Puma Biotechnology (PBYI) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 07, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	PBYI
Entity Registrant Name	PUMA BIOTECHNOLOGY, INC.
Entity Central Index Key	1,401,667
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		37,811,611

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 78,552	$ 81,698
Accounts receivable, net	16,309	9,670
Inventory	2,742	2,029
Prepaid expenses and other, current	13,583	12,997
Total current assets	111,186	106,394
Property and equipment, net	4,320	4,470
Prepaid expenses and other, long-term	2,448	1,989
Intangible assets, net	47,368	48,355
Restricted cash	4,317	4,317
Total assets	169,639	165,525
Current liabilities:
Accounts payable	23,560	27,692
Accrued expenses	34,558	30,648
Total current liabilities	58,118	58,340
Deferred rent	5,509	5,406
Long-term debt	48,556	48,477
Total liabilities	112,183	112,223
Commitments and contingencies (Note 10)
Stockholders' equity:
Common stock - $.0001 par value per share; 100,000,000 shares authorized; 37,762,519 shares issued and outstanding at March 31, 2018 and 37,594,851 issued and outstanding at December 31, 2017	4	4
Additional paid-in capital	1,170,331	1,142,213
Receivable from exercise of stock options	(68)	(449)
Accumulated deficit	(1,112,811)	(1,088,466)
Total stockholders' equity	57,456	53,302
Total liabilities and stockholders' equity	$ 169,639	$ 165,525

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
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	37,762,519	37,594,851
Common stock, shares outstanding	37,762,519	37,594,851

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Product revenue, net	$ 36,016
License revenue	30,500
Total revenue	66,516
Operating costs and expenses:
Cost of sales	6,383
Selling, general and administrative	36,602	$ 18,401
Research and development	46,925	54,801
Total operating costs and expenses	89,910	73,202
Loss from operations	(23,394)	(73,202)
Other (expenses) income:
Interest income	174	350
Interest expense	(1,079)
Other expenses	(46)	(13)
Total other (expenses) income:	(951)	337
Net loss	(24,345)	(72,865)
Net loss applicable to common stockholders	$ (24,345)	$ (72,865)
Net loss per common share—basic and diluted	$ (0.65)	$ (1.97)
Weighted-average common shares outstanding—basic and diluted	37,699,024	36,931,167

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (24,345)	$ (72,865)
Other comprehensive loss
Unrealized loss on available-for-sale securities		(37)
Comprehensive loss	$ (24,345)	$ (72,902)

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Receivables from the Exercises of Options	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	37,594,851
Stock-based compensation	$ 25,352		25,352
Shares issued or restricted stock units vested under employee stock plans	3,147		2,766	381
Shares issued or RSUs vested under employee stock plans (in shares)		167,668
Net loss	(24,345)				(24,345)
Ending Balance at Mar. 31, 2018	$ 57,456	$ 4	$ 1,170,331	$ (68)	$ (1,112,811)
Ending Balance (in shares) at Mar. 31, 2018	37,762,519	37,762,519

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (24,345)	$ (72,865)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,341	277
Stock-based compensation	25,352	29,764
Changes in operating assets and liabilities:
Accounts receivable, net	(6,639)
Inventory	(713)
Prepaid expenses and other	(1,045)	516
Accounts payable	(4,217)	3,935
Accrued expenses	3,910	2,334
Accrual of deferred rent	103	(3)
Net cash used in operating activities	(6,253)	(36,042)
Investing activities:
Purchase of property and equipment	(40)	(124)
Purchase of available-for-sale securities		(79,728)
Sale/maturity of available-for-sale securities		25,779
Net cash used in investing activities	(40)	(54,073)
Financing activities:
Net proceeds from exercise of stock options	3,147	706
Net cash provided by financing activities	3,147	706
Net decrease in cash, cash equivalents and restricted cash	(3,146)	(89,409)
Cash, cash equivalents and restricted cash, beginning of period	86,015	198,811
Cash, cash equivalents and restricted cash, end of period	82,869	$ 109,402
Supplemental disclosures of non-cash investing and financing activities:
Property and equipment purchases in accounts payable	85
Receivables related to stock option exercises	68
Supplemental disclosure of cash flow information:
Interest paid	$ 989

Business and Basis of Presentat

Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2018
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 in-licenses the global development and commercialization rights to three drug candidates—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 development and commercialization of the oral version of neratinib, and its most advanced drug candidates are directed at the treatment of HER2-positive breast cancer. The Company believes that neratinib has clinical application in the treatment of several other cancers as well, including non-small cell lung cancer and other tumor types that over-express or have a mutation in HER2. In November 2012, the Company established and incorporated Puma Biotechnology Ltd., a wholly owned subsidiary, for the sole purpose of serving as the Company’s legal representative in the United Kingdom and the European Union in connection with the Company’s clinical trial activity in those countries. 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 non-small cell lung cancer, HER2-negative breast cancer that has a HER2 mutation and other solid tumors that have an activating mutation in HER2. The Company has reported a net loss of approximately $24.3 million and negative cash flows from operations of approximately $6.3 million for the three months ended March 31, 2018. Management believes that the Company will continue to incur net losses and negative net cash flows from operating activities through the drug development process and early commercialization. The Company has incurred significant operating losses and negative cash flows from operations since its inception, which raises substantial doubt about its ability to continue as a going concern. On July 17, 2017, the Company received U.S. Food and Drug Administration, or 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 entered into exclusive license agreements with Specialised Therapeutics Asia Pte Ltd., or STA, Medison Pharma Ltd., or Medison, and CANbridgepharma Limited, or CANbridge, and, most recently, Pint Pharma International SA, or Pint, to pursue regulatory approval and commercialize NERLYNX, if approved, in South East Asia, Israel, greater China and South America, respectively. The Company plans to continue to pursue commercialization of NERLYNX in other countries outside the United States, if approved, and is evaluating various commercialization options in those countries, including developing a direct sales force, contracting with third parties to provide sales and marketing capabilities, or some combination of these two options. Since its inception through March 31, 2018, the Company’s financing has primarily been through public offerings of Company common stock, private equity placements, borrowings under its loan and security agreement with Silicon Valley Bank, or SVB and licensing of its intellectual property. The Company may need additional financing before it can achieve profitability, if ever. There can be no assurance that additional capital will be available on favorable terms or at all or that any additional capital that the Company is able to obtain will be sufficient to meet its needs. If it is unable to raise additional capital, the Company could likely be forced to curtail desired development activities, which will delay the development of its product candidates.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
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 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 subsidiary. 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 Inc., or the Licensor. 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 Licensor. 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 for the three months ended March 31, 2018. As of March 31, 2018, estimated future amortization expense related to the Company’s intangible asset was approximately $2.9 million for the remainder of 2018, approximately $3.9 million for each year starting 2019 through 2029, and approximately $1.0 million for 2030. Royalties: Royalties incurred in connection with the Company’s license agreement with the Licensor are expensed to cost of sales as revenue from product sales is recognized. 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 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. Inventory acquired prior to receipt of marketing approval of a product candidate is recorded as research and development expense as incurred. Inventory that can be used in either the production of clinical or commercial product is recorded as research and development expense when selected for use in a clinical trial. Starter kits, provided to patients prior to insurance approval, are expensed by the Company to sales and marketing expense as incurred. As of March 31, 2018, the Company’s inventory balance consisted primarily of raw materials purchased subsequent to FDA approval of NERLYNX. Revenue Recognition: The Company adopted Accounting Standards Codification, or 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 the FDA approved NERLYNX on July 17, 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 60 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 March 31, 2018. Product revenue from customers who individually accounted for 10% or more of the Company’s total revenue for the three months ended March 31, 2018 consisted of the following, shown as a percentage of total revenue: Three Months Ended March 31, 2018 Customer A 37 % Customer B 22 % Customer C 14 % License Revenue: The Company also recognizes license revenue under certain of the Company’s license agreements that are within the scope of ASC 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 606 to determine the distinct performance obligations. Non-refundable, up-front fees that are not contingent on any future performance and require no consequential continuing involvement by the Company, are recognized as 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 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. Variable consideration may include nonrefundable upfront license fees, payments for research and development activities, reimbursement of certain third-party costs, payments based upon the achievement of specified milestones, and royalty payments based on product sales derived from the collaboration. 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. Revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations. During the three months ended March 31, 2018, the Company entered into sub-licensing agreements with CANbridgepharma Limited, or CANbridge, and Medison Pharma Ltd., or Medison, to pursue regulatory approval and commercialize NERLYNX, if approved, in the People’s Republic of China (including mainland China, Hong Kong, Macao, and Taiwan) and Israel, respectively. The license agreements granted intellectual property rights and set forth the parties’ respective obligations with respect to development, commercialization and supply of the licensed product. For both license agreements, non-refundable, upfront license fees were received and recognized as license revenue in accordance with ASC 606. Each respective 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. The Company is obligated to supply both CANBridge and Medison with the licensed product in accordance with the respective supply agreements. These supply arrangements have been identified as separate performance obligations. To determine the respective stand-alone selling prices, the Company 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 no additional variable consideration, significant financing components, noncash consideration, or consideration payable to the customer in these agreements. Additionally, on March 30, 2018, the Company also entered into a sub-license agreement with Pint Pharma International SA (Pint), or Pint. The license agreement granted intellectual property rights and set forth the respective obligations with respect to development, commercialization and supply of NERYLNX in 22 countries and territories in Central and South America. 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. Under the terms of the license agreement, the Company is entitled to receive a $10M non-deductible, non-creditable upfront payment. Prior to receipt of such payment, the Company must provide certain required documents on or before September 30, 2018 to the satisfaction of Pint. At March 31, 2018 the Company had not satisfied this performance obligation and no revenue has been recognized 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 no additional variable consideration, significant financing components, noncash consideration, or consideration payable to the customer in these agreements. The period between when we transfer control of the promised goods to a customer and when we receive payment from such customer is expected to be one year or less. 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 a current liability. These estimates take into consideration a range of possible outcomes which are probability-weighted in accordance with the expected value method in ASC 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 which 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 March 31, 2018 and, therefore, the transaction price was not reduced further during the quarter ended March 31, 2018. 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 revenue in the period the related product revenue is recognized. The reserve for discounts is established in the same period that the related 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. However, 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 revenue within the statement of operations and comprehensive loss through March 31, 2018. 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 revenue in the period the related product revenue is recognized, as well 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 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 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 that 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 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. For Medicare, the Company also estimates the number of patients in the prescription drug coverage gap for whom the Company will owe an additional liability under the Medicare Part D program. 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 estimated 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 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 March 31, 2018 and December 31, 2017, 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): March 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 78,552 $ — $ — $ 78,552 $ 78,552 $ — $ — $ 78,552 December 31, 2017 Level 1 Level 2 Level 3 Total Cash equivalents $ 81,698 $ — $ — $ 81,698 $ 81,698 $ — $ — $ 81,698 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 March 31, 2018 (in years) cost Gains Losses fair value Cash equivalents $ 78,552 $ — $ — $ 78,552 $ 78,552 $ — $ — $ 78,552 Maturity Amortized Unrealized Estimated December 31, 2017 (in years) cost Gains Losses fair value Cash equivalents $ 81,698 $ — $ — $ 81,698 $ 81,698 $ — $ — $ 81,698 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 March 31, 2018, were approximately $83.1 million. The Company does not believe it is exposed to any significant credit risk due to the quality 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 revenues. The creditworthiness of its customers is continuously monitored, and the Company has internal policies regarding customer credit limits. The Company estimates an allowance for doubtful accounts primarily based on the credit worthiness of our 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, which was approved by the FDA for the extended adjuvant treatment of early stage, HER2-positive breast cancer in the United States on July 17, 2017, 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 levels or prices. 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 and other 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. The Company intends to rely on one or more third-party contractors to manufacture the commercial supply of drugs. Research and Development Expenses: Research and development expenses, or R&D, are charged to operations as incurred. The major components of research and development expenses 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. The objective of the Company’s accrual policy is to match the recording of expenses in the unaudited condensed consolidated financial statements to the actual services received and efforts expended. 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 unaudited condensed 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 payme

Prepaid Expenses and Other

Prepaid Expenses and Other	3 Months Ended
	Mar. 31, 2018
Banking And Thrift [Abstract]
Prepaid Expenses and Other	Note 3—Prepaid Expenses and Other: Prepaid expenses and other consisted of the following (in thousands): March 31, 2018 December 31, 2017 Current: CRO services $ 6,279 $ 7,188 Other clinical development 1,183 878 Insurance 963 1,306 Other 5,158 3,625 13,583 12,997 Long-term: CRO services 876 860 Other clinical development 1,389 886 Insurance 36 26 Other 147 217 2,448 1,989 Totals $ 16,031 $ 14,986

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	Note 4—Property and Equipment: Property and equipment consisted of the following (in thousands ): March 31, 2018 December 31, 2017 Property and Equipment: Leasehold improvements $ 3,878 $ 3,878 Computer equipment 2,269 2,147 Telephone equipment 302 302 Furniture and fixtures 2,206 2,206 8,655 8,533 Less: accumulated depreciation and amortization (4,335 ) (4,063 ) Totals $ 4,320 $ 4,470

Intangible assets, net

Intangible assets, net	3 Months Ended
	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible assets, net	Note 5—Intangible assets, net: Intangible assets, net consisted of the following (dollars in thousands): March 31, 2018 Estimated useful life Acquired and in-licensed rights $ 50,000 13 Years Less: accumulated amortization (2,632 ) Total intangible asset, net $ 47,368

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2018
Payables And Accruals [Abstract]
Accrued Expenses	Note 6—Accrued Expenses: Accrued expenses consisted of the following (in thousands): March 31, 2018 December 31, 2017 Accrued CRO services $ 7,493 $ 8,335 Accrued other clinical development 4,513 3,438 Accrued legal fees 3,136 2,046 Accrued compensation 4,359 2,797 Accrued bonus 2,478 3,376 Accrued royalties 5,357 3,922 Accrued variable consideration 3,922 1,425 Other 3,300 5,309 Totals $ 34,558 $ 30,648 Accrued CRO services and accrued other clinical development expenses represent the Company’s estimate of such costs. Accrued compensation includes sales commissions and vacation. Additionally, vacation is accrued at the rate the employee earns vacation and reduced as vacation is used by the employee. Accrued royalties represent royalties incurred in connection with the Company’s license agreement with the Licensor and accrued variable consideration represents estimates of variable consideration for which reserves are established.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	Note 7—Debt: Long term debt consisted of the following at March 31, 2018 (dollars in thousands): March 31, 2018 Maturity Date Long term debt $ 50,000 October 31, 2022 Less: deferred financing costs (1,444 ) Total long term debt, net $ 48,556 On October 31, 2017, the Company entered into a loan and security agreement with SVB, as administrative and collateral agent, and the lenders party thereto from time to time, including Oxford Finance LLC and SVB, pursuant to which the lenders agreed to make term loans available to the Company in an aggregate amount of $100 million, consisting of (i) an aggregate amount of $50 million available on October 31, 2017 and (ii) an aggregate amount of $50 million available to be drawn at the Company’s option between March 31, 2018 and June 30, 2018, provided the Company has achieved a specified minimum revenue milestone and no event of default is occurring. Proceeds from the term loans may be used for working capital and general business purposes. The term loans available under the credit facility are 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 subsidiary, Puma Biotechnology Ltd. The 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 credit facility bear interest at an annual rate equal to the greater of (i) 7.75% 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 outstanding 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 December 1, 2019. Commencing on December 1, 2019, and continuing on the first calendar day of each calendar month thereafter, the Company is required to make consecutive equal monthly payments of principal, together with applicable interest, in arrears to each lender, calculated pursuant to the credit facility. All unpaid principal and accrued and unpaid interest with respect to each term loan is due and payable in full on October 31, 2022. Upon repayment of the term loans, the Company is also required to make a final payment to the lenders equal to 7.5% of the original principal amount of term loans funded. At the Company’s option, it may prepay the outstanding principal balance of any term loan in whole but not in part, subject to a prepayment fee of 2.0% of any amount prepaid if the prepayment occurs through and including the first anniversary of the funding date of such term loan, or 1.0% 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. The credit facility includes affirmative and negative covenants applicable to the Company, its current subsidiary and any subsidiaries it may create in the future. The affirmative covenants include, among others, covenants requiring the Company to maintain its corporate existence and governmental approvals, deliver certain financial reports, maintain insurance coverage and satisfy certain requirements regarding deposit accounts. The Company must also achieve product revenue, measured as of the last day of each fiscal quarter on a trailing three-month basis, that is (i) The 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 SVB, as collateral agent, with the right to exercise remedies against us and the collateral securing the credit facility, including foreclosure against the property securing the credit facilities, including its cash. These events of default include, among other things, any failure by the Company to pay principal or interest due under the credit facility, a breach of certain covenants under the 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.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Stockholders' Equity	Note 8—Stockholders’ Equity: 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 March 31, 2018, a total of 12,529,412 shares of the Company’s common stock had been reserved for issuance under the 2011 Plan. As of March 31, 2018, 7,480,378 shares had been issued under the 2011 Plan. 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 March 31, 2018, a total of 1,000,000 shares of the Company’s common stock had been reserved for issuance under the 2017 Plan. As of March 31, 2018, 295,250 shares had been issued under the 2017 Plan. Stock-based compensation was as follows for the three months ended March 31 (in thousands except per share data): Three Months Ended March 31, 2018 2017 Stock-based compensation: Options - Research and development, or R&D $ 10,072 $ 20,356 Selling, general and administrative, or SG&A 4,471 6,189 Restricted stock units - Selling, general and administrative, or SG&A 4,495 1,095 Research and development, or R&D 6,314 2,124 Total stock-based compensation expense $ 25,352 $ 29,764 The fair value of options granted to employees was estimated using the Black-Scholes Option Pricing Method (see Note 2 –Significant Accounting Policies) with the following weighted-average assumptions used during the three months ended March 31, 2018 and 2017. 2018 2017 Dividend yield 0.0 % 0.0 % Expected volatility 95.5 % 70.1 % Risk-free interest rate 2.5 % 2.0 % Expected life in years 5.85 5.85 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, 2017 6,134,513 $ 87.91 7.2 $ 220,060 Granted 225,566 $ 73.40 9.8 Forfeited (80,604 ) $ 54.33 Exercised (72,571 ) $ 38.11 $ 2,256 Expired (43,597 ) $ 145.51 Outstanding at March 31, 2018 6,163,307 $ 88.00 6.9 $ 100,125 Nonvested at March 31, 2018 1,514,373 $ 55.60 8.6 $ 27,237 At March 31, 2018, total estimated unrecognized employee compensation cost related to non-vested stock options granted prior to that date was approximately $46.3 million, which is expected to be recognized over a weighted-average period of 1.6 years. At March 31, 2018, the total estimated unrecognized employee compensation cost related to non-vested RSUs was approximately $111.2 million, which is expected to be recognized over a weighted-average period of 2.4 years. The weighted-average grant date fair value of options granted during the three months ended March 31, 2018 and 2017 was $56.46 and $22.86 per share, respectively. The weighted average grant date fair value of RSUs awarded during the three months ended March 31, 2018 and 2017, were $72.43 and $0, per share, respectively. Weighted Average Grant-Date Stock options Shares Fair Value Nonvested shares at December 31, 2017 1,788,436 $ 33.37 Granted 225,566 $ 56.46 Vested/Issued (419,025 ) $ 38.79 Forfeited (80,604 ) $ 32.66 Nonvested shares at March 31, 2018 1,514,373 $ 35.34 Weighted Average Grant-Date Restricted stock units Shares Fair Value Nonvested shares at December 31, 2017 1,637,662 $ 85.58 Granted 168,050 $ 72.43 Vested/Issued (96,347 ) $ 54.35 Forfeited (97,044 ) $ 84.02 Nonvested shares at March 31, 2018 1,612,321 $ 86.17

401(k) Savings Plan

401(k) Savings Plan	3 Months Ended
	Mar. 31, 2018
Postemployment Benefits [Abstract]
401(k) Savings Plan	Note 9—401(k) Savings Plan: During 2012, the Company adopted 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 $0.5 million and $0.2 million

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10—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 those 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. Legal Proceedings The Company and certain of its executive officers were named as defendants in the lawsuits detailed below. Due to the stage of these proceedings, the Company cannot reasonably predict the outcome, nor can it estimate the amount of loss or range of loss, if any, that may result. 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. An adverse outcome in these proceedings would likely not have a material adverse effect on the Company’s results of operations, cash flows or financial condition. Hsu vs. Puma Biotechnology, Inc., et. al. 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 the Company’s 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. The consolidated complaint alleges that the Company and certain of its executive officers made false or misleading statements and Eshelman vs. Puma Biotechnology, Inc., et. al. On February 2, 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 alleges that Mr. Auerbach and the Company made defamatory statements regarding Dr. Eshelman in connection with a proxy contest. Dr. Eshelman seeks compensatory and punitive damages and expenses and costs, including attorneys’ fees. On April 4, 2016, the Company filed a motion to dismiss the complaint. On May 2, 2016, Dr. Eshelman filed a notice of voluntary dismissal of the claims against Mr. Auerbach. On February 6, 2017, the court denied the Company’s motion to dismiss. Discovery ended in September 2017. The Company intends to vigorously defend against Dr. Eshelman’s claims. Derivative Actions On April 12 and April 14, 2016, purported stockholders of the Company filed two derivative lawsuits purportedly on behalf of the Company against certain of the Company’s officers and directors in the Superior Court of the State of California, Los Angeles, captioned Xing Xie v. Alan H. Auerbach, No. BC616617, and Kevin McKenney v. Auerbach, No. BC617059. The complaints assert claims for breach of fiduciary duty, unjust enrichment, abuse of control, mismanagement and waste of corporate assets arising from substantially similar allegations as those contained in the securities class action described above. The complaints seek an unspecified sum of damages and equitable relief. The Company intends to vigorously defend against this matter. Separately, on February 9, 2018, another purported stockholder filed a derivative lawsuit purportedly on behalf of the Company against certain of its officers and directors in the United States District Court, Central District of California, captioned Arnaud Van Der Gracht De Rommerswael vs. Alan H. Auerbach, et al., No. 8:18-cv-00236. The complaint asserts claims for violation of securities law, breach of fiduciary duty, waste of corporate assets, and unjust enrichment arising from substantially similar allegations as those contained in the securities class action described above. The complaint seeks an unspecified sum of damages, corporate reforms, equitable relief, and restitution. The Company intends to vigorously defend against this matter. Stockholder Demand On September 13, 2017, a purported stockholder filed a complaint in the Court of Chancery of the State of Delaware seeking an equitable apportionment of attorneys’ fees in an unspecified amount. The purported stockholder alleges that his actions caused the Company’s board of directors to implement certain governance reforms and enhancements to its director compensation program, and that, as a result of his actions, the purported stockholder is entitled to attorneys’ fees in an amount commensurate to those purported benefits. The Company filed an answer to the complaint on October 20, 2017. The Company intends to vigorously defend against this matter. The pending proceedings described in this section involve complex questions of fact and law and will require the expenditure of significant funds and the diversion of other resources to defend. The results of legal proceedings are inherently uncertain, and material adverse outcomes are possible

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 11—Subsequent Events: The Company entered into a loan agreement with Silicon Valley Bank and Oxford Finance for a term loan of up to $155.0 million, subject to funding in two tranches. The Company received gross proceeds of $125.0 million from the first tranche of the credit facility upon closing on May 8, 2018 and intends to use the funds to pay down the existing term loan of $50 million, for general corporate purposes and to further support NERLYNX commercial initiatives. The second tranche of $30.0 million may be drawn at the Company’s option between September 30, 2018 and December 31, 2018 provided the Company has achieved a specified minimum revenue milestone and no event of default is occurring. The loan will mature on May 1, 2023.

Significant Accounting Polici19

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
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 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 subsidiary. 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 Inc., or the Licensor. 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 Licensor. 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 for the three months ended March 31, 2018. As of March 31, 2018, estimated future amortization expense related to the Company’s intangible asset was approximately $2.9 million for the remainder of 2018, approximately $3.9 million for each year starting 2019 through 2029, and approximately $1.0 million for 2030.
Royalties	Royalties: Royalties incurred in connection with the Company’s license agreement with the Licensor are expensed to cost of sales as revenue from product sales is recognized.
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 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. Inventory acquired prior to receipt of marketing approval of a product candidate is recorded as research and development expense as incurred. Inventory that can be used in either the production of clinical or commercial product is recorded as research and development expense when selected for use in a clinical trial. Starter kits, provided to patients prior to insurance approval, are expensed by the Company to sales and marketing expense as incurred. As of March 31, 2018, the Company’s inventory balance consisted primarily of raw materials purchased subsequent to FDA approval of NERLYNX.
Revenue Recognition	Revenue Recognition: The Company adopted Accounting Standards Codification, or 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 the FDA approved NERLYNX on July 17, 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 60 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 March 31, 2018. Product revenue from customers who individually accounted for 10% or more of the Company’s total revenue for the three months ended March 31, 2018 consisted of the following, shown as a percentage of total revenue: Three Months Ended March 31, 2018 Customer A 37 % Customer B 22 % Customer C 14 % License Revenue: The Company also recognizes license revenue under certain of the Company’s license agreements that are within the scope of ASC 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 606 to determine the distinct performance obligations. Non-refundable, up-front fees that are not contingent on any future performance and require no consequential continuing involvement by the Company, are recognized as 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 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. Variable consideration may include nonrefundable upfront license fees, payments for research and development activities, reimbursement of certain third-party costs, payments based upon the achievement of specified milestones, and royalty payments based on product sales derived from the collaboration. 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. Revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations. During the three months ended March 31, 2018, the Company entered into sub-licensing agreements with CANbridgepharma Limited, or CANbridge, and Medison Pharma Ltd., or Medison, to pursue regulatory approval and commercialize NERLYNX, if approved, in the People’s Republic of China (including mainland China, Hong Kong, Macao, and Taiwan) and Israel, respectively. The license agreements granted intellectual property rights and set forth the parties’ respective obligations with respect to development, commercialization and supply of the licensed product. For both license agreements, non-refundable, upfront license fees were received and recognized as license revenue in accordance with ASC 606. Each respective 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. The Company is obligated to supply both CANBridge and Medison with the licensed product in accordance with the respective supply agreements. These supply arrangements have been identified as separate performance obligations. To determine the respective stand-alone selling prices, the Company 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 no additional variable consideration, significant financing components, noncash consideration, or consideration payable to the customer in these agreements. Additionally, on March 30, 2018, the Company also entered into a sub-license agreement with Pint Pharma International SA (Pint), or Pint. The license agreement granted intellectual property rights and set forth the respective obligations with respect to development, commercialization and supply of NERYLNX in 22 countries and territories in Central and South America. 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. Under the terms of the license agreement, the Company is entitled to receive a $10M non-deductible, non-creditable upfront payment. Prior to receipt of such payment, the Company must provide certain required documents on or before September 30, 2018 to the satisfaction of Pint. At March 31, 2018 the Company had not satisfied this performance obligation and no revenue has been recognized 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 no additional variable consideration, significant financing components, noncash consideration, or consideration payable to the customer in these agreements. The period between when we transfer control of the promised goods to a customer and when we receive payment from such customer is expected to be one year or less. 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 a current liability. These estimates take into consideration a range of possible outcomes which are probability-weighted in accordance with the expected value method in ASC 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 which 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 March 31, 2018 and, therefore, the transaction price was not reduced further during the quarter ended March 31, 2018. 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 revenue in the period the related product revenue is recognized. The reserve for discounts is established in the same period that the related 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. However, 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 revenue within the statement of operations and comprehensive loss through March 31, 2018. 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 revenue in the period the related product revenue is recognized, as well 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 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 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 that 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 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. For Medicare, the Company also estimates the number of patients in the prescription drug coverage gap for whom the Company will owe an additional liability under the Medicare Part D program. 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 estimated 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 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 March 31, 2018 and December 31, 2017, 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): March 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 78,552 $ — $ — $ 78,552 $ 78,552 $ — $ — $ 78,552 December 31, 2017 Level 1 Level 2 Level 3 Total Cash equivalents $ 81,698 $ — $ — $ 81,698 $ 81,698 $ — $ — $ 81,698 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 March 31, 2018 (in years) cost Gains Losses fair value Cash equivalents $ 78,552 $ — $ — $ 78,552 $ 78,552 $ — $ — $ 78,552 Maturity Amortized Unrealized Estimated December 31, 2017 (in years) cost Gains Losses fair value Cash equivalents $ 81,698 $ — $ — $ 81,698 $ 81,698 $ — $ — $ 81,698
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 March 31, 2018, were approximately $83.1 million. The Company does not believe it is exposed to any significant credit risk due to the quality 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 revenues. The creditworthiness of its customers is continuously monitored, and the Company has internal policies regarding customer credit limits. The Company estimates an allowance for doubtful accounts primarily based on the credit worthiness of our 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, which was approved by the FDA for the extended adjuvant treatment of early stage, HER2-positive breast cancer in the United States on July 17, 2017, 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 levels or prices. 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 and other 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. The Company intends to rely on one or more third-party contractors to manufacture the commercial supply of drugs.
Research and Development Expenses	Research and Development Expenses: Research and development expenses, or R&D, are charged to operations as incurred. The major components of research and development expenses 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. The objective of the Company’s accrual policy is to match the recording of expenses in the unaudited condensed consolidated financial statements to the actual services received and efforts expended. 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 unaudited condensed 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 research and development 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: In accordance with ASC 740, Income Taxes Our income tax returns are based on calculations and assumptions subject to audit by various tax authorities. In addition, the calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws. On December 22, 2017, H.R. 1/Public Law No. 115-97 known as the Tax Cuts and Jobs Act (the “Tax Act”), was signed into law. The effects of this new federal legislation are recognized upon enactment, which is the date a bill is signed into law. The Tax Act includes numerous changes in existing tax law, including a permanent reduction in the federal corporate income tax rate from 35% (as the top corporate tax rate) to 21%. As a result of the Tax Act, the Company has revalued its net deferred tax assets as of December 31, 2017 to reflect the rate reduction. Tax rates used for the ASC 740 interim reporting reflect the newly enacted corporate tax rate of 21% and adjustments used for the estimated annual effective tax rate calculation reflect changes from The Act Pursuant to the SEC Staff Accounting Bulletin No. 118, "Income Tax Accounting Implications of the Tax Cuts and Jobs Act”, or SAB 118, a company may select between one of three scenarios to determine a reasonable estimate arising from the Tax Act. Those scenarios are (i) a final estimate which effectively closes the measurement window; (ii) a reasonable estimate leaving the measurement window open for future revisions; and (iii) no estimate as the law is still being analyzed. The Company was able to provide a reasonable estimate for the revaluation of deferred taxes by recording a net tax provision of $141.1 million in the period ending December 31, 2017, which is offset by a full valuation allowance. Other impacts of the Act including, but not limited to, a limitation of the deduction for net operating losses, expensing of qualified property and additional limitations on the deductibility of executive compensation are not expected to have a material impact to the financial statement presentation or disclosures. The Company’s review of the final impact of the Tax Act may be different from certain provisional amounts reported due to changes in interpretations and assumptions of the current guidance available as well as the issuance of new regulatory guidance in the future. As of March 31, 2018, the Company has not made any measurement period adjustments related to SAB 118, which was elected during the fourth quarter of 2017. The other income tax accounting implications resulting from the act do not have a material impact to the Company. The Company anticipates the full financial impact will be determined at the time its 2017 U.S. corporate income tax return is filed in 2018.
Segment Reporting	Segment Reporting: Management has determined that the Company operates in one business segment, which is the development and commercialization of innovative products to enhance cancer care.
Net Loss per Common Share	Net Loss per Common Share: Basic net loss per common share is computed by dividing net loss applicable to common stockholders by the weighted average number of common shares outstanding during the periods presented as required by ASC 260, Earnings per Share
Recently Issued Accounting Standards	Recently Issued Accounting Standards: In January 2016, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities In February 2016, the FASB issued ASU No. 2016-02, Leases In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows Topic 230 : Classification of Certain Cash Receipts and Cash Payments a consensus of the Emerging Issues Task Force In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows Topic 230 Restricted Cash

Significant Accounting Polici20

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
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 March 31, 2018 consisted of the following, shown as a percentage of total revenue: Three Months Ended March 31, 2018 Customer A 37 % Customer B 22 % Customer C 14 %
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 March 31, 2018 and December 31, 2017, 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): March 31, 2018 Level 1 Level 2 Level 3 Total Cash equivalents $ 78,552 $ — $ — $ 78,552 $ 78,552 $ — $ — $ 78,552 December 31, 2017 Level 1 Level 2 Level 3 Total Cash equivalents $ 81,698 $ — $ — $ 81,698 $ 81,698 $ — $ — $ 81,698
Summary of Short-term Investments	The following tables summarize the Company’s short-term investments (in thousands): Maturity Amortized Unrealized Estimated March 31, 2018 (in years) cost Gains Losses fair value Cash equivalents $ 78,552 $ — $ — $ 78,552 $ 78,552 $ — $ — $ 78,552 Maturity Amortized Unrealized Estimated December 31, 2017 (in years) cost Gains Losses fair value Cash equivalents $ 81,698 $ — $ — $ 81,698 $ 81,698 $ — $ — $ 81,698

Prepaid Expenses and Other (Tab

Prepaid Expenses and Other (Tables)	3 Months Ended
	Mar. 31, 2018
Banking And Thrift [Abstract]
Components of Prepaid Expenses and Other	Prepaid expenses and other consisted of the following (in thousands): March 31, 2018 December 31, 2017 Current: CRO services $ 6,279 $ 7,188 Other clinical development 1,183 878 Insurance 963 1,306 Other 5,158 3,625 13,583 12,997 Long-term: CRO services 876 860 Other clinical development 1,389 886 Insurance 36 26 Other 147 217 2,448 1,989 Totals $ 16,031 $ 14,986

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	Property and equipment consisted of the following (in thousands ): March 31, 2018 December 31, 2017 Property and Equipment: Leasehold improvements $ 3,878 $ 3,878 Computer equipment 2,269 2,147 Telephone equipment 302 302 Furniture and fixtures 2,206 2,206 8,655 8,533 Less: accumulated depreciation and amortization (4,335 ) (4,063 ) Totals $ 4,320 $ 4,470

Intangible assets, net (Tables)

Intangible assets, net (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Intangible assets, net	Intangible assets, net consisted of the following (dollars in thousands): March 31, 2018 Estimated useful life Acquired and in-licensed rights $ 50,000 13 Years Less: accumulated amortization (2,632 ) Total intangible asset, net $ 47,368

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2018
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses consisted of the following (in thousands): March 31, 2018 December 31, 2017 Accrued CRO services $ 7,493 $ 8,335 Accrued other clinical development 4,513 3,438 Accrued legal fees 3,136 2,046 Accrued compensation 4,359 2,797 Accrued bonus 2,478 3,376 Accrued royalties 5,357 3,922 Accrued variable consideration 3,922 1,425 Other 3,300 5,309 Totals $ 34,558 $ 30,648

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long Term Debt	Long term debt consisted of the following at March 31, 2018 (dollars in thousands): March 31, 2018 Maturity Date Long term debt $ 50,000 October 31, 2022 Less: deferred financing costs (1,444 ) Total long term debt, net $ 48,556

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Employee Stock-based Compensation	Stock-based compensation was as follows for the three months ended March 31 (in thousands except per share data): Three Months Ended March 31, 2018 2017 Stock-based compensation: Options - Research and development, or R&D $ 10,072 $ 20,356 Selling, general and administrative, or SG&A 4,471 6,189 Restricted stock units - Selling, general and administrative, or SG&A 4,495 1,095 Research and development, or R&D 6,314 2,124 Total stock-based compensation expense $ 25,352 $ 29,764
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 –Significant Accounting Policies) with the following weighted-average assumptions used during the three months ended March 31, 2018 and 2017. 2018 2017 Dividend yield 0.0 % 0.0 % Expected volatility 95.5 % 70.1 % Risk-free interest rate 2.5 % 2.0 % Expected life in years 5.85 5.85
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, 2017 6,134,513 $ 87.91 7.2 $ 220,060 Granted 225,566 $ 73.40 9.8 Forfeited (80,604 ) $ 54.33 Exercised (72,571 ) $ 38.11 $ 2,256 Expired (43,597 ) $ 145.51 Outstanding at March 31, 2018 6,163,307 $ 88.00 6.9 $ 100,125 Nonvested at March 31, 2018 1,514,373 $ 55.60 8.6 $ 27,237
Stock Options	The weighted-average grant date fair value of options granted during the three months ended March 31, 2018 and 2017 was $56.46 and $22.86 per share, respectively. Weighted Average Grant-Date Stock options Shares Fair Value Nonvested shares at December 31, 2017 1,788,436 $ 33.37 Granted 225,566 $ 56.46 Vested/Issued (419,025 ) $ 38.79 Forfeited (80,604 ) $ 32.66 Nonvested shares at March 31, 2018 1,514,373 $ 35.34
Restricted Stock Units	The weighted average grant date fair value of RSUs awarded during the three months ended March 31, 2018 and 2017, were $72.43 and $0, per share, respectively. Weighted Average Grant-Date Restricted stock units Shares Fair Value Nonvested shares at December 31, 2017 1,637,662 $ 85.58 Granted 168,050 $ 72.43 Vested/Issued (96,347 ) $ 54.35 Forfeited (97,044 ) $ 84.02 Nonvested shares at March 31, 2018 1,612,321 $ 86.17

Business and Basis of Present27

Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Net loss	$ (24,345)	$ (72,865)
Net cash used in operating activities	(6,253)	$ (36,042)
Cash and cash equivalents	$ 78,552		$ 81,698

Significant Accounting Polici28

Significant Accounting Policies - Additional Information (Detail)	Mar. 30, 2018USD ($)Country	Mar. 31, 2018USD ($)Segmentshares	Mar. 31, 2017shares	Dec. 31, 2017
Significant Accounting Policies [Line Items]
Amortization expenses related to intangible assets		$ 1,000,000
Estimated future amortization expense related to intangible assets, remainder of 2018		2,900,000
Estimated future amortization expense related to intangible assets, 2019		3,900,000
Estimated future amortization expense related to intangible assets, 2020		3,900,000
Estimated future amortization expense related to intangible assets, 2021		3,900,000
Estimated future amortization expense related to intangible assets, 2022		3,900,000
Estimated future amortization expense related to intangible assets, 2023		3,900,000
Estimated future amortization expense related to intangible assets, 2024		3,900,000
Estimated future amortization expense related to intangible assets, 2025		3,900,000
Estimated future amortization expense related to intangible assets, 2026		3,900,000
Estimated future amortization expense related to intangible assets, 2027		3,900,000
Estimated future amortization expense related to intangible assets, 2028		3,900,000
Estimated future amortization expense related to intangible assets, 2029		3,900,000
Estimated future amortization expense related to intangible assets, 2030		1,000,000
Incremental costs expenses		0
Cash and cash equivalents and restricted cash in excess of insured limits		$ 83,100,000
Federal corporate income tax rate		21.00%		35.00%
Provisional tax impact related to the revaluation of deferred tax assets		$ 141,100,000
Number of segments | Segment		1
Anti-dilutive securities excluded from the calculation of diluted earnings per share | shares		9,891,878	9,549,076
Pint Pharma International SA
Significant Accounting Policies [Line Items]
Number of countries covered under sub-license agreement | Country	22
Non-deductible, non-creditable upfront payment	$ 10,000,000
Revenue recognized under terms of arrangement		$ 0
Contract with customer, description		The period between when we transfer control of the promised goods to a customer and when we receive payment from such customer is expected to be one year or less.
Minimum
Significant Accounting Policies [Line Items]
Revenue recognition, payment terms		10 days
Maximum
Significant Accounting Policies [Line Items]
Revenue recognition, payment terms		60 days
Amortization period recognized		1 year
Maximum | Pint Pharma International SA
Significant Accounting Policies [Line Items]
Potential development and commercial performance obligations milestones	$ 24,500,000

Summary of Product Revenues fro

Summary of Product Revenues from Customers (Detail) - Customer Concentration Risk - Sales Revenue, Net	3 Months Ended
	Mar. 31, 2018
Customer A
Significant Accounting Policies [Line Items]
Concentration risk percentage	37.00%
Customer B
Significant Accounting Policies [Line Items]
Concentration risk percentage	22.00%
Customer C
Significant Accounting Policies [Line Items]
Concentration risk percentage	14.00%

Assets Measured at Fair Value o

Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 78,552	$ 81,698
Total	78,552	81,698
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	78,552	81,698
Total	$ 78,552	$ 81,698

Summary of Short-term Investmen

Summary of Short-term Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	$ 78,552	$ 81,698
Estimated fair value	78,552	81,698
Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	78,552	81,698
Estimated fair value	$ 78,552	$ 81,698

Components of Prepaid Expenses

Components of Prepaid Expenses and Other (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	$ 13,583	$ 12,997
Prepaid expenses and other, long-term	2,448	1,989
Totals	16,031	14,986
CRO services
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	6,279	7,188
Prepaid expenses and other, long-term	876	860
Other clinical development
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	1,183	878
Prepaid expenses and other, long-term	1,389	886
Insurance
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	963	1,306
Prepaid expenses and other, long-term	36	26
Other
Prepaid Expenses [Line Items]
Prepaid expenses and other, current	5,158	3,625
Prepaid expenses and other, long-term	$ 147	$ 217

Property and Equipment (Detail)

Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 8,655	$ 8,533
Less: accumulated depreciation and amortization	(4,335)	(4,063)
Totals	4,320	4,470
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	3,878	3,878
Computer Equipment
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	2,269	2,147
Telephone Equipment
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	302	302
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,206	$ 2,206

Schedule of Intangible assets,

Schedule of Intangible assets, net (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Acquired and in-licensed rights	$ 50,000
Less: accumulated amortization	(2,632)
Total intangible asset, net	$ 47,368	$ 48,355
Acquired and in-licensed rights
Finite Lived Intangible Assets [Line Items]
Estimated useful life	13 years

Accrued Expenses (Detail)

Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued CRO services	$ 7,493	$ 8,335
Accrued other clinical development	4,513	3,438
Accrued legal fees	3,136	2,046
Accrued compensation	4,359	2,797
Accrued bonus	2,478	3,376
Accrued royalties	5,357	3,922
Accrued variable consideration	3,922	1,425
Other	3,300	5,309
Totals	$ 34,558	$ 30,648

Debt - Schedule of Long Term De

Debt - Schedule of Long Term Debt (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Long term debt	$ 50,000
Less: deferred financing costs	(1,444)
Total long term debt, net	$ 48,556	$ 48,477
Long term debt, maturity date	Oct. 31, 2022

Debt - Additional Information (

Debt - Additional Information (Detail) - Silicon Valley Bank and Oxford finance - Term Loan - USD ($)	Oct. 31, 2017	Mar. 31, 2018
Debt Instrument [Line Items]
Line of credit facility, effective date		Oct. 31, 2017
Line of credit facility, description		the lenders agreed to make term loans available to the Company in an aggregate amount of $100 million, consisting of (i) an aggregate amount of $50 million available on October 31, 2017 and (ii) an aggregate amount of $50 million available to be drawn at the Company’s option between March 31, 2018 and June 30, 2018, provided the Company has achieved a specified minimum revenue milestone and no event of default is occurring.
Term loan, maximum borrowing capacity	$ 100,000,000
Amount available on effective date under agreement	50,000,000
Line of credit facility available upon achievement of specified minimum revenue milestone	$ 50,000,000
Percentage of issued and outstanding capital stock of its subsidiary pledged	65.00%
Interest rate, description		The term loans under the credit facility bear interest at an annual rate equal to the greater of (i) 7.75% 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 outstanding 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 December 1, 2019.
Annual interest rate	7.75%
Redemption period start date	Dec. 1, 2019
Line of credit facility closing date	Oct. 31, 2022
Percentage of original principal amount payable in final payment	7.50%
Covenant, description		The credit facility includes affirmative and negative covenants applicable to the Company, its current subsidiary and any subsidiaries it may create in the future. The affirmative covenants include, among others, covenants requiring the Company to maintain its corporate existence and governmental approvals, deliver certain financial reports, maintain insurance coverage and satisfy certain requirements regarding deposit accounts. The Company must also achieve product revenue, measured as of the last day of each fiscal quarter on a trailing three-month basis, that is (i) greater than or equal to 50% of its revenue target set forth in its board-approved projections for the 2018 fiscal year, and (ii) greater than or equal to 50% of its revenue target set forth in its board-approved projections for the 2019 fiscal year. New minimum revenue levels will be established for each subsequent fiscal year by mutual agreement of the Company, SVB, as administrative agent, and the 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.
Credit facility covenants, percentage of target revenue to be achieved for 2018 fiscal year	50.00%
Credit facility covenants, percentage of target revenue to be achieved for 2019 fiscal year	50.00%
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
First Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fee, percentage	2.00%
Between First Anniversary and Second Anniversary
Debt Instrument [Line Items]
Prepayment fee, percentage	1.00%
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	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stockholders Equity Note [Line Items]
Share based compensation issued	225,566
Weighted-average grant date fair value of options granted	$ 56.46	$ 22.86
Non Vested Stock Options
Stockholders Equity Note [Line Items]
Estimated unrecognized employee compensation cost related to non-vested stock options granted	$ 46.3
Estimated unrecognized employee compensation cost related to non-vested stock options granted, Weighted-average period of recognition	1 year 7 months 6 days
RSUs
Stockholders Equity Note [Line Items]
Estimated unrecognized employee compensation cost related to non-vested stock options granted	$ 111.2
Estimated unrecognized employee compensation cost related to non-vested stock options granted, Weighted-average period of recognition	2 years 4 months 24 days
Weighted-average grant date fair value of restricted stock units	$ 72.43	$ 0
2011 Plan
Stockholders Equity Note [Line Items]
Common stock shares reserved for issuance	12,529,412
Share based compensation issued	7,480,378
2011 Plan | Maximum
Stockholders Equity Note [Line Items]
Stock options granted, term	10 years
2017 Employment Inducement Incentive Award Plan
Stockholders Equity Note [Line Items]
Common stock shares reserved for issuance	1,000,000
Share based compensation issued	295,250
2017 Employment Inducement Incentive Award Plan | Maximum
Stockholders Equity Note [Line Items]
Stock options granted, term	10 years

Stock-based Compensation (Detai

Stock-based Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 25,352	$ 29,764
Employee Stock Option | Research and development, or R&D
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	10,072	20,356
Employee Stock Option | Selling, general and administrative, or SG&A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	4,471	6,189
Restricted Stock Units | Research and development, or R&D
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	6,314	2,124
Restricted Stock Units | Selling, general and administrative, or SG&A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 4,495	$ 1,095

Fair Value Options Weighted-Ave

Fair Value Options Weighted-Average Assumptions (Detail) - Employee Stock Option	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
Expected volatility	95.50%	70.10%
Risk-free interest rate	2.50%	2.00%
Expected life in years	5 years 10 months 6 days	5 years 10 months 6 days

Activity with Respect to Option

Activity with Respect to Options Granted (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Shares
Beginning balance, shares	6,134,513
Granted, shares	225,566
Forfeited, shares	(80,604)
Exercised, shares	(72,571)
Expired, shares	(43,597)
Ending balance, shares	6,163,307	6,134,513
Nonvested, shares	1,514,373	1,788,436
Weighted Average Exercise Price
Beginning Balance, Weighted Average Exercise Price	$ 87.91
Granted, Weighted Average Exercise Price	73.40
Forfeited, Weighted Average Exercise Price	54.33
Exercised, Weighted Average Exercise Price	38.11
Expired, Weighted Average Exercise Price	145.51
Ending Balance, Weighted Average Exercise Price	88	$ 87.91
Nonvested, Weighted Average Exercise Price	$ 55.60
Weighted Average Remaining Contractual Term (years)
Weighted Average Remaining Contractual Term (years)	6 years 10 months 24 days	7 years 2 months 12 days
Granted, Weighted Average Remaining Contractual Term (years)	9 years 9 months 18 days
Nonvested, Weighted Average Remaining Contractual Term (years)	8 years 7 months 6 days
Aggregate Intrinsic Value
Shares, Outstanding, Aggregate Intrinsic Value	$ 100,125	$ 220,060
Exercised, Aggregate Intrinsic Value	2,256
Nonvested, Aggregate Intrinsic Value	$ 27,237

Stock Options (Detail)

Stock Options (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Shares
Nonvested shares, Beginning balance	1,788,436
Granted, shares	225,566
Vested/Issued, shares	(419,025)
Forfeited, shares	(80,604)
Nonvested shares, Ending balance	1,514,373
Weighted Average Grant-Date Fair Value
Nonvested, Beginning balance, Weighted Average Grant-Date Fair Value	$ 33.37
Granted, Weighted Average Grant-Date Fair Value	56.46	$ 22.86
Vested/Issued, Weighted Average Grant-Date Fair Value	38.79
Forfeited, Weighted Average Grant-Date Fair Value	32.66
Nonvested, Ending balance, Weighted Average Grant-Date Fair Value	$ 35.34

Restricted Stock Units (Detail)

Restricted Stock Units (Detail) - Restricted Stock Units - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Shares
Nonvested shares, Beginning balance	1,637,662
Granted, shares	168,050
Vested/Issued, shares	(96,347)
Forfeited, shares	(97,044)
Nonvested shares, Ending balance	1,612,321
Weighted Average Grant-Date Fair Value
Nonvested, Beginning balance, Weighted Average Grant-Date Fair Value	$ 85.58
Granted, Weighted Average Grant-Date Fair Value	72.43	$ 0
Vested/Issued, Weighted Average Grant-Date Fair Value	54.35
Forfeited, Weighted Average Grant-Date Fair Value	84.02
Nonvested, Ending balance, Weighted Average Grant-Date Fair Value	$ 86.17

401(K) Savings Plan - Additiona

401(K) Savings Plan - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution expenses	$ 0.5	$ 0.2
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)	Apr. 14, 2016DerivativeLawsuit
Commitments And Contingencies Disclosure [Abstract]
Number of stockholders derivative lawsuits	2

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Silicon Valley Bank and Oxford finance - Term Loan	May 10, 2018USD ($)Tranche	May 08, 2018USD ($)	Oct. 31, 2017USD ($)	Mar. 31, 2018
Subsequent Event [Line Items]
Term loan, maximum borrowing capacity			$ 100,000,000
Gross proceeds from credit facility			50,000,000
Line of credit facility available upon achievement of specified minimum revenue milestone			$ 50,000,000
Line of credit facility closing date			Oct. 31, 2022
Line of credit facility, description				the lenders agreed to make term loans available to the Company in an aggregate amount of $100 million, consisting of (i) an aggregate amount of $50 million available on October 31, 2017 and (ii) an aggregate amount of $50 million available to be drawn at the Company’s option between March 31, 2018 and June 30, 2018, provided the Company has achieved a specified minimum revenue milestone and no event of default is occurring.
Subsequent Event
Subsequent Event [Line Items]
Payment of existing term loan	$ 50,000,000
Subsequent Event | Loan Agreement
Subsequent Event [Line Items]
Term loan, maximum borrowing capacity	$ 155,000,000
Number of tranches | Tranche	2
First Tranche | Subsequent Event | Loan Agreement
Subsequent Event [Line Items]
Gross proceeds from credit facility		$ 125,000,000
Line of credit facility closing date		May 8, 2018
Second Tranche | Subsequent Event | Loan Agreement
Subsequent Event [Line Items]
Line of credit facility available upon achievement of specified minimum revenue milestone	$ 30,000,000
Line of credit facility closing date	May 1, 2023
Line of credit facility, description	The second tranche of $30.0 million may be drawn at the Company’s option between September 30, 2018 and December 31, 2018 provided the Company has achieved a specified minimum revenue milestone and no event of default is occurring.