Merrimack Pharmaceuticals (MACK) 10-Q 9 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Aug. 08, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	MACK
Entity Registrant Name	MERRIMACK PHARMACEUTICALS INC
Entity Central Index Key	1,274,792
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		132,793,256

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 135,501	$ 21,524
Restricted cash	102	102
Accounts receivable, net	43	275
Prepaid expenses and other current assets	5,917	2,239
Assets held for sale		33,295
Total current assets	141,563	57,435
Restricted cash	60,682	674
Property and equipment, net	11,178	14,212
Other assets	27	27
Assets held for sale, net of current portion		9,135
Total assets	213,450	81,483
Current liabilities:
Accounts payable, accrued expenses and other	33,989	29,369
Deferred rent	2,077	2,014
Accrued intraperiod tax allocation	13,530
Income taxes payable	8,141
Liabilities held for sale		56,839
Total current liabilities	57,737	88,222
Deferred rent, net of current portion	2,330	3,386
Long-term debt	48,906	216,861
Liabilities held for sale, net of current portion		25,673
Total liabilities	108,973	334,142
Commitments and contingencies
Non-controlling interest	(2,031)	(1,539)
Stockholders’ equity/(deficit):
Preferred stock, $0.01 par value: 10,000 shares authorized at June 30, 2017 and December 31, 2016; no shares issued or outstanding at June 30, 2017 or December 31, 2016
Common stock, $0.01 par value: 200,000 shares authorized at June 30, 2017 and December 31, 2016; 132,741 and 130,197 shares issued and outstanding at June 30, 2017 and December 31, 2016, respectively	1,327	1,302
Additional paid-in capital	578,103	702,377
Accumulated (deficit)	(472,922)	(954,799)
Total stockholders’ equity/(deficit)	106,508	(251,120)
Total liabilities, non-controlling interest and stockholders’ equity/(deficit)	$ 213,450	$ 81,483

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	132,741,000	130,197,000
Common stock, shares outstanding	132,741,000	130,197,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Costs and expenses:
Research and development expenses	$ 19,751	$ 27,695	$ 41,356	$ 55,697
General and administrative expenses	14,798	8,138	20,432	14,590
Total costs and expenses	34,549	35,833	61,788	70,287
Loss from continuing operations	(34,549)	(35,833)	(61,788)	(70,287)
Other income and expenses:
Interest income	382	122	396	194
Interest expense	(26,762)	(15,858)	(28,741)	(19,148)
Gain on sale of asset	1,703		1,703
Other expense, net	(659)	(64)	(661)	(107)
Net loss from continuing operations before income tax benefit	(59,885)	(51,633)	(89,091)	(89,348)
Income tax benefit	30,239		30,239
Net loss from continuing operations	(29,646)	(51,633)	(58,852)	(89,348)
Discontinued operations:
Income (loss) from discontinued operations, net of tax	540,485	675	539,538	(268)
Net income (loss)	510,839	(50,958)	480,686	(89,616)
Net loss attributable to non-controlling interest	(724)	(208)	(1,191)	(393)
Net income (loss) attributable to Merrimack Pharmaceuticals, Inc.	511,563	(50,750)	481,877	(89,223)
Other comprehensive income (loss):
Unrealized gain on available-for-sale securities		15		1
Other comprehensive loss		15		1
Comprehensive income (loss)	511,563	(50,735)	481,877	(89,222)
Amounts attributable to Merrimack Pharmaceuticals, Inc.:
Net loss from continuing operations	(28,922)	(51,425)	(57,661)	(88,955)
Income (loss) from discontinued operations, net of tax	540,485	675	539,538	(268)
Net income (loss) attributable to Merrimack Pharmaceuticals, Inc.	$ 511,563	$ (50,750)	$ 481,877	$ (89,223)
Basic and dilutive net income (loss) per common share
Net loss from continuing operations	$ (0.22)	$ (0.41)	$ (0.44)	$ (0.74)
Net income (loss) from discontinued operations, net of tax	4.08	0.01	4.10	0
Net income (loss) per share	$ 3.86	$ (0.40)	$ 3.66	$ (0.74)
Weighted-average common shares used per share calculations—basic and diluted	132,457	126,161	131,528	121,112
Cash dividend paid per common share	$ 1.055		$ 1.055

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities
Net income (loss)	$ 480,686	$ (89,616)
Income (loss) from discontinued operations	539,538	(268)
Loss from continuing operations	(58,852)	(89,348)
Adjustments to reconcile net loss to net cash used in operating activities
Non-cash interest expense	2,374	3,505
Loss on extinguishment of debt	4,887	14,566
Benefit from intraperiod tax allocation	(30,239)
Depreciation and amortization expense	2,058	2,333
Non-cash activity related to discontinued operations	15,025
(Gain) loss on sale of property and equipment	(512)	228
Stock-based compensation expense	9,529	6,077
Changes in operating assets and liabilities:
Accounts receivable	232	11
Prepaid expenses and other current assets	(4,022)	605
Income taxes payable	8,141
Accounts payable, accrued expenses and other	2,494	(8,454)
Deferred rent	(209)	579
Net cash used in continuing operations for operating activities	(49,094)	(69,898)
Net cash used in discontinuing operations for operating activities	(46,416)	(34,528)
Net cash used in operating activities	(95,510)	(104,426)
Cash flows from investing activities
Purchase of property and equipment	(287)	(2,050)
Proceeds from maturities and sales of available for sale securities		23,000
Proceeds on sale of property and equipment	1,104
Purchases of available for sale securities		(84,262)
Proceeds from sale of business	575,000
Changes in restricted cash	(60,008)
Net cash provided by (used in) investing activities	515,809	(63,312)
Cash flows from financing activities
Proceeds from exercise of options to purchase common stock	6,079	2,598
Repayment of debt	(175,000)
Payment of dividend	(140,000)
Proceeds from issuance of Silver Creek convertible promissory notes		1,025
Net cash provided by (used in) financing activities	(306,322)	3,623
Net increase (decrease) in cash and cash equivalents	113,977	(164,115)
Cash and cash equivalents, beginning of period	21,524	185,606
Cash and cash equivalents, end of period	135,501	21,491
Non-cash investing and financing activities
Purchases of property and equipment in accounts payable, accrued expenses and other	349	434
Receivables related to stock option exercises in prepaid expenses and other current assets		13
Receivables related to property and equipment sale in other current assets	155
Conversion of convertible debt into shares of common stock		$ 64,209
Supplemental disclosure of cash flows
Cash paid for interest	28,872
Silver Creek Inc. [Member]
Cash flows from financing activities
Proceeds from issuance of Series C preferred stock by Silver Creek Inc., net of issuance costs	2,599
Cash and cash equivalents, end of period	$ 2,600

Nature of the Business

Nature of the Business	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Merrimack Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company based in Cambridge, Massachusetts that is outthinking cancer to ensure that patients and their families live fulfilling lives. The Company’s mission is to transform cancer care through the smart design and development of targeted solutions based on a deep understanding of cancer pathways and biological markers. All of the Company’s product candidates, including three in clinical studies and several others in preclinical development, fit into the Company’s strategy of (1) understanding the biological problems the Company is trying to solve, (2) designing specific solutions and (3) developing those solutions for biomarker-selected patients. This three-pronged strategy seeks to ensure optimal patient outcomes. On April 3, 2017, The Company’s non-commercial assets, including its clinical and preclinical development programs (the “Pipeline Business”), were not included in the Asset Sale and remain assets of the Company. As of the closing of the Asset Sale, the Company’s most advanced programs are as follows: • MM-121 (seribantumab), a fully human monoclonal antibody that binds to the ErbB3 (HER3) receptor and targets heregulin positive cancers. The Company is currently conducting the Phase 2 randomized SHERLOC clinical trial evaluating MM-121 in heregulin positive non-small cell lung cancer patients and plans to initiate the Phase 2 randomized SHERBOC clinical trial in 2017 in heregulin positive, hormone receptor positive, ErbB2 (HER2) negative, metastatic breast cancer patients; • MM-141 (istiratumab), a fully human bispecific tetravalent monoclonal antibody designed to block tumor survival signals by targeting receptor complexes containing the insulin-like growth factor 1 (“IGF-1”) receptor and ErbB3 (HER3) cell surface receptors. The Company is currently conducting the Phase 2 randomized CARRIE clinical trial evaluating MM-141 in previously untreated metastatic pancreatic cancer patients with high levels of free IGF-1 in combination with nab-paclitaxel and gemcitabine; and • MM-310, an antibody-directed nanotherapeutic (“ADN”) that contains a novel prodrug of the highly potent chemotherapy docetaxel and targets the ephrin receptor A2 (“EphA2”) receptor, which is highly expressed in most solid tumor types. MM-310 was designed to improve the therapeutic window of docetaxel in major oncology indications, such as prostate, ovarian, bladder, gastric, pancreatic and lung cancers. The Company initiated a Phase 1 clinical trial to evaluate safety and preliminary activity of MM-310 in the first quarter of 2017. In addition to its clinical-stage programs, the Company has several product candidates in preclinical development and a discovery effort advancing additional candidate medicines. The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, among other things, its ability to secure additional capital to fund operations, success of clinical trials, development by competitors of new technological innovations, dependence on collaborative arrangements, protection of proprietary technology, compliance with government regulations and dependence on key personnel. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of capital, adequate personnel, infrastructure and extensive compliance reporting capabilities. The accompanying condensed consolidated financial statements have been prepared on a basis which assumes that the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. Until such time, if ever, as the Company can generate sufficient product revenues, the Company expects to finance its cash needs through a combination of equity offerings, debt financings, collaborations, licensing arrangements and other marketing and distribution arrangements. The Company could also engage in discussions with third parties regarding partnerships, joint ventures, combinations or divestitures of one or more of its businesses as it seeks to further the development of its research programs, improve its cash position and maximize stockholder value.

Basis of Presentation and Conso

Basis of Presentation and Consolidation	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation and Consolidation	2. Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements as of June 30, 2017 and December 31, 2016, and for the three and six months ended June 30, 2017 and 2016, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and generally accepted accounting principles in the United States of America (“GAAP”) for condensed consolidated financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, these condensed consolidated financial statements reflect all adjustments which are necessary for a fair statement of the Company’s financial position and results of its operations, as of and for the periods presented. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 filed with the SEC on March 1, 2017. The information presented in the condensed consolidated financial statements and related notes as of June 30, 2017, and for the three and six months ended June 30, 2017 and 2016, is unaudited. The December 31, 2016 condensed consolidated balance sheets included herein were derived from the audited financial statements as of that date, but does not include all disclosures, including notes, required by GAAP for complete financial statements. Interim results for the three and six months ended June 30, 2017 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2017, or any future period. As of March 31, 2017, the Commercial Business met all the conditions to be classified as a discontinued operation since the disposal of the Commercial Business represented a strategic shift that will have a major effect on the Company’s operations and financial results. The Company will not have further significant involvement in the operations of the discontinued Commercial Business. The operating results of the Commercial Business are reported as a loss from discontinued operations, net of tax in the condensed consolidated statements of operations and comprehensive income (loss) for all periods presented. The gain recognized on the sale of the Commercial Business is presented in income (loss) from discontinued operations, net of tax in the consolidated statement of operations and comprehensive income (loss). In addition, in the condensed consolidated balance sheets as of December 31, 2016, the assets and liabilities held for sale have been presented separately. For additional information, see Note 3, “Sale of Commercial Business.” These condensed consolidated financial statements include the accounts of the Company and Silver Creek Pharmaceuticals, Inc. (“Silver Creek”), representing a variable interest entity that the Company is required to consolidate. All intercompany transactions and balances have been eliminated in consolidation. As of June 30, 2017, the Company’s unrestricted cash and cash equivalents includes $2.6 million of cash and cash equivalents held by Silver Creek. This $2.6 million held by Silver Creek is designated for the operations of Silver Creek. In the first quarter of 2017, Silver Creek entered into a Series C preferred stock financing, issuing 1.4 million shares of Series C preferred stock at $1.50 per share for proceeds of $2.0 million. In conjunction with this sale in the first quarter of 2017, Silver Creek also issued warrants to purchase 1.8 million shares of Silver Creek Series C preferred stock to investors. In the second quarter of 2017, Silver Creek issued 0.4 million shares of Series C preferred stock at $1.50 per share for proceeds of $0.6 million. In conjunction with this sale in the second quarter of 2017, Silver Creek issued warrants to purchase 0.3 million shares of Silver Creek Series C preferred stock to investors. In June 2017, Silver Creek amended the warrant purchase agreements to increase the number of shares for which each warrant is redeemable. The incremental increase in the number of shares the warrants may be redeemed for as a result of the amendment was 1.3 million shares. As of June 30, 2017, the Company held a 51% ownership interest in Silver Creek and maintained control over the Silver Creek Board of Directors through its voting rights. As such, the Company remains the primary beneficiary of Silver Creek. The change in the non-controlling interest related to Silver Creek was as follows: (in thousands) Non- Controlling Interest Balance at December 31, 2016 $ (1,539 ) Net loss attributable to Silver Creek (1,191 ) Issuance of Silver Creek Series C preferred stock 699 Balance at June 30, 2017 $ (2,031 ) (in thousands) Non- Controlling Interest Balance at December 31, 2015 $ 239 Net loss attributable to Silver Creek (393 ) Balance at June 30, 2016 $ (154 )

Sale of Commercial Business

Sale of Commercial Business	6 Months Ended
	Jun. 30, 2017
Discontinued Operations And Disposal Groups [Abstract]
Sale of Commercial Business	3. Sale of Commercial Business Ipsen On April 3, 2017, the Company completed the sale of the Commercial Business to Ipsen. Pursuant to the Asset Sale Agreement, the Company may be entitled to up to $450.0 million in additional payments based on the achievement by or on behalf of Ipsen of certain milestone events if the U.S. Food and Drug Administration (the “FDA”) approves ONIVYDE for certain indications as follows: (i) $225.0 million upon the regulatory approval by the FDA of ONIVYDE for the first-line treatment of metastatic adenocarcinoma of the pancreas (a) in combination with fluorouracil and leucovorin (with or without oxaliplatin), (b) in combination with gemcitabine and abraxane or (c) following submission and filing of regulatory approval by Ipsen for purposes of commercialization by Ipsen; (ii) $150.0 million upon the regulatory approval by the FDA of ONIVYDE for the treatment of small cell lung cancer after failure of first-line chemotherapy; and (iii) $75.0 million upon the regulatory approval by the FDA of ONIVYDE for an additional indication unrelated to those described above. In connection with the sale of the Commercial Business, on April 3, 2017, the Company entered into a transition services agreement In connection with the completion of the Asset Sale, on April 3, 2017, the Company irrevocably deposited the redemption price of the 11.50% senior secured notes due 2022 (the “2022 Notes”) of $175.0 million outstanding aggregate principal amount, interest of $7.4 million through the redemption date and an additional make-whole premium payment of approximately $20.1 million with U.S. Bank National Association as trustee (the “Trustee”) under the Indenture dated as of December 22, 2015 (the “Indenture”) and irrevocably instructed the Trustee to apply such amount to the redemption in full of the 2022 Notes on the redemption date of April 27, 2017. The Indenture was satisfied and discharged on April 3, 2017. In connection with the completion of the Asset Sale, on April 3, 2017, the Company entered into a sublease with Ipsen, pursuant to which Ipsen is subleasing from the Company approximately 70,237 square feet of leased space in the Company’s Cambridge, Massachusetts facility through the end of the term of the lease on June 30, 2019. Payments under the sublease are recorded as an offset to rent expense in the condensed consolidated statement of operations and comprehensive income (loss). Also in connection with the completion of the Asset Sale, on April 3, 2017, the Company entered into an intellectual property license agreement with Ipsen, pursuant to which Ipsen granted to the Company a perpetual, worldwide, non-exclusive, royalty-free, fully paid-up license in and to all patents included in the transferred intellectual property, other than certain patents relating to generic liposomal technology, with respect to which the license will be exclusive, in each case for use outside of the Commercial Business. The Company granted to Ipsen a non-exclusive, royalty-free, fully paid up, perpetual, irrevocable and worldwide license to all patents it owned at the time of the closing of the transaction contemplated by the Asset Sale Agreement for use in connection with the Commercial Business. This transfer of intellectual property did not impact the financial statements as no amounts related to the intellectual property had previously been recorded. On April 5, 2017, the Company announced that its Board of Directors authorized and declared a special cash dividend of $140.0 million on the Company's common stock. The special dividend was payable on May 26, 2017 to stockholders of record as of the close of business on May 17, 2017. The special dividend resulted in a decrease to additional paid-in capital. Discontinued Operations and Assets Held for Sale The condensed consolidated financial statements for the three and six months ended June 30, 2017 and 2016 reflect the operations of the Commercial Business as a discontinued operation. The Company recorded a gain of approximately $598.2 million on the Asset Sale, which is included in gain from discontinued operations on the condensed consolidated statements of operations and comprehensive income (loss). Discontinued operations for the three and six months ended June 30, 2017 and 2016 includes the following: (in thousands) Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Revenues: Product revenues, net $ — $ 12,851 $ 16,135 $ 22,819 License and collaboration revenues — 19,332 7,797 30,645 Other revenues — 1,498 1,973 1,498 Total revenues — 33,681 25,905 54,962 Costs and expenses: Cost of revenues — 1,872 3,890 2,583 Research and development expenses — 13,302 3,700 18,181 Selling, general and administrative expenses — 12,542 8,709 23,885 Restructuring expenses 4,216 — 9,535 — Total costs and expenses 4,216 27,716 25,834 44,649 Other income and expenses: Interest expense (1,509 ) (5,290 ) (6,743 ) (10,581 ) Gain on sale of commercial business 598,120 — 598,120 — Income (loss) from discontinued operations $ 592,395 $ 675 $ 591,448 $ (268 ) Income tax expense (51,910 ) — (51,910 ) — Total income (loss) from discontinued operations $ 540,485 $ 675 $ 539,538 $ (268 ) The carrying value of the assets and liabilities of the Commercial Business classified as “Discontinued operations” in the condensed consolidated balance sheets is as follows: (in thousands) December 31, 2016 Assets Current assets: Accounts receivable, net $ 17,194 Inventory 14,554 Prepaid expenses and other current assets 1,547 Total current assets held for sale 33,295 Property and equipment, net 1,553 Intangible assets, net 3,977 Goodwill 3,605 Total long-term assets held for sale 9,135 Liabilities Current liabilities: Accounts payable, accrued expenses and other 20,613 Deferred revenues 36,226 Total current liabilities held for sale 56,839 Deferred revenues, net of current portion 25,673 Total liabilities held for sale 25,673 Inventory Inventory of the Commercial Business as of December 31, 2016 consisted of the following: (in thousands) December 31, 2016 Raw materials $ 4,483 Work in process 8,651 Finished goods 1,420 Total inventory $ 14,554 Restructuring Activities On January 8, 2017, the Company announced a reduction in headcount by approximately 30% in connection with the Asset Sale and the completion of its strategic pipeline review. Upon the closing of the Asset Sale and the completion of its strategic pipeline review, the Company had approximately 80 employees. Under this corporate restructuring, for the three and six months ended June 30, 2017, the Company recognized total restructuring expenses of $4.2 million and $9.5 million, respectively, which was related to contractual termination benefits for employees with pre-existing severance arrangements. These one-time employee termination benefits are comprised of severance, benefits and related costs, all of which are expected to result in cash expenditures. The majority of these payments were made during the second quarter of 2017. The remaining payments represent severance payments that will be paid over one year. The expense of $9.5 million was included in discontinued operations, as the costs are directly associated with the sale of the Commercial Business. The following table summarizes the charges related to the restructuring activities as of June 30, 2017: (in thousands) Accrued Restructuring Expenses at December 31, 2016 Expenses Less: Payments Accrued Restructuring Expenses at June 30, 2017 Severance, benefits and related costs $ — $ 9,521 $ 8,124 $ 1,397 Totals $ — $ 9,521 $ 8,124 $ 1,397 These amounts are included in accounts payable, accrued expenses and other in the June 30, 2017 balance sheet. License and Collaboration Agreements Related to the Asset Sale Baxalta On September 23, 2014, the Company and Baxter International Inc., Baxter Healthcare Corporation and Baxter Healthcare SA entered into a license and collaboration agreement (the “Baxalta Agreement”) for the development and commercialization of ONIVYDE outside of the United States and Taiwan (the “Licensed Territory”). In connection with Baxter International Inc.’s separation of the Baxalta business, the Baxalta Agreement was assigned to Baxalta during the second quarter of 2015. As part of the Baxalta Agreement, the Company granted Baxalta an exclusive, royalty-bearing right and license under the Company’s patent rights and know-how to develop and commercialize ONIVYDE in the Licensed Territory. On April 3, 2017, the Baxalta Agreement and all related agreements, including the Company’s agreement related to the commercial supply of ONIVYDE, were assigned to Ipsen in connection with the Asset Sale. Pursuant to the Asset Sale Agreement, the Company retained the right to receive net milestone payments of up to $33.0 million that may become payable pursuant to the Baxalta Agreement for the ex-U.S. development and commercialization of ONIVYDE, which is comprised of potential payments of $18.0 million from the sale of ONIVYDE in two additional major European countries, $5.0 million related to the sale of ONIVYDE in the first major non-European, non-Asian country and $10.0 million for the first patient dosed in a pivotal clinical trial in an indication other than pancreatic cancer. PharmaEngine, Inc. On May 5, 2011, the Company and PharmaEngine, Inc. (“PharmaEngine”) entered into an assignment, sublicense and collaboration agreement (the “PharmaEngine Agreement”) under which the Company reacquired rights in Europe and certain countries in Asia to ONIVYDE. In exchange, the Company agreed to pay PharmaEngine a nonrefundable, noncreditable upfront payment of $10.0 million and up to an additional $80.0 million in aggregate development and regulatory milestones and $130.0 million in aggregate sales milestones. On April 3, 2017, the PharmaEngine Agreement and all related agreements, including the Company’s agreement related to its commercial supply of ONIVYDE, were assigned to Ipsen in connection with the Asset Sale.

Going Concern

Going Concern	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Going Concern	4. Going Concern In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern As of December 31, 2016, the Company had $21.5 million in unrestricted cash and cash equivalents, had suffered recurring losses from operations and had negative working capital and cash outflows from operating activities. Based on the evaluation completed in connection with the filing of the Company’s Annual Report on Form 10-K for the year ended December 31, 2016, including consideration of management’s plans, the Company previously concluded that there was substantial doubt as to its ability to continue as a going concern within one year after March 1, 2017, the date that the consolidated financial statements were issued. On April 3, 2017, the Company closed the Asset Sale with Ipsen and received a $575.0 million upfront cash payment, subject to a working capital adjustment. The working capital adjustment is currently estimated as a $2.2 million receivable expected to be received in the third quarter of 2017. The Company used a portion of the cash payment to redeem the $175.0 million outstanding aggregate principal amount of the 2022 Notes, which also required an additional make-whole premium payment of approximately $20.1 million, and deposited $60.0 million into an escrow account in response to a lawsuit filed by the trustee and certain holders of its 4.50% convertible notes due 2020 (the “Convertible Notes”). The Company distributed $140.0 million of the upfront cash payment in the form of a special cash dividend to stockholders, which was payable on May 26, 2017 to stockholders of record as of the close of business on May 17, 2017. After consideration of the Company’s cash and cash equivalents balance at March 31, 2017 of $17.2 million and the net proceeds from the Asset Sale, the Company has concluded that the previous conditions and events that raised substantial doubt about its ability to continue as a going concern have been alleviated. The Company updated its going concern assessment for the three months ended June 30, 2017 and concluded the Company is able to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	5. Income Taxes Deferred tax assets and liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using future enacted tax rates. A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. The Company completed the Asset Sale and recorded the income tax implications of the sale in the second quarter of 2017. The Asset Sale generated taxable income for the Company which has resulted in income tax expense. The Company released a portion of its valuation allowance in the three months ended June 30, 2017 as it is now able to utilize its net operating loss carryforwards to offset the taxable income generated from the Asset Sale. The Company’s current income tax expense for the six months ended June 30, 2017 is $8.1 million, which is comprised primarily of federal Alternative Minimum Tax and state income tax. Intraperiod tax allocation rules require the Company to allocate the provision for income taxes between continuing operations and other categories of earnings, such as discontinued operations. In periods in which there is pre-tax loss from continuing operations and pre-tax income in other categories of earnings, such as discontinued operations, the Company must allocate to continuing operations a tax benefit for the loss in continuing operations with an offsetting tax expense to discontinued operations. For the three and six months ended June 30, 2017, the Company recognized an income tax benefit of $30.2 million in continuing operations and income tax expense in discontinued operations of $51.9 million related to the income generated in connection with the Asset Sale. As of June 30, 2017, the Company recorded an accrued income tax provision of $13.5 million. In connection with the Asset Sale, the Company recorded an income tax provision in discontinued operations of $223.3 million prior to the release of the valuation allowance. The Company released $171.4 million of its valuation allowance in discontinued operations during the three months ended June 30, 2017, resulting in a total income tax expense of $51.9 million in discontinued operations.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	6. Net Income (Loss) Per Common Share Basic net income (loss) per share is calculated by dividing the net income (loss) attributable to Merrimack Pharmaceuticals, Inc, by the weighted-average number of common shares outstanding during the period. Diluted net income (loss) per share is computed by dividing the net income (loss) attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of dilutive common shares outstanding during the period. Dilutive shares outstanding is calculated by adding to the weighted shares outstanding any potential (unissued) shares of common stock from outstanding stock options based on the treasury stock method. In a period when a net loss is reported, all common stock equivalents are excluded from the calculation because they would have an anti-dilutive effect, meaning the loss per share would be reduced. Therefore, in periods where a loss is reported, there is no difference in basic and dilutive loss per share. . The Company follows the two-class method when computing net income (loss) per share, when it has issued shares that meet the definition participating securities. The two–class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participating rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based on their respective rights to receive dividends, as if all income for the period has been distributed or losses to be allocated if they are contractually required to fund losses. There were no amounts allocated to participating securities for the three and six months ended June 30, 2017 and 2016, as the Company was in a loss position and had no shares that met the definition of participating securities outstanding as of June 30, 2017 and 2016. In addition, as discussed in Note 10, “Borrowings,” in July 2013, the Company issued $125.0 million aggregate principal amount of Convertible Notes in an underwritten public offering. Following the repayment and satisfaction in full of the Company’s obligations to Hercules Technology Growth Capital, Inc. (“Hercules”) under its Loan and Security Agreement with Hercules (the “Loan Agreement”), which occurred in December 2015, upon any conversion of the Convertible Notes, the Convertible Notes may be settled, at the Company’s election, in cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock. For purposes of calculating the maximum dilutive impact, it is presumed that the conversion premium will be settled in common stock, inclusive of a contractual make-whole provision resulting from a fundamental change, and the resulting potential common shares included in diluted earnings per share if the effect is more dilutive. As of June 30, 2017, $60.8 million aggregate principal amount of the Convertible Notes remained outstanding. The stock options and conversion premium on the Convertible Notes are excluded from the calculation of diluted loss per share because the net loss for the three and six months ended June 30, 2016 causes such securities to be anti-dilutive. Outstanding securities excluded from the calculation of diluted loss per share for the three and six months ended June 30, 2017 and 2016 are shown in the chart below: Three Months Ended June 30, Six Months Ended June 30, (in thousands) 2017 2016 2017 2016 Outstanding options to purchase common stock 18,915 21,647 18,915 21,647 Conversion of the Convertible Notes 12,158 12,158 12,158 12,158

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	7. Fair Value of Financial Instruments Fair value is an exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value is determined based on observable and unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, while unobservable inputs reflect certain market assumptions. As a basis for considering such assumptions, GAAP establishes a three-tier value hierarchy, which prioritizes the inputs used to develop the assumptions and for measuring fair value as follows: (Level 1) observable inputs such as quoted prices in active markets for identical assets; (Level 2) inputs other than the quoted prices in active markets that are observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. Recurring Fair Value Measurements The carrying values of cash, restricted cash, prepaid expenses, accounts receivable, accounts payable and accrued expenses, and other short-term assets and liabilities approximate their respective fair values due to the short-term maturities of these assets and liabilities. The following tables show assets measured at fair value on a recurring basis as of June 30, 2017 and December 31, 2016: June 30, 2017 (in thousands) Level 1 Level 2 Level 3 Assets: Money market funds $ 128,931 $ — $ — Totals $ 128,931 $ — $ — Liabilities: Silver Creek warrant liability $ — $ — $ 4,062 Totals $ — $ — $ 4,062 December 31, 2016 (in thousands) Level 1 Level 2 Level 3 Assets: Money market funds $ 12,373 $ — $ — Totals $ 12,373 $ — $ — Liabilities: Silver Creek warrant liability $ — $ — $ 1,499 Totals $ — $ — $ 1,499 In December 2016, Silver Creek issued warrants to purchase an aggregate of 1.9 million shares of Silver Creek Series C preferred stock (the “Silver Creek warrants”). During the first quarter of 2017, Silver Creek issued additional Silver Creek warrants to purchase an aggregate of 1.8 million shares of Silver Creek Series C preferred stock. During the second quarter of 2017, Silver Creek issued additional Silver Creek warrants to purchase an aggregate of 0.3 million shares of Silver Creek Series C preferred stock. In June 2017, Silver Creek amended the outstanding warrant purchase agreements to increase the number of shares for which each warrant is redeemable. There were no changes in valuation techniques or transfers between the fair value measurement levels during the three or six months ended June 30, 2017 or during the year ended December 31, 2016. Other Fair Value Measurements The estimated fair value of the Convertible Notes was $36.7 million as of June 30, 2017. The Company estimated the fair value of the Convertible Notes by using a quoted market rate in an inactive market, which is classified as a Level 2 input. The carrying value of the Convertible Notes was $48.9 million as of June 30, 2017 due to the bifurcation of the conversion feature of the Convertible Notes as described more fully in Note 10, “Borrowings.” As discussed in Note 10, “Borrowings,” in December 2015, the Company closed a private placement of $175.0 million aggregate principal amount of 2022 Notes. The Company estimated the fair value of the 2022 Notes by using publicly-available information related to one of the 2022 Notes borrower’s portfolio of debt investments based on unobservable inputs, which is classified as a Level 3 input. In connection with the completion of the Asset Sale, on April 3, 2017, the liability under the 2022 Notes was satisfied. The Company incurred a loss on extinguishment of $25.0 million as a result of the early repayment of the 2022 Notes, which is included in interest expense on the statement of operations. For additional information, see Note 3, “Sale of Commercial Business.”

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2017
Investments Debt And Equity Securities [Abstract]
Marketable Securities	8. Marketable Securities As of both June 30, 2017 and December 31, 2016, the Company maintained only cash equivalents comprised of money market funds. As of June 30, 2017, the Company did not hold any securities that were in an unrealized loss position. There were no realized gains or losses on available-for-sale securities for the three or six months ended June 30, 2017 or 2016.

Accounts Payable, Accrued Expen

Accounts Payable, Accrued Expenses and Other	6 Months Ended
	Jun. 30, 2017
Payables And Accruals [Abstract]
Accounts Payable, Accrued Expenses and Other	9. Accounts Payable, Accrued Expenses and Other Accounts payable, accrued expenses and other as of June 30, 2017 and December 31, 2016 consisted of the following: (in thousands) June 30, 2017 December 31, 2016 Accounts payable $ 8,298 $ 2,692 Accrued goods and services 5,467 8,233 Accrued clinical trial costs 10,382 8,776 Accrued drug purchase costs — 480 Accrued payroll and related benefits 1,362 3,394 Accrued severance expenses 1,736 774 Accrued interest 1,261 2,100 Accrued dividends payable 19 19 Silver Creek warrant liability 4,062 1,499 Deferred tax incentives 1,402 1,402 Total accounts payable, accrued expenses and other $ 33,989 $ 29,369

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Borrowings	10. Borrowings 2022 Notes On December 22, 2015, the Company closed a private placement of $175.0 million aggregate principal amount of 2022 Notes. As a result of this placement, the Company received net proceeds of approximately $168.5 million, after deducting private placement and offering expenses payable by the Company. In connection with the completion of the Asset Sale on April 3, 2017, the liability under the 2022 Notes was satisfied. For additional information, see Note 3, “Sale of Commercial Business.” The 2022 Notes bore interest at a rate of 11.50% per year, payable semi-annually on June 15 and December 15 of each year, beginning on June 15, 2016. The 2022 Notes contained customary covenants, including covenants that limited or restricted the Company’s ability to incur liens, incur indebtedness and make certain restricted payments, but did not contain covenants related to future financial performance. The 2022 Notes were secured by a first priority lien on substantially all of the Company’s assets. The Company assessed the 2022 Notes pursuant to ASC 815, Derivatives and Hedging Debt issuance costs incurred by the Company are accounted for as a direct deduction to the carrying value of the 2022 Notes and are amortized to interest expense using the effective interest method over the life of the 2022 Notes. In connection with the completion of the Asset Sale, on April 3, 2017, the Company voluntarily settled the principle liability of the 2022 Notes. As a result of the early repayment, for the three and six months ended June 30, 2017 a loss on extinguishment of $25.0 million was incurred As a result of the early repayment, a loss on extinguishment of $25.0 million was recognized in interest expense in the condensed consolidated statement of operations and comprehensive income (loss) for the three and six months ended June 30, 2017. The $25.0 million loss on extinguishment included a $20.1 million prepayment penalty and $4.9 million of amortization expense recognized for the remaining debt discount at settlement as a result of the early repayment, which is included in interest expense on the statement of operations. For the three and six months ended June 30, 2017, interest expense related to the 2022 Notes was $1.5 million and $6.7 million, respectively. For the three and six months ended June 30, 2016, interest expense related to the 2022 Notes was $5.2 million and $10.4 million, respectively. These amounts are included in discontinued operations. Convertible Notes In July 2013, the Company issued $125.0 million aggregate principal amount of Convertible Notes in an underwritten public offering. As a result of the Convertible Notes offering, the Company received net proceeds of approximately $120.6 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The Convertible Notes bear interest at a rate of 4.50% per year, payable semiannually in arrears on January 15 and July 15 of each year, beginning on January 15, 2014. The Convertible Notes are general unsecured senior obligations of the Company and rank (i) senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the Convertible Notes, (ii) equal in right of payment to any of the Company’s unsecured indebtedness that is not so subordinated, (iii) effectively junior in right of payment to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness and (iv) structurally junior to all indebtedness and other liabilities (including trade payables) of the Company’s subsidiaries. The Company separately accounted for the liability and equity components of the Convertible Notes by bifurcating gross proceeds between the indebtedness, or liability component, and the embedded conversion option, or equity component. This bifurcation was done by estimating an effective interest rate as of the date of issuance for similar notes which do not contain an embedded conversion option. The gross proceeds received from the issuance of the Convertible Notes less the initial amount allocated to the indebtedness resulted in a $53.8 million allocation to the embedded conversion option. The embedded conversion option was recorded in stockholders’ deficit and as debt discount, to be subsequently amortized as interest expense over the term of the Convertible Notes. Underwriting discounts and commissions and offering expenses totaled $4.4 million and were allocated to the indebtedness and the embedded conversion option based on their relative values. On April 13, 2016, the Company entered into separate, privately-negotiated conversion agreements (the “Conversion Agreements”) with certain holders of the Convertible Notes. Under the Conversion Agreements, such holders agreed to convert an aggregate principal amount of $64.2 million of Convertible Notes held by them. The Company initially settled each $1,000 principal amount of Convertible Notes surrendered for conversion by delivering 136 shares of the Company’s common stock on April 18, 2016. In total, the Company issued an aggregate of 8,732,152 shares of its common stock on this initial closing date. In addition, pursuant to the Conversion Agreements, at the additional closings (as defined in the Conversion Agreements), the Company issued an aggregate of 3,635,511 shares of the Company’s common stock representing an aggregate of $27.7 million as additional payments in respect of the conversion of the Convertible Notes. The number of additional shares was determined based on the daily VWAP (as defined in the Conversion Agreements) of the Company’s common stock for each of the trading days in the 10-day trading period following the date of the Conversion Agreements. The issuance of 12,367,663 total shares of the Company’s common stock pursuant to the Conversion Agreements resulted in an increase to common stock and additional paid-in capital of $101.0 million. As a result of the conversion, the Company recognized an overall loss on extinguishment of $14.6 million representing the difference between the total settlement consideration transferred to the holders that was attributed to the liability component of the Convertible Notes, based on the fair value of that component at the time of conversion, and the net carrying value of the liability. The loss on extinguishment was recorded as interest expense during the second quarter of 2016. The remaining settlement consideration transferred was allocated to the reacquisition of the embedded conversion option and recognized as a $39.8 million reduction of additional paid-in capital. Transaction costs incurred with third parties related to the conversion were allocated to the liability and equity components and resulted in an additional $0.2 million of interest expense and a $0.2 million reduction of additional paid-in capital. The outstanding Convertible Notes will mature on July 15, 2020 (the “Maturity Date”), unless earlier repurchased by the Company or converted at the option of holders. Holders may convert their Convertible Notes at their option at any time prior to the close of business on the business day immediately preceding April 15, 2020 only under the following circumstances: • during any calendar quarter commencing after September 30, 2013 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; • during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the Convertible Notes) per $1,000 principal amount of Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; or • upon the occurrence of specified corporate events set forth in the indenture governing the Convertible Notes. On or after April 15, 2020 until the close of business on the business day immediately preceding the Maturity Date, holders may convert their Convertible Notes at any time, regardless of the foregoing circumstances. Following the repayment and satisfaction in full of the Company’s obligations to Hercules under the Loan Agreement, which occurred in December 2015, upon any conversion of the Convertible Notes, the Convertible Notes may be settled, at the Company’s election, in cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock. The initial conversion rate of the Convertible Notes was 160.0000 shares of the Company’s common stock per $1,000 principal amount of Convertible Notes, which is equivalent to an initial conversion price of $6.25 per share of common stock. As a result of the special dividend that was payable on May 26, 2017 to stockholders of record as of the close of business on May 17, 2017, the conversion rate of the Convertible Notes was adjusted from 160.0000 shares of the Company’s common stock per $1,000 principal amount of Convertible Notes to 235.2112 shares of the Company’s common stock per $1,000 principal amount of Convertible Notes. The conversion rate will be subject to further adjustment in some events, but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the Maturity Date, the Company will increase the conversion rate for a holder who elects to convert its Convertible Notes in connection with such a corporate event in certain circumstances. In connection with a lawsuit filed by the trustee and certain holders of the Convertible Notes in the Court of Chancery in the State of Delaware, captioned Wells Fargo Bank, National Association, Wolverine Flagship Fund Trading Limited, Highbridge International LLC, and Highbridge Tactical Credit & Convertibles Master Fund, L.P. v. Merrimack Pharmaceuticals, Inc. For the three and six months ended June 30, 2017, interest expense related to the Convertible Notes was $1.7 million and $3.3 million, respectively. For the three and six months ended June 30, 2016, interest expense related to the Convertible Notes was $1.9 million and $5.3 million, respectively. The year-over-year decrease was primarily attributable to interest expense related to a reduction in the principal based on the conversion of some of the Convertible Notes that occurred in April 2016. Future Minimum Payments under Outstanding Borrowings Future minimum payments under outstanding borrowings as of June 30, 2017 are as follows: (in thousands) Convertible Notes Remainder of 2017 $ 1,368 2018 2,736 2019 2,736 2020 and thereafter 63,527 Total 70,367 Less interest (9,576 ) Less unamortized discount (11,885 ) Less current portion — Long-term debt $ 48,906

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation As of December 31, 2015, there were 2.5 million shares of common stock available to be granted under the Company’s 2011 Stock Incentive Plan (the “2011 Plan”). The 2011 Plan is administered by the Company’s board of directors and permits the Company to grant incentive and non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards. In February 2016, 4.1 million additional shares of common stock became available for grant to employees, officers, directors and consultants under the 2011 Plan. At June 30, 2017, there were 2.3 million shares remaining available for grant under the 2011 Plan. During both the three and six months ended June 30, 2017, the Company issued options to purchase 19.4 million shares of common stock. During the six months ended June 30, 2016 the Company issued options to purchase 3.8 million shares of common stock. These options generally vest over a three-year period for employees. Options granted to directors vest immediately. As described in Note 3, “Sale of Commercial Business,” the Board of Directors authorized and declared a special cash dividend of $140.0 million on the Company's common stock, which was payable on May 26, 2017 to stockholders of record as of the close of business on May 17, 2017. The Board of Directors determined, in accordance with the adjustment provision of each of the Company’s 1999 Stock Option Plan, as amended, the 2008 Stock Incentive Plan, as amended, and the 2011 Plan (collectively, the “Equity Plans”), that the special cash dividend was unusual and non-recurring and that appropriate adjustment to the stock options to purchase shares of the Corporation’s common stock outstanding under the Equity Plans was required. The Company treated this adjustment as a modification to the original stock option grant because the terms of the agreements were modified in order to preserve the value of the option awards after a large non-recurring cash dividend. The calculation of the incremental compensation expense is based on the excess of the fair value of the award measured immediately before and after the modification. As a result, the Company recognized an incremental compensation expense of $5.6 million associated with the modification in the second quarter of 2017. The fair value of stock options granted to employees during the three and six months ended June 30, 2017 and 2016 was estimated at the date of grant using the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Risk-free interest rate 1.7 – 2.0% 1.1 – 1.5% 1.7 – 2.1% 1.5 – 1.8% Expected dividend yield 0% 0% 0% 0% Expected term 5.7 – 6.1 years 5.0 – 5.8 years 5.7 – 6.1 years 5.0 – 5.9 years Expected volatility 65% 67 – 69% 65 – 68% 66 – 67% The Company uses the simplified method to calculate the expected term, as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term. The computation of expected volatility is based on the historical volatility of comparable companies from a representative peer group selected based on industry and market capitalization. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected life of the stock options. Management estimates expected forfeitures based on historical experience and recognizes compensation costs only for those equity awards expected to vest. In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-09, “Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting,” which simplifies several areas of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either liabilities or equity and classification of excess tax benefits on the statement of cash flows. This guidance also permits a new entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. The Company adopted the guidance, electing to account for forfeitures when they occur, and it did not have an impact on the consolidated financial statements. The Company recognized stock-based compensation expense during the three and six months ended June 30, 2017 and 2016 as follows: Three Months Ended June 30, Six Months Ended June 30, (in thousands) 2017 2016 2017 2016 Employee awards: Research and development expense $ 4,916 $ 1,465 $ 5,383 $ 2,991 General and administrative expense 3,818 2,102 4,146 3,086 Total stock-based compensation expense $ 8,734 $ 3,567 $ 9,529 $ 6,077 The following table summarizes stock option activity during the six months ended June 30, 2017: Weighted-Average Remaining Aggregate (in thousands, except per share amounts) Options Weighted-Average Exercise Price Contractual Term (in years) Intrinsic Value Outstanding at December 31, 2016 19,024 $ 5.77 5.97 $ 7,564 Granted 19,388 $ 2.46 Exercised (2,562 ) $ 2.29 Forfeited (16,935 ) $ 6.24 Outstanding at June 30, 2017 18,915 $ 2.43 5.87 $ 440 Vested and expected to vest at June 30, 2017 18,870 $ 2.43 5.86 $ 440 Exercisable at June 30, 2017 12,560 $ 2.81 3.98 $ 440 The weighted-average grant date fair value per share of stock options granted during the three and six months ended June 30, 2017 was $0.38 and $0.38, respectively. The weighted-average grant date fair value per share of stock options granted during the three and six months ended June 30, 2016 was $3.73 and $3.35, respectively. The aggregate intrinsic value is calculated as the difference between the exercise price of the stock options and the fair value of the underlying common stock. The aggregate intrinsic value of stock options exercised during the three and six months ended June 30, 2017 was $0.9 million and $2.3 million, respectively. The aggregate intrinsic value of stock options exercised during the three and six months ended June 30, 2016 was $0.6 million and $2.7 million, respectively. As of June 30, 2017, there was $6.1 million of total unrecognized stock-based compensation expense related to unvested employee stock awards. The Company expects to recognize this expense over a weighted-average period of approximately 2.9 years.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2017
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	12. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. This guidance was originally effective for interim and annual periods beginning after December 15, 2016 and allows for adoption using a full retrospective method, or a modified retrospective method. Early adoption was originally not permitted. Subsequent to the issuance of ASU 2014-09, the FASB also issued the following updates related to ASC 606, Revenue from Contracts with Customers • In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” whereby the effective date for the new revenue standard was deferred by one year. As a result of ASU 2015-14, the new revenue standard is now effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017, and early adoption is now permitted for annual periods beginning after December 15, 2016, including interim periods within that annual period. • In March 2016, the FASB issued ASU 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” to clarify the implementation guidance on principal versus agent considerations. • In April 2016, the FASB issued ASU 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing,” to clarify the principle for determining whether a good or service is “separately identifiable” from other promises in the contract and to clarify the categorization of licenses of intellectual property. • In May 2016, the FASB issued ASU 2016-12, “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Technical Expedients,” to clarify guidance on transition, determining collectability, non-cash consideration and the presentation of sales and other similar taxes. The Company does not currently have any revenue generating contracts with customers due to the sale of its commercial business in the second quarter of 2017. The Company expects to adopt the new revenue standard on January 1, 2018 using the modified retrospective approach. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities,” which contains a number of provisions related to the measurement, presentation and disclosure of financial instruments. This guidance will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual periods. Early adoption of this guidance is not permitted with the exception of certain specific presentation requirements that are not currently applicable to the Company. The Company does not anticipate a material impact to the consolidated financial statements as a result of the adoption of this guidance. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which supersedes all existing lease accounting guidance within ASC 840, Leases In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which represents a new credit loss standard that will change the impairment model for most financial assets and certain other financial instruments. Specifically, this guidance will require entities to utilize a new “expected loss” model as it relates to trade and other receivables. In addition, entities will be required to recognize an allowance for estimated credit losses on available-for-sale debt securities, regardless of the length of time that a security has been in an unrealized loss position. This guidance will be effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods, and early adoption is permitted. The Company is currently evaluating the potential impact that the adoption of this guidance may have on the consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which is intended to reduce diversity in practice in how entities present certain types of cash transactions in the statement of cash flows. This guidance also clarifies how the predominance principle should be applied when classifying cash receipts and cash payments that have attributes of more than one class of cash flows. This guidance will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual reporting periods, and early adoption is permitted. An entity that elects early adoption must adopt all of the amendments in the same period. The Company does not anticipate a material impact to the consolidated financial statements as a result of the adoption of this guidance. In May 2017, the FASB issued ASU 2017-09, “Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting,” which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The standard should be applied prospectively to awards modified on or after the adoption date. This guidance will be effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period. The Company is currently evaluating the potential impact that the adoption of this guidance may have on the consolidated financial statements. Other accounting standards that have been issued by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s consolidated financial statements upon adoption.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events In July 2017, Silver Creek issued 1.7 million shares of Series C preferred stock at $1.50 per share for proceeds of $2.6 million. As of June 30, 2017, the Company held a 51% ownership interest in Silver Creek and maintained control over the Silver Creek board of directors through its voting rights. As a result of Silver Creek’s issuance of additional shares of Series C preferred stock in July 2017, the Company will evaluate whether the Silver Creek financial statements should continue to be consolidated.

Recent Accounting Pronounceme19

Recent Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. This guidance was originally effective for interim and annual periods beginning after December 15, 2016 and allows for adoption using a full retrospective method, or a modified retrospective method. Early adoption was originally not permitted. Subsequent to the issuance of ASU 2014-09, the FASB also issued the following updates related to ASC 606, Revenue from Contracts with Customers • In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” whereby the effective date for the new revenue standard was deferred by one year. As a result of ASU 2015-14, the new revenue standard is now effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017, and early adoption is now permitted for annual periods beginning after December 15, 2016, including interim periods within that annual period. • In March 2016, the FASB issued ASU 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” to clarify the implementation guidance on principal versus agent considerations. • In April 2016, the FASB issued ASU 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing,” to clarify the principle for determining whether a good or service is “separately identifiable” from other promises in the contract and to clarify the categorization of licenses of intellectual property. • In May 2016, the FASB issued ASU 2016-12, “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Technical Expedients,” to clarify guidance on transition, determining collectability, non-cash consideration and the presentation of sales and other similar taxes. The Company does not currently have any revenue generating contracts with customers due to the sale of its commercial business in the second quarter of 2017. The Company expects to adopt the new revenue standard on January 1, 2018 using the modified retrospective approach. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities,” which contains a number of provisions related to the measurement, presentation and disclosure of financial instruments. This guidance will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual periods. Early adoption of this guidance is not permitted with the exception of certain specific presentation requirements that are not currently applicable to the Company. The Company does not anticipate a material impact to the consolidated financial statements as a result of the adoption of this guidance. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which supersedes all existing lease accounting guidance within ASC 840, Leases In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which represents a new credit loss standard that will change the impairment model for most financial assets and certain other financial instruments. Specifically, this guidance will require entities to utilize a new “expected loss” model as it relates to trade and other receivables. In addition, entities will be required to recognize an allowance for estimated credit losses on available-for-sale debt securities, regardless of the length of time that a security has been in an unrealized loss position. This guidance will be effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods, and early adoption is permitted. The Company is currently evaluating the potential impact that the adoption of this guidance may have on the consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which is intended to reduce diversity in practice in how entities present certain types of cash transactions in the statement of cash flows. This guidance also clarifies how the predominance principle should be applied when classifying cash receipts and cash payments that have attributes of more than one class of cash flows. This guidance will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within those annual reporting periods, and early adoption is permitted. An entity that elects early adoption must adopt all of the amendments in the same period. The Company does not anticipate a material impact to the consolidated financial statements as a result of the adoption of this guidance. In May 2017, the FASB issued ASU 2017-09, “Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting,” which provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. The standard should be applied prospectively to awards modified on or after the adoption date. This guidance will be effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period. The Company is currently evaluating the potential impact that the adoption of this guidance may have on the consolidated financial statements. Other accounting standards that have been issued by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company’s consolidated financial statements upon adoption.

Basis of Presentation and Con20

Basis of Presentation and Consolidation (Tables)	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Non-Controlling Interest in Subsidiary	The change in the non-controlling interest related to Silver Creek was as follows: (in thousands) Non- Controlling Interest Balance at December 31, 2016 $ (1,539 ) Net loss attributable to Silver Creek (1,191 ) Issuance of Silver Creek Series C preferred stock 699 Balance at June 30, 2017 $ (2,031 ) (in thousands) Non- Controlling Interest Balance at December 31, 2015 $ 239 Net loss attributable to Silver Creek (393 ) Balance at June 30, 2016 $ (154 )

Sale of Commercial Business (Ta

Sale of Commercial Business (Tables)	6 Months Ended
	Jun. 30, 2017
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Discontinued Operations and Assets Held for Sale	Discontinued operations for the three and six months ended June 30, 2017 and 2016 includes the following: (in thousands) Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Revenues: Product revenues, net $ — $ 12,851 $ 16,135 $ 22,819 License and collaboration revenues — 19,332 7,797 30,645 Other revenues — 1,498 1,973 1,498 Total revenues — 33,681 25,905 54,962 Costs and expenses: Cost of revenues — 1,872 3,890 2,583 Research and development expenses — 13,302 3,700 18,181 Selling, general and administrative expenses — 12,542 8,709 23,885 Restructuring expenses 4,216 — 9,535 — Total costs and expenses 4,216 27,716 25,834 44,649 Other income and expenses: Interest expense (1,509 ) (5,290 ) (6,743 ) (10,581 ) Gain on sale of commercial business 598,120 — 598,120 — Income (loss) from discontinued operations $ 592,395 $ 675 $ 591,448 $ (268 ) Income tax expense (51,910 ) — (51,910 ) — Total income (loss) from discontinued operations $ 540,485 $ 675 $ 539,538 $ (268 )
Schedule of Carrying Value of Assets and Liabilities Classified as Discontinued Operations Relates to Commercial Business	The carrying value of the assets and liabilities of the Commercial Business classified as “Discontinued operations” in the condensed consolidated balance sheets is as follows: (in thousands) December 31, 2016 Assets Current assets: Accounts receivable, net $ 17,194 Inventory 14,554 Prepaid expenses and other current assets 1,547 Total current assets held for sale 33,295 Property and equipment, net 1,553 Intangible assets, net 3,977 Goodwill 3,605 Total long-term assets held for sale 9,135 Liabilities Current liabilities: Accounts payable, accrued expenses and other 20,613 Deferred revenues 36,226 Total current liabilities held for sale 56,839 Deferred revenues, net of current portion 25,673 Total liabilities held for sale 25,673
Schedule of Inventory of Commercial Business	Inventory of the Commercial Business as of December 31, 2016 consisted of the following: (in thousands) December 31, 2016 Raw materials $ 4,483 Work in process 8,651 Finished goods 1,420 Total inventory $ 14,554
Summary of Charges Related to Restructuring Activities	The following table summarizes the charges related to the restructuring activities as of June 30, 2017: (in thousands) Accrued Restructuring Expenses at December 31, 2016 Expenses Less: Payments Accrued Restructuring Expenses at June 30, 2017 Severance, benefits and related costs $ — $ 9,521 $ 8,124 $ 1,397 Totals $ — $ 9,521 $ 8,124 $ 1,397

Net Income (Loss) Per Common 22

Net Income (Loss) Per Common Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Schedule of Outstanding Securities Excluded from Computation of Diluted Loss Per Share	Outstanding securities excluded from the calculation of diluted loss per share for the three and six months ended June 30, 2017 and 2016 are shown in the chart below: Three Months Ended June 30, Six Months Ended June 30, (in thousands) 2017 2016 2017 2016 Outstanding options to purchase common stock 18,915 21,647 18,915 21,647 Conversion of the Convertible Notes 12,158 12,158 12,158 12,158

Fair Value of Financial Instr23

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables show assets measured at fair value on a recurring basis as of June 30, 2017 and December 31, 2016: June 30, 2017 (in thousands) Level 1 Level 2 Level 3 Assets: Money market funds $ 128,931 $ — $ — Totals $ 128,931 $ — $ — Liabilities: Silver Creek warrant liability $ — $ — $ 4,062 Totals $ — $ — $ 4,062 December 31, 2016 (in thousands) Level 1 Level 2 Level 3 Assets: Money market funds $ 12,373 $ — $ — Totals $ 12,373 $ — $ — Liabilities: Silver Creek warrant liability $ — $ — $ 1,499 Totals $ — $ — $ 1,499

Accounts Payable, Accrued Exp24

Accounts Payable, Accrued Expenses and Other (Tables)	6 Months Ended
	Jun. 30, 2017
Payables And Accruals [Abstract]
Schedule of Accounts Payable, Accrued Expenses and Other	Accounts payable, accrued expenses and other as of June 30, 2017 and December 31, 2016 consisted of the following: (in thousands) June 30, 2017 December 31, 2016 Accounts payable $ 8,298 $ 2,692 Accrued goods and services 5,467 8,233 Accrued clinical trial costs 10,382 8,776 Accrued drug purchase costs — 480 Accrued payroll and related benefits 1,362 3,394 Accrued severance expenses 1,736 774 Accrued interest 1,261 2,100 Accrued dividends payable 19 19 Silver Creek warrant liability 4,062 1,499 Deferred tax incentives 1,402 1,402 Total accounts payable, accrued expenses and other $ 33,989 $ 29,369

Borrowings (Tables)

Borrowings (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Schedule of Future Minimum Payments under the Loans Payable	Future minimum payments under outstanding borrowings as of June 30, 2017 are as follows: (in thousands) Convertible Notes Remainder of 2017 $ 1,368 2018 2,736 2019 2,736 2020 and thereafter 63,527 Total 70,367 Less interest (9,576 ) Less unamortized discount (11,885 ) Less current portion — Long-term debt $ 48,906

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Assumptions Used to Calculate Fair Value of Options Granted to Employees	The fair value of stock options granted to employees during the three and six months ended June 30, 2017 and 2016 was estimated at the date of grant using the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 Risk-free interest rate 1.7 – 2.0% 1.1 – 1.5% 1.7 – 2.1% 1.5 – 1.8% Expected dividend yield 0% 0% 0% 0% Expected term 5.7 – 6.1 years 5.0 – 5.8 years 5.7 – 6.1 years 5.0 – 5.9 years Expected volatility 65% 67 – 69% 65 – 68% 66 – 67%
Schedule of Recognized Stock-Based Compensation Expense	The Company recognized stock-based compensation expense during the three and six months ended June 30, 2017 and 2016 as follows: Three Months Ended June 30, Six Months Ended June 30, (in thousands) 2017 2016 2017 2016 Employee awards: Research and development expense $ 4,916 $ 1,465 $ 5,383 $ 2,991 General and administrative expense 3,818 2,102 4,146 3,086 Total stock-based compensation expense $ 8,734 $ 3,567 $ 9,529 $ 6,077
Summary of Stock Option Activity	The following table summarizes stock option activity during the six months ended June 30, 2017: Weighted-Average Remaining Aggregate (in thousands, except per share amounts) Options Weighted-Average Exercise Price Contractual Term (in years) Intrinsic Value Outstanding at December 31, 2016 19,024 $ 5.77 5.97 $ 7,564 Granted 19,388 $ 2.46 Exercised (2,562 ) $ 2.29 Forfeited (16,935 ) $ 6.24 Outstanding at June 30, 2017 18,915 $ 2.43 5.87 $ 440 Vested and expected to vest at June 30, 2017 18,870 $ 2.43 5.86 $ 440 Exercisable at June 30, 2017 12,560 $ 2.81 3.98 $ 440

Nature of the Business - Additi

Nature of the Business - Additional Information (Detail)	Apr. 03, 2017USD ($)
Ipsen [Member] | Asset Sale Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront cash payment received	$ 575,000,000
Working capital adjustment receivable	2,200,000
Ipsen [Member] | Asset Sale Agreement [Member] | Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional payments receivable on achievement of certain milestone events	450,000,000
Baxalta [Member] | License and Collaboration Agreements [Member] | Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Net milestone payments expected to be received	$ 33,000,000

Basis of Presentation and Con28

Basis of Presentation and Consolidation - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 135,501	$ 17,200	$ 135,501	$ 21,524	$ 21,491	$ 185,606
Preferred stock issued	0		0	0
Silver Creek [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 2,600		$ 2,600
Net cash proceeds from stock issuance			$ 2,599
Ownership interest percentage held by parent and its de facto agents	51.00%		51.00%
Silver Creek [Member] | Series C Preferred Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Preferred stock issued	400	1,400	400
Preferred stock price per share	$ 1.50	$ 1.50	$ 1.50
Net cash proceeds from stock issuance	$ 600	$ 2,000
Warrants issued to purchase preferred stock, shares	300	1,800	300	1,900
Silver Creek [Member] | Warrant Purchase Agreements [Member]
Summary Of Significant Accounting Policies [Line Items]
Warrants issued to purchase preferred stock, shares	1,300		1,300

Basis of Presentation and Con29

Basis of Presentation and Consolidation - Schedule of Non-Controlling Interest in Subsidiary (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Minority Interest [Line Items]
Balance at the beginning of the period			$ (1,539)	$ 239
Net loss attributable to Silver Creek	$ (724)	$ (208)	(1,191)	(393)
Balance at the end of the period	$ (2,031)	$ (154)	(2,031)	$ (154)
Series C Preferred Stock [Member]
Minority Interest [Line Items]
Issuance of Silver Creek Series C preferred stock			$ 699

Sale of Commercial Business - A

Sale of Commercial Business - Additional Information (Detail)	Apr. 05, 2017USD ($)	Apr. 03, 2017USD ($)ft²	Jan. 08, 2017Employee	May 05, 2011USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Dec. 22, 2015
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount outstanding redeemed						$ 175,000,000
Dividend date declared						Apr. 5, 2017
Special cash dividend paid	$ 140,000,000
Dividend paid date						May 26, 2017
Dividend payable, date of record						May 17, 2017
January 2017 Corporate Restructuring [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Restructuring activity, announcement date						Jan. 8, 2017
Restructuring and related cost, headcount reduction percentage			30.00%
Restructuring and related cost, number of employees after headcount reduction | Employee			80
January 2017 Corporate Restructuring [Member] | Discontinued Operations [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Restructuring expenses						$ 9,500,000
January 2017 Corporate Restructuring [Member] | Contractual Termination Benefits [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Restructuring expenses					$ 4,200,000	$ 9,500,000
January 2017 Corporate Restructuring [Member] | One-time Employee Termination Benefits [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Restructuring And Related Activities Description						One-time employee termination benefits are comprised of severance, benefits and related costs, all of which are expected to result in cash expenditures. The majority of these payments were made during the second quarter of 2017. The remaining payments represent severance payments that will be paid over one year.
Severance payments payment period						1 year
2022 Notes [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Interest rate (as a percent)							11.50%
Asset Sale Agreement [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Transition services agreement period		24 months
Special cash dividend paid		$ 140,000,000
Gain from discontinued operations						$ 598,200,000
Asset Sale Agreement [Member] | 2022 Notes [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Aggregate principal amount outstanding redeemed		175,000,000
Additional premium payment		$ 20,100,000
Interest rate (as a percent)		11.50%
Aggregate principal amount of interest redeemed		$ 7,400,000
Ipsen [Member] | Asset Sale Agreement [Member] | Manufacturing Facility [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Area of sublease property | ft²		70,237
Lease expiration date		Jun. 30, 2019
Ipsen [Member] | Asset Sale Agreement [Member] | Clinical Trials in Pancreas as First-Line Treatment [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Additional payments receivable on achievement of certain milestone events		$ 225,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Clinical Trials in Small Cell Lung Cancer [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Additional payments receivable on achievement of certain milestone events		150,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Other Unrelated Clinical Trials [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Additional payments receivable on achievement of certain milestone events		75,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Development and Commercialization Milestones [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Maximum amount of milestone payments that can be received		33,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Sale Milestones in Major European Countries [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Potential milestone payments receivable		18,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Sale Milestones in Major Non-European and Non-Asian Country [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Potential milestone payments receivable		5,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Clinical Trials in Lung Cancer [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Potential milestone payments receivable		10,000,000
Ipsen [Member] | Asset Sale Agreement [Member] | Maximum [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Additional payments receivable on achievement of certain milestone events		$ 450,000,000
PharmaEngine [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Upfront license fees paid				$ 10,000,000
PharmaEngine [Member] | Development and Regulatory Milestone [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Maximum milestone payment obligation				80,000,000
PharmaEngine [Member] | Sales Milestone [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Maximum milestone payment obligation				$ 130,000,000

Sale of Commercial Business - S

Sale of Commercial Business - Schedule of Discontinued Operations and Assets Held for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other income and expenses:
Income tax expense	$ (51,900)		$ (51,900)
Total income (loss) from discontinued operations	540,485	$ 675	539,538	$ (268)
Commercial Business [Member]
Revenues:
Product revenues, net		12,851	16,135	22,819
License and collaboration revenues		19,332	7,797	30,645
Other revenues		1,498	1,973	1,498
Total revenues		33,681	25,905	54,962
Costs and expenses:
Cost of revenues		1,872	3,890	2,583
Research and development expenses		13,302	3,700	18,181
Selling, general and administrative expenses		12,542	8,709	23,885
Restructuring expenses	4,216		9,535
Total costs and expenses	4,216	27,716	25,834	44,649
Other income and expenses:
Interest expense	(1,509)	(5,290)	(6,743)	(10,581)
Gain on sale of commercial business	598,120		598,120
Income (loss) from discontinued operations	592,395	675	591,448	(268)
Income tax expense	(51,910)		(51,910)
Total income (loss) from discontinued operations	$ 540,485	$ 675	$ 539,538	$ (268)

Sale of Commercial Business -32

Sale of Commercial Business - Schedule of Carrying Value of Assets and Liabilities Classified as Assets Held for Sale Relates to Commercial Business (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Current assets:
Total current assets held for sale	$ 33,295
Total long-term assets held for sale	9,135
Current liabilities:
Total current liabilities held for sale	56,839
Total liabilities held for sale	25,673
Commercial Business [Member]
Current assets:
Accounts receivable, net	17,194
Inventory	14,554
Prepaid expenses and other current assets	1,547
Total current assets held for sale	33,295
Property and equipment, net	1,553
Intangible assets, net	3,977
Goodwill	3,605
Total long-term assets held for sale	9,135
Current liabilities:
Accounts payable, accrued expenses and other	20,613
Deferred revenues	36,226
Total current liabilities held for sale	56,839
Deferred revenues, net of current portion	25,673
Total liabilities held for sale	$ 25,673

Sale of Commercial Business -33

Sale of Commercial Business - Schedule of Inventory of Commercial Business (Detail) - Commercial Business [Member] $ in Thousands	Dec. 31, 2016USD ($)
Inventory [Line Item]
Raw materials	$ 4,483
Work in process	8,651
Finished goods	1,420
Total inventory	$ 14,554

Sale of Commercial Business -34

Sale of Commercial Business - Summary of Charges Related to Restructuring Activities (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses at Dec 31, 2016	$ 774
Accrued Restructuring Expenses at June 30, 2017	1,736
Commercial Business [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	9,521
Less: Payments	8,124
Accrued Restructuring Expenses at June 30, 2017	1,397
Commercial Business [Member] | Severance Benefits and Related Costs [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	9,521
Less: Payments	8,124
Accrued Restructuring Expenses at June 30, 2017	$ 1,397

Going Concern - Additional Info

Going Concern - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 05, 2017	Apr. 03, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015	Dec. 22, 2015	Jul. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Unrestricted cash and cash equivalents			$ 135,501	$ 17,200	$ 21,524	$ 21,491	$ 185,606
Special cash dividend distributed	$ 140,000
Dividend paid date			May 26, 2017
Dividend payable, date of record			May 17, 2017
Aggregate principal amount outstanding redeemed			$ 175,000
Convertible Notes [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Interest rate (as a percent)		4.50%							4.50%
Deposited into escrow account		$ 60,000	$ 60,000
2022 Notes [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Interest rate (as a percent)								11.50%
Asset Sale Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Special cash dividend distributed		$ 140,000
Asset Sale Agreement [Member] | 2022 Notes [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Interest rate (as a percent)		11.50%
Aggregate principal amount outstanding redeemed		$ 175,000
Additional premium payment		20,100
Ipsen [Member] | Asset Sale Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront cash payment received		575,000
Working capital adjustment receivable		$ 2,200

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2017USD ($)
Income Tax Disclosure [Abstract]
Current Income tax expense		$ 8,100
Income tax expense (benefit)	$ (30,239)	(30,239)
Income tax expense in discontinued operations	51,900	51,900
Accrued income tax provision	13,530	$ 13,530
Income tax provision in discontinued operations	223,300
Valuation allowance in discontinued operations	$ 171,400

Net Income (Loss) Per Common 37

Net Income (Loss) Per Common Share - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jul. 31, 2013
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Amounts allocated to participating securities	$ 0	$ 0	$ 0	$ 0
Participating securities outstanding, shares	0	0	0	0
Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Aggregate principal amount					$ 125,000,000
Aggregate principal amount of outstanding debt	$ 60,800,000		$ 60,800,000

Net Income (Loss) Per Common 38

Net Income (Loss) Per Common Share - Schedule of Outstanding Securities Excluded from Computation of Diluted Loss Per Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Outstanding Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities excluded from calculation of diluted loss per share	18,915	21,647	18,915	21,647
Conversion of the Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities excluded from calculation of diluted loss per share	12,158	12,158	12,158	12,158

Fair Value of Financial Instr39

Fair Value of Financial Instruments - Schedule of Assets Measured at Fair Value on a Recurring Basis (Detail) - Recurring Basis [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	$ 128,931	$ 12,373
Level 1 [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets	128,931	12,373
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	4,062	1,499
Level 3 [Member] | Silver Creek [Member] | Warrant Liability [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	$ 4,062	$ 1,499

Fair Value of Financial Instr40

Fair Value of Financial Instruments - Additional Information (Detail) - USD ($) shares in Millions	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Mar. 31, 2017	Dec. 22, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Transfers between fair value measurement levels	$ 0	$ 0		$ 0
Loss on extinguishment of debt		4,887,000	$ 14,566,000
Senior Convertible Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal amount of outstanding debt	48,900,000	48,900,000
Senior Convertible Notes [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value of debt	36,700,000	36,700,000
2022 Notes [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal amount of loan						$ 175,000,000
Loss on extinguishment of debt	25,000,000	$ 25,000,000
Silver Creek Inc. [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Risk-free interest rate		2.10%		2.30%
Expected dividend yield		0.00%		0.00%
Expected volatility		60.40%		61.70%
Expected term				6 years 10 months 24 days
Change in fair value of warrant	1,000,000	$ 1,000,000
Change in fair value of warrant, incremental change	$ 800,000	$ 800,000
Silver Creek Inc. [Member] | Minimum [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Expected term		6 years 4 months 24 days
Silver Creek Inc. [Member] | Maximum [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Expected term		7 years
Silver Creek Inc. [Member] | Series C Preferred Stock [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Warrants issued to purchase preferred stock, shares	0.3	0.3		1.9	1.8
Warrants to purchase preferred stock, value	$ 4,100,000	$ 4,100,000		$ 1,500,000

Marketable Securities - Additio

Marketable Securities - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)Security	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)Security	Jun. 30, 2016USD ($)
Amortized Cost And Fair Value Debt Securities [Abstract]
Number of securities held in unrealized loss position | Security	0		0
Realized gains (losses) on sale of available-for-sale securities | $	$ 0	$ 0	$ 0	$ 0

Accounts Payable, Accrued Exp42

Accounts Payable, Accrued Expenses and Other - Schedule of Accounts Payable, Accrued Expenses and Other (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts Payable And Accrued Liabilities [Line Items]
Accounts payable	$ 8,298	$ 2,692
Accrued goods and services	5,467	8,233
Accrued clinical trial costs	10,382	8,776
Accrued drug purchase costs		480
Accrued payroll and related benefits	1,362	3,394
Accrued severance expenses	1,736	774
Accrued interest	1,261	2,100
Accrued dividends payable	19	19
Deferred tax incentives	1,402	1,402
Total accounts payable, accrued expenses and other	33,989	29,369
Silver Creek [Member]
Accounts Payable And Accrued Liabilities [Line Items]
Warrant liability	$ 4,062	$ 1,499

Borrowings - 2022 Notes - Addit

Borrowings - 2022 Notes - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 22, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule Of Debt Instruments [Line Items]
Loss on extinguishment of debt				$ 4,887	$ 14,566
Interest expense		$ 26,762	$ 15,858	28,741	19,148
2022 Notes [Member]
Schedule Of Debt Instruments [Line Items]
Aggregate principal amount	$ 175,000
Net proceeds from the debt issuance	$ 168,500
Interest rate (as a percent)	11.50%
Loss on extinguishment of debt		25,000		25,000
Interest expense		$ 1,500	$ 5,200	6,700	$ 10,400
Prepayment penalty of extinguishment of debt				20,100
Amortization expense recognized for remaining debt discount at settlement				4,900
2022 Notes [Member] | Interest Expense [Member]
Schedule Of Debt Instruments [Line Items]
Loss on extinguishment of debt				$ 25,000

Borrowings - Convertible Notes

Borrowings - Convertible Notes - Additional Information (Detail)	May 26, 2017	Apr. 18, 2016shares	Apr. 13, 2016USD ($)shares	Jul. 31, 2013USD ($)$ / shares	Jul. 31, 2013USD ($)$ / shares	Jun. 30, 2017USD ($)shares	Jun. 30, 2016USD ($)shares	Jun. 30, 2017USD ($)shares	Jun. 30, 2016USD ($)shares	Apr. 03, 2017USD ($)	Dec. 31, 2016shares
Debt Instrument [Line Items]
Common stock, shares issued | shares						132,741,000		132,741,000			130,197,000
Loss on extinguishment of debt								$ 4,887,000	$ 14,566,000
Debt maturity date								Jul. 15, 2020
Interest expense						$ 26,762,000	$ 15,858,000	$ 28,741,000	$ 19,148,000
Convertible Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount				$ 125,000,000	$ 125,000,000
Net proceeds from the debt issuance					$ 120,600,000
Interest rate (as a percent)				4.50%	4.50%					4.50%
Embedded conversion option				$ 53,800,000	$ 53,800,000
Underwriting discounts and commissions and offering expenses				4,400,000
Principal amount of convertible notes due 2020 converted into shares of common stock			$ 64,200,000
Conversion ratio, principal amount			$ 1,000	$ 1,000	$ 1,000
Conversion rate of common stock shares per $1,000 principal amount	235.2112	136		160
Common stock, shares issued | shares		8,732,152	3,635,511				12,367,663		12,367,663
Value of additional shares issued for conversion			$ 27,700,000
Trading period			10 days
Increase to additional paid in capital pursuant to conversion							$ 101,000,000
Loss on extinguishment of debt							14,600,000
Reduction in additional paid-in capital attributable to embedded conversion option							39,800,000		$ 39,800,000
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be convertible				30 days
Convertibility of debt, closing price of stock test, percentage of stock price to conversion price for the notes that must be exceeded				130.00%
Number of consecutive business days immediately after any five consecutive trading day period during the note measurement period				5 days
Number of consecutive trading days before five consecutive business days during the note measurement period				5 days
Initial conversion price of shares (in dollars per share) | $ / shares				$ 6.25	$ 6.25
Deposited into escrow account						60,000,000		60,000,000		$ 60,000,000
Interest expense						$ 1,700,000	$ 1,900,000	3,300,000	$ 5,300,000
Convertible Notes [Member] | Minimum [Member]
Debt Instrument [Line Items]
Number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be convertible				20 days
Convertible Notes [Member] | Maximum [Member]
Debt Instrument [Line Items]
Convertibility of debt, trading price of debt test, percentage of closing price of stock used in calculation				98.00%
Convertible Notes [Member] | Transaction Costs Incurred With Third Parties [Member]
Debt Instrument [Line Items]
Reduction in additional paid-in capital								200,000
Convertible Notes [Member] | Interest Expense [Member] | Transaction Costs Incurred With Third Parties [Member]
Debt Instrument [Line Items]
Transaction costs related to conversion of convertible notes due 2020 incurred and paid								$ 200,000

Borrowings - Schedule of Future

Borrowings - Schedule of Future Minimum Payments under the Loans Payable (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt	$ 48,906	$ 216,861
Convertible Notes [Member]
Debt Instrument [Line Items]
Remainder of 2017	1,368
2,018	2,736
2,019	2,736
2020 and thereafter	63,527
Loans payable, gross including contractual interest	70,367
Less interest	(9,576)
Less unamortized discount	(11,885)
Long-term debt	$ 48,906

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Apr. 05, 2017	Feb. 29, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Granted					19,388,000
Special cash dividend paid	$ 140
Dividend paid date					May 26, 2017
Dividend payable, date of record					May 17, 2017
Incremental compensation expense			$ 5.6
Weighted-average grant date fair value per share of stock options			$ 0.38	$ 3.73	$ 0.38	$ 3.35
Aggregate intrinsic value of options exercised			$ 0.9	$ 0.6	$ 2.3	$ 2.7
Unrecognized stock-based compensation expense related to nonvested stock awards			$ 6.1		$ 6.1
Weighted average period over which unrecognized stock-based compensation expense is expected to be recognized					2 years 10 months 24 days
Stock Incentive Plan 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for grant (in shares)			2,300,000		2,300,000		2,500,000
Additional common stock available for issuance (in shares)		4,100,000
Number of Options, Granted			19,400,000		19,400,000	3,800,000
Stock Incentive Plan 2011 [Member] | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vesting period					3 years

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Assumptions Used to Calculate Fair Value of Options Granted to Employees (Detail) - Options to Purchase Common Stock [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	65.00%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.70%	1.10%	1.70%	1.50%
Expected volatility		67.00%	65.00%	66.00%
Expected term	5 years 8 months 12 days	5 years	5 years 8 months 12 days	5 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.00%	1.50%	2.10%	1.80%
Expected volatility		69.00%	68.00%	67.00%
Expected term	6 years 1 month 6 days	5 years 9 months 18 days	6 years 1 month 6 days	5 years 10 months 25 days

Stock-Based Compensation - Sc48

Stock-Based Compensation - Schedule of Recognized Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 8,734	$ 3,567	$ 9,529	$ 6,077
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense for employee awards	4,916	1,465	5,383	2,991
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense for employee awards	$ 3,818	$ 2,102	$ 4,146	$ 3,086

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Number of Options, Outstanding, Beginning balance | shares	19,024
Number of Options, Granted | shares	19,388
Number of Options, Exercised | shares	(2,562)
Number of Options, Forfeited | shares	(16,935)
Number of Options, Outstanding, Ending balance | shares	18,915	19,024
Number of Options, Vested and expected to vest | shares	18,870
Number of Options, Exercisable | shares	12,560
Weighted-Average Exercise Price, Outstanding, Beginning balance | $ / shares	$ 5.77
Weighted-Average Exercise Price, Granted | $ / shares	2.46
Weighted-Average Exercise Price, Exercised | $ / shares	2.29
Weighted-Average Exercise Price, Forfeited | $ / shares	6.24
Weighted-Average Exercise Price, Outstanding, Ending balance | $ / shares	2.43	$ 5.77
Weighted-Average Exercise Price, Vested and expected to vest | $ / shares	2.43
Weighted-Average Exercise Price, Exercisable | $ / shares	$ 2.81
Weighted-Average Remaining Contractual Term	5 years 10 months 14 days	5 years 11 months 19 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest	5 years 10 months 10 days
Weighted-Average Remaining Contractual Term, Exercisable	3 years 11 months 23 days
Aggregate Intrinsic Value, Outstanding | $	$ 440	$ 7,564
Aggregate Intrinsic Value, Vested and expected to vest | $	440
Aggregate Intrinsic Value, Exercisable | $	$ 440

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jul. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Preferred stock issued		0		0	0
Silver Creek [Member]
Subsequent Event [Line Items]
Net cash proceeds from stock issuance				$ 2,599
Ownership interest percentage held by parent and its de facto agents		51.00%		51.00%
Silver Creek [Member] | Series C Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock issued		400	1,400	400
Preferred stock price per share		$ 1.50	$ 1.50	$ 1.50
Net cash proceeds from stock issuance		$ 600	$ 2,000
Silver Creek [Member] | Series C Preferred Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Preferred stock issued	1,700
Preferred stock price per share	$ 1.50
Net cash proceeds from stock issuance	$ 2,600