Puma Biotechnology (PBYI) 10-Q 7 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 01, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	PBYI
Entity Registrant Name	PUMA BIOTECHNOLOGY, INC.
Entity Central Index Key	0001401667
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		38,960,995
Entity File Number	001-35703
Entity Tax Identification Number	77-0683487
Entity Address, Address Line One	10880 Wilshire Boulevard
Entity Address, Address Line Two	Suite 2150
Entity Address, City or Town	Los Angeles
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90024
City Area Code	424
Local Phone Number	248-6500
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 58,904	$ 108,419
Marketable securities	51,535	57,002
Accounts receivable, net	27,182	20,773
Inventory, net	3,123	2,625
Prepaid expenses, current	9,990	12,397
Deferred rent	39
Other current assets	322	1,787
Total current assets	151,095	203,003
Lease right-of-use assets, net	20,194
Property and equipment, net	3,204	3,963
Intangible assets, net	41,447	44,408
Restricted cash	13,173	4,319
Prepaid expenses and other, long-term	2,931	3,429
Total assets	232,044	259,122
Current liabilities:
Accounts payable	9,056	20,684
Accrued expenses	76,771	46,431
Lease liabilities	2,516
Total current liabilities	88,343	67,115
Deferred rent		5,815
Lease liabilities, long-term	23,336
Post-marketing commitment liability	9,000
Long-term debt	94,185	151,886
Total liabilities	214,864	224,816
Stockholders' equity:
Common stock - $.0001 par value per share; 100,000,000 shares authorized; 38,943,774 shares issued and outstanding at September 30, 2019 and 38,325,037 issued and outstanding at December 31, 2018	4	4
Additional paid-in capital	1,283,498	1,236,355
Accumulated other comprehensive income (loss)	115	(12)
Accumulated deficit	(1,266,437)	(1,202,041)
Total stockholders' equity	17,180	34,306
Total liabilities and stockholders' equity	$ 232,044	$ 259,122

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	38,943,774	38,325,037
Common stock, shares outstanding	38,943,774	38,325,037

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue:
Total revenue	$ 56,352	$ 62,629	$ 209,338	$ 179,912
Operating costs and expenses:
Cost of sales	9,371	9,048	26,673	24,262
Selling, general and administrative	31,402	28,502	110,435	105,239
Research and development	30,027	36,360	102,610	126,529
Total operating costs and expenses	70,800	73,910	239,718	256,030
Loss from operations	(14,448)	(11,281)	(30,380)	(76,118)
Other income (expenses):
Interest income	569	590	2,349	1,093
Interest expense	(3,052)	(3,499)	(11,943)	(7,165)
Legal verdict expense			(16,350)
Loss on debt extinguishment			(8,103)
Other income (expenses):	46	(11)	31	(690)
Total other expenses:	(2,437)	(2,920)	(34,016)	(6,762)
Net loss	(16,885)	(14,201)	(64,396)	(82,880)
Net loss applicable to common stockholders	$ (16,885)	$ (14,201)	$ (64,396)	$ (82,880)
Net loss per share of common stock—basic and diluted	$ (0.44)	$ (0.37)	$ (1.67)	$ (2.19)
Weighted-average shares of common stock outstanding—basic and diluted	38,893,757	38,043,174	38,675,961	37,855,249
Product Revenue, Net
Revenue:
Total revenue	$ 53,482	$ 52,629	$ 152,913	$ 139,412
License Revenue
Revenue:
Total revenue	2,750	$ 10,000	56,250	$ 40,500
Royalty Revenue
Revenue:
Total revenue	$ 120		$ 175

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (16,885)	$ (14,201)	$ (64,396)	$ (82,880)
Other comprehensive loss
Unrealized gain (loss) on available-for-sale securities	15	(2)	115	(3)
Reclassifications of (gain) loss on available-for-sale securities	(10)		12
Comprehensive loss	$ (16,880)	$ (14,203)	$ (64,269)	$ (82,883)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Receivables from Exercises of Options	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2017	$ 53,302	$ 4	$ 1,142,213	$ (449)		$ (1,088,466)
Beginning Balance (in shares) at Dec. 31, 2017		37,594,851
Stock-based compensation	68,343		68,343
Shares issued or restricted stock units vested under employee stock plans	7,151		6,702	449
Shares issued or RSUs vested under employee stock plans (in shares)		530,271
Unrealized gain (loss) on available-for-sale securities	(3)				$ (3)
Net loss	(82,880)					(82,880)
Ending Balance at Sep. 30, 2018	45,913	$ 4	1,217,258		(3)	(1,171,346)
Ending Balance (in shares) at Sep. 30, 2018		38,125,122
Beginning Balance at Jun. 30, 2018	38,299	$ 4	1,195,600	(159)	(1)	(1,157,145)
Beginning Balance (in shares) at Jun. 30, 2018		37,890,220
Stock-based compensation	20,807		20,807
Shares issued or restricted stock units vested under employee stock plans	1,010		851	$ 159
Shares issued or RSUs vested under employee stock plans (in shares)		234,902
Unrealized gain (loss) on available-for-sale securities	(2)				(2)
Net loss	(14,201)					(14,201)
Ending Balance at Sep. 30, 2018	45,913	$ 4	1,217,258		(3)	(1,171,346)
Ending Balance (in shares) at Sep. 30, 2018		38,125,122
Beginning Balance at Dec. 31, 2018	$ 34,306	$ 4	1,236,355		(12)	(1,202,041)
Beginning Balance (in shares) at Dec. 31, 2018	38,325,037	38,325,037
Stock-based compensation	$ 45,791		45,791
Shares issued or restricted stock units vested under employee stock plans	1,352		1,352
Shares issued or RSUs vested under employee stock plans (in shares)		618,737
Unrealized gain (loss) on available-for-sale securities	127				127
Net loss	(64,396)					(64,396)
Ending Balance at Sep. 30, 2019	$ 17,180	$ 4	1,283,498		115	(1,266,437)
Ending Balance (in shares) at Sep. 30, 2019	38,943,774	38,943,774
Beginning Balance at Jun. 30, 2019	$ 21,771	$ 4	1,271,209		110	(1,249,552)
Beginning Balance (in shares) at Jun. 30, 2019		38,738,707
Stock-based compensation	12,213		12,213
Shares issued or restricted stock units vested under employee stock plans	76		76
Shares issued or RSUs vested under employee stock plans (in shares)		205,067
Unrealized gain (loss) on available-for-sale securities	5				5
Net loss	(16,885)					(16,885)
Ending Balance at Sep. 30, 2019	$ 17,180	$ 4	$ 1,283,498		$ 115	$ (1,266,437)
Ending Balance (in shares) at Sep. 30, 2019	38,943,774	38,943,774

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Net loss	$ (64,396)	$ (82,880)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	6,178	5,279
Stock-based compensation	45,791	68,343
Disposal of property and equipment	54
Loss on debt extinguishment	8,047
Debt modification fees		289
Changes in operating assets and liabilities:
Accounts receivable, net	(6,409)	(10,080)
Inventory	(498)	(803)
Prepaid expenses and other	2,905	244
Other current assets	1,465	(11,495)
Accounts payable	(11,628)	(11,388)
Accrued expenses	30,340	10,869
Deferred rent	(39)	470
Post-marketing commitment liability	9,000
Net cash provided by (used in) operating activities	20,810	(31,152)
Investing activities:
Purchase of property and equipment		(550)
Purchase of available-for-sale securities	(127,072)	(71,112)
Sale of available-for-sale securities	28,135
Maturity of available-for-sale securities	104,532	11,457
Net cash provided by (used in) investing activities	5,595	(60,205)
Financing activities:
Net proceeds from shares issued under employee stock plans	1,352	7,151
Proceeds from long-term debt	25,000	75,000
Payment of debt	(80,000)
Payment of debt extinguishment costs	(7,793)
Payment of debt issuance costs	(5,625)	(4,192)
Net cash (used in) provided by financing activities	(67,066)	77,959
Net decrease in cash, cash equivalents and restricted cash	(40,661)	(13,398)
Cash, cash equivalents and restricted cash, beginning of period	112,738	86,015
Cash, cash equivalents and restricted cash, end of period	72,077	72,617
Supplemental disclosures of non-cash investing and financing activities:
Property and equipment purchases in accounts payable		59
Supplemental disclosure of cash flow information:
Interest paid	$ 9,464	$ 5,134

Business and Basis of Presentat

Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business and Basis of Presentation	Note 1—Business and Basis of Presentation: Business: Puma Biotechnology, Inc., or the Company, is a biopharmaceutical company based in Los Angeles, California with a focus on the development and commercialization of innovative products to enhance cancer care. The Company has in-licensed the global development and commercialization rights to PB272 (neratinib (oral)), PB272 (neratinib (intravenous)) and PB357. Neratinib is a potent irreversible tyrosine kinase inhibitor that blocks signal transduction through the epidermal growth factor receptors HER1, HER2 and HER4. Currently, the Company is primarily focused on the U.S. commercialization of NERLYNX (neratinib), its first U.S. Food and Drug Administration, or FDA, approved product, and on the further development of the oral version of neratinib for additional indications in the treatment of HER2-positive breast cancer. The Company has two subsidiaries, Puma Biotechnology Ltd., a United Kingdom company, and Puma Biotechnology, B.V., a Netherlands company. These subsidiaries were established for the purpose of legal representation in the European Union. Basis of Presentation: The Company is focused on developing and commercializing neratinib for the treatment of patients with human epidermal growth factor receptor type 2, or HER2-positive, breast cancer, HER2 mutated breast cancer and non-small cell lung cancer, and other solid tumors that have an activating mutation in HER2. The Company has reported a net loss of approximately $16.9 million and $64.4 million for the three and nine months ended September 30, 2019, and cash flows from operations of approximately $20.8 million for the nine months ended September 30, 2019. The Company believes that it will continue to incur net losses and may incur negative net cash flows from operating activities through the drug development process and global commercialization. The Company has incurred significant operating losses since its inception. On July 17, 2017, the Company received FDA approval for its first product, NERLYNX® (neratinib), formerly known as PB272 (neratinib (oral)), for the extended adjuvant treatment of adult patients with early stage HER2-overexpressed/amplified breast cancer following adjuvant trastuzumab-based therapy. Following FDA approval in July 2017, NERLYNX became available by prescription in the United States, and the Company commenced commercialization. The Company in-licenses PB272 (neratinib (oral)), PB272 (neratinib (intravenous)) and PB357, as well as certain related compounds, Additionally, the Company has entered into exclusive license agreements with Specialised Therapeutics Asia Pte Ltd., or STA, Medison Pharma Ltd., or Medison, CANbridgepharma Limited, or CANbridge, Pint Pharma International SA, or Pint, and, most recently, Knight Therapeutics Inc., or Knight, and Pierre Fabre Medicament SAS, or Pierre Fabre, to pursue regulatory approval and/or commercialize NERLYNX, if approved, in various specified regions outside of the United States. The Company plans to continue to pursue commercialization of NERLYNX in additional countries outside the United States, if approved, and is evaluating various commercialization options in those countries, including developing a direct salesforce, contracting with third parties to provide sales and marketing capabilities, or some combination of these two options. In September 2018, the European Commission, or EC, granted marketing authorisation for NERLYNX for the extended adjuvant treatment of adult patients with early stage hormone receptor positive HER2-overexpressed/amplified breast cancer and who are less than one year from the completion of prior adjuvant trastuzumab based therapy. The Company’s commercialization, research and development, or R&D, or marketing efforts may require funding in addition to the cash and cash equivalents totaling approximately $58.9 million and marketable securities totaling approximately $51.5 million available at September 30, 2019. The Company believes that its existing cash and cash equivalents and marketable securities as of September 30, 2019 and proceeds that will become available to the Company through product sales and license payments are sufficient to satisfy its operating cash and needs for at least one year after the filing of the Quarterly Report on Form 10-Q. The Company continues to remain dependent on its ability to obtain sufficient funding to sustain operations and continue to successfully commercialize neratinib in the United States. While the Company has been successful in raising capital in the past, there can be no assurance that it will be able to do so in the future. The Company’s ability to obtain funding may be adversely impacted by uncertain market conditions, unfavorable decisions of regulatory authorities or adverse clinical trial results. The outcome of these matters cannot be predicted at this time. Since its inception through September 30, 2019, the Company’s financing has primarily been proceeds from product and license revenue, public offerings of its common stock, private equity placements, and borrowings under its loan and security agreement.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	Note 2—Significant Accounting Policies: The significant accounting policies followed in the preparation of these unaudited condensed consolidated financial statements are as follows: Financial Instruments: The carrying value of financial instruments, such as cash equivalents, accounts receivable and accounts payable, approximate their fair value because of their short-term nature. The carrying value of long-term debt approximates its fair value as the principal amounts outstanding are subject to variable interest rates that are based on market rates, which are regularly reset. Use of Estimates: The preparation of consolidated financial statements in conformity with Generally Accepted Accounting Principles, or GAAP, requires management to make estimates and assumptions that affect reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the date of the balance sheet, and reported amounts of expenses for the period presented. Accordingly, actual results could differ from those estimates. Significant estimates include estimates for variable consideration for which reserves were established. These estimates are included in the calculation of net revenues and include trade discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within contracts between the Company and its customers, payors, and other indirect customers relating to the Company’s sale of its products. Principles of Consolidation: The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Investment Securities: The Company classifies all investment securities (short-term and long-term) as available-for-sale, as the sale of such securities may be required prior to maturity to implement management’s strategies. These securities are carried at fair value, with the unrealized gains and losses, reported as a component of accumulated other comprehensive loss in stockholders’ equity until realized. Realized gains and losses from the sale of available-for-sale securities, if any, are determined on a specific identification basis. A decline in the market value of any available-for-sale security below cost that is determined to be other than temporary results in the revaluation of its carrying amount to fair value. The impairment is charged to earnings and a new cost basis for the security is established. Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the straight-line method. Interest income is recognized when earned. License Fees and Intangible Assets: The Company expenses amounts paid to acquire licenses associated with products under development when the ultimate recoverability of the amounts paid is uncertain and the technology has no alternative future use when acquired. Acquisitions of technology licenses are charged to expense or capitalized based upon the asset achieving technological feasibility in accordance with management’s assessment regarding the ultimate recoverability of the amounts paid and the potential for alternative future use. The Company has determined that technological feasibility for its product candidates is reached when the requisite regulatory approvals are obtained to make the product available for sale. The Company capitalizes technology licenses upon reaching technological feasibility. The Company maintains definite-lived intangible assets related to the Company’s license with Pfizer. These assets are amortized over their remaining useful lives, which are estimated based on the shorter of the remaining patent life or the estimated useful life of the underlying product. Intangible assets are amortized using the economic consumption method if anticipated future revenues can be reasonably estimated. The straight-line method is used when future revenues cannot be reasonably estimated. Amortization costs are recorded as part of cost of sales. The Company assesses its intangible assets for impairment if indicators are present or changes in circumstance suggest that impairment may exist. Events that could result in an impairment, or trigger an interim impairment assessment, include the receipt of additional clinical or nonclinical data regarding one of the Company’s drug candidates or a potentially competitive drug candidate, changes in the clinical development program for a drug candidate, or new information regarding potential sales of the drug. If impairment indicators are present or changes in circumstance suggest that impairment may exist, the Company performs a recoverability test by comparing the sum of the estimated undiscounted cash flows of each intangible asset to its carrying value on the consolidated balance sheet. If the undiscounted cash flows used in the recoverability test are less than the carrying value, the Company would determine the fair value of the intangible asset and recognize an impairment loss if the carrying value of the intangible asset exceeds its fair value. The FDA approval of NERLYNX in July 2017 triggered a one-time milestone payment pursuant to the Company’s license agreement with the Pfizer. The Company capitalized the milestone payment as an intangible asset and is amortizing the asset to cost of sales on a straight-line basis through 2030, the estimated useful life of the licensed patent. The Company recorded amortization expense related to its intangible asset of $1.0 million and $3.0 million for the three and nine months ended September 30, 2019, respectively. As of September 30, 2019, estimated future amortization expense related to the Company’s intangible asset was approximately $0.9 million for the remainder of 2019, approximately $3.9 million for each year starting 2020 through 2029, and approximately $1.0 million for 2030. Royalties: Royalties incurred in connection with the Company’s license agreement with Pfizer, as disclosed in Note 13 Commitments and Contingencies, are expensed to cost of sales as revenue from product sales is recognized. Leases: In February 2016, the FASB issued an accounting standards update which requires lessees to recognize most leases on the balance sheet with a corresponding right-of-use asset. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of fixed lease payments over the lease term. Leases will be classified as financing or operating which will drive the expense recognition pattern. For lessees, the income statement presentation and expense recognition pattern for financing and operating leases is similar to the current model for capital and operating leases, respectively. The Company has elected to exclude short-term leases. The update also requires additional disclosures that will better enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company adopted this guidance as of January 1, 2019, the required effective date, using the effective date transition method. As permitted under the effective date transition method, financial information and disclosure for periods prior to the date of initial application will not be updated. An adjustment to opening retained earnings was not required in conjunction with our adoption. For additional information, see Note 6 — The Company leases office space and copy machines, all of which are operating leases. Most leases include the option to renew and the exercise of the renewals options is at the Company’s sole discretion. Options to extend or terminate a lease are considered in the lease term to the extent that the option is reasonably certain of exercise. The leases do not include the options to purchase the leased property. The depreciable life of assets and leasehold improvements are limited by the expected lease term. Covenants imposed by the leases include letters of credit required to be obtained by the lessee. The incremental borrowing rate presents the rate of interest that the Company would expect to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. When determinable, the Company uses the rate implicit in the lease to determine the present value of lease payments. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company’s average incremental borrowing rate, or IBR, for existing leases on the transition date (January 1, 2019) was calculated as 10.9%. Inventory: The Company values its inventories at the lower of cost and estimated net realizable value. The Company determines the cost of its inventories, which includes amounts related to materials and manufacturing overhead, on a first-in, first-out basis. The Company performs an assessment of the recoverability of capitalized inventory during each reporting period, and it writes down any excess and obsolete inventories to their estimated net realizable value in the period in which the impairment is first identified. Such impairment charges, should they occur, are recorded within the cost of sales. The determination of whether inventory costs will be realizable requires estimates by management. If actual market conditions are less favorable than projected by management, additional write-downs of inventory may be required, which would be recorded as a cost of sales in the consolidated statements of operations and comprehensive loss. The Company capitalizes inventory costs associated with the Company’s products after regulatory approval, if any, when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. The Company previously expensed $4.5 million of product prior to receipt of marketing approval, which was recorded as R&D expense at the time it was incurred. Inventory that can be used in either the production of clinical or commercial product is recorded as R&D expense when selected for use in a clinical trial. Starter kits, provided to patients prior to insurance approval, are expensed by the Company to selling, general and administrative costs in the consolidated statements of operations and comprehensive loss as incurred. As of September 30, 2019, the Company’s inventory balance consisted primarily of raw materials purchased subsequent to FDA approval of NERLYNX. Revenue Recognition: The Company adopted ASC Topic 606 - Revenue from Contracts with Customers, or ASC 606, on January 1, 2017. This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements, and financial instruments. Under ASC 606, when its customer obtains control of the promised goods or services, an entity recognizes revenue in an amount that reflects the consideration which the entity expects to be entitled in exchange for those goods or services. The Company had no contracts with customers until after the FDA approved NERLYNX in July 2017. Subsequent to receiving FDA approval, the Company entered into a limited number of arrangements with specialty pharmacies and specialty distributors in the United States to distribute NERLYNX. These arrangements are the Company’s initial contracts with customers. The Company has determined that these sales channels with customers are similar. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identifies the contract(s) with a customer, (ii) identifies the performance obligations in the contract, (iii) determines the transaction price, (iv) allocates the transaction price to the performance obligations in the contract, and (v) recognizes revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to arrangements that meet the definition of a contract under ASC 606, including when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. For a complete discussion of accounting for product revenue, see Product Revenue, Net (below). Product Revenue, Net: The Company sells NERLYNX to a limited number of specialty pharmacies and specialty distributors in the United States. These customers subsequently resell the Company’s products to patients and certain medical centers or hospitals. In addition to distribution agreements with these customers, the Company enters into arrangements with health care providers and payors that provide for government mandated and/or privately negotiated rebates, chargebacks and discounts with respect to the purchase of the Company’s products. The Company recognizes revenue on product sales when the specialty pharmacy or specialty distributor, as applicable, obtains control of the Company's product, which occurs at a point in time (upon delivery). Product revenue is recorded net of applicable reserves for variable consideration, including discounts and allowances. The Company’s payment terms range between 10 and 68 days. Shipping and handling costs for product shipments occur prior to the customer obtaining control of the goods, and are recorded in cost of sales. If taxes should be collected from these customers relating to product sales and remitted to governmental authorities, they will be excluded from revenue. The Company expenses incremental costs of obtaining a contract when incurred, if the expected amortization period of the asset that the Company would have recognized is one year or less. However, no such costs were incurred during the three months ended September 30, 2019. Product revenue from customers who individually accounted for 10% or more of the Company’s total revenue for the three months ended September 30, 2019 consisted of the following, shown as a percentage of total revenue: Three Months Ended September 30, 2019 CVS/Caremark 36% Accredo/Acaria 21% License Revenue: The Company also recognizes license revenue under certain of the Company’s license agreements that are within the scope of ASC Topic 606. The terms of these agreements may contain multiple performance obligations, which may include licenses and research and development activities. The Company evaluates these agreements under ASC Topic 606 to determine the distinct performance obligations. Non-refundable, upfront fees that are not contingent on any future performance and require no consequential continuing involvement by the Company, are recognized as license revenue when the license term commences and the licensed data, technology or product is delivered. The Company defers recognition of non-refundable upfront license fees if the performance obligations are not satisfied. Prior to recognizing license revenue, the Company makes estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. If there are multiple distinct performance obligations, the Company allocates the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost plus margin. License revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations using an input measure. Knight Agreement During the first quarter of 2019, the Company entered into a license agreement, or the Knight Agreement, with Knight. Pursuant to the Knight Agreement, the Company granted to Knight, under certain of the Company’s intellectual property rights relating to neratinib, an exclusive, sublicensable (under certain circumstances) license (i) to commercialize any product containing neratinib and certain related compounds in Canada, (ii) to seek and maintain regulatory approvals for the licensed products in Canada and (iii) to manufacture the licensed products anywhere in the world solely for the development and commercialization of the licensed products in Canada for human use, subject to the terms of the Knight Agreement and the related supply agreement. During the first quarter of 2019, a non-refundable, upfront license fee was received and recognized as license revenue in accordance with ASC Topic 606. This license agreement met the contract existence criteria and contained distinct, identifiable performance obligations for which the stand-alone selling prices were readily determinable and allocable. As a separate promise under the terms of the license agreement, the Company is obligated to supply Knight with the licensed product in accordance with the supply agreement entered in connection with the license agreement. The Company is also obligated to participate in a Joint Steering Committee, which was identified as a separate performance obligation. To determine the stand-alone selling price, the Company This license agreement also includes potential future milestone and royalty payments due to the Company upon successful completion of certain separate, distinct performance obligations. At this time, the Company cannot estimate when these milestone-related performance obligations might be achieved. Pierre Fabre Agreement During the first quarter of 2019, the Company entered into a license agreement, or the Pierre Fabre Agreement, with Pierre Fabre Medicament SAS, or Pierre Fabre. The Pierre Fabre Agreement granted intellectual property rights and set forth the parties’ respective obligations with respect to development, commercialization and supply of the licensed product in European countries excluding Russia and Ukraine, along with countries in North Africa and francophone countries of West Africa. The Company satisfied the necessary performance obligations to recognize this license revenue under the terms of the arrangement. estimated the transaction prices, including any variable consideration, at contract inception and determined the fair value of such obligations based on similar arrangements. When determining the transaction prices, the Company assumed that the goods or services will be transferred to the customer based on the terms of the existing contract, and did not take into consideration the possibility of a contract being canceled, renewed, or modified. The Company noted there was approximately $9.0 million of additional variable consideration in this agreement related to a post-marketing commitment liability, while there were no significant financing components, non-cash consideration, or consideration payable to the customer. Pursuant to the Pierre Fabre Agreement, the Company will potentially receive additional regulatory and commercial milestone payments totaling up to $345 million. In addition, the Company will receive double-digit royalties on NERLYNX sales throughout the territory covered by the . Pint Agreement During the first quarter of 2018, the Company entered into a license agreement, or the Pint Agreement, with Pint. The Pint Agreement granted intellectual property rights and set forth the respective obligations with respect to development, commercialization and supply of NERLYNX in Mexico and 21 countries and territories in Central and South America. The Pint Agreement includes potential future milestone and royalty payments due to the Company upon successful completion of certain performance obligations, such as achieving regulatory approvals. Pursuant to the Pint Agreement, the Company received an upfront payment of $10.0 million during the third quarter of 2018 and will potentially receive additional regulatory and commercial milestone payments totaling up to approximately $24.5 million, as well as double-digit royalties on NERLYNX sales throughout the territory covered by the Pint Agreement. During the third quarter of 2019, the Company achieved a certain development-based milestone, which satisfied a performance obligation necessary to recognize the associated license revenue. The payment associated with this license revenue is expected to be received from Pint during the third quarter of 2020. At this time, the Company cannot estimate when the remaining milestone-related performance obligations might be achieved. Royalty Revenue: Royalty revenue consists of consideration earned related to international sales of NERLYNX made by the Company’s in their respective territories. The Company recognizes royalty revenue when the performance obligations have been satisfied. Reserves for Variable Consideration: Revenue from product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established. Components of variable consideration include trade discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within contracts between the Company and its customers, payors, and other indirect customers relating to the Company’s sale of its products. These reserves, as detailed below, are based on the related sales, and are classified as reductions of accounts receivable or as a current liability. These estimates take into consideration a range of possible outcomes that are probability-weighted in accordance with the expected value method in ASC Topic 606 for relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. The amount of variable consideration that is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized under the contract will not occur in a future period. The Company’s analyses also contemplated application of the constraint in accordance with the guidance, under which it determined a material reversal of revenue would not occur in a future period for the estimates detailed below as of September 30, 2019 and, therefore, the transaction price was not reduced further during the quarter ended September 30, 2019. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. Trade Discounts and Allowances: The Company generally provides customers with discounts, which include incentive fees that are explicitly stated in the Company’s contracts and are recorded as a reduction of product revenue in the period the related product revenue is recognized. The reserve for discounts is established in the same period that the related product revenue is recognized, together with reductions to trade receivables, net on the consolidated balance sheets. In addition, the Company compensates its customers for sales order management, data, and distribution services. The Company has determined such services received to date are not distinct from the Company’s sale of products to its customers and, therefore, these payments have been recorded as a reduction of product revenue within the statement of operations and comprehensive loss through September 30, 2019. Product Returns: Consistent with industry practice, the Company offers the specialty pharmacies and specialty distributors that are its customers limited product return rights for damaged and expiring product, provided it is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of product revenue in the period the related product revenue is recognized, as well as a reduction to trade receivables, net on the consolidated balance sheets. The Company currently estimates product returns using available industry data and its own sales information, including its visibility into the inventory remaining in the distribution channel. The Company has experienced an insignificant amount of returns to date and believes that returns of its products will continue to be minimal. Provider Chargebacks and Discounts: Chargebacks for fees and discounts to providers represent the estimated obligations resulting from contractual commitments to sell products to qualified healthcare providers at prices lower than the list prices charged to its customers who directly purchase the product from the Company. Customers charge the Company for the difference between what they pay for the product and the ultimate selling price to the qualified healthcare providers. The reserve for chargebacks is established in the same period that the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Chargeback amounts are generally determined at the time of resale to the qualified healthcare provider by customers, and the Company generally issues payments for such amounts within a few weeks of the customer’s notification to the Company of the resale. Reserves for chargebacks consist of payments the Company expects to issue for units that remain in the distribution channel at each reporting period-end that the Company expects will be sold to qualified healthcare providers and chargebacks that customers have claimed, but for which the Company has not yet issued a payment . Government Rebates: The Company is subject to discount obligations under state Medicaid programs and Medicare. These reserves are recorded in the same period the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability, which is included in accrued expenses and other current liabilities on the consolidated balance sheets. The Company’s liability for these rebates consists of invoices received for claims from prior quarters that have not been paid or for which an invoice has not yet been received, estimates of claims for the current quarter, and estimates of future claims that will be made for product that has been recognized as revenue, but which remains in the distribution channel at the end of each reporting period. Payor Rebates: The Company contracts with certain private payor organizations, primarily insurance companies and pharmacy benefit managers, for the payment of rebates with respect to utilization of its products. The Company estimates these rebates and records such estimates in the same period the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Other Incentives: Other incentives the Company offers include voluntary patient assistance programs, such as the co-pay assistance program, which are intended to provide financial assistance to qualified commercially-insured patients with prescription drug co-payments required by payors. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to receive associated with product that has been recognized as revenue, but remains in the distribution channel at the end of each reporting period. The adjustments are recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability, which is included as a component of accrued expenses and other current liabilities on the consolidated balance sheets. Assets Measured at Fair Value on a Recurring Basis: ASC, 820, Fair Value Measurement Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets. Level 3: Valuations derived from valuation techniques in which one or more significant inputs are unobservable. Following are the major categories of assets measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018, using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3) (in thousands): September 30, 2019 Level 1 Level 2 Level 3 Total Cash equivalents $ 40,935 $ — $ — $ 40,935 Commercial paper — — — — Corporate bonds — 41,501 — 41,501 U.S. government securities 10,034 — — 10,034 Totals $ 50,969 $ 41,501 $ — $ 92,470 December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 83,329 $ 2,987 $ — $ 86,316 Commercial paper — 35,941 — 35,941 Corporate bonds — 18,077 — 18,077 U.S. government securities 2,984 — — 2,984 Totals $ 86,313 $ 57,005 $ — $ 143,318 The Company’s investments in commercial paper, corporate bonds and U.S. government securities are exposed to price fluctuations. The fair value measurements for commercial paper, corporate bonds and U.S. government securities are based upon the quoted prices of similar items in active markets multiplied by the number of securities owned. The following tables summarize the Company’s short-term investments (in thousands): Maturity Amortized Unrealized Estimated September 30, 2019 (in years) cost Gains Losses fair value Cash equivalents $ 40,935 $ — $ — $ 40,935 Commercial paper Less than 1 — — — — Corporate bonds Less than 1 41,396 105 — 41,501 U.S. government securities Less than 1 10,024 10 — 10,034 Totals $ 92,355 $ 115 $ — $ 92,470 Maturity Amortized Unrealized Estimated December 31, 2018 (in years) cost Gains Losses fair value Cash equivalents $ 86,316 $ — $ — $ 86,316 Commercial paper Less than 1 35,941 — — $ 35,941 Corporate bonds Less than 1 18,089 — (12 ) $ 18,077 U.S. government securities Less than 1 2,984 — — $ 2,984 Totals $ 143,330 $ — $ (12 ) $ 143,318 Concentration of Risk: Financial instruments, which potentially subject the Company to concentrations of credit risk, principally consist of cash and cash equivalents and accounts receivable. The Company’s cash and cash equivalents and restricted cash in excess of the Federal Deposit Insurance Corporation and the Securities Investor Protection Corporation insured limits at September 30, 2019, were approximately $75.7 million. The Company does not believe it is exposed to any significant credit risk due to the nature of the financial instruments in which the money is held. Pursuant to the Company’s internal investment policy, investments must be rated A-1/P-1 or better by Standard and Poor’s Rating Service and Moody’s Investors Service at the time of purchase. The Company sells its products in the United States primarily through specialty pharmacies and specialty distributors. Therefore, wholesale distributors and large pharmacy chains account for a large portion of it

Accounts Receivable, Net

Accounts Receivable, Net	9 Months Ended
	Sep. 30, 2019
Accounts Receivable Net [Abstract]
Accounts Receivable, Net	Note 3—Accounts Receivable, Net: Accounts receivable, net consisted of the following (in thousands): September 30, 2019 December 31, 2018 Accounts receivable $ 24,682 $ 20,773 License revenue receivable 2,500 — Total accounts receivable, net $ 27,182 $ 20,773 Accounts receivable, net, consists entirely of amounts owed from our customers related to product sales. The license revenue receivable relates to amounts owed from Pint relating to license revenue recognized during the third quarter of 2019.

Prepaid Expenses and Other

Prepaid Expenses and Other	9 Months Ended
	Sep. 30, 2019
Banking And Thrift [Abstract]
Prepaid Expenses and Other	Note 4—Prepaid Expenses and Other: Prepaid expenses and other consisted of the following (in thousands): September 30, 2019 December 31, 2018 Current: CRO services $ 4,661 $ 5,824 Other clinical development 2,053 888 Insurance 407 2,446 Professional fees 597 272 Other 2,272 2,967 9,990 12,397 Long-term: CRO services 1,657 1,073 Other clinical development 7 650 Other 1,267 1,706 2,931 3,429 Totals $ 12,921 $ 15,826 Other prepaid amounts consist primarily of deposits, licenses, subscriptions, software and professional fees.

Other Current Assets

Other Current Assets	9 Months Ended
	Sep. 30, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Other Current Assets	Note 5—Other Current Assets: Other current assets consisted of the following (in thousands): September 30, 2019 December 31, 2018 Insurance receivable $ — $ 1,175 Other 322 612 Totals $ 322 $ 1,787 Other current asset amounts consist primarily of capitalized sublease commission and sublease tenant improvement allowances, net of amortization.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Note 6—Leases: Components of lease expense include fixed lease expense and variable lease expense of approximately $3.6 million and $0.3 million, respectively, for the nine months ended September 30, 2019. For purposes of determining straight-line rent expense, the lease term is calculated from the date the Company first takes possession of the facility, including any periods of free rent and any renewal option periods that the Company is reasonably certain of exercising. Our office and equipment leases generally have contractually specified minimum rent and annual rent increases are included in the measurement of the right-of-use asset and related lease liability. Additionally, under these lease arrangements, we may be required to pay directly, or reimburse the lessors, for real estate taxes, insurance, utilities, maintenance and other operating costs. Such amounts are generally variable and therefore not included in the measurement of the ROU asset and related lease liability but are instead recognized as variable lease expense in selling, general and administrative costs in the consolidated statements of operations and comprehensive loss when they are incurred. The Company recorded operating sublease income of $0.1 million for the three and nine months ended September 30, 2019 in other income in the consolidated statements of operations and comprehensive loss. Supplemental cash flow information related to leases for the nine months ended September 30, 2019: Operating cash flows from operating leases (in thousands) $ 4,050 Right-of-use assets obtained in exchange for new operating lease liabilities — Weighted average remaining lease term (in years) 6.5 Weighted average discount rate 10.9 % The maturity of lease liabilities as of September 30, 2019 were as follows (in thousands): Amount 2019 (remaining) $ 1,274 2020 5,207 2021 5,365 2022 5,483 2023 5,631 Thereafter 13,296 Total $ 36,256 Less: imputed interest (10,404 ) Total lease liabilities $ 25,852 The future minimum lease payments as of December 31, 2018 under ASC 840 were as follows (in thousands): Amount 2019 $ 4,924 2020 5,141 2021 5,300 2022 5,464 2023 5,631 Thereafter 13,296 Total $ 39,756

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	Note 7—Property and Equipment: Property and equipment consisted of the following (in thousands ): September 30, 2019 December 31, 2018 Leasehold improvements $ 3,780 $ 4,048 Computer equipment 2,367 2,402 Telephone equipment 340 343 Furniture and fixtures 2,346 2,346 8,833 9,139 Less: accumulated depreciation (5,629 ) (5,176 ) Totals $ 3,204 $ 3,963 For the three months and nine months ended September 30, 2019, the Company incurred depreciation expense of $0.2 million and $0.7 million, respectively.

Intangible Assets, Net

Intangible Assets, Net	9 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	Note 8—Intangible assets, net: Intangible assets, net consisted of the following (dollars in thousands): September 30, 2019 Estimated Useful Life Acquired and in-licensed rights $ 50,000 13 Years Less: accumulated amortization (8,553 ) Total intangible asset, net $ 41,447 For the three months and nine months ended September 30, 2019, the Company incurred amortization expense of $1.0 million and $3.0 million, respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	Note 9—Accrued Expenses: Accrued expenses consisted of the following (in thousands): September 30, 2019 December 31, 2018 Accrued legal verdict expense $ 31,350 $ 9,000 Accrued CRO services 13,923 10,187 Accrued royalties 8,040 9,162 Accrued variable consideration 6,406 3,818 Accrued compensation 3,569 4,435 Accrued professional fees 1,061 2,175 Accrued other clinical development 3,425 2,380 Accrued bonus 5,119 1,705 Accrued legal fees 886 1,379 Accrued manufacturing costs 1,095 788 Other 1,897 1,402 Totals $ 76,771 $ 46,431 Accrued CRO services, accrued other clinical development expenses, and accrued legal fees represent the Company’s estimates of such costs and are recognized as incurred. Accrued royalties represent royalties incurred in connection with the Company’s license agreement with Pfizer. Accrued compensation includes accrued commissions and accrued vacation, which is accrued at the rate the employee earns vacation and reduced as vacation is used by the employee. Accrued variable consideration represents estimates of adjustments to product revenue, net for which reserves are established. Accrued legal verdict expense represents an estimate of a range between $9.0 million and $18.0 million that may be owed to class action participants as a result of the recent jury verdict in Hsu v. Puma Biotechnology, Inc., Eshelman v. Puma Biotechnology, Inc., et al . Hsu Eshelman Hsu, All accrued expenses are adjusted in the period the actual costs become known.

Debt

Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt	Note 10—Debt: Long term debt consisted of the following at September 30, 2019 (dollars in thousands): September 30, 2019 Maturity Date Long term debt $ 100,000 June 1, 2024 Accretion of final interest payment 1,603 Less: deferred financing costs (7,418 ) Total long term debt, net $ 94,185 In October 2017, the Company entered into a loan and security agreement with Silicon Valley Bank, or SVB, as administrative agent, and the lenders party thereto from time to time, or the Original Lenders, including Oxford Finance LLC, or Oxford, and SVB. Pursuant to the terms of the credit facility provided for by the loan and security agreement, or the Original Credit Facility, the Company borrowed $50.0 million. In May 2018, the Company entered into an amendment to the loan and security agreement, which provided for an amended credit facility, or the Amended Credit Facility. Under the Amended Credit Facility, the Original Lenders agreed to make term loans available to the Company in an aggregate amount of $155.0 million, consisting of (i) an aggregate amount of $125.0 million, the proceeds of which, in part, were used to repay the $50.0 million borrowed under the Original Credit Facility, and (ii) an aggregate amount of $30.0 million that the Company drew in December 2018, which was available under the Amended Credit Facility as a result of achieving a specified minimum revenue milestone. The Company was in compliance with all applicable financial covenants during the entire term of the Amended Credit Facility. Prior to the amendment and restatement of the loan and security agreement in June 2019, which provided for a new credit facility, or the New Credit Facility, the term loans under the Amended Credit Facility bore interest at an annual rate equal to the greater of (i) 8.25% and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the month that immediately preceded the month in which the interest accrued, plus (b) 3.5%. The Company was required to make monthly interest-only payments on each term loan commencing on the first calendar day of the calendar month following the funding date of such term loan, and continuing on the first calendar day of each calendar month thereafter through July 1, 2020. Commencing on July 1, 2020, and continuing on the first calendar day of each calendar month thereafter, the Company would have been required to make consecutive equal monthly payments of principal, together with applicable interest, in arrears to each original lender, calculated pursuant to the Amended Credit Facility. All unpaid principal and accrued and unpaid interest with respect to each term loan would have been due and payable in full on May 1, 2023. Upon repayment of the term loans, the Company was also required to make a final payment to the Original Lenders equal to 7.5% of the original principal amount of term loans funded. The Company was also permitted to prepay the outstanding principal balance of any term loan under the Amended Credit Facility, in whole but not in part, subject to a prepayment fee of 3.0% of any amount prepaid if the prepayment were to occur through and including the first anniversary of the funding date of such term loan, 2.0% of any amount prepaid if the prepayment were to occur after the first anniversary of the funding date of such term loan through and including the second anniversary of the funding date of such term loan, and 1.0% of the amount prepaid if the prepayment were to occur after the second anniversary of the funding date of such term loan and prior to May 1, 2023. On June 28, 2019, or the Effective Date, the Company entered into the New Credit Facility with Oxford, as collateral agent, and the lenders party thereto from time to time, including Oxford, pursuant to which the Company repaid the $155.0 million outstanding under the Amended Credit Facility, as well as all applicable exit and prepayment fees owed to the Original Lenders under the Amended Credit Facility, using cash on hand and $100.0 million in new borrowings from the New Credit Facility. Under the New Credit Facility, the Company issued to Oxford new and/or replacement secured promissory notes in an aggregate principal amount for all such promissory notes of $100.0 million evidencing the New Credit Facility. No additional money remains available to the Company under the New Credit Facility. The New Credit Facility is secured by substantially all of the Company’s personal property other than its intellectual property. The Company also pledged 65% of the issued and outstanding capital stock of its subsidiaries, Puma Biotechnology Ltd. and Puma Biotechnology B.V. The New Credit Facility limits the Company’s ability to grant any interest in its intellectual property to certain permitted licenses and permitted encumbrances set forth in the agreement. The term loans under the New Credit Facility bear interest at an annual rate equal to the greater of (i) 9.0% and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue, plus (b) 3.5%. The Company is required to make monthly interest-only payments on each term loan under the New Credit Facility commencing on the first calendar day of the calendar month following the funding date of such term loan, and continuing on the first calendar day of each calendar month thereafter through August 1, 2021 or, the Amortization Date. Commencing on the Amortization Date, and continuing on the first calendar day of each calendar month thereafter, the Company will make consecutive equal monthly payments of principal, together with applicable interest, in arrears to each lender under the New Credit Facility, calculated pursuant to the New Credit Facility. All unpaid principal and accrued and unpaid interest with respect to each term loan under the New Credit Facility is due and payable in full on June 1, 2024, or the Maturity Date. Upon repayment of such term loans, the Company is also required to make a final payment to the lenders equal to 7.5% of the aggregate principal amount of such term loans outstanding as of the Effective Date. At the Company’s option, the Company may prepay the outstanding principal balance of any term loan in whole but not in part, subject to a prepayment fee of 3.0% of any amount prepaid if the prepayment occurs through and including the first anniversary of the funding date of such term loan, 2.0% of the amount prepaid if the prepayment occurs after the first anniversary of the funding date of such term loan through and including the second anniversary of the funding date of such term loan, and 1.0% of the amount prepaid if the prepayment occurs after the second anniversary of the funding date of such term loan and prior to the Maturity Date. The New Credit Facility includes affirmative and negative covenants applicable to the Company, its current subsidiary and any subsidiaries the Company creates in the future. The affirmative covenants include, among others, covenants requiring the Company to maintain its legal existence and governmental approvals, deliver certain financial reports, maintain insurance coverage and satisfy certain requirements regarding deposit accounts. The Company must also achieve certain product revenue targets , measured as of the last day of each fiscal quarter on a trailing year to date basis, for the periods ending June 30, 2019, September 30, 2019 and December 31, 2019. New minimum revenue levels will be established for each subsequent fiscal year by mutual agreement of the Company, Oxford, as collateral agent, and the new lenders . The negative covenants include, among others, restrictions on the Company’s transferring collateral, incurring additional indebtedness, engaging in mergers or acquisitions, paying dividends or making other distributions, making investments, creating liens, selling assets and suffering a change in control, in each case subject to certain exceptions. The New Credit Facility also includes events of default, the occurrence and continuation of which could cause interest to be charged at the rate that is otherwise applicable plus 5.0% and would provide Oxford, as collateral agent, with the right to exercise remedies against the Company and the collateral securing the New Credit Facility, including foreclosure against the property securing the New Credit Facility, including its cash. These events of default include, among other things, the Company’s failure to pay principal or interest due under the New Credit Facility, a breach of certain covenants under the New Credit Facility, the Company’s insolvency, a material adverse change, the occurrence of any default under certain other indebtedness in an amount greater than $500,000 and one or more judgments against the Company in an amount greater than $500,000 individually or in the aggregate that remains unsatisfied, unvacated, or unstayed for a period of 10 days after its entry. As of September 30, 2019, there was $100.0 million in term loans outstanding under the New Credit Facility, representing all of the Company’s long-term debt outstanding as of that date, and the Company was in compliance with all applicable covenants under the New Credit Facility.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Stockholders' Equity	Note 11—Stockholders’ Equity: Common Stock: The Company issued 87,625 and 187,754 Authorized Shares: The Company has 100,000,000 shares of stock authorized for issuance, all of which Warrants: In October 2011, the Company issued an anti-dilutive warrant to Alan Auerbach, the Company’s founder and chief executive officer. The warrant was issued to provide Mr. Auerbach with the right to maintain ownership of at least 20% of the Company’s common stock in the event that the Company raised capital through the sale of its securities in the future. In connection with the closing of a public offering in October 2012, the exercise price and number of shares underlying the warrant issued to Mr. Auerbach were established and, accordingly, the final value of the warrant became fixed. Pursuant to the terms of the warrant, Mr. Auerbach may exercise the warrant to acquire 2,116,250 shares of the Company’s common stock at $16 per share until October 4, 2021. Stock Options and Restricted Stock Units: The Company’s 2011 Incentive Award Plan, as amended, or the 2011 Plan, was adopted by the Company’s board of directors on September 15, 2011. Pursuant to the 2011 Plan, the Company may grant incentive stock options and nonqualified stock options, as well as other forms of equity-based compensation. Incentive stock options may be granted only to employees, while consultants, employees, officers and directors are eligible for the grant of nonqualified options under the 2011 Plan. The maximum term of stock options granted under the 2011 Plan is 10 years. The exercise price of incentive stock options granted under the 2011 Plan must be at least equal to the fair value of such shares on the date of grant. Through September 30, 2019, a total of 12,529,412 shares of the Company’s common stock had been reserved for issuance under the 2011 Plan. As of September 30, 2019, 6,146,363 shares of the Company’s common stock are issuable upon the exercise of outstanding awards granted under the 2011 Plan and 2,801,058 shares of the Company’s common stock are available for future issuance under the 2011 Plan. The fair value of options granted to employees was estimated using the Black-Scholes Option Pricing Method (see Note 2) with the following weighted-average assumptions used during the nine months ended September 30, 2019 and 2018: 2019 2018 Dividend yield 0.0 % 0.0 % Expected volatility 99.9 % 95.5 % Risk-free interest rate 2.5 % 2.5 % Expected life in years 5.76 5.85 The Company’s 2017 Employment Inducement Incentive Award Plan, or the 2017 Plan, was adopted by the Company’s Board of Directors on April 27, 2017. Pursuant to the 2017 Plan, the Company may grant stock options and RSUs, as well as other forms of equity-based compensation to employees, as an inducement to join the Company. The maximum term of stock options granted under the 2017 Plan is 10 years. The exercise price of stock options granted under the 2017 Plan must be at least equal to the fair market value of such shares on the date of grant. As of September 30, 2019, a total of 1,000,000 shares of the Company’s common stock have been reserved for issuance under the 2017 Plan. As of September 30, 2019, 565,645 shares have been awarded under the 2017 Plan. Stock-based compensation was as follows for the three and nine months ended September 30 (in thousands): For the Three Months Ended For the Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Stock-based compensation: Options - Selling, general, and administrative $ 1,768 $ 3,132 $ 6,706 $ 11,721 Research and development 1,786 5,387 6,001 22,689 Restricted stock units - Selling, general, and administrative 3,832 6,280 16,221 15,228 Research and development 4,827 6,008 16,863 18,705 Total stock-based compensation expense $ 12,213 $ 20,807 $ 45,791 $ 68,343 Activity with respect to options granted under the 2011 Plan and 2017 Plan is summarized as follows: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2018 5,708,544 $ 87.49 6.1 $ 7,762 Granted 129,734 $ 27.76 9.4 Forfeited (69,969 ) $ 40.50 Exercised (87,625 ) $ 15.42 $ 995 Expired (603,918 ) $ 102.39 Outstanding at September 30, 2019 5,076,766 $ 86.08 5.4 $ 2,450 Nonvested at September 30, 2019 396,948 $ 39.99 8.6 At September 30, 2019, total estimated unrecognized employee compensation cost related to non-vested stock options granted prior to that date was approximately $10.0 million, which is expected to be recognized over a weighted-average period of 1.4 years. At September 30, 2019, the total estimated unrecognized employee compensation cost related to non-vested RSUs was approximately $48.8 million, which is expected to be recognized over a weighted-average period of 1.6 years. The weighted-average grant date fair value of options granted during the nine months ended September 30, 2019 and 2018 was $21.82 and $56.46 per share, respectively. The weighted average grant date fair value of RSUs awarded during the nine months ended September 30, 2019 and 2018 was $20.36 and $62.11 per share, respectively. Stock Option Rollforward Stock options Shares Weighted Average Grant-Date Fair Value Nonvested shares at December 31, 2018 779,292 $ 33.75 Granted 129,734 21.82 Vested/Issued (442,109 ) 35.13 Forfeited (69,969 ) 25.06 Nonvested shares at September 30, 2019 396,948 $ 29.85 Restricted Stock Unit Rollforward Restricted stock units Shares Weighted Average Grant-Date Fair Value Nonvested shares at December 31, 2018 1,838,670 $ 60.08 Granted 776,730 20.36 Vested/Issued (531,112 ) 70.06 Forfeited (449,046 ) 53.02 Nonvested shares at September 30, 2019 1,635,242 $ 39.91

401(k) Savings Plan

401(k) Savings Plan	9 Months Ended
	Sep. 30, 2019
Postemployment Benefits [Abstract]
401(k) Savings Plan	Note 12—401(k) Savings Plan: The Company maintains a 401(k) savings plan for the benefit of its employees. The Company is required to make matching contributions to the 401(k) plan equal to 100% of the first 3% of wages deferred by each participating employee and 50% on the next 2% of wages deferred by each participating employee. The Company incurred expenses for employer matching contributions of approximately $1.2 million and $1.3 million

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13—Commitments and Contingencies: Contractual Obligations: Contractual obligations represent future cash commitments and liabilities under agreements with third parties, and exclude contingent liabilities for which the Company cannot reasonably predict future payment. The Company’s contractual obligations result primarily from obligations for various contract manufacturing organizations and clinical research organizations, which include potential payments we may be required to make under our agreements. The contracts also contain variable costs and milestones that are hard to predict as they are based on such things as patients enrolled and clinical trial sites. The timing of payments and actual amounts paid under contract manufacturing organization, or CMO, and CRO agreements may be different depending on the timing of receipt of goods or services or changes to agreed-upon terms or amounts for some obligations. Also, those agreements are cancelable upon written notice by the Company and, therefore, not long-term liabilities. License Agreement: In August 2011, the Company entered into an agreement pursuant to which Pfizer agreed to grant it a worldwide license for the development, manufacture and commercialization of PB272 neratinib (oral), PB272 neratinib (intravenous) and PB357, and certain related compounds. The license is exclusive with respect to certain patent rights owned by or licensed to Pfizer. Under the agreement, the Company is obligated to commence a new clinical trial for a product containing one of these compounds within a specified period of time and to use commercially reasonable efforts to complete clinical trials and to achieve certain milestones as provided in a development plan. From the closing date of the agreement through December 31, 2011, Pfizer continued to conduct the existing clinical trials on behalf of the Company at Pfizer’s sole expense. At the Company’s request, Pfizer has agreed to continue to perform certain services in support of the existing clinical trials at the Company’s expense. These services will continue through the completion of the transitioned clinical trials. The license agreement “capped” the out of pocket expense the Company would be responsible for completing the then existing clinical trials. All agreed upon costs incurred by the Company above the “cost cap” would be reimbursed by Pfizer. The Company exceeded the “cost cap” during the fourth quarter of 2012. In accordance with the license agreement, the Company billed Pfizer for agreed upon costs above the “cost cap” until December 31, 2013. On July 18, 2014, the Company entered into an amendment to the license agreement with Pfizer. The amendment amends the agreement to (1) reduce the royalty rate payable by the Company to Pfizer on sales of licensed products; (2) release Pfizer from its obligation to pay for certain out-of-pocket costs incurred or accrued on or after January 1, 2014 to complete certain ongoing clinical studies; and (3) provide that Pfizer and the Company will continue to cooperate to effect the transfer to the Company of certain records, regulatory filings, materials and inventory controlled by Pfizer as promptly as reasonably practicable. As consideration for the license, the Company is required to make substantial payments upon the achievement of certain milestones totaling approximately $187.5 million if all such milestones are achieved. In connection with the FDA approval of NERLYNX in July of 2017, the Company triggered a one-time milestone payment pursuant to the agreement. Should the Company commercialize any more of the compounds licensed from Pfizer or any products containing any of these compounds, the Company will be obligated to pay to Pfizer annual royalties at a fixed rate in the low-to-mid teens of net sales of all such products, subject to certain reductions and offsets in some circumstances. The Company’s royalty obligation continues, on a product-by-product and country-by-country basis, until the later of (1) the last to expire licensed patent covering the applicable licensed product in such country, or (2) the earlier of generic competition for such licensed product reaching a certain level in such country or expiration of a certain time period after first commercial sale of such licensed product in such country. In the event that the Company sublicenses the rights granted to the Company under the license agreement with Pfizer to a third party, the same milestone and royalty payments are required. The Company can terminate the license agreement at will, or for safety concerns, in each case upon specified advance notice. Legal Proceedings: The Company and certain of its executive officers were named as defendants in the lawsuits detailed below. The Company records a liability in the consolidated financial statements for loss contingencies when a loss is known or considered probable and the amount can be reasonably estimated. If the reasonable estimate of a known or probable loss is a range, and no amount within the range is a better estimate than any other, the minimum amount of the range is accrued. If a loss is reasonably possible but not known or probable, and can be reasonably estimated, the estimated loss or range of loss is disclosed. When determining the estimated loss or range of loss, significant judgment is required to estimate the amount and timing of a loss to be recorded. Currently, the Company has accrued estimated losses of $9 million related to Hsu v. Puma Biotechnology, Inc. Eshelman v. Puma Biotechnology, Inc., et al. Hsu v. Puma Biotechnology, Inc. On June 3, 2015, Hsingching Hsu, individually and on behalf of all others similarly situated, filed a class action lawsuit against the Company and certain of its executive officers in the United States District Court for the Central District of California (Case No. 8:15-cv-00865-AG-JCG). On October 16, 2015, lead plaintiff Norfolk Pension Fund filed a consolidated complaint on behalf of all persons who purchased the Company’s securities between July 22, 2014 and May 29, 2015. A trial on the claims relating to four statements alleged to have been false or misleading was held from January 15 to January 29, 2019. At trial, the jury found that three of the four challenged statements were not false or misleading, and thus found in the defendants’ favor on those claims. The jury found liability as to one statement and awarded a maximum of $4.50 per share in damages, which represents approximately 5% of the total claimed damages of $87.20 per share. The total amount of aggregate class-wide damages is uncertain and will be ascertained only after an extensive claims process and the exhaustion of any appeals. Trading models suggest that approximately ten million shares traded during the class period may be eligible to claim damages. Based on prior lawsuits, the Company believes that the number of stockholders who submit proof of claims sufficient to recover damages is typically in the range of 20% to 40% of the total eligible shares. Based on these assumptions, total damages after claims could range from $9 million to $18 million. It is also reasonably possible that the total damages will be higher than this estimate, however, at this time, the amount is not estimable. On September 9, 2019, the Court entered an order specifying the rate of prejudgment interest to be awarded on any valid claims at the 52-week Treasury Bill rate. The Court’s order also established a claims process, which is expected to take about twelve months. A final judgment has not been entered. Eshelman v. Puma Biotechnology, Inc., et al. In February 2016, Fredric N. Eshelman filed a lawsuit against the Company’s Chief Executive Officer and President, Alan H. Auerbach, and the Company in the United States District Court for the Eastern District of North Carolina (Case No. 7:16-cv-00018-D). The complaint generally alleged that Mr. Auerbach and the Company made defamatory statements regarding Dr. Eshelman in connection with a proxy contest. In May 2016, Dr. Eshelman filed a notice of voluntary dismissal of the claims against Mr. Auerbach. A trial on the remaining defamation claims against the Company took place from March 11 to March 15, 2019. At trial, the jury found the Company liable and awarded Dr. Eshelman $15.9 million in compensatory damages and $6.5 million in punitive damages. The plaintiff has since filed motions seeking attorneys’ fees and The Company estimates the high end of potential damages in the matter could be approximately $26.3 million; however, the actual amount of damages payable by the Company is still uncertain and will be ascertained only after completion of post-trial proceedings and the exhaustion of any appeals, and such amount could be greater than the amount of expense already recognized or the high end of the estimate.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Note 14—Subsequent Events: The Company noted no events or transactions subsequent to the balance-sheet date that would have a material effect on the financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Financial Instruments	Financial Instruments: The carrying value of financial instruments, such as cash equivalents, accounts receivable and accounts payable, approximate their fair value because of their short-term nature. The carrying value of long-term debt approximates its fair value as the principal amounts outstanding are subject to variable interest rates that are based on market rates, which are regularly reset.
Use of Estimates	Use of Estimates: The preparation of consolidated financial statements in conformity with Generally Accepted Accounting Principles, or GAAP, requires management to make estimates and assumptions that affect reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the date of the balance sheet, and reported amounts of expenses for the period presented. Accordingly, actual results could differ from those estimates. Significant estimates include estimates for variable consideration for which reserves were established. These estimates are included in the calculation of net revenues and include trade discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within contracts between the Company and its customers, payors, and other indirect customers relating to the Company’s sale of its products.
Principles of Consolidation	Principles of Consolidation: The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Investment Securities	Investment Securities: The Company classifies all investment securities (short-term and long-term) as available-for-sale, as the sale of such securities may be required prior to maturity to implement management’s strategies. These securities are carried at fair value, with the unrealized gains and losses, reported as a component of accumulated other comprehensive loss in stockholders’ equity until realized. Realized gains and losses from the sale of available-for-sale securities, if any, are determined on a specific identification basis. A decline in the market value of any available-for-sale security below cost that is determined to be other than temporary results in the revaluation of its carrying amount to fair value. The impairment is charged to earnings and a new cost basis for the security is established. Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the straight-line method. Interest income is recognized when earned.
License Fees and Intangible Assets	License Fees and Intangible Assets: The Company expenses amounts paid to acquire licenses associated with products under development when the ultimate recoverability of the amounts paid is uncertain and the technology has no alternative future use when acquired. Acquisitions of technology licenses are charged to expense or capitalized based upon the asset achieving technological feasibility in accordance with management’s assessment regarding the ultimate recoverability of the amounts paid and the potential for alternative future use. The Company has determined that technological feasibility for its product candidates is reached when the requisite regulatory approvals are obtained to make the product available for sale. The Company capitalizes technology licenses upon reaching technological feasibility. The Company maintains definite-lived intangible assets related to the Company’s license with Pfizer. These assets are amortized over their remaining useful lives, which are estimated based on the shorter of the remaining patent life or the estimated useful life of the underlying product. Intangible assets are amortized using the economic consumption method if anticipated future revenues can be reasonably estimated. The straight-line method is used when future revenues cannot be reasonably estimated. Amortization costs are recorded as part of cost of sales. The Company assesses its intangible assets for impairment if indicators are present or changes in circumstance suggest that impairment may exist. Events that could result in an impairment, or trigger an interim impairment assessment, include the receipt of additional clinical or nonclinical data regarding one of the Company’s drug candidates or a potentially competitive drug candidate, changes in the clinical development program for a drug candidate, or new information regarding potential sales of the drug. If impairment indicators are present or changes in circumstance suggest that impairment may exist, the Company performs a recoverability test by comparing the sum of the estimated undiscounted cash flows of each intangible asset to its carrying value on the consolidated balance sheet. If the undiscounted cash flows used in the recoverability test are less than the carrying value, the Company would determine the fair value of the intangible asset and recognize an impairment loss if the carrying value of the intangible asset exceeds its fair value. The FDA approval of NERLYNX in July 2017 triggered a one-time milestone payment pursuant to the Company’s license agreement with the Pfizer. The Company capitalized the milestone payment as an intangible asset and is amortizing the asset to cost of sales on a straight-line basis through 2030, the estimated useful life of the licensed patent. The Company recorded amortization expense related to its intangible asset of $1.0 million and $3.0 million for the three and nine months ended September 30, 2019, respectively. As of September 30, 2019, estimated future amortization expense related to the Company’s intangible asset was approximately $0.9 million for the remainder of 2019, approximately $3.9 million for each year starting 2020 through 2029, and approximately $1.0 million for 2030.
Royalties	Royalties: Royalties incurred in connection with the Company’s license agreement with Pfizer, as disclosed in Note 13 Commitments and Contingencies, are expensed to cost of sales as revenue from product sales is recognized.
Leases	Leases: In February 2016, the FASB issued an accounting standards update which requires lessees to recognize most leases on the balance sheet with a corresponding right-of-use asset. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the estimated present value of fixed lease payments over the lease term. Leases will be classified as financing or operating which will drive the expense recognition pattern. For lessees, the income statement presentation and expense recognition pattern for financing and operating leases is similar to the current model for capital and operating leases, respectively. The Company has elected to exclude short-term leases. The update also requires additional disclosures that will better enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company adopted this guidance as of January 1, 2019, the required effective date, using the effective date transition method. As permitted under the effective date transition method, financial information and disclosure for periods prior to the date of initial application will not be updated. An adjustment to opening retained earnings was not required in conjunction with our adoption. For additional information, see Note 6 — The Company leases office space and copy machines, all of which are operating leases. Most leases include the option to renew and the exercise of the renewals options is at the Company’s sole discretion. Options to extend or terminate a lease are considered in the lease term to the extent that the option is reasonably certain of exercise. The leases do not include the options to purchase the leased property. The depreciable life of assets and leasehold improvements are limited by the expected lease term. Covenants imposed by the leases include letters of credit required to be obtained by the lessee. The incremental borrowing rate presents the rate of interest that the Company would expect to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. When determinable, the Company uses the rate implicit in the lease to determine the present value of lease payments. As the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company’s average incremental borrowing rate, or IBR, for existing leases on the transition date (January 1, 2019) was calculated as 10.9%.
Inventory	Inventory: The Company values its inventories at the lower of cost and estimated net realizable value. The Company determines the cost of its inventories, which includes amounts related to materials and manufacturing overhead, on a first-in, first-out basis. The Company performs an assessment of the recoverability of capitalized inventory during each reporting period, and it writes down any excess and obsolete inventories to their estimated net realizable value in the period in which the impairment is first identified. Such impairment charges, should they occur, are recorded within the cost of sales. The determination of whether inventory costs will be realizable requires estimates by management. If actual market conditions are less favorable than projected by management, additional write-downs of inventory may be required, which would be recorded as a cost of sales in the consolidated statements of operations and comprehensive loss. The Company capitalizes inventory costs associated with the Company’s products after regulatory approval, if any, when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. The Company previously expensed $4.5 million of product prior to receipt of marketing approval, which was recorded as R&D expense at the time it was incurred. Inventory that can be used in either the production of clinical or commercial product is recorded as R&D expense when selected for use in a clinical trial. Starter kits, provided to patients prior to insurance approval, are expensed by the Company to selling, general and administrative costs in the consolidated statements of operations and comprehensive loss as incurred. As of September 30, 2019, the Company’s inventory balance consisted primarily of raw materials purchased subsequent to FDA approval of NERLYNX.
Revenue Recognition	Revenue Recognition: The Company adopted ASC Topic 606 - Revenue from Contracts with Customers, or ASC 606, on January 1, 2017. This standard applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements, and financial instruments. Under ASC 606, when its customer obtains control of the promised goods or services, an entity recognizes revenue in an amount that reflects the consideration which the entity expects to be entitled in exchange for those goods or services. The Company had no contracts with customers until after the FDA approved NERLYNX in July 2017. Subsequent to receiving FDA approval, the Company entered into a limited number of arrangements with specialty pharmacies and specialty distributors in the United States to distribute NERLYNX. These arrangements are the Company’s initial contracts with customers. The Company has determined that these sales channels with customers are similar. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identifies the contract(s) with a customer, (ii) identifies the performance obligations in the contract, (iii) determines the transaction price, (iv) allocates the transaction price to the performance obligations in the contract, and (v) recognizes revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to arrangements that meet the definition of a contract under ASC 606, including when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. For a complete discussion of accounting for product revenue, see Product Revenue, Net (below). Product Revenue, Net: The Company sells NERLYNX to a limited number of specialty pharmacies and specialty distributors in the United States. These customers subsequently resell the Company’s products to patients and certain medical centers or hospitals. In addition to distribution agreements with these customers, the Company enters into arrangements with health care providers and payors that provide for government mandated and/or privately negotiated rebates, chargebacks and discounts with respect to the purchase of the Company’s products. The Company recognizes revenue on product sales when the specialty pharmacy or specialty distributor, as applicable, obtains control of the Company's product, which occurs at a point in time (upon delivery). Product revenue is recorded net of applicable reserves for variable consideration, including discounts and allowances. The Company’s payment terms range between 10 and 68 days. Shipping and handling costs for product shipments occur prior to the customer obtaining control of the goods, and are recorded in cost of sales. If taxes should be collected from these customers relating to product sales and remitted to governmental authorities, they will be excluded from revenue. The Company expenses incremental costs of obtaining a contract when incurred, if the expected amortization period of the asset that the Company would have recognized is one year or less. However, no such costs were incurred during the three months ended September 30, 2019. Product revenue from customers who individually accounted for 10% or more of the Company’s total revenue for the three months ended September 30, 2019 consisted of the following, shown as a percentage of total revenue: Three Months Ended September 30, 2019 CVS/Caremark 36% Accredo/Acaria 21% License Revenue: The Company also recognizes license revenue under certain of the Company’s license agreements that are within the scope of ASC Topic 606. The terms of these agreements may contain multiple performance obligations, which may include licenses and research and development activities. The Company evaluates these agreements under ASC Topic 606 to determine the distinct performance obligations. Non-refundable, upfront fees that are not contingent on any future performance and require no consequential continuing involvement by the Company, are recognized as license revenue when the license term commences and the licensed data, technology or product is delivered. The Company defers recognition of non-refundable upfront license fees if the performance obligations are not satisfied. Prior to recognizing license revenue, the Company makes estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. If there are multiple distinct performance obligations, the Company allocates the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost plus margin. License revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations using an input measure. Knight Agreement During the first quarter of 2019, the Company entered into a license agreement, or the Knight Agreement, with Knight. Pursuant to the Knight Agreement, the Company granted to Knight, under certain of the Company’s intellectual property rights relating to neratinib, an exclusive, sublicensable (under certain circumstances) license (i) to commercialize any product containing neratinib and certain related compounds in Canada, (ii) to seek and maintain regulatory approvals for the licensed products in Canada and (iii) to manufacture the licensed products anywhere in the world solely for the development and commercialization of the licensed products in Canada for human use, subject to the terms of the Knight Agreement and the related supply agreement. During the first quarter of 2019, a non-refundable, upfront license fee was received and recognized as license revenue in accordance with ASC Topic 606. This license agreement met the contract existence criteria and contained distinct, identifiable performance obligations for which the stand-alone selling prices were readily determinable and allocable. As a separate promise under the terms of the license agreement, the Company is obligated to supply Knight with the licensed product in accordance with the supply agreement entered in connection with the license agreement. The Company is also obligated to participate in a Joint Steering Committee, which was identified as a separate performance obligation. To determine the stand-alone selling price, the Company This license agreement also includes potential future milestone and royalty payments due to the Company upon successful completion of certain separate, distinct performance obligations. At this time, the Company cannot estimate when these milestone-related performance obligations might be achieved. Pierre Fabre Agreement During the first quarter of 2019, the Company entered into a license agreement, or the Pierre Fabre Agreement, with Pierre Fabre Medicament SAS, or Pierre Fabre. The Pierre Fabre Agreement granted intellectual property rights and set forth the parties’ respective obligations with respect to development, commercialization and supply of the licensed product in European countries excluding Russia and Ukraine, along with countries in North Africa and francophone countries of West Africa. The Company satisfied the necessary performance obligations to recognize this license revenue under the terms of the arrangement. estimated the transaction prices, including any variable consideration, at contract inception and determined the fair value of such obligations based on similar arrangements. When determining the transaction prices, the Company assumed that the goods or services will be transferred to the customer based on the terms of the existing contract, and did not take into consideration the possibility of a contract being canceled, renewed, or modified. The Company noted there was approximately $9.0 million of additional variable consideration in this agreement related to a post-marketing commitment liability, while there were no significant financing components, non-cash consideration, or consideration payable to the customer. Pursuant to the Pierre Fabre Agreement, the Company will potentially receive additional regulatory and commercial milestone payments totaling up to $345 million. In addition, the Company will receive double-digit royalties on NERLYNX sales throughout the territory covered by the . Pint Agreement During the first quarter of 2018, the Company entered into a license agreement, or the Pint Agreement, with Pint. The Pint Agreement granted intellectual property rights and set forth the respective obligations with respect to development, commercialization and supply of NERLYNX in Mexico and 21 countries and territories in Central and South America. The Pint Agreement includes potential future milestone and royalty payments due to the Company upon successful completion of certain performance obligations, such as achieving regulatory approvals. Pursuant to the Pint Agreement, the Company received an upfront payment of $10.0 million during the third quarter of 2018 and will potentially receive additional regulatory and commercial milestone payments totaling up to approximately $24.5 million, as well as double-digit royalties on NERLYNX sales throughout the territory covered by the Pint Agreement. During the third quarter of 2019, the Company achieved a certain development-based milestone, which satisfied a performance obligation necessary to recognize the associated license revenue. The payment associated with this license revenue is expected to be received from Pint during the third quarter of 2020. At this time, the Company cannot estimate when the remaining milestone-related performance obligations might be achieved. Royalty Revenue: Royalty revenue consists of consideration earned related to international sales of NERLYNX made by the Company’s in their respective territories. The Company recognizes royalty revenue when the performance obligations have been satisfied. Reserves for Variable Consideration: Revenue from product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established. Components of variable consideration include trade discounts and allowances, product returns, provider chargebacks and discounts, government rebates, payor rebates, and other incentives, such as voluntary patient assistance, and other allowances that are offered within contracts between the Company and its customers, payors, and other indirect customers relating to the Company’s sale of its products. These reserves, as detailed below, are based on the related sales, and are classified as reductions of accounts receivable or as a current liability. These estimates take into consideration a range of possible outcomes that are probability-weighted in accordance with the expected value method in ASC Topic 606 for relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. The amount of variable consideration that is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized under the contract will not occur in a future period. The Company’s analyses also contemplated application of the constraint in accordance with the guidance, under which it determined a material reversal of revenue would not occur in a future period for the estimates detailed below as of September 30, 2019 and, therefore, the transaction price was not reduced further during the quarter ended September 30, 2019. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company will adjust these estimates, which would affect net product revenue and earnings in the period such variances become known. Trade Discounts and Allowances: The Company generally provides customers with discounts, which include incentive fees that are explicitly stated in the Company’s contracts and are recorded as a reduction of product revenue in the period the related product revenue is recognized. The reserve for discounts is established in the same period that the related product revenue is recognized, together with reductions to trade receivables, net on the consolidated balance sheets. In addition, the Company compensates its customers for sales order management, data, and distribution services. The Company has determined such services received to date are not distinct from the Company’s sale of products to its customers and, therefore, these payments have been recorded as a reduction of product revenue within the statement of operations and comprehensive loss through September 30, 2019. Product Returns: Consistent with industry practice, the Company offers the specialty pharmacies and specialty distributors that are its customers limited product return rights for damaged and expiring product, provided it is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of product revenue in the period the related product revenue is recognized, as well as a reduction to trade receivables, net on the consolidated balance sheets. The Company currently estimates product returns using available industry data and its own sales information, including its visibility into the inventory remaining in the distribution channel. The Company has experienced an insignificant amount of returns to date and believes that returns of its products will continue to be minimal. Provider Chargebacks and Discounts: Chargebacks for fees and discounts to providers represent the estimated obligations resulting from contractual commitments to sell products to qualified healthcare providers at prices lower than the list prices charged to its customers who directly purchase the product from the Company. Customers charge the Company for the difference between what they pay for the product and the ultimate selling price to the qualified healthcare providers. The reserve for chargebacks is established in the same period that the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Chargeback amounts are generally determined at the time of resale to the qualified healthcare provider by customers, and the Company generally issues payments for such amounts within a few weeks of the customer’s notification to the Company of the resale. Reserves for chargebacks consist of payments the Company expects to issue for units that remain in the distribution channel at each reporting period-end that the Company expects will be sold to qualified healthcare providers and chargebacks that customers have claimed, but for which the Company has not yet issued a payment . Government Rebates: The Company is subject to discount obligations under state Medicaid programs and Medicare. These reserves are recorded in the same period the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability, which is included in accrued expenses and other current liabilities on the consolidated balance sheets. The Company’s liability for these rebates consists of invoices received for claims from prior quarters that have not been paid or for which an invoice has not yet been received, estimates of claims for the current quarter, and estimates of future claims that will be made for product that has been recognized as revenue, but which remains in the distribution channel at the end of each reporting period. Payor Rebates: The Company contracts with certain private payor organizations, primarily insurance companies and pharmacy benefit managers, for the payment of rebates with respect to utilization of its products. The Company estimates these rebates and records such estimates in the same period the related product revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Other Incentives: Other incentives the Company offers include voluntary patient assistance programs, such as the co-pay assistance program, which are intended to provide financial assistance to qualified commercially-insured patients with prescription drug co-payments required by payors. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to receive associated with product that has been recognized as revenue, but remains in the distribution channel at the end of each reporting period. The adjustments are recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability, which is included as a component of accrued expenses and other current liabilities on the consolidated balance sheets.
Assets Measured at Fair Value on a Recurring Basis	Assets Measured at Fair Value on a Recurring Basis: ASC, 820, Fair Value Measurement Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets. Level 3: Valuations derived from valuation techniques in which one or more significant inputs are unobservable. Following are the major categories of assets measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018, using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3) (in thousands): September 30, 2019 Level 1 Level 2 Level 3 Total Cash equivalents $ 40,935 $ — $ — $ 40,935 Commercial paper — — — — Corporate bonds — 41,501 — 41,501 U.S. government securities 10,034 — — 10,034 Totals $ 50,969 $ 41,501 $ — $ 92,470 December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 83,329 $ 2,987 $ — $ 86,316 Commercial paper — 35,941 — 35,941 Corporate bonds — 18,077 — 18,077 U.S. government securities 2,984 — — 2,984 Totals $ 86,313 $ 57,005 $ — $ 143,318 The Company’s investments in commercial paper, corporate bonds and U.S. government securities are exposed to price fluctuations. The fair value measurements for commercial paper, corporate bonds and U.S. government securities are based upon the quoted prices of similar items in active markets multiplied by the number of securities owned. The following tables summarize the Company’s short-term investments (in thousands): Maturity Amortized Unrealized Estimated September 30, 2019 (in years) cost Gains Losses fair value Cash equivalents $ 40,935 $ — $ — $ 40,935 Commercial paper Less than 1 — — — — Corporate bonds Less than 1 41,396 105 — 41,501 U.S. government securities Less than 1 10,024 10 — 10,034 Totals $ 92,355 $ 115 $ — $ 92,470 Maturity Amortized Unrealized Estimated December 31, 2018 (in years) cost Gains Losses fair value Cash equivalents $ 86,316 $ — $ — $ 86,316 Commercial paper Less than 1 35,941 — — $ 35,941 Corporate bonds Less than 1 18,089 — (12 ) $ 18,077 U.S. government securities Less than 1 2,984 — — $ 2,984 Totals $ 143,330 $ — $ (12 ) $ 143,318
Concentration of Risk	Concentration of Risk: Financial instruments, which potentially subject the Company to concentrations of credit risk, principally consist of cash and cash equivalents and accounts receivable. The Company’s cash and cash equivalents and restricted cash in excess of the Federal Deposit Insurance Corporation and the Securities Investor Protection Corporation insured limits at September 30, 2019, were approximately $75.7 million. The Company does not believe it is exposed to any significant credit risk due to the nature of the financial instruments in which the money is held. Pursuant to the Company’s internal investment policy, investments must be rated A-1/P-1 or better by Standard and Poor’s Rating Service and Moody’s Investors Service at the time of purchase. The Company sells its products in the United States primarily through specialty pharmacies and specialty distributors. Therefore, wholesale distributors and large pharmacy chains account for a large portion of its trade receivables and net product revenue. The Company monitors the creditworthiness of its customers and has internal policies regarding customer credit limits. The Company estimates an allowance for doubtful accounts primarily based on the credit worthiness of its customers, historical payment patterns, aging of receivable balances and general economic conditions. The Company’s success depends on its ability to successfully commercialize NERLYNX. The Company currently has a single product with limited commercial sales experience, which makes it difficult to evaluate its current business, predict its future prospects and forecast financial performance and growth. The Company has invested a significant portion of its efforts and financial resources in the development and commercialization of the lead product, NERLYNX, and expects NERLYNX to constitute the vast majority of product revenue for the foreseeable future. The Company’s success depends on its ability to effectively commercialize NERLYNX. The Company relies exclusively on third parties to formulate and manufacture NERLYNX and its drug candidates. The commercialization of NERLYNX and any other drug candidates, if approved, could be stopped, delayed or made less profitable if those third parties fail to provide sufficient quantities of product or fail to do so at acceptable quality or price. The Company has no experience in drug formulation or manufacturing and does not intend to establish its own manufacturing facilities. The Company lacks the resources and expertise to formulate or manufacture NERLYNX or its drug candidates. While the drug candidates were being developed by Pfizer, both the drug substance and drug product were manufactured by third-party contractors. The Company is using the same third-party contractors to manufacture, supply, store and distribute drug supplies for clinical trials and the commercialization of NERLYNX. If the Company is unable to continue its relationships with one or more of these third-party contractors, it could experience delays in the development or commercialization efforts as it locates and qualifies new manufacturers.
Research and Development Expenses	Research and Development Expenses: R&D expenses are charged to operations as incurred. The major components of R&D costs include clinical manufacturing costs, clinical trial expenses, consulting and other third-party costs, salaries and employee benefits, stock-based compensation expense, supplies and materials, and allocations of various overhead costs. Clinical trial expenses include, but are not limited to, investigator fees, site costs, comparator drug costs, and clinical research organization, or CRO, costs. In the normal course of business, the Company contracts with third parties to perform various clinical trial activities in the ongoing development of potential products. The financial terms of these agreements are subject to negotiation and variations from contract to contract and may result in uneven payment flows. Payments under the contracts depend on factors such as the achievement of certain events, the successful enrollment of patients and the completion of portions of the clinical trial or similar conditions. The Company’s accruals for clinical trials are based on estimates of the services received and efforts expended pursuant to contracts with numerous clinical trial sites, cooperative groups and CROs. As actual costs become known, the Company adjusts its accruals in that period. In instances where the Company enters into agreements with third parties for clinical trials and other consulting activities, upfront amounts are recorded to prepaid expenses and other in the accompanying consolidated balance sheets and expensed as services are performed or as the underlying goods are delivered. If the Company does not expect the services to be rendered or goods to be delivered, any remaining capitalized amounts for non-refundable upfront payments are charged to expense immediately. Amounts due under such arrangements may be either fixed fee or fee for service, and may include upfront payments, monthly payments and payments upon the completion of milestones or receipt of deliverables. Costs related to the acquisition of technology rights and patents for which development work is still in process are charged to operations as incurred and considered a component of R&D costs.
Stock-Based Compensation	Stock-Based Compensation: Stock option awards: ASC 718, Compensation-Stock Compensation Restricted stock units: Restricted stock units, or RSUs, are valued on the grant date and the fair value of the RSUs is equal to the market price of the Company’s common stock on the grant date. The RSU expense is recognized over the requisite service period. When the requisite service period begins prior to the grant date (because the service inception date occurs prior to the grant date), the Company is required to begin recognizing compensation cost before there is a measurement date (i.e., the grant date). The service inception date is the beginning of the requisite service period. If the service inception date precedes the grant date, accrual of compensation cost for periods before the grant date shall be based on the fair value of the award at the reporting date. In the period in which the grant date occurs, cumulative compensation cost shall be adjusted to reflect the cumulative effect of measuring compensation cost based on fair value at the grant date rather than the fair value previously used at the service inception date (or any subsequent reporting date).
Income Taxes	Income Taxes: The Company follows ASC 740, Income Taxes, or ASC 740, which requires recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Under this method, deferred tax assets and liabilities are based on the differences between the consolidated financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the temporary differences are expected to be recovered or settled. The standard addresses the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the consolidated financial statements. Under ASC 740, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such a position should be measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. ASC 740 also provides guidance on de-recognition, classification, interest and penalties on income taxes, accounting in interim periods and requires increased disclosures. As of September 30, 2019, the Company has established a reserve of 20% of its R&D credit carryover balance.
Segment Reporting	Segment Reporting: Management has determined that the Company operates in one business segment, which is the development and commercialization of innovative drugs to enhance cancer care.
Net Loss per Common Share	Net Loss per Common Share: Basic net loss per share of common stock is computed by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during the periods presented, as required by ASC 260, Earnings per Share
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards: In February 2016, the FASB issued ASU No. 2016-02, Leases

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Product Revenues from Customers	Product revenue from customers who individually accounted for 10% or more of the Company’s total revenue for the three months ended September 30, 2019 consisted of the following, shown as a percentage of total revenue: Three Months Ended September 30, 2019 CVS/Caremark 36% Accredo/Acaria 21%
Assets Measured at Fair Value on Recurring Basis	Following are the major categories of assets measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018, using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3) (in thousands): September 30, 2019 Level 1 Level 2 Level 3 Total Cash equivalents $ 40,935 $ — $ — $ 40,935 Commercial paper — — — — Corporate bonds — 41,501 — 41,501 U.S. government securities 10,034 — — 10,034 Totals $ 50,969 $ 41,501 $ — $ 92,470 December 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 83,329 $ 2,987 $ — $ 86,316 Commercial paper — 35,941 — 35,941 Corporate bonds — 18,077 — 18,077 U.S. government securities 2,984 — — 2,984 Totals $ 86,313 $ 57,005 $ — $ 143,318
Summary of Short-term Investments	The following tables summarize the Company’s short-term investments (in thousands): Maturity Amortized Unrealized Estimated September 30, 2019 (in years) cost Gains Losses fair value Cash equivalents $ 40,935 $ — $ — $ 40,935 Commercial paper Less than 1 — — — — Corporate bonds Less than 1 41,396 105 — 41,501 U.S. government securities Less than 1 10,024 10 — 10,034 Totals $ 92,355 $ 115 $ — $ 92,470 Maturity Amortized Unrealized Estimated December 31, 2018 (in years) cost Gains Losses fair value Cash equivalents $ 86,316 $ — $ — $ 86,316 Commercial paper Less than 1 35,941 — — $ 35,941 Corporate bonds Less than 1 18,089 — (12 ) $ 18,077 U.S. government securities Less than 1 2,984 — — $ 2,984 Totals $ 143,330 $ — $ (12 ) $ 143,318

Accounts Receivable, Net (Table

Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 30, 2019
Accounts Receivable Net [Abstract]
Schedule of Accounts Receivable, Net	Accounts receivable, net consisted of the following (in thousands): September 30, 2019 December 31, 2018 Accounts receivable $ 24,682 $ 20,773 License revenue receivable 2,500 — Total accounts receivable, net $ 27,182 $ 20,773

Prepaid Expenses and Other (Tab

Prepaid Expenses and Other (Tables)	9 Months Ended
	Sep. 30, 2019
Banking And Thrift [Abstract]
Components of Prepaid Expenses and Other	Prepaid expenses and other consisted of the following (in thousands): September 30, 2019 December 31, 2018 Current: CRO services $ 4,661 $ 5,824 Other clinical development 2,053 888 Insurance 407 2,446 Professional fees 597 272 Other 2,272 2,967 9,990 12,397 Long-term: CRO services 1,657 1,073 Other clinical development 7 650 Other 1,267 1,706 2,931 3,429 Totals $ 12,921 $ 15,826

Other Current Assets (Tables)

Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Other Current Assets	Other current assets consisted of the following (in thousands): September 30, 2019 December 31, 2018 Insurance receivable $ — $ 1,175 Other 322 612 Totals $ 322 $ 1,787

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases for the nine months ended September 30, 2019: Operating cash flows from operating leases (in thousands) $ 4,050 Right-of-use assets obtained in exchange for new operating lease liabilities — Weighted average remaining lease term (in years) 6.5 Weighted average discount rate 10.9 %
Maturity of Lease Liabilities	The maturity of lease liabilities as of September 30, 2019 were as follows (in thousands): Amount 2019 (remaining) $ 1,274 2020 5,207 2021 5,365 2022 5,483 2023 5,631 Thereafter 13,296 Total $ 36,256 Less: imputed interest (10,404 ) Total lease liabilities $ 25,852
Future Minimum Lease Payments under ASC 840	The future minimum lease payments as of December 31, 2018 under ASC 840 were as follows (in thousands): Amount 2019 $ 4,924 2020 5,141 2021 5,300 2022 5,464 2023 5,631 Thereafter 13,296 Total $ 39,756

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	Property and equipment consisted of the following (in thousands ): September 30, 2019 December 31, 2018 Leasehold improvements $ 3,780 $ 4,048 Computer equipment 2,367 2,402 Telephone equipment 340 343 Furniture and fixtures 2,346 2,346 8,833 9,139 Less: accumulated depreciation (5,629 ) (5,176 ) Totals $ 3,204 $ 3,963

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets, Net	Intangible assets, net consisted of the following (dollars in thousands): September 30, 2019 Estimated Useful Life Acquired and in-licensed rights $ 50,000 13 Years Less: accumulated amortization (8,553 ) Total intangible asset, net $ 41,447

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses consisted of the following (in thousands): September 30, 2019 December 31, 2018 Accrued legal verdict expense $ 31,350 $ 9,000 Accrued CRO services 13,923 10,187 Accrued royalties 8,040 9,162 Accrued variable consideration 6,406 3,818 Accrued compensation 3,569 4,435 Accrued professional fees 1,061 2,175 Accrued other clinical development 3,425 2,380 Accrued bonus 5,119 1,705 Accrued legal fees 886 1,379 Accrued manufacturing costs 1,095 788 Other 1,897 1,402 Totals $ 76,771 $ 46,431

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Long Term Debt	Long term debt consisted of the following at September 30, 2019 (dollars in thousands): September 30, 2019 Maturity Date Long term debt $ 100,000 June 1, 2024 Accretion of final interest payment 1,603 Less: deferred financing costs (7,418 ) Total long term debt, net $ 94,185

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Fair Value Options Weighted-Average Assumptions	The fair value of options granted to employees was estimated using the Black-Scholes Option Pricing Method (see Note 2) with the following weighted-average assumptions used during the nine months ended September 30, 2019 and 2018: 2019 2018 Dividend yield 0.0 % 0.0 % Expected volatility 99.9 % 95.5 % Risk-free interest rate 2.5 % 2.5 % Expected life in years 5.76 5.85
Stock-based Compensation	Stock-based compensation was as follows for the three and nine months ended September 30 (in thousands): For the Three Months Ended For the Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Stock-based compensation: Options - Selling, general, and administrative $ 1,768 $ 3,132 $ 6,706 $ 11,721 Research and development 1,786 5,387 6,001 22,689 Restricted stock units - Selling, general, and administrative 3,832 6,280 16,221 15,228 Research and development 4,827 6,008 16,863 18,705 Total stock-based compensation expense $ 12,213 $ 20,807 $ 45,791 $ 68,343
Activity with Respect to Options Granted	Activity with respect to options granted under the 2011 Plan and 2017 Plan is summarized as follows: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2018 5,708,544 $ 87.49 6.1 $ 7,762 Granted 129,734 $ 27.76 9.4 Forfeited (69,969 ) $ 40.50 Exercised (87,625 ) $ 15.42 $ 995 Expired (603,918 ) $ 102.39 Outstanding at September 30, 2019 5,076,766 $ 86.08 5.4 $ 2,450 Nonvested at September 30, 2019 396,948 $ 39.99 8.6
Stock Options	The weighted-average grant date fair value of options granted during the nine months ended September 30, 2019 and 2018 was $21.82 and $56.46 per share, respectively. Stock options Shares Weighted Average Grant-Date Fair Value Nonvested shares at December 31, 2018 779,292 $ 33.75 Granted 129,734 21.82 Vested/Issued (442,109 ) 35.13 Forfeited (69,969 ) 25.06 Nonvested shares at September 30, 2019 396,948 $ 29.85
Restricted Stock Units	The weighted average grant date fair value of RSUs awarded during the nine months ended September 30, 2019 and 2018 was $20.36 and $62.11 per share, Restricted stock units Shares Weighted Average Grant-Date Fair Value Nonvested shares at December 31, 2018 1,838,670 $ 60.08 Granted 776,730 20.36 Vested/Issued (531,112 ) 70.06 Forfeited (449,046 ) 53.02 Nonvested shares at September 30, 2019 1,635,242 $ 39.91

Business and Basis of Present_2

Business and Basis of Presentation - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)Subsidiary	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of subsidiaries | Subsidiary			2
Net loss	$ (16,885)	$ (14,201)	$ (64,396)	$ (82,880)
Net cash used in operating activities			20,810	$ (31,152)
Cash and cash equivalents	58,904		58,904		$ 108,419
Marketable securities	$ 51,535		$ 51,535		$ 57,002

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)shares	Sep. 30, 2018USD ($)shares	Sep. 30, 2019USD ($)Segmentshares	Sep. 30, 2018shares	Jan. 01, 2019
Significant Accounting Policies [Line Items]
Amortization expenses related to intangible assets	$ 1,000,000		$ 3,000,000
Estimated future amortization expense related to intangible assets, remainder of 2019	900,000		900,000
Estimated future amortization expense related to intangible assets, 2020	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2021	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2022	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2023	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2024	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2025	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2026	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2027	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2028	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2029	3,900,000		3,900,000
Estimated future amortization expense related to intangible assets, 2030	1,000,000		$ 1,000,000
Lessee, operating lease, existence of option to extend			true
Lessee, operating lease, option to extend, descrption			Options to extend or terminate a lease are considered in the lease term to the extent that the option is reasonably certain of exercise.
Lessee, operating lease, existence of option to terminate			true
Lessee, operating lease, option to terminate, description			Options to extend or terminate a lease are considered in the lease term to the extent that the option is reasonably certain of exercise.
Average incremental borrowing rate					10.90%
R&D expense related to inventory			$ 4,500,000
Incremental costs expenses	0		0
Cash and cash equivalents and restricted cash in excess of insured limits	75,700,000		$ 75,700,000
Reserve for R&D credit carryover balance			20.00%
Number of segments | Segment			1
Right-of-use assets	20,194,000		$ 20,194,000
Lease liabilities	23,336,000		23,336,000
ASU 2016-02
Significant Accounting Policies [Line Items]
Right-of-use assets	21,600,000		21,600,000
Lease liabilities	$ 27,400,000		$ 27,400,000
Employee Stock Option
Significant Accounting Policies [Line Items]
Anti-dilutive securities excluded from the calculation of diluted earnings per share | shares	5,076,766	5,763,609	5,076,766	5,763,609
Warrants
Significant Accounting Policies [Line Items]
Anti-dilutive securities excluded from the calculation of diluted earnings per share | shares	2,116,250	2,116,250	2,116,250	2,116,250
Restricted Stock Units
Significant Accounting Policies [Line Items]
Anti-dilutive securities excluded from the calculation of diluted earnings per share | shares	1,635,242	1,541,970	1,635,242	1,541,970
Pint Pharma International SA
Significant Accounting Policies [Line Items]
Upfront payment received		$ 10,000,000
Pierre Fabre Agreement | Pierre Fabre
Significant Accounting Policies [Line Items]
Non-deductible, non-creditable upfront payment	$ 51,000,000		$ 51,000,000
Additional variable consideration			$ 9,000,000
Minimum
Significant Accounting Policies [Line Items]
Revenue recognition, payment terms			10 days
Maximum
Significant Accounting Policies [Line Items]
Revenue recognition, payment terms			68 days
Amortization period recognized			1 year
Maximum | Knight Agreement
Significant Accounting Policies [Line Items]
Company obligations for potential milestone payments for CRO Contracts	7,200,000		$ 7,200,000
Maximum | Pierre Fabre Agreement | Pierre Fabre
Significant Accounting Policies [Line Items]
Company obligations for potential milestone payments for CRO Contracts	345,000,000		345,000,000
Maximum | License Agreement | Pint Pharma International SA
Significant Accounting Policies [Line Items]
Upfront payment, potential regulatory and commercial milestone payments	$ 24,500,000		$ 24,500,000

Summary of Product Revenues fro

Summary of Product Revenues from Customers (Detail) - Customer Concentration Risk - Total Revenues	3 Months Ended
	Sep. 30, 2019
CVS/Caremark
Significant Accounting Policies [Line Items]
Concentration risk percentage	36.00%
Accredo/Acaria
Significant Accounting Policies [Line Items]
Concentration risk percentage	21.00%

Assets Measured at Fair Value o

Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 40,935	$ 86,316
Totals	92,470	143,318
Commercial paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities		35,941
Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	41,501	18,077
U.S. government securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	10,034	2,984
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	40,935	83,329
Totals	50,969	86,313
Level 1 | U.S. government securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	10,034	2,984
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents		2,987
Totals	41,501	57,005
Level 2 | Commercial paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities		35,941
Level 2 | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	$ 41,501	$ 18,077

Summary of Short-term Investmen

Summary of Short-term Investments (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, Amortized cost	$ 58,904	$ 108,419
Marketable securities, Amortized cost	92,355	143,330
Marketable securities, Unrealized Gains	115
Marketable securities, Unrealized Losses		(12)
Marketable securities, Estimated fair value	92,470	143,318
Cash equivalents
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, Amortized cost	40,935	86,316
Cash equivalents, Estimated fair value	$ 40,935	$ 86,316
Commercial paper
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, Maturity (in years)	Less than 1	Less than 1
Marketable securities, Amortized cost		$ 35,941
Marketable securities, Estimated fair value		$ 35,941
Corporate bonds
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, Maturity (in years)	Less than 1	Less than 1
Marketable securities, Amortized cost	$ 41,396	$ 18,089
Marketable securities, Unrealized Gains	105
Marketable securities, Unrealized Losses		(12)
Marketable securities, Estimated fair value	$ 41,501	$ 18,077
U.S. government securities
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, Maturity (in years)	Less than 1	Less than 1
Marketable securities, Amortized cost	$ 10,024	$ 2,984
Marketable securities, Unrealized Gains	10
Marketable securities, Estimated fair value	$ 10,034	$ 2,984

Accounts Receivable, Net - Sche

Accounts Receivable, Net - Schedule of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Receivable Net [Abstract]
Accounts receivable	$ 24,682	$ 20,773
License revenue receivable	2,500
Total accounts receivable, net	$ 27,182	$ 20,773

Components of Prepaid Expenses

Components of Prepaid Expenses and Other (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	$ 9,990	$ 12,397
Prepaid expenses and other, long-term	2,931	3,429
Totals	12,921	15,826
CRO services
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	4,661	5,824
Prepaid expenses and other, long-term	1,657	1,073
Other clinical development
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	2,053	888
Prepaid expenses and other, long-term	7	650
Insurance
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	407	2,446
Professional fees
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	597	272
Other
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	2,272	2,967
Prepaid expenses and other, long-term	$ 1,267	$ 1,706

Schedule of Other Current Asset

Schedule of Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Insurance receivable		$ 1,175
Other	$ 322	612
Totals	$ 322	$ 1,787

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Fixed lease expense		$ 3.6
Variable lease expense		0.3
Operating sublease income	$ 0.1	$ 0.1

Supplemental Cash Flow Informat

Supplemental Cash Flow Information Related to Leases (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating cash flows from operating leases (in thousands)	$ 4,050
Weighted average remaining lease term (in years)	6 years 6 months
Weighted average discount rate	10.90%

Maturity of Lease Liabilities (

Maturity of Lease Liabilities (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
2019 (remaining)	$ 1,274
2020	5,207
2021	5,365
2022	5,483
2023	5,631
Thereafter	13,296
Total	36,256
Less: imputed interest	(10,404)
Total lease liabilities	$ 25,852

Future Minimum Lease Payments u

Future Minimum Lease Payments under ASC 840 (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 4,924
2020	5,141
2021	5,300
2022	5,464
2023	5,631
Thereafter	13,296
Total	$ 39,756

Property and Equipment (Detail)

Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 8,833	$ 9,139
Less: accumulated depreciation	(5,629)	(5,176)
Totals	3,204	3,963
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	3,780	4,048
Computer Equipment
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	2,367	2,402
Telephone Equipment
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	340	343
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,346	$ 2,346

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Depreciation expense	$ 0.2	$ 0.7

Schedule of Intangible assets,

Schedule of Intangible assets, net (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Acquired and in-licensed rights	$ 50,000
Less: accumulated amortization	(8,553)
Total intangible asset, net	$ 41,447	$ 44,408
Acquired and in-licensed rights
Finite Lived Intangible Assets [Line Items]
Estimated Useful Life	13 years

Intangible Assets, Net - Additi

Intangible Assets, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense	$ 1	$ 3

Accrued Expenses (Detail)

Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued legal verdict expense	$ 31,350	$ 9,000
Accrued CRO services	13,923	10,187
Accrued royalties	8,040	9,162
Accrued variable consideration	6,406	3,818
Accrued compensation	3,569	4,435
Accrued professional fees	1,061	2,175
Accrued other clinical development	3,425	2,380
Accrued bonus	5,119	1,705
Accrued legal fees	886	1,379
Accrued manufacturing costs	1,095	788
Other	1,897	1,402
Totals	$ 76,771	$ 46,431

Accrued Expenses - Additional I

Accrued Expenses - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accrued Expenses [Line Items]
Accrued legal verdict expense, estimate owed	$ 31,350	$ 9,000
Eshelman v. Puma Biotechnology, Inc.
Accrued Expenses [Line Items]
Accrued legal verdict expense, estimate owed	22,400
Minimum | Hsu v. Puma Biotechnology, Inc.
Accrued Expenses [Line Items]
Accrued legal verdict expense, estimate owed	9,000
Maximum | Hsu v. Puma Biotechnology, Inc.
Accrued Expenses [Line Items]
Accrued legal verdict expense, estimate owed	$ 18,000

Debt - Schedule of Long Term De

Debt - Schedule of Long Term Debt (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Long term debt	$ 100,000
Accretion of final interest payment	1,603
Less: deferred financing costs	(7,418)
Total long term debt, net	$ 94,185	$ 151,886
Long term debt, maturity date	Jun. 1, 2024

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Jun. 28, 2019	May 31, 2018	Oct. 31, 2017	Sep. 30, 2019
Silicon Valley Bank and Oxford finance | Term Loan
Debt Instrument [Line Items]
Line of credit facility, effective date				2017-10
Amount borrowed under credit facility		$ 125,000,000	$ 50,000,000
Term loan, maximum borrowing capacity		155,000,000
Payment of existing credit facility		50,000,000
Line of credit facility available upon achievement of specified minimum revenue milestone		$ 30,000,000
Interest rate, description				Prior to the amendment and restatement of the loan and security agreement in June 2019, which provided for a new credit facility, or the New Credit Facility, the term loans under the Amended Credit Facility bore interest at an annual rate equal to the greater of (i) 8.25% and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the month that immediately preceded the month in which the interest accrued, plus (b) 3.5%. The Company was required to make monthly interest-only payments on each term loan commencing on the first calendar day of the calendar month following the funding date of such term loan, and continuing on the first calendar day of each calendar month thereafter through July 1, 2020
Annual interest rate		8.25%
Redemption period start date		Jul. 1, 2020
Line of credit facility closing date		May 1, 2023
Percentage of original principal amount payable in final payment		7.50%
Silicon Valley Bank and Oxford finance | Term Loan | First Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fee, percentage		3.00%
Silicon Valley Bank and Oxford finance | Term Loan | Between First Anniversary and Second Anniversary
Debt Instrument [Line Items]
Prepayment fee, percentage		2.00%
Silicon Valley Bank and Oxford finance | Term Loan | After Second Anniversary and Prior to May 1, 2023
Debt Instrument [Line Items]
Prepayment fee, percentage		1.00%
Silicon Valley Bank and Oxford finance | Term Loan | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.50%
Oxford | Secured Promissory Notes
Debt Instrument [Line Items]
Term loan, maximum borrowing capacity	$ 100,000,000
Payment of existing credit facility	$ 155,000,000
Interest rate, description				The term loans under the New Credit Facility bear interest at an annual rate equal to the greater of (i) 9.0% and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue, plus (b) 3.5%. The Company is required to make monthly interest-only payments on each term loan under the New Credit Facility commencing on the first calendar day of the calendar month following the funding date of such term loan, and continuing on the first calendar day of each calendar month thereafter through August 1, 2021 or, the Amortization Date.
Annual interest rate	9.00%
Redemption period start date	Aug. 1, 2021
Line of credit facility closing date	Jun. 1, 2024
Percentage of original principal amount payable in final payment	7.50%
Aggregate principal amount	$ 100,000,000
Additional money remains available under new credit facility	$ 0
Percentage of issued and outstanding capital stock of its subsidiary pledged	65.00%
Percentage of additional interest rate to be charged on the event of default	5.00%
Amount of indebtedness or judgments against company to be considered as threshold limit for default	$ 500,000
Term loan, outstanding amount				$ 100,000,000
Oxford | Secured Promissory Notes | First Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fee, percentage	3.00%
Oxford | Secured Promissory Notes | Between First Anniversary and Second Anniversary
Debt Instrument [Line Items]
Prepayment fee, percentage	2.00%
Oxford | Secured Promissory Notes | After Second Anniversary and Prior to Maturity Date
Debt Instrument [Line Items]
Prepayment fee, percentage	1.00%
Oxford | Secured Promissory Notes | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate	3.50%

Stockholders Equity - Additiona

Stockholders Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Oct. 31, 2011
Stockholders Equity Note [Line Items]
Issuance of common stock on exercise of option	87,625
Common stock issued upon vesting of RSUs	531,112	332,173
Common stock, shares authorized	100,000,000		100,000,000
Common stock, par value	$ 0.0001		$ 0.0001
Warrant expiration date	Oct. 4, 2021
Issuance of common stock on exercise of option	5,076,766		5,708,544
Share based compensation awarded	129,734
Weighted-average grant date fair value of options granted	$ 21.82	$ 56.46
Non Vested Stock Options
Stockholders Equity Note [Line Items]
Estimated unrecognized employee compensation cost related to non-vested stock options granted	$ 10
Estimated unrecognized employee compensation cost related to non-vested stock options granted, Weighted-average period of recognition	1 year 4 months 24 days
Restricted Stock Units
Stockholders Equity Note [Line Items]
Common stock issued upon vesting of RSUs	531,112
Estimated unrecognized employee compensation cost related to non-vested stock options granted	$ 48.8
Estimated unrecognized employee compensation cost related to non-vested stock options granted, Weighted-average period of recognition	1 year 7 months 6 days
Weighted-average grant date fair value of RSUs	$ 20.36	$ 62.11
2011 Plan
Stockholders Equity Note [Line Items]
Common stock shares reserved for issuance	12,529,412
Issuance of common stock on exercise of option	6,146,363
Common stock shares available for future issuance	2,801,058
2017 Employment Inducement Incentive Award Plan
Stockholders Equity Note [Line Items]
Common stock shares reserved for issuance	1,000,000
Share based compensation awarded	565,645
Maximum | 2011 Plan
Stockholders Equity Note [Line Items]
Stock options granted, term	10 years
Maximum | 2017 Employment Inducement Incentive Award Plan
Stockholders Equity Note [Line Items]
Stock options granted, term	10 years
Common Stock
Stockholders Equity Note [Line Items]
Issuance of common stock on exercise of option	87,625	187,754
Shares of common stock that could be acquired by warrant	2,116,250
Common stock price	$ 16
Common Stock | Alan Auerbach | Minimum
Stockholders Equity Note [Line Items]
Minimum ownership percentage of outstanding shares of common stock the president need to maintain after issuance of warrants				20.00%

Fair Value Options Weighted-Ave

Fair Value Options Weighted-Average Assumptions (Detail) - Employee Stock Option	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
Expected volatility	99.90%	95.50%
Risk-free interest rate	2.50%	2.50%
Expected life in years	5 years 9 months 3 days	5 years 10 months 6 days

Stock-based Compensation (Detai

Stock-based Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 12,213	$ 20,807	$ 45,791	$ 68,343
Employee Stock Option | Selling, general and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	1,768	3,132	6,706	11,721
Employee Stock Option | Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	1,786	5,387	6,001	22,689
Restricted Stock Units | Selling, general and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	3,832	6,280	16,221	15,228
Restricted Stock Units | Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 4,827	$ 6,008	$ 16,863	$ 18,705

Activity with Respect to Option

Activity with Respect to Options Granted (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Shares
Beginning balance, shares	5,708,544
Granted, shares	129,734
Forfeited, shares	(69,969)
Exercised, shares	(87,625)
Expired, shares	(603,918)
Ending balance, shares	5,076,766	5,708,544
Nonvested, shares	396,948	779,292
Weighted Average Exercise Price
Beginning Balance, Weighted Average Exercise Price	$ 87.49
Granted, Weighted Average Exercise Price	27.76
Forfeited, Weighted Average Exercise Price	40.50
Exercised, Weighted Average Exercise Price	15.42
Expired, Weighted Average Exercise Price	102.39
Ending Balance, Weighted Average Exercise Price	86.08	$ 87.49
Nonvested, Weighted Average Exercise Price	$ 39.99
Weighted Average Remaining Contractual Term (years)
Weighted Average Remaining Contractual Term (years)	5 years 4 months 24 days	6 years 1 month 6 days
Granted, Weighted Average Remaining Contractual Term (years)	9 years 4 months 24 days
Nonvested, Weighted Average Remaining Contractual Term (years)	8 years 7 months 6 days
Aggregate Intrinsic Value
Shares, Outstanding, Aggregate Intrinsic Value	$ 2,450	$ 7,762
Exercised, Aggregate Intrinsic Value	$ 995

Stock Options (Detail)

Stock Options (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Shares
Nonvested shares, Beginning balance	779,292
Granted, shares	129,734
Vested/Issued, shares	(442,109)
Forfeited, shares	(69,969)
Nonvested shares, Ending balance	396,948
Weighted Average Grant-Date Fair Value
Nonvested, Beginning balance, Weighted Average Grant-Date Fair Value	$ 33.75
Granted, Weighted Average Grant-Date Fair Value	21.82	$ 56.46
Vested/Issued, Weighted Average Grant-Date Fair Value	35.13
Forfeited, Weighted Average Grant-Date Fair Value	25.06
Nonvested, Ending balance, Weighted Average Grant-Date Fair Value	$ 29.85

Restricted Stock Units (Detail)

Restricted Stock Units (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Shares
Vested/Issued, shares	(531,112)	(332,173)
Restricted Stock Units
Shares
Nonvested shares, Beginning balance	1,838,670
Granted, shares	776,730
Vested/Issued, shares	(531,112)
Forfeited, shares	(449,046)
Nonvested shares, Ending balance	1,635,242
Weighted Average Grant-Date Fair Value
Nonvested, Beginning balance, Weighted Average Grant-Date Fair Value	$ 60.08
Granted, Weighted Average Grant-Date Fair Value	20.36	$ 62.11
Vested/Issued, Weighted Average Grant-Date Fair Value	70.06
Forfeited, Weighted Average Grant-Date Fair Value	53.02
Nonvested, Ending balance, Weighted Average Grant-Date Fair Value	$ 39.91

401(K) Savings Plan - Additiona

401(K) Savings Plan - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution expenses	$ 1.2	$ 1.3
First 3% of each Participant's Contributions
Defined Benefit Plan Disclosure [Line Items]
Company's matching contributions to the 401(k)plan	100.00%
Second 2% of each Participant's Contributions
Defined Benefit Plan Disclosure [Line Items]
Company's matching contributions to the 401(k)plan	50.00%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	Jan. 29, 2019	Sep. 30, 2019
Commitments And Contingencies Disclosure [Line Items]
License agreement, expected milestone payment		$ 187,500,000
Hsingching Hsu
Commitments And Contingencies Disclosure [Line Items]
Accrued estimated losses		9,000,000
Loss contingency damages awarded percent of total claim	5.00%
Loss contingency claimed damages awarded per share	$ 87.20
Number of shares traded to claim damages	10
Hsingching Hsu | Minimum
Commitments And Contingencies Disclosure [Line Items]
Percentage of stockholders sufficient to recover damages	20.00%
Amount of damages after claims	$ 9,000,000
Hsingching Hsu | Maximum
Commitments And Contingencies Disclosure [Line Items]
Damages awarded per share	$ 4.50
Percentage of stockholders sufficient to recover damages	40.00%
Amount of damages after claims	$ 18,000,000
Eshelman v. Puma Biotechnology, Inc.
Commitments And Contingencies Disclosure [Line Items]
Accrued estimated losses		22,400,000
Eshelman v. Puma Biotechnology, Inc. | Compensatory
Commitments And Contingencies Disclosure [Line Items]
Damages awarded, value		15,900,000
Eshelman v. Puma Biotechnology, Inc. | Punitive
Commitments And Contingencies Disclosure [Line Items]
Damages awarded, value		6,500,000
Eshelman v. Puma Biotechnology, Inc. | Maximum
Commitments And Contingencies Disclosure [Line Items]
Amount of damages after claims		$ 26,300,000