																					$ 25,000
Common Class A [Member] | Allergan [Member]
Long-term Purchase Commitment [Line Items]
Stock issued (shares) | shares																			25,000
Common stock issued under an at-market-issuance sales agreement (Note 7)																			$ 100
Regulatory [Member]
Long-term Purchase Commitment [Line Items]
License fee and service revenue					$ 2,000
Regulatory [Member] | Maximum [Member]
Long-term Purchase Commitment [Line Items]
Potential milestone payments																																	16,000
Commercial progress and sales-dependent [Member] | Maximum [Member]
Long-term Purchase Commitment [Line Items]
Potential milestone payments																																	$ 107,000
FOLOTYN [Member]
Long-term Purchase Commitment [Line Items]
Percentage of royalty on annual worldwide sales under condition one																					8.00%												8.00%
Percentage of royalty on annual worldwide sales under condition two																					9.00%												9.00%
Percentage of royalty on annual worldwide sales under condition three																					11.00%												11.00%
Potential payment based on achievement of regulatory milestones																																	$ 3,500
FOLOTYN [Member] | Minimum [Member]
Long-term Purchase Commitment [Line Items]
Amount of annual worldwide sales on which royalty is payable under condition two																																	150,000
Amount of annual worldwide sales on which royalty is payable under condition three																																	300,000
FOLOTYN [Member] | Maximum [Member]
Long-term Purchase Commitment [Line Items]
Amount of annual worldwide sales on which royalty is payable under condition one																																	150,000
Amount of annual worldwide sales on which royalty is payable under condition two																																	300,000
KHAPZORY [Member]
Long-term Purchase Commitment [Line Items]
Milestone payments		$ 2,700
BELEODAQ distribution rights [Member]
Long-term Purchase Commitment [Line Items]
Intangible assets, gross																					$ 25,000				25,000							25,000	25,000	25,000
Duration of automatic stay triggered upon ANDA	30 months
ZEVALIN [Member]
Long-term Purchase Commitment [Line Items]
Potential payment based on achievement of sales milestones																																	$ 5,000
Acquisition-related contingent obligations																									100							100		100
ZEVALIN [Member] | Licensing Agreements [Member]
Long-term Purchase Commitment [Line Items]
Fees paid to Bayer for acquiring licensing rights | €																€ 19
Minimum number of countries outside U.S. approved ZEVALIN for treatment | Country																																	40
Percentage of royalty on net sales										20.00%																							20.00%
Term										15 years
Up-front non-refundable payment													$ 500
Payments receivable on achievement of potential sales milestones																					1,500												$ 1,500
Aggregate amount receivable based on achievement of milestones																																	3,000
Payment receivable on achievement of regulatory milestones																																	1,500
Talon Therapeutics, Inc. [Member]
Long-term Purchase Commitment [Line Items]
Acquisition-related contingent obligations																					4,300				$ 6,200							$ 6,200	4,300	6,200
Contingent value rights future cash payments																					195,000												195,000					$ 195,000
SPI-2012 [Member]
Long-term Purchase Commitment [Line Items]
Potential payment based on achievement of sales milestones																																	225,000
Potential payment based on achievement of regulatory milestones																																	13,000
SPI-2012 [Member]
Long-term Purchase Commitment [Line Items]
Issued for services (shares) | shares								318,750
Proceeds from stock								$ 2,300
Cash paid for income taxes								400
Milestone payments								2,700
Poziotinib [Member] | Licensing Agreements [Member]
Long-term Purchase Commitment [Line Items]
Potential payment based on achievement of sales milestones																																	325,000
Potential payment based on achievement of regulatory milestones																																	33,000
Zevalin Rights [Member] | Total Consideration [Member]
Long-term Purchase Commitment [Line Items]
Total consideration received																				$ 18,000
Zevalin Rights [Member] | Payment One [Member]
Long-term Purchase Commitment [Line Items]
Total consideration received												$ 15,000
Zevalin Rights [Member] | Payment Two [Member]
Long-term Purchase Commitment [Line Items]
Total consideration received											$ 3,000
ZEVALIN, FOLOTYN, BELEODAQ, And MARQIBO [Member]
Long-term Purchase Commitment [Line Items]
Total consideration received		$ 1,000																											$ 6,000
Payment receivable on achievement of regulatory milestones																																	1,000
INDIA [Member] | ZEVALIN [Member] | Licensing Agreements [Member]
Long-term Purchase Commitment [Line Items]
Term														15 years
License and Service [Member]
Long-term Purchase Commitment [Line Items]
Total revenues																																	4,867	12,189	$ 17,848
License and Service [Member] | Regulatory [Member] | Maximum [Member]
Long-term Purchase Commitment [Line Items]
Total revenues					$ 3,000
License and Service [Member] | Zevalin Rights [Member]
Long-term Purchase Commitment [Line Items]
Total revenues			$ 2,000
License and Service [Member] | Zevalin Rights [Member] | Total Consideration [Member]
Long-term Purchase Commitment [Line Items]
Total revenues							$ 3,000																							$ 15,000
License and Service [Member] | ZEVALIN, FOLOTYN, BELEODAQ, And MARQIBO [Member]
Long-term Purchase Commitment [Line Items]
Total revenues																													$ 6,000
License [Member] | Allergan [Member]
Long-term Purchase Commitment [Line Items]
License costs																			$ 300
Ligand Pharmaceuticals Inc [Member]
Long-term Purchase Commitment [Line Items]
Milestone payments								$ 6,000	$ 6,000
Medac [Member] | KHAPZORY [Member]
Long-term Purchase Commitment [Line Items]
Milestone payments																																	2,700	$ 300
MD Anderson [Member]
Long-term Purchase Commitment [Line Items]
Potential payment based on achievement of sales milestones																																	23,000
Payment of all royalty obligations			$ 500
Potential payment based on achievement of regulatory milestones																																	11,000
Restatement Adjustment [Member] | Melphalan In Process Research and Development [Member]
Long-term Purchase Commitment [Line Items]
Intangible assets, gross																					$ (7,700)												$ (7,700)
Accounting Standards Update 2016-02 [Member] | Scenario, Forecast [Member]
Long-term Purchase Commitment [Line Items]
Right-of-use asset																																				$ 4,400
Lease liability																																				$ 4,400

Financial Commitments and Con_4

Financial Commitments and Contingencies and License Agreements - Schedule of Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 1,486
2,020	1,441
2,021	1,465
2,022	828
2023 and thereafter	87
Operating lease future minimum payments, Total	$ 5,308

Income Taxes - Components of (L

Income Taxes - Components of (Loss) Income before (Provision) Benefit for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
United States	$ (125,177)	$ (109,678)	$ (69,976)
Foreign	5,167	1,652	(2,107)
Loss before income taxes	$ (120,010)	$ (108,026)	$ (72,083)

Income Taxes - Provision (Benef

Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ (11)	$ (10,608)	$ (2,001)
State	(19)	(940)	(216)
Foreign	0	7	8
Current, total	(30)	(11,541)	(2,209)
Deferred:
Federal	12	(5,256)	(93)
State	19	19	(11)
Foreign	0	0	0
Deferred, total	31	(5,237)	(104)
Total income tax provision (benefit)	$ 1	$ (16,778)	$ (2,313)

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision (Benefit) Differs from Computed Using Federal Statutory Rate Applied to Income before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax provision computed at the federal statutory rate	$ (25,202)	$ (37,809)	$ (25,217)
State tax, net of federal benefit	(4,827)	(1,849)	(307)
Research credits	(4,884)	(1,176)	(3,232)
Change in tax credit carryforwards	(3,056)	386	11,042
Officers compensation	600	(9,292)	1,196
Stock based compensation	(12,610)	(2,735)	588
Permanent items and other	(116)	1,450	12
Tax differential on foreign earnings	(32)	33	15
Change in tax rate	(1,329)	37,769	(744)
Refundable ATM credit	0	(1,336)	0
Uncertain tax positions	0	(561)	0
Change in prior year deferred taxes	6,595	(1,218)	0
Valuation allowance	44,862	(440)	14,334
Total income tax provision (benefit)	$ 1	$ (16,778)	$ (2,313)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Valuation allowance		$ 131,042	$ 86,021
Increase (decrease) in valuation allowance due to deferred tax assets		(45,000)	800
Research and development tax credits		21,618	14,255
Unrecognized tax benefits, if recognized, would affect the effective tax rate		200	$ 200	$ 700
Benefits from share compensation				$ 2,700
Accounting Standards Update 2016-09 [Member]
Income Taxes [Line Items]
Increase (decrease) in valuation allowance due to deferred tax assets	$ 2,700
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards		$ 452,000
Net operating loss carryforwards expiration year		2,018
Research and development tax credits		$ 15,200
Research and development tax credits beginning expiration year		2,027
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards		$ 241,600
Research and development tax credits		8,200
Foreign [Member]
Income Taxes [Line Items]
Net operating loss carryforwards		$ 4,500
Net operating loss carryforwards expiration year		2,022

Income Taxes - Components of Co

Income Taxes - Components of Company's Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carry forwards	$ 106,446	$ 60,771
Research credits	21,618	14,255
Stock based compensation	5,057	10,046
Deferred revenue	0	1,017
Development costs	3,938	4,143
Returns and allowances	1,976	1,636
Other, net	(5,066)	0
Total deferred tax assets before valuation allowance	133,969	91,868
Valuation allowance	(131,042)	(86,021)
Total deferred tax assets	2,927	5,847
Deferred tax liabilities:
Basis difference in debt	0	(28)
Depreciation and amortization differences	(4,396)	(6,836)
Other, net	0	(421)
Net deferred tax liabilities	$ (1,469)	$ (1,438)

Income Taxes - Summary of Unrec

Income Taxes - Summary of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 2,715	$ 3,271	$ 4,498
Adjustments related to prior year tax positions	(551)	(39)	(1,638)
Increases related to current year tax positions	1,084	374	411
Decreases due to expiration of tax statutes	0	(891)	0
Balance at end of year	$ 3,248	$ 2,715	$ 3,271

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101	$ 109,333	$ 128,367	$ 146,444
Loss from Operations	(42,578)	(29,024)	(34,311)	(25,264)	(41,088)	(15,054)	(18,609)	(21,909)	(131,177)	(96,660)	(62,886)
Net (loss) income	$ (49,221)	$ (68,718)	$ 13,744	$ (15,816)	$ (28,556)	$ (18,293)	$ (20,852)	$ (23,547)	$ (120,011)	$ (91,248)	$ (69,770)
Net loss per share, basic and diluted ($ per share)	$ (0.47)	$ (0.66)	$ 0.13	$ (0.16)	$ (0.29)	$ (0.22)	$ (0.27)	$ (0.30)

New Revenue Recognition Stand_3

New Revenue Recognition Standard - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in retained earnings due to revenue recognition	$ (599,886)		$ (502,107)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in retained earnings due to revenue recognition	$ (3,087)	$ 4,700

New Revenue Recognition Stand_4

New Revenue Recognition Standard - Condensed Consolidated Statement of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Total revenues	$ 29,402	$ 25,268	$ 24,168	$ 30,495	$ 28,570	$ 36,395	$ 34,301	$ 29,101	$ 109,333	$ 128,367	$ 146,444
Loss from Operations	(42,578)	(29,024)	(34,311)	(25,264)	(41,088)	(15,054)	(18,609)	(21,909)	(131,177)	(96,660)	(62,886)
Loss before income taxes									(120,010)	(108,026)	(72,083)
Net loss	$ (49,221)	$ (68,718)	$ 13,744	$ (15,816)	$ (28,556)	$ (18,293)	$ (20,852)	$ (23,547)	$ (120,011)	$ (91,248)	$ (69,770)
Net income per share:
Basic ($ per share)									$ (1.16)	$ (1.07)	$ (0.96)
Diluted ($ per share)									$ (1.16)	$ (1.07)	$ (0.96)
Weighted average shares outstanding:
Basic (shares)									103,305,911	85,115,592	72,824,070
Diluted (shares)									103,305,911	85,115,592	72,824,070
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenues:
Total revenues									$ 1,085
Loss from Operations									1,085
Loss before income taxes									1,085
Net loss									$ 1,085
Net income per share:
Basic ($ per share)									$ 0.01
Diluted ($ per share)									$ 0.01
Weighted average shares outstanding:
Basic (shares)									103,305,911
Diluted (shares)									103,305,911
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenues:
Total revenues									$ 110,418
Loss from Operations									(130,092)
Loss before income taxes									(118,925)
Net loss									$ (118,926)
Net income per share:
Basic ($ per share)									$ (1.15)
Diluted ($ per share)									$ (1.15)
Weighted average shares outstanding:
Basic (shares)									103,305,911
Diluted (shares)									103,305,911
Product [Member]
Revenues:
Total revenues									$ 104,466	$ 116,178	$ 128,596
Product [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenues:
Total revenues									906
Product [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenues:
Total revenues									105,372
License and Service [Member]
Revenues:
Total revenues									4,867	$ 12,189	$ 17,848
License and Service [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenues:
Total revenues									179
License and Service [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenues:
Total revenues									$ 5,046

New Revenue Recognition Stand_5

New Revenue Recognition Standard - Condensed Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Current assets:
Accounts receivable, net	$ 29,873		$ 32,260
Total current assets	250,688		277,746
Total assets	390,886		487,439
Current liabilities:
Deferred revenue	0		3,872
Total current liabilities	86,474		109,749
Deferred revenue, less current portion	0
Total liabilities	107,624		136,100
Stockholders’ equity:
Accumulated deficit	(599,886)		(502,107)
Total stockholders’ equity	283,262		351,339
Total liabilities and stockholders’ equity	390,886		$ 487,439
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Current assets:
Accounts receivable, net	127
Total current assets	127
Total assets	127
Current liabilities:
Deferred revenue	2,963
Total current liabilities	2,963
Deferred revenue, less current portion	251
Total liabilities	3,214
Stockholders’ equity:
Accumulated deficit	(3,087)	$ 4,700
Total stockholders’ equity	(3,087)
Total liabilities and stockholders’ equity	127
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Current assets:
Accounts receivable, net	30,000
Total current assets	250,815
Total assets	391,013
Current liabilities:
Deferred revenue	2,963
Total current liabilities	89,437
Deferred revenue, less current portion	251
Total liabilities	110,838
Stockholders’ equity:
Accumulated deficit	(602,973)
Total stockholders’ equity	280,175
Total liabilities and stockholders’ equity	$ 391,013

New Revenue Recognition Stand_6

New Revenue Recognition Standard - Condensed Consolidated Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss	$ (49,221)	$ (68,718)	$ 13,744	$ (15,816)	$ (28,556)	$ (18,293)	$ (20,852)	$ (23,547)	$ (120,011)	$ (91,248)	$ (69,770)
Changes in operating assets and liabilities:
Accounts receivable, net									2,844	7,694	(9,494)
Deferred revenue									0	$ 593	$ (2,985)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss									1,085
Changes in operating assets and liabilities:
Accounts receivable, net									127
Deferred revenue									(958)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net loss									(118,926)
Changes in operating assets and liabilities:
Accounts receivable, net									(2,717)
Deferred revenue									$ (958)

Subsequent Event (Details)

Subsequent Event (Details) - FUSILEV, FOLOTYN, ZEVALIN, MARQIBO, BELEODAQ, EVOMELA, and KHAPZORY [Member] - Acrotech Biopharma LLC [Member] - Subsequent Event [Member] $ in Millions	Jan. 17, 2019USD ($)employee
Subsequent Event [Line Items]
Upfront payment expected to be received	$ 160
Consideration held in escrow for six months	$ 4
Period consideration is held in escrow	6 months
Payment receivable on achievement of regulatory milestones	$ 140
Reduction in employees, number of employees | employee	90
Maximum [Member]
Subsequent Event [Line Items]
Upfront payment expected to be received	$ 300

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Detail) - SEC Schedule, 12-09, Allowance, Credit Loss [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 71	$ 88	$ 120
Additions (Recovery) to Bad Debt Expense	12	(17)	57
Charged to Other Accounts	0	0	0
Deductions	(16)	0	(89)
Balance at End of Period	$ 67	$ 71	$ 88

Uncategorized Items - sppi-2018

Label	Element	Value
Cumulative Effect of Foreign Currency Adjustment Due to New Accounting Adoption	sppi_CumulativeEffectofForeignCurrencyAdjustmentDuetoNewAccountingAdoption	$ 343,000
Retained Earnings [Member]
Cumulative Effect of Foreign Currency Adjustment Due to New Accounting Adoption	sppi_CumulativeEffectofForeignCurrencyAdjustmentDuetoNewAccountingAdoption	343,000
Accounting Standards Update 2014-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	4,678,000
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 4,678,000