Clovis Oncology (CLVSQ) 10-K 29 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 19, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	CLVS
Entity Registrant Name	CLOVIS ONCOLOGY, INC.
Entity Central Index Key	1,466,301
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		38,359,454
Entity Public Float			$ 2,122,270,803

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	[1]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
License and milestone revenue									$ 13,625		$ 13,625
Operating expenses:
Research and development	$ 75,995	$ 76,138		$ 60,368	$ 56,750	$ 50,149	$ 34,965	$ 28,440	24,151	$ 269,251	137,705	$ 66,545
General and administrative	8,238	8,331		7,204	6,751	5,605	5,267	5,265	5,320	30,524	21,457	16,567
Acquired in-process research and development		12,000						400	8,406	12,000	8,806	250
Impairment of intangible asset	89,557								3,409	89,557	3,409
Change in fair value of contingent purchase consideration	(26,882)	783		764	724	(1,864)	888	861	822	(24,611)	707	405
Total expenses	146,908	97,252		68,336	64,225	53,890	41,120	34,966	42,108	376,721	172,084	83,767
Operating loss	(146,908)	(97,252)		(68,336)	(64,225)	(53,890)	(41,120)	(34,966)	(28,483)	(376,721)	(158,459)	(83,767)
Other income (expense):
Interest expense	(2,101)	(2,099)		(2,097)	(2,075)	(2,093)	(511)			(8,372)	(2,604)
Foreign currency gains (losses)	736	(101)		(1,142)	3,247	1,001	2,323	316	(60)	2,740	3,580	(535)
Other income (expense)	164	179		62	11	(106)	(42)	(46)	(46)	416	(240)	(178)
Other income (expense), net	(1,201)	(2,021)		(3,177)	1,183	(1,198)	1,770	270	(106)	(5,216)	736	(713)
Loss before income taxes	(148,109)	(99,273)		(71,513)	(63,042)	(55,088)	(39,350)	(34,696)	(28,589)	(381,937)	(157,723)	(84,480)
Income tax benefit (expense)	28,568	628		(18)	(102)	181	(292)	(68)	(2,129)	29,076	(2,308)	(52)
Net loss	$ (119,541)	$ (98,645)		$ (71,531)	$ (63,144)	$ (54,907)	$ (39,642)	$ (34,764)	$ (30,718)	$ (352,861)	$ (160,031)	$ (84,532)
Basic and diluted net loss per common share	$ (3.12)	$ (2.62)		$ (2.10)	$ (1.86)	$ (1.62)	$ (1.17)	$ (1.03)	$ (0.91)	$ (9.79)	$ (4.72)	$ (2.95)
Basic and diluted weighted average common shares outstanding	38,321	37,613		34,088	34,011	33,941	33,921	33,872	33,820	36,026	33,889	28,672
[1]	In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (352,861)	$ (160,031)	$ (84,532)
Other comprehensive (loss) income
Foreign currency translation adjustments	(22,629)	(29,144)	4,643
Net unrealized loss on available-for-sale securities	(383)
Other comprehensive (loss) income	(23,012)	(29,144)	4,643
Comprehensive loss	$ (375,873)	$ (189,175)	$ (79,889)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 278,756	$ 482,677
Available-for-sale securities	249,832
Prepaid research and development expenses	3,377	3,765
Other current assets	7,736	4,730
Total current assets	539,701	491,172
Property and equipment, net	4,946	2,718
Intangible assets	101,500	212,900
Goodwill	59,327	66,055
Other assets	7,912	4,541
Total assets	713,386	777,386
Current liabilities:
Accounts payable	11,260	2,917
Accrued research and development expenses	53,011	37,257
Other accrued expenses	11,305	7,598
Total current liabilities	75,576	47,772
Contingent purchase consideration	24,661	52,453
Deferred income taxes, net	31,133	66,851
Convertible senior notes	279,885	278,680
Deferred rent, long-term	1,481
Total liabilities	$ 412,736	$ 445,756
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, par value $0.001 per share; 10,000,000 shares authorized, no shares issued and outstanding at December 31, 2015 and 2014
Common stock, $0.001 par value per share, 100,000,000 shares authorized at December 31, 2015 and 2014; 38,359,454 and 33,977,187 shares issued and outstanding at December 31, 2015 and 2014, respectively	$ 38	$ 34
Additional paid-in capital	1,129,978	785,089
Accumulated other comprehensive loss	(47,460)	(24,448)
Accumulated deficit	(781,906)	(429,045)
Total stockholders' equity	300,650	331,630
Total liabilities and stockholders' equity	$ 713,386	$ 777,386

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	38,359,454	33,977,187
Common stock, shares outstanding	38,359,454	33,977,187

Consolidated Statements of Stoc

Consolidated Statements of Stockholders Equity - USD ($) $ in Thousands	Total	Ethical Oncology Science, S.p.A.	Common Stock	Common StockEthical Oncology Science, S.p.A.	Additional Paid-In Capital	Additional Paid-In CapitalEthical Oncology Science, S.p.A.	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance at Dec. 31, 2012	$ 133,496		$ 26		$ 317,899		$ 53	$ (184,482)
Beginning Balance (in shares) at Dec. 31, 2012			26,207,190
Issuance of stock	259,071		$ 4		259,067
Issuance of stock (in shares)			3,819,444
Issuance of common stock related to EOS acquisition		$ 173,654		$ 4		$ 173,650
Issuance of common stock related to EOS acquisition (in shares)				3,713,731
Issuance of common stock under employee stock purchase plan	378				378
Issuance of common stock under employee stock purchase plan (in shares)			16,324
Exercise of stock options	1,671				1,671
Exercise of stock options (in shares)			140,632
Share-based compensation expense	9,505				9,505
Foreign currency translation adjustments	4,643						4,643
Net loss	(84,532)							(84,532)
Ending Balance at Dec. 31, 2013	497,886		$ 34		762,170		4,696	(269,014)
Ending Balance (in shares) at Dec. 31, 2013			33,897,321
Issuance of common stock under employee stock purchase plan	481				481
Issuance of common stock under employee stock purchase plan (in shares)			13,633
Exercise of stock options	921				921
Exercise of stock options (in shares)			66,233
Share-based compensation expense	21,517				21,517
Foreign currency translation adjustments	(29,144)						(29,144)
Net loss	(160,031)							(160,031)
Ending Balance at Dec. 31, 2014	$ 331,630		$ 34		785,089		(24,448)	(429,045)
Ending Balance (in shares) at Dec. 31, 2014	33,977,187		33,977,187
Issuance of stock	$ 298,509		$ 4		298,505
Issuance of stock (in shares)			4,054,487
Issuance of common stock under employee stock purchase plan	493				493
Issuance of common stock under employee stock purchase plan (in shares)			32,021
Exercise of stock options	$ 5,534				5,534
Exercise of stock options (in shares)	295,759		295,759
Share-based compensation expense	$ 40,357				40,357
Net unrealized loss on available-for-sale securities	(383)						(383)
Foreign currency translation adjustments	(22,629)						(22,629)
Net loss	(352,861)							(352,861)
Ending Balance at Dec. 31, 2015	$ 300,650		$ 38		$ 1,129,978		$ (47,460)	$ (781,906)
Ending Balance (in shares) at Dec. 31, 2015	38,359,454		38,359,454

Consolidated Statements of Sto7

Consolidated Statements of Stockholders Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013
Statement Of Stockholders Equity [Abstract]
Issuance of stock, issuance costs	$ 17,741	$ 15,929

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net loss	$ (352,861)	$ (160,031)	$ (84,532)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	40,357	21,517	9,505
Depreciation and amortization	761	444	250
Amortization of premiums and discounts on available-for-sale securities	1,400
Amortization of debt issuance costs	1,205	368
Impairment of intangible asset	89,557	3,409
Change in fair value of contingent purchase consideration	(27,792)	(3,301)	1,028
Loss on disposal of equipment	39	67
Deferred income taxes	(28,874)	761
Changes in operating assets and liabilities, net of acquisition of a business:
Prepaid and accrued research and development expenses	14,122	18,112	3,276
Other operating assets	(4,380)	(910)	(995)
Accounts payable	8,105	(1,369)	958
Other accrued expenses	5,295	3,882	(1,202)
Net cash used in operating activities	(253,066)	(117,051)	(71,712)
Investing activities
Purchases of property and equipment	(3,035)	(2,286)	(121)
Purchases of available-for-sale securities	(392,540)
Sales of available-for-sale securities	140,997
Acquisition of business, net of cash acquired			(9,913)
Net cash used in investing activities	(254,578)	(2,286)	(10,034)
Financing activities
Proceeds from the sale of common stock, net of issuance costs	298,509		259,071
Proceeds from the issuance of convertible senior notes, net of issuance costs		278,313
Proceeds from the exercise of stock options and employee stock purchases	5,971	1,163	1,771
Net cash provided by financing activities	304,480	279,476	260,842
Effect of exchange rate changes on cash and cash equivalents	(757)	(690)	35
(Decrease) increase in cash and cash equivalents	(203,921)	159,449	179,131
Cash and cash equivalents at beginning of period	482,677	323,228	144,097
Cash and cash equivalents at end of period	278,756	$ 482,677	323,228
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 7,307
Non-cash investing and financing activities:
Issuance of shares for acquisition of business			173,654
Contingent consideration for acquisition of business			$ 55,754

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Clovis Oncology, Inc. (the “Company”) is a biopharmaceutical company focused on acquiring, developing and commercializing innovative anti-cancer agents in the United States, Europe and other international markets. The Company has and intends to continue to license or acquire rights to oncology compounds in all stages of clinical development. In exchange for the right to develop and commercialize these compounds, the Company generally expects to provide the licensor with a combination of upfront payments, milestone payments and royalties on future sales. In addition, the Company generally expects to assume the responsibility for future drug development and commercialization costs. The Company currently operates in one segment. Since inception, the Company’s operations have consisted primarily of developing in-licensed compounds, evaluating new product acquisition candidates and general corporate activities. In July 2015, the Company submitted a New Drug Application (“NDA”) regulatory filing and a Marketing Authorization Application (“MAA”) for rociletinib to the U.S. Food and Drug Administration (“FDA”) and the European Medicines Agency (“EMA”), respectively. Both the FDA and EMA subsequently accepted the respective filings, and they are currently under active review. In December 2015, the FDA extended the Prescription Drug User Fee Act goal date for the rociletinib NDA by three months to June 28, 2016 to allow additional time for review of additional clinical data submitted by the Company in a Major Amendment in November 2015. The FDA has scheduled the NDA for rociletinib for discussion by the Oncologic Drugs Advisory Committee (“ODAC”) on April 12, 2016. The ODAC reviews and evaluates data concerning the safety and effectiveness of marketed and investigational human drug products used in the treatment of cancer and makes recommendations to the FDA. Liquidity The Company has incurred significant net losses since inception and has relied on its ability to fund its operations through debt and equity financings. Management expects operating losses and negative cash flows to continue for the foreseeable future. As the Company continues to incur losses, transition to profitability is dependent upon the successful development, approval and commercialization of its product candidates and achieving a level of revenues adequate to support the Company’s cost structure. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional cash. Management intends to fund future operations through additional private or public debt or equity offerings and may seek additional capital through arrangements with strategic partners or from other sources. Based on current estimates, management believes that existing working capital at December 31, 2015 is sufficient to meet the cash requirements to fund planned operations through the next 12 months, although there can be no assurance that this can, in fact, be accomplished.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Reclassifications Certain reclassifications have been made to prior year amounts to conform to the current year presentation. These reclassifications had no effect on the Company’s previously reported results of operations, financial position or cash flows. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, expenses and revenue and related disclosures. On an ongoing basis, management evaluates its estimates, including estimates related to contingent purchase consideration, the allocation of purchase consideration, intangible asset impairment, clinical trial accruals and share-based compensation expense. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions. Fair Value of Financial Instruments Cash, cash equivalents, available-for-sale securities and contingent purchase consideration are carried at fair value (see Note 5). Financial instruments, including other current assets and accounts payable, are carried at cost, which approximates fair value given their short-term nature. Cash, Cash Equivalents and Available-for-Sale Securities The Company considers all highly liquid investments with original maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include bank demand deposits and money market funds that invest primarily in certificate of deposits, commercial paper and U.S. government and U.S. government agency obligations. Marketable securities are considered to be available-for-sale securities and consist of U.S. treasury securities. Available-for-sale securities are reported at fair value on the Consolidated Balance Sheets and unrealized gains and losses are included in accumulated other comprehensive income (loss) on the Consolidated Balance Sheets. Realized gains and losses, amortization of premiums and discounts and interest and dividends earned are included in other income (expense) on the Consolidated Statements of Operations. The cost of investments for purposes of computing realized and unrealized gains and losses is based on the specific identification method. Investments with maturities beyond one year are classified as short-term based on management’s intent to fund current operations with these securities or to make them available for current operations. A decline in the market value of a security below its cost that is deemed to be other than temporary is charged to earnings and results in the establishment of a new cost basis for the security. Factors evaluated to determine if an investment is other-than-temporarily impaired include significant deterioration in earnings performance, credit rating, asset quality or business prospects of the issuer; adverse changes in the general market conditions in which the issuer operates; and the Company’s intent and ability to hold the security until an anticipated recovery in value occurs. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Equipment purchased for use in manufacturing and clinical trials is evaluated to determine whether the equipment is solely beneficial for a drug candidate in the development stage or whether it has an alternative use. Equipment with an alternative use is capitalized. Leasehold improvements are amortized over the economic life of the asset or the lease term, whichever is shorter. Maintenance and repairs are expensed as incurred. The estimated useful lives of our capitalized assets are as follows: Estimated Useful Life Computer hardware and software 3 to 5 years Leasehold improvements 6 years Laboratory, manufacturing and office equipment 5 to 7 years Furniture and fixtures 10 years Long-Lived Assets The Company reviews long-lived assets for impairment when events or changes in circumstances indicate that the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the assets’ book value to future net undiscounted cash flows that the assets are expected to generate. If the carrying value of the assets exceed their future net undiscounted cash flows, an impairment charge is recognized for the amount by which the carrying value of the assets exceeds the fair value of the assets. Intangible Assets Intangible acquired in-process research and development (“IPR&D”) assets were established as part of the acquisition of Ethical Oncology Science, S.p.A. (“EOS”) (see Note 3) and are not amortized. Amortization of these assets will commence upon completion of the related research and development activities. IPR&D intangible assets are evaluated for impairment at least annually in the fourth quarter or more frequently if impairment indicators exist and any reduction in fair value would be recorded as impairment of intangible asset on the Consolidated Statements of Operations. During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge to the IPR&D intangible assets (see Note 7). Goodwill Goodwill represents the excess of the purchase price over the fair value of net assets acquired in a business combination accounted for under the acquisition method of accounting and is not amortized, but is subject to impairment testing at least annually in the fourth quarter or when a triggering event is identified that could indicate a potential impairment. We are organized as a single reporting unit and perform impairment testing by comparing the carrying value of the reporting unit to the fair value of the Company. Other Current Assets Other current assets are comprised of the following (in thousands): December 31, 2015 2014 Receivable from partners $ 3,241 $ 1,991 Prepaid insurance 1,231 1,190 Receivable from landlord 1,153 — Prepaid expenses - other 1,023 1,168 Receivable - other 889 281 Other 199 100 Total $ 7,736 $ 4,730 Other Accrued Expenses Other accrued expenses are comprised of the following (in thousands): December 31, 2015 2014 Accrued personnel costs $ 8,250 $ 4,726 Accrued interest payable 2,096 2,236 Accrued expenses - other 959 636 Total $ 11,305 $ 7,598 Valuation of Contingent Consideration Resulting from a Business Combination Subsequent to the acquisition date, we re-measure contingent consideration arrangements at fair value each reporting period and record changes in fair value to change in fair value of contingent purchase consideration and foreign currency gains (losses) for changes in the foreign currency translation rate on the Consolidated Statements of Operations. Changes in fair value are primarily attributed to new information about the IPR&D assets, including changes in timeline and likelihood of success, and the passage of time. In the absence of new information, changes in fair value reflect only the passage of time. During the fourth quarter of 2015, the Company recorded a $26.9 million reduction in the fair value of the contingent purchase consideration liability (see Note 5). Research and Development Expense Research and development costs are charged to expense as incurred and include, but are not limited to, salary and benefits, share-based compensation, clinical trial activities, drug development and manufacturing, companion diagnostic development and third-party service fees, including clinical research organizations and investigative sites. During 2015, we completed the hiring of our U.S. sales and marketing and medical affairs organizations in preparation for the potential commercial launch of rociletinib. These costs are also included in research and development expense. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations or information provided to us by our vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred and are reflected on the Consolidated Balance Sheets as prepaid or accrued research and development expenses. Acquired In-Process Research and Development Expense The Company has acquired and expects to continue to acquire the rights to develop and commercialize new drug candidates. The upfront payments to acquire a new drug compound, as well as subsequent milestone payments, are immediately expensed as acquired in-process research and development provided that the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, has no alternative future use. Share-Based Compensation Expense Share-based compensation is recognized as expense for all share-based awards made to employees and directors and is based on estimated fair values. The Company determines equity-based compensation at the grant date using the Black-Scholes option pricing model. The value of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the requisite service period. Any changes to the estimated forfeiture rates are accounted for prospectively. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances in the form of money market accounts with financial institutions that management believes are creditworthy. Available-for-sale securities are invested in accordance with the Company’s investment policy. The investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company has no financial instruments with off-balance sheet risk of accounting loss. Foreign Currency The assets and liabilities of the Company’s foreign operations are translated into U.S. dollars at current exchange rates and the results of operations are translated at the average exchange rates for the reported periods. The resulting translation adjustments are included in accumulated other comprehensive loss on the Consolidated Balance Sheets. Transactions denominated in currencies other than the functional currency are recorded based on exchange rates at the time such transactions arise. Transaction gains and losses are recorded to foreign currency gains (losses) on the Consolidated Statements of Operations. As of December 31, 2015 and 2014, approximately 3% and 7%, respectively, of the Company’s total liabilities were denominated in currencies other than the functional currency. Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Tax benefits are recognized when it is more likely than not that a tax position will be sustained during an audit. Deferred tax assets are reduced by a valuation allowance if current evidence indicates that it is considered more likely than not that these benefits will not be realized. Revenue Recognition Revenue is recognized from license milestone payments when the following criteria have been met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the price is fixed or determinable; and (4) collectability is reasonably assured. We exercise judgment in determining that collectability is reasonably assured or that services have been delivered in accordance with the arrangement. We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. We assess collectability based primarily on the customer's payment history and creditworthiness of the customer. Payments that are contingent upon the achievement of a substantive milestone will be recognized in the period in which the milestone is achieved. Recently Adopted Accounting Standards In April 2015, the FASB issued ASU No. 2015-03, “Interest – Imputation of Interest (Subtopic 835-30) – Simplifying the Presentation of Debt Issuance Costs.” ASU No. 2015-03 requires debt issuance costs to be presented as a deduction from the corresponding debt liability rather than as an asset. This update is effective for fiscal years beginning after December 15, 2015, including interim periods within those years. Early adoption is permitted. Upon adoption, the guidance must be applied retrospectively to all periods presented in the financial statements. The Company elected to early adopt this standard effective December 31, 2015. Adoption of the standard resulted in the reclassification of the Company’s debt issuance costs from other assets to convertible senior notes on its Consolidated Balance Sheets. In November 2015, the FASB issued ASU No. 2015-17, “Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes.” ASU No. 2015-17 requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. This update is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. Early adoption is permitted. Upon adoption, the guidance may be applied either prospectively, for all deferred tax assets and liabilities, or retrospectively to all periods presented in the financial statements. The Company elected to early adopt this standard effective December 31, 2015. Adoption of this standard was applied retrospectively and resulted in no change to the Company’s Consolidated Balance Sheets. Recently Issued Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 specifies the accounting for revenue from contracts with customers and establishes disclosure requirements relating to the nature, timing and uncertainty of revenue and cash flows arising from an entity’s contracts with customers. In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” which delayed the effective date of the standard to annual and interim periods beginning after December 15, 2017. Early application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods. ASU 2014-09 allows for either full retrospective or modified retrospective adoption. The Company is currently evaluating its planned method of adoption and the impact the standard may have on its consolidated financial statements and related disclosures. In August 2014, the FASB issued ASU No. 2014-15, “Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern,” which requires management to evaluate whether there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern and to provide disclosures when certain criteria are met. The guidance is effective for annual periods beginning in 2016 and interim reporting periods starting in the first quarter of 2017. Early application is permitted. The Company is currently evaluating the impact the standard may have on its disclosures. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842),” which requires lessees to recognize assets and liabilities for the rights and obligations created by most leases on their balance sheet. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted. ASU 2016-02 requires modified retrospective adoption for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The Company is currently evaluating the impact the standard may have on its consolidated financial statements and related disclosures.

EOS Acquisition

EOS Acquisition	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
EOS Acquisition	3. EOS Acquisition On November 19, 2013, the Company acquired all of the outstanding common and preferred stock of EOS (now known as Clovis Oncology Italy S.r.l.). EOS was a biopharmaceutical company located in Italy that focused on the development of novel medicines for the treatment of cancer. The primary reason for the business acquisition was to obtain development and commercialization rights to lucitanib, an oral, selective tyrosine kinase inhibitor. The Company paid $11.8 million in cash and issued $173.7 million of common stock at the acquisition date and may make additional future cash payments if certain regulatory and sales milestones are achieved. The results of operations for EOS were included in our consolidated financial statements from the acquisition date, and the assets acquired and liabilities assumed of EOS were recorded as of the acquisition date at their respective fair values and consolidated with those of the Company. As part of the acquisition of EOS, the Company recorded intangible assets on the Consolidated Balance Sheets to reflect the fair value of IPR&D, which was based on two components. The first was the estimated fair value of lucitanib development and commercialization rights sublicensed by EOS to Servier (see Note 12 – Lucitanib). The estimated fair value of these rights was $56.1 million at the date of the acquisition based on probability-weighted cash flow payments due from Servier upon the achievement of certain development, regulatory and commercial milestones, as well as future royalty payments resulting from the sale of lucitanib in the sublicensed territories. The second component was based on the fair value of the expected net cash flows for the development and commercialization rights of lucitanib in the United States and Japan held by EOS at acquisition. The estimated fair value of $183.8 million for these rights was based on probability-weighted net cash flows of the anticipated lucitanib development and sales activities. Key assumptions used in the discounted cash flow models include estimates related to the timing of development, probability of development and regulatory success, sales and commercialization factors and estimated product life. The excess purchase price over the fair value of amounts assigned to the assets acquired and liabilities assumed was recorded as goodwill on the Consolidated Balance Sheets. The Company is obligated to pay additional consideration to the former EOS shareholders if certain future regulatory and lucitanib-related sales milestones are achieved. The estimated fair value of these payments was recorded as contingent purchase consideration on the Consolidated Balance Sheets. The initial estimated fair value of the contingent purchase consideration was $54.7 million at the acquisition date, which was determined based on the assumptions described below. Pursuant to the sublicense agreement with Servier, the Company is eligible to receive future milestone payments based on the achievement of development, regulatory and sales milestones. Certain of the contingent consideration payments owed from the Company to the former EOS shareholders are tied to the receipt of milestone payments from Servier. A summary of the contingent payment obligations is as follows (in thousands and payment currency): Amount Initial approval of an NDA for lucitanib in the U.S. $ 65,000 Obligations associated with the receipt of milestone payments from Servier: Initial filing of a MAA for lucitanib in the E.U. € 15,000 Initial approval of a MAA for lucitanib in the E.U. € 45,000 Initial achievement of lucitanib net sales in Servier licensed territory of €500 million in any four consecutive quarters € 55,000 Total € 115,000 The fair value of the MAA filing and approval obligations of $52.5 million was based on the discounting of the probability-weighted future milestone payments using an estimated borrowing rate ranging from 5.2% to 5.8%, which represented our estimated borrowing rate for the various terms the payment obligations were expected to be outstanding. The sales milestone fair value of $2.2 million was based on the probability-weighted future milestone payments using the risk-adjusted discount rate of 18.7%. The potential contingent milestone payments range from a zero payment, which assumes lucitanib fails to achieve any of the regulatory milestones, to $190.5 million ($65.0 million and €115.0 million) if all regulatory and sales milestones are met, utilizing the translation rate at December 31, 2015. During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge to the IPR&D intangible assets and a $26.9 million reduction in the fair value of the contingent purchase consideration liability (see Note 5 and Note 7).

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment consisted of the following (in thousands): December 31, 2015 2014 Laboratory, manufacturing and office equipment $ 2,556 $ 2,452 Leasehold improvements 1,861 260 Furniture and fixtures 1,487 667 Computer hardware and software 833 414 Total property and equipment 6,737 3,793 Less: accumulated depreciation (1,791 ) (1,075 ) Total property and equipment, net $ 4,946 $ 2,718 Depreciation expense related to property and equipment was approximately $761 thousand, $444 thousand and $250 thousand for the years ended December 31, 2015, 2014 and 2013, respectively.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. Fair Value Measurements Fair value is defined as the exchange price that would be received to sell an asset or paid to transfer a liability (at exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The three levels of inputs that may be used to measure fair value include: Level 1: Quoted prices in active markets for identical assets or liabilities. The Company’s Level 1 assets consist of money market investments. The Company does not have Level 1 liabilities. Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities in active markets or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 assets consist of U.S. treasury securities. The Company does not have Level 2 liabilities. Level 3: Unobservable inputs that are supported by little or no market activity. The Company does not have Level 3 assets. The contingent purchase consideration related to the undeveloped lucitanib product rights acquired with the purchase of EOS is a Level 3 liability. The fair value of this liability is based on unobservable inputs and includes valuations for which there is little, if any, market activity. See Note 3 for further discussion of the valuation methodology. The following table identifies the Company’s assets and liabilities that were measured at fair value on a recurring basis (in thousands): Balance Level 1 Level 2 Level 3 December 31, 2015 Assets: Money market $ 251,037 $ 251,037 $ — $ — U.S. treasury securities 249,832 — 249,832 — Total assets at fair value $ 500,869 $ 251,037 $ 249,832 $ — Liabilities: Contingent purchase consideration $ 24,661 $ — $ — $ 24,661 Total liabilities at fair value $ 24,661 $ — $ — $ 24,661 December 31, 2014 Assets: Money market $ 447,994 $ 447,994 $ — $ — Total assets at fair value $ 447,994 $ 447,994 $ — $ — Liabilities: Contingent purchase consideration $ 52,453 $ — $ — $ 52,453 Total liabilities at fair value $ 52,453 $ — $ — $ 52,453 There were no transfers between the Level 1 and Level 2 categories or into or out of the Level 3 category during the year ended December 31, 2015. The following table rolls forward the fair value of Level 3 instruments (significant unobservable inputs) (in thousands): Year Ended December 31, 2015 Liabilities: Balance at beginning of period $ 52,453 Change in fair value (a) (24,611 ) Change in foreign currency gains and losses (3,181 ) Balance at end of period $ 24,661 (a) The decrease in the fair value of the contingent purchase consideration was due to a change in the estimated probability-weighted future milestone payments discounted using an estimated borrowing rate ranging from 8.5% to 8.6%, as well as the timing of such payments, for the lucitanib program. The change in the fair value of Level 3 instruments is included in change in fair value of contingent purchase consideration and foreign currency gains (losses) for changes in the foreign currency translation rate on the Consolidated Statements of Operations. Financial instruments not recorded at fair value include the Company’s convertible senior notes. At December 31, 2015, the carrying amount of the convertible senior notes was $287.5 million, which represents the aggregate principal amount, and the fair value was $248.7 million. The fair value was determined using Level 2 inputs based on the indicative pricing published by certain investment banks or trading levels of the convertible senior notes, which are not listed on any securities exchange or quoted on an inter-dealer automated quotation system. See Note 8 for discussion of the convertible senior notes.

Available-for-Sale Securities

Available-for-Sale Securities	12 Months Ended
	Dec. 31, 2015
Available For Sale Securities [Abstract]
Available-for-Sale Securities	6. Available-for-Sale Securities As of December 31, 2015, available-for-sale securities consisted of the following (in thousands): Gross Gross Aggregate Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. treasury securities $ 250,215 $ — $ (383 ) $ 249,832 As of December 31, 2015, the fair value and gross unrealized losses of available-for-sale securities that have been in a continuous unrealized loss position for less than 12 months were as follows (in thousands): Aggregate Gross Fair Unrealized Value Losses U.S. treasury securities $ 249,832 $ (383 ) The Company’s investments have been in an unrealized loss position for between two to three months. Based upon our evaluation of all relevant factors, we believe that the decline in fair value of securities held at December 31, 2015 below cost is temporary, and we intend to retain our investment in these securities for a sufficient period of time to allow for recovery of the fair value. As of December 31, 2015, the amortized cost and fair value of available-for-sale securities by contractual maturity were (in thousands): Amortized Fair Cost Value Due in one year or less $ 200,147 $ 199,912 Due in one year to two years 50,068 49,920 Total $ 250,215 $ 249,832

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	7. Intangible Assets and Goodwill IPR&D assets and goodwill were established as part of the purchase accounting of EOS (see Note 3) and consisted of the following (in thousands): December 31, 2015 2014 IPR&D assets: Balance at beginning of period $ 212,900 $ 244,518 Impairment of intangible asset (a) (89,557 ) (3,409 ) Change in foreign currency gains and losses (21,843 ) (28,209 ) Balance at end of period $ 101,500 $ 212,900 Goodwill: Balance at beginning of period $ 66,055 $ 74,811 Change in foreign currency gains and losses (6,728 ) (8,756 ) Balance at end of period $ 59,327 $ 66,055 (a) During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge due to the Company’s and its development partner’s decision to terminate the development of lucitanib for lung cancer, as well as updates to the probability-weighted discounted cash flow assumptions for the breast cancer indication. As of December 31, 2015, no impairment to the carrying value of the goodwill was identified.

Convertible Senior Notes

Convertible Senior Notes	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Convertible Senior Notes	8. Convertible Senior Notes On September 9, 2014, we completed a private placement of $287.5 million aggregate principal amount of 2.5% convertible senior notes due 2021 (the “Notes”) resulting in net proceeds to the Company of $278.3 million after deducting offering expenses. In accordance with the accounting guidance, the conversion feature did not meet the criteria for bifurcation, and the entire principal amount was recorded as a long-term liability on the Consolidated Balance Sheets. The Notes are governed by the terms of the indenture between the Company, as issuer, and The Bank of New York Mellon Trust Company, N.A., as trustee. The Notes are senior unsecured obligations and bear interest at a rate of 2.5% per year, payable semi-annually in arrears on March 15 and September 15 of each year. The Notes will mature on September 15, 2021, unless earlier converted, redeemed or repurchased. Holders may convert all or any portion of the Notes at any time prior to the close of business on the business day immediately preceding the maturity date. Upon conversion, the holders will receive shares of our common stock at an initial conversion rate of 16.1616 shares per $1,000 in principal amount of Notes, equivalent to a conversion price of approximately $61.88 per share. The conversion rate is subject to adjustment upon the occurrence of certain events described in the indenture, but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date or upon our issuance of a notice of redemption, we will increase the conversion rate for holders who elect to convert the Notes in connection with such a corporate event or during the related redemption period in certain circumstances. On or after September 15, 2018, we may redeem the Notes, at our option, in whole or in part, if the last reported sale price of our common stock has been at least 150% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending not more than two trading days preceding the date on which we provide written notice of redemption at a redemption price equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the Notes. If we undergo a fundamental change, as defined in the indenture, prior to the maturity date of the Notes, holders may require us to repurchase for cash all or any portion of the Notes at a fundamental change repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The Notes rank senior in right of payment to any of our indebtedness that is expressly subordinated in right of payment to the Notes; equal in right of payment to all of our liabilities that are not so subordinated; effectively junior in right of payment to any secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of our subsidiaries. In connection with the issuance of the Notes, the Company incurred $9.2 million of debt issuance costs, which was included in other assets on the Consolidated Balance Sheets. Pursuant to its adoption of ASU No. 2015-03 on December 31, 2015, the Company reclassified the debt issuance costs from other assets to convertible senior notes (see Note 2 – Recently Adopted Accounting Standards). The debt issuance costs are amortized as interest expense over the expected life of the Notes using the effective interest method. The Company determined the expected life of the debt was equal to the seven-year term of the Notes. As of December 31, 2015 and 2014, the balance of unamortized debt issuance costs was $7.6 million and $8.8 million, respectively. The following table sets forth total interest expense recognized related to the Notes during the years ended December 31, 2015 and 2014 (in thousands): Year Ended December 31, 2015 2014 Contractual interest expense $ 7,167 $ 2,236 Amortization of debt issuance costs 1,205 368 Total interest expense $ 8,372 $ 2,604

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	9. Stockholders’ Equity Common Stock In June 2013, the Company sold 3,819,444 shares of its common stock in a public offering at $72.00 per share. The net offering proceeds realized after deducting offering expenses and underwriters’ discounts and commissions were $259.1 million. In November 2013, the Company issued 3,713,731 shares of its common stock at a value of $173.7 million to acquire all of the outstanding common and preferred stock of EOS. In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million, after deducting underwriting discounts and commissions and offering expenses. The holders of common stock are entitled to one vote per share on all matters to be voted upon by the stockholders of the Company. Subject to the preferences that may be applicable to any outstanding shares of preferred stock, the holders of common stock are entitled to receive ratably such dividends, if any, as may be declared by the Company’s Board of Directors. Accumulated Other Comprehensive Loss Accumulated other comprehensive loss consists of changes in foreign currency translation adjustments, which includes changes in a subsidiary’s functional currency, and unrealized gains and losses on available-for-sale securities. The accumulated balances related to each component of other comprehensive income (loss) are summarized as follows (in thousands): Total Foreign Accumulated Currency Other Translation Unrealized Comprehensive Adjustments Losses Income (Loss) Balance December 31, 2013 $ 4,696 $ — $ 4,696 Period change (29,144 ) — (29,144 ) Balance December 31, 2014 (24,448 ) — (24,448 ) Period change (22,629 ) (383 ) (23,012 ) Balance December 31, 2015 $ (47,077 ) $ (383 ) $ (47,460 ) The period change between December 31, 2015 and 2014 was primarily due to the currency translation of the IPR&D intangible assets, goodwill and deferred income taxes associated with the acquisition of EOS (see Note 3 and Note 7).

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	10. Share-Based Compensation Stock Options In May 2009, the Company’s Board of Directors approved the 2009 Equity Incentive Plan (the “2009 Plan”). The 2009 Plan provided for the granting of stock options and other share-based awards, including restricted stock, stock appreciation rights and restricted stock units to its employees, directors and consultants. Common shares authorized for issuance under the 2009 Plan were 1,317,125 at December 31, 2015. Options to purchase common stock under the 2009 Plan were designated as incentive stock options or non-statutory stock options. Stock options granted under the 2009 Plan vest over either a one-year period or three-year period for Board of Director grants and over a four-year period for employee grants and expire 10 years from the date of grant. Upon the closing of the Company’s initial public offering in November 2011, the 2009 Plan was closed, resulting in the termination of new grants from this plan and the transfer of all shares available for future issuance to the 2011 Stock Incentive Plan. Future forfeitures and cancellations of options previously granted under the 2009 Plan were transferred to the 2011 Stock Incentive Plan and are available for grant under the 2011 Plan. In August 2011, the Company’s Board of Directors approved the 2011 Stock Incentive Plan (the “2011 Plan”), which became effective upon the closing of the Company’s initial public offering in November 2011. The 2011 Plan provides for the granting of incentive and nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units, performance awards and other share-based awards to its employees, directors and consultants. Common shares authorized for issuance under the 2011 Plan were 6,262,641 at December 31, 2015, which represents the initial reserve of 1,250,000 shares of common stock plus 191,496 shares of common stock remaining for future grant from the 2009 Equity Incentive Plan and 4,821,145 new shares authorized by the Board of Directors at the annual meetings of stockholders. Stock options granted vest over either a one-year period or three-year period for Board of Director grants or over a four-year period for employee grants and expire 10 years from the date of grant. Share-based compensation expense for the years ended December 31, 2015, 2014 and 2013, respectively, was recognized in the accompanying Consolidated Statements of Operations as follows (in thousands): Year Ended December 31, 2015 2014 2013 Research and development (a) $ 27,321 $ 11,474 $ 4,289 General and administrative 13,036 10,043 5,216 Total share-based compensation expense $ 40,357 $ 21,517 $ 9,505 (a) During the third quarter of 2015, the Company recognized $2.9 million in share-based compensation expense associated with a modification to the terms of a former executive’s stock option agreement. The Company did not recognize a tax benefit related to share-based compensation expense during the years ended December 31, 2015, 2014 and 2013, respectively, as the Company maintains net operating loss carryforwards and has established a valuation allowance against the entire net deferred tax asset as of December 31, 2015. The following table summarizes the activity relating to the Company’s options to purchase common stock: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (Thousands) Outstanding at December 31, 2014 4,159,362 $ 37.69 Granted (a) 1,600,593 80.04 Exercised (295,759 ) 18.52 Forfeited (103,939 ) 56.93 Outstanding at December 31, 2015 5,360,257 $ 51.53 7.1 $ 33,927 Vested and expected to vest at December 31, 2015 5,030,757 $ 50.22 7.0 $ 33,678 Exercisable at December 31, 2015 2,608,239 $ 34.56 6.0 $ 29,607 (a) Includes 120,000 performance-based stock options granted to executives of the Company in the first quarter of 2015. Fifty percent of the grant vests contingent on approval by the FDA to commercially distribute, sell or market rociletinib and 50% of the grant vests contingent on approval by the FDA to commercially distribute, sell or market rucaparib. Stock compensation expense will be recognized when the condition for vesting is probable of being met. The aggregate intrinsic value in the table above represents the pretax intrinsic value, based on our closing stock price of $35.00 as of December 31, 2015, which would have been received by the option holders had all option holders with in-the-money options exercised their options as of that date. The following table summarizes information about our stock options as of and for the years ended December 31, 2015, 2014 and 2013: Year Ended December 31, 2015 2014 2013 Weighted-average grant date fair value per share $ 52.70 $ 38.47 $ 18.59 Intrinsic value of options exercised $ 19,976,769 $ 2,906,304 $ 6,114,436 Cash received from stock option exercises $ 5,478,211 $ 682,678 $ 1,393,053 The fair value of each share-based award is estimated on the grant date using the Black-Scholes option pricing model based upon the weighted-average assumptions provided in the following table: Year Ended December 31, 2015 2014 2013 Dividend yield — — — Volatility (a) 72 % 70 % 69 % Risk-free interest rate (b) 1.77 % 1.92 % 1.16 % Expected term (years) (c) 6.1 6.2 6.2 (a) Volatility : The expected volatility was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans. (b) Risk-free interest rate: The rate is based on the yield on the grant date of a zero-coupon U.S. Treasury bond whose maturity period approximates the option’s expected term. (c) Expected term: The expected term of the award was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans. Unrecognized share-based compensation expense related to non-vested options, adjusted for expected forfeitures, was $88.6 million as of December 31, 2015. The unrecognized share-based compensation expense is expected to be recognized over the weighted-average remaining vesting period of 2.7 years. Common Stock Reserved for Issuance As of December 31, 2015, the Company reserved shares of common stock for future issuance as follows: Options Outstanding Available for Grant or Future Issuance Total Shares of Common Stock Reserved 2009 Equity Incentive Plan 494,031 — 494,031 2011 Stock Incentive Plan 4,866,226 1,181,722 6,047,948 2011 Employee Stock Purchase Plan — 376,231 376,231 Total 5,360,257 1,557,953 6,918,210 Employee Stock Purchase Plan In August 2011, our Board of Directors approved the Clovis Oncology, Inc. 2011 Employee Stock Purchase Plan (the “Purchase Plan”). Each year, on the date of our annual meeting of stockholders and at the discretion of our board of directors, the amount of shares reserved for issuance under the Purchase Plan may be increased by up to the lesser of (1) a number of additional shares of our common stock representing 1% of our then-outstanding shares of common stock, (2) 344,828 shares of our common stock and (3) a lesser number of shares as approved by the Board. The Purchase Plan provides for consecutive six-month offering periods, during which participating employees may elect to have up to 10% of their compensation withheld and applied to the purchase of common stock at the end of each offering period. The purchase price of the common stock is 85% of the lower of the fair value of a share of common stock on the first trading date of each offering period or the fair value of a share of common stock on the last trading day of the offering period. The Purchase Plan will terminate on August 24, 2021, the tenth anniversary of the date of initial adoption of the Purchase Plan. We sold 32,021 and 13,633 shares to employees in 2015 and 2014, respectively. There were 376,231 shares available for sale under the Purchase Plan as of December 31, 2015. The weighted-average estimated grant date fair value of purchase awards under the Purchase Plan during the years ended December 31, 2015 and 2014 was $26.80 and $17.31 per share, respectively. The total share-based compensation expense recorded as a result of the Purchase Plan was approximately $858 thousand, $236 thousand and $169 thousand during the years ended December 31, 2015, 2014 and 2013, respectively. The fair value of purchase awards granted to our employees during the years ended December 31, 2015, 2014 and 2013, respectively, was estimated using the Black-Scholes option pricing model based upon the weighted-average assumptions provided in the following table: Year Ended December 31, 2015 2014 2013 Dividend yield — — — Volatility (a) 71 % 71 % 72 % Risk-free interest rate (b) 0.11 % 0.07 % 0.09 % Expected term (years) (c) 0.5 0.5 0.5 (a) Volatility : The expected volatility was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans. (b) Risk-free interest rate: The rate is based on the U.S. Treasury yield in effect at the time of grant with terms similar to the contractual term of the purchase right. (c) Expected term: The expected life of the award represents the six-month offering period for the Purchase Plan.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies The Company leases office space in Boulder, Colorado, San Francisco, California, Cambridge, UK and Milan, Italy under non-cancelable operating lease agreements that expire through 2023. The lease agreements contain periodic rent increases that result in the Company recording deferred rent over the terms of certain leases. In June 2015, the Company entered into a seven-year lease agreement for new office space in Boulder, Colorado. Pursuant to the terms of the lease, the landlord will reimburse the Company for $1.1 million of leasehold improvement expenditures (the “Tenant Improvement Allowance”). In December 2015, upon completion of construction, the Company recorded the Tenant Improvement Allowance as deferred rent, which is being amortized as a reduction to rental expense over the lease term. Rental expense under these leases was $2.4 million, $1.4 million and $1.1 million for the years ended December 31, 2015, 2014 and 2013, respectively. Future minimum rental commitments, by fiscal year and in the aggregate, for the Company’s operating leases are provided below (in thousands): December 31, 2015 2016 $ 1,795 2017 1,746 2018 1,783 2019 1,837 2020 1,891 Thereafter 2,547 Total future minimum lease payments $ 11,599 Development and Manufacturing Agreement Commitments In February 2013, the Company entered into a development and manufacturing agreement with a third-party supplier for the production of the active ingredient for rucaparib. Under the Development and Manufacturing Agreement, the Company will provide the third-party supplier a rolling 24-month forecast that will be updated by the Company on a quarterly basis. The Company is obligated to order the quantity specified in the first 12 months of any forecast. During the years ended December 31, 2015, 2014 and 2013, $6.0 million, $3.3 million and $6.4 million, respectively, of purchases were performed under this agreement. As of December 31, 2015, $16.1 million of purchase commitments exist under this agreement. Legal Proceedings The Company and certain of its officers were named as defendants in several lawsuits, as described below. We cannot reasonably predict the outcome of these legal proceedings, nor can we estimate the amount of loss or range of loss, if any, that may result. An adverse outcome in these proceedings could have a material adverse effect on our results of operations, cash flows or financial condition. On November 19, 2015, Steve Kimbro, a purported shareholder of Clovis, filed a purported class action complaint (the “Kimbro Complaint”) against Clovis and certain of its officers in the United States District Court for the District of Colorado. The Kimbro Complaint purports to be asserted on behalf of a class of persons who purchased Clovis stock between October 31, 2013 and November 15, 2015. The Kimbro Complaint generally alleges that Clovis and certain of its officers violated federal securities laws by making allegedly false and misleading statements regarding the progress toward FDA approval and the potential for market success of rociletinib. The Kimbro Complaint seeks unspecified damages. Also on November 19, 2015, a second purported shareholder class action complaint was filed by Sonny P. Medina, another purported Clovis shareholder, containing similar allegations to those set forth in the Kimbro Complaint, also in the United States District Court for the District of Colorado (the “Medina Complaint”). The Medina Complaint purports to be asserted on behalf of a class of persons who purchased Clovis stock between May 20, 2014 and November 13, 2015. On November 20, 2015, a third complaint was filed by John Moran in the United States District Court for the Northern District of California (the “Moran Complaint”). The Moran Complaint contains similar allegations to those asserted in the Kimbro and Medina Complaints and purports to be asserted on behalf of a plaintiff class who purchased Clovis stock between October 31, 2013 and November 13, 2015. On December 14, 2015, Ralph P. Rocco, a fourth purported shareholder of Clovis, filed a complaint in the United States District Court for the District of Colorado (the “Rocco Complaint”). The Rocco Complaint contains similar allegations to those set forth in the previous complaints and purports to be asserted on behalf of a plaintiff class who purchased Clovis stock between October 31, 2013 and November 15, 2015. On January 19, 2016, a number of motions were filed in both the District of Colorado and the Northern District of California seeking to consolidate the shareholder class actions into one matter and for appointment of a lead plaintiff. All lead plaintiff movants other than M.Arkin (1999) LTD and Arkin Communications LTD (the “Arkin Plaintiffs”) subsequently filed notices of non-opposition to the Arkin Plaintiffs’ application. On February 2, 2016, the Arkin Plaintiffs filed a motion to transfer the Moran Complaint to the District of Colorado (the “Motion to Transfer”). Also on February 2, 2016, the defendants filed a statement in the Northern District of California supporting the consolidation of all actions in a single court, the District of Colorado. On February 3, 2016, the Northern District of California court denied without prejudice the lead plaintiff motions filed in that court pending a decision on the Motion to Transfer. On February 16, 2016, the defendants filed a memorandum in support of the Motion to Transfer, and plaintiff Moran filed a notice of non-opposition to the Motion to Transfer. On February 17, 2016, the Northern District of California court granted the Motion to Transfer. On February 18, 2016, the Medina court issued an opinion and order addressing the various motions for consolidation and appointment of lead plaintiff and lead counsel in the District of Colorado actions. By this ruling, the court consolidated the Medina, Kimbro and Rocco actions into a single proceeding. The court also appointed the Arkin Plaintiffs as the lead plaintiffs and Bernstein Litowitz Berger & Grossman as lead counsel for the putative class. The Company intends to vigorously defend against the allegations contained in the Kimbro, Medina, Moran and Rocco Complaints, but there can be no assurance that the defense will be successful. On December 30, 2015, Jamie McCall, a purported shareholder of Clovis, filed a shareholder derivative complaint (the “McCall Complaint”) against certain officers and directors of Clovis in the Colorado District Court, County of Boulder. The McCall Complaint generally alleges that the defendants breached their fiduciary duties owed to Clovis by participating in misrepresentation of the Company’s business operations and prospects. The McCall Complaint also alleges claims for abuse of control, gross mismanagement and unjust enrichment. The McCall Complaint seeks, among other things, an award of money damages, declaratory and injunctive relief concerning the alleged fiduciary breaches and other forms of equitable relief. The Company intends to vigorously defend against the allegations contained in the McCall Complaint, but there can be no assurance that the defense will be successful. On January 22, 2016, the Electrical Workers Local #357 Pension and Health & Welfare Trusts, a purported shareholder of Clovis, filed a purported class action complaint (the “Electrical Workers Complaint”) against Clovis and certain of its officers, directors, investors and underwriters in the Superior Court of the State of California, County of San Mateo. The Electrical Workers Complaint purports to be asserted on behalf of a class of persons who purchased stock in Clovis’ July 8, 2015 follow-on offering. The Electrical Workers Complaint generally alleges that the defendants violated the Securities Act because the offering documents for the July 8, 2015 follow-on offering contained allegedly false and misleading statements regarding the progress toward FDA approval and the potential for market success of rociletinib. The Electrical Workers Complaint seeks unspecified damages. On February 25, 2016, the defendants removed the case to the United States District Court for the Northern District of California and thereafter moved to transfer the case to the District of Colorado. The Company intends to vigorously defend against the allegations contained in the Electrical Workers Complaint, but there can be no assurance that the defense will be successful. On February 19, 2016, Maris Sanchez, a purported shareholder of Clovis, filed a shareholder derivative complaint (the “Sanchez Complaint”) against certain officers and directors of Clovis in the United States District Court for the District of Colorado. The Sanchez Complaint generally alleges that the defendants breached their fiduciary duties owed to Clovis by participating in misrepresentation of the Company’s business operations and prospects. The Sanchez Complaint also alleges claims for abuse of control and gross mismanagement. The Sanchez Complaint seeks, among other things, an award of money damages. The Company intends to vigorously defend against the allegations contained in the Sanchez Complaint, but there can be no assurance that the defense will be successful.

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2015
Research And Development [Abstract]
License Agreements	12. License Agreements Rociletinib In May 2010, we entered into an exclusive worldwide license agreement with Avila Therapeutics, Inc. (now Celgene Avilomics Research Inc., part of Celgene Corporation (“Celgene”)) to discover, develop and commercialize a covalent inhibitor of mutant forms of the epidermal growth factor receptor (“EGFR”) gene product. As a result of the collaboration contemplated by the agreement, rociletinib was identified as the lead inhibitor candidate, which we are developing under the terms of the license agreement. We are responsible for all non-clinical, clinical, regulatory and other activities necessary to develop and commercialize rociletinib. We made an upfront payment of $2.0 million upon execution of the license agreement, a $4.0 million milestone payment in the first quarter of 2012 upon the acceptance by the FDA of our Investigational New Drug application for rociletinib and a $5.0 million milestone payment in the first quarter of 2014 upon initiation of the Phase II study for rociletinib. In the third quarter of 2015, we made milestone payments totaling $12.0 million upon acceptance of the NDA and MAA for rociletinib by the FDA and EMA, respectively. We recognized all payments prior to commercial approval as acquired in-process research and development expense. When and if commercial sales of rociletinib commence, we will pay Celgene tiered royalties at percentage rates ranging from mid-single digits to low teens based on annual net sales achieved. We are required to pay up to an additional aggregate of $98.0 million in development and regulatory milestone payments if certain clinical study objectives and regulatory filings, acceptances and approvals are achieved, including $15.0 million upon the first approval of an NDA by the FDA and $15.0 million upon the first approval of an MAA by the EMA. In addition, we are required to pay up to an aggregate of $120.0 million in sales milestone payments if certain annual sales targets are achieved, the majority of which relate to annual sales targets of $500.0 million and above. In January 2013, the Company entered into an exclusive license agreement with Gatekeeper Pharmaceuticals, Inc. (“Gatekeeper”) to acquire exclusive rights under patent applications associated with mutant EGFR inhibitors and methods of treatment. Pursuant to the terms of the license agreement, the Company made an upfront payment of $0.25 million upon execution of the agreement, which was recognized as acquired in-process research and development expense. If rociletinib is approved for commercial sale, the Company will pay royalties to Gatekeeper on future net sales. Rucaparib In June 2011, the Company entered into a worldwide license agreement with Pfizer Inc. to acquire exclusive development and commercialization rights to rucaparib. This drug candidate is a small molecule inhibitor of poly (ADP-ribose) polymerase (“PARP”), which the Company is developing for the treatment of selected solid tumors. Under the terms of the license agreement, we made a $7.0 million upfront payment to Pfizer. In April 2014, the Company initiated a pivotal registration study for rucaparib, which resulted in a $0.4 million milestone payment to Pfizer as required by the license agreement. This payment was recognized as acquired in-process research and development expense. We are obligated under the license agreement to use commercially reasonable efforts to develop and commercialize rucaparib, and we are responsible for all remaining development and commercialization costs of rucaparib. When and if commercial sales of rucaparib begin, we will pay Pfizer tiered royalties at a mid-teen percentage rate on our net sales, with standard provisions for royalty offsets to the extent we need to obtain any rights from third parties to commercialize rucaparib. In addition, Pfizer is eligible to receive up to $258.5 million of further payments, in aggregate, if certain development, regulatory and sales milestones are achieved, including $20.75 million associated with the first approval of an NDA by the FDA. In April 2012, the Company entered into a license agreement with AstraZeneca UK Limited to acquire exclusive rights associated with rucaparib under a family of patents and patent applications that claim methods of treating patients with PARP inhibitors in certain indications. The license enables the development and commercialization of rucaparib for the uses claimed by these patents. Pursuant to the terms of the license agreement, the Company made an upfront payment of $0.25 million upon execution of the agreement, which was recognized as acquired in-process research and development expense. The Company may be required to pay up to an aggregate of $0.7 million in milestone payments if certain regulatory filings, acceptances and approvals are achieved. If approved, AstraZeneca will also receive royalties on any net sales of rucaparib. Lucitanib In connection with its acquisition of EOS (see Note 3), the Company gained rights to develop and commercialize lucitanib, an oral, selective tyrosine kinase inhibitor. As further described below, EOS licensed the worldwide rights, excluding China, to develop and commercialize lucitanib from Advenchen Laboratories LLC (“Advenchen”). Subsequently, rights to develop and commercialize lucitanib in markets outside the U.S. and Japan were sublicensed by EOS to Servier in exchange for upfront milestone fees, royalties on sales of lucitanib in the sublicensed territories and research and development funding commitments. In October 2008, EOS entered into an exclusive license agreement with Advenchen to develop and commercialize lucitanib on a global basis, excluding China. If and when commercial sales commence, we are obligated to pay Advenchen tiered royalties at percentage rates in the mid-single digits on net sales of lucitanib, based on the volume of annual net sales achieved. In addition, we are required to pay to Advenchen 25% of any consideration, excluding royalties, received pursuant to any sublicense agreements for lucitanib, including the agreement with Servier. We are obligated under the agreement to use commercially reasonable efforts to develop and commercialize at least one product candidate containing lucitanib, and we are also responsible for all remaining development and commercialization costs for lucitanib. In the first quarter of 2014, the Company recognized acquired in-process research and development expense of $3.4 million, which represents 25% of the sublicense agreement consideration of $13.6 million received from Servier upon the end of opposition and appeal of the lucitanib patent by the European Patent Office. In September 2012, EOS entered into a collaboration and license agreement with Servier whereby EOS sublicensed to Servier exclusive rights to develop and commercialize lucitanib in all countries outside of the U.S., Japan and China. In exchange for these rights, EOS received an upfront payment of €45.0 million. We are entitled to receive additional payments upon achievement of specified development, regulatory and commercial milestones up to €90.0 million in the aggregate. In addition, we are entitled to receive sales milestone payments if specified annual sales targets for lucitanib are met, which, in the aggregate, could total €250.0 million. We are also entitled to receive royalties at percentage rates ranging from low to mid-teens on sales of lucitanib by Servier. The development, regulatory and commercial milestones represent non-refundable amounts that would be paid by Servier to the Company if certain milestones are achieved in the future. These milestones, if achieved, are substantive as they relate solely to past performance, are commensurate with estimated enhancement of value associated with the achievement of each milestone as a result of the Company’s performance, which are reasonable relative to the other deliverables and terms of the arrangement, and are unrelated to the delivery of any further elements under the arrangement. The Company and Servier are developing lucitanib pursuant to a development plan agreed to between the parties. Servier is responsible for all of the initial global development costs under the agreed upon plan up to €80.0 million. Cumulative global development costs, if any, in excess of €80.0 million will be shared equally between the Company and Servier. Based on current estimates, we expect that Servier’s €80.0 million funding commitment will be fulfilled in late 2016 or early 2017, and thereafter, we will share with Servier in future development costs pursuant to a mutually agreed upon global development plan. Reimbursements are recorded as a reduction to research and development expense on the Consolidated Statements of Operations. The Company recorded a $3.2 million and $2.0 million receivable at December 31, 2015 and 2014, respectively, for the reimbursable development costs incurred under the global development plan, which is included in other current assets on the Consolidated Balance Sheets. During the years ending December 31, 2015, 2014 and 2013, we incurred $13.7 million, $9.5 million and $1.4 million, respectively, in research and development costs and recorded reductions in research and development expense of $11.8 million, $10.0 million and $1.3 million, respectively, for reimbursable development costs due from Servier.

Net Loss Per Common Share

Net Loss Per Common Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Loss Per Common Share	13. Net Loss Per Common Share Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common share equivalents outstanding using the treasury-stock method for the stock options and the if-converted method for the Notes. As a result of our net losses for the periods presented, all potentially dilutive common share equivalents were considered anti-dilutive and were excluded from the computation of diluted net loss per share. The shares outstanding at the end of the respective periods presented in the table below were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect (in thousands): Year ended December 31, 2015 2014 2013 Common shares under option 2,031 2,973 2,344 Convertible senior notes 4,646 4,646 — Total potential dilutive shares 6,677 7,619 2,344

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The geographical components of income (loss) before income taxes consisted of the following (in thousands): Year ended December 31, 2015 2014 2013 Domestic $ (290,342 ) $ (165,220 ) $ (84,534 ) Foreign (91,595 ) 7,497 54 Total loss before income taxes $ (381,937 ) $ (157,723 ) $ (84,480 ) The income tax provision consists of the following current and deferred foreign tax expenses (in thousands). No U.S. tax expense was recognized in the 2015 and 2014 and the 2013 tax provisions are not significant. Year ended December 31, 2015 2014 Foreign: Current expense $ — $ 1,547 Deferred (benefit) expense (29,076 ) 761 Total income tax (benefit) expense $ (29,076 ) $ 2,308 A reconciliation of the U.S. statutory income tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2015 2014 2013 Federal income tax benefit at statutory rate (34.0 )% (34.0 )% (34.0 )% State income tax benefit, net of federal benefit (3.0 ) (3.5 ) (3.0 ) Tax credits (13.6 ) (20.5 ) (15.5 ) Change in tax status of foreign subsidiary — (13.5 ) — Limitation on future foreign tax credits (5.0 ) — — Other 0.4 1.0 2.1 Change in valuation allowance 47.6 72.0 50.5 Effective income tax rate (7.6 )% 1.5 % 0.1 % The components of the Company’s deferred tax assets and liabilities are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating loss carryforward $ 189,663 $ 111,309 Tax credit carryforwards 179,865 101,469 Intangible assets 26,766 — Deductible foreign taxes 10,836 22,729 Share-based compensation expense 23,844 10,777 Foreign currency translation 17,471 9,092 Product acquisition costs 10,470 6,866 Accrued liabilities and other 4,147 2,051 Total deferred tax assets 463,062 264,293 Valuation allowance (449,080 ) (259,004 ) Deferred tax assets, net of valuation allowance 13,982 5,289 Deferred tax liabilities: Intangible assets (31,871 ) (70,084 ) Contingent purchase consideration (11,142 ) (843 ) Prepaid expenses and other (2,102 ) (1,213 ) Total deferred tax liabilities (45,115 ) (72,140 ) Net deferred tax liability $ (31,133 ) $ (66,851 ) The realization of deferred tax assets is dependent upon a number of factors including future earnings, the timing and amount of which is uncertain. A valuation allowance was established for the net deferred tax asset balance due to management’s belief that the realization of these assets is not likely to occur in the foreseeable future. The Company recorded an increase to the valuation allowance of $190.1 million and $122.7 million during the years ended December 31, 2015 and 2014, respectively, primarily due to an increase in net operating loss and tax credit carryforwards and future tax deductions associated with EOS acquisition intangible assets. As of December 31, 2015, the Company had approximately $504.8 million, $728.1 million and $2.7 million of U.S. federal, state and foreign net operating loss carryforwards, respectively. The U.S. net operating losses will expire from 2029 to 2035 if not utilized. Included in the U.S. net operating loss was approximately $16.7 million of stock compensation expense, the benefit of which, if realized, will be an increase to additional paid-in-capital and a reduction to taxes payable. In addition, the Company has research and development and orphan drug tax credit carryforwards of $177.7 million that will expire from 2029 through 2035 if not utilized. We believe that a change in ownership as defined under Section 382 of the U.S. Internal Revenue Code occurred as a result of the Company’s public offering of common stock completed in April 2012. Future utilization of the federal net operating losses (“NOL”) and tax credit carryforwards accumulated from inception to the change in ownership date will be subject to annual limitations to offset future taxable income. At this time, we do not believe, however, this limitation will prevent the utilization of the federal NOL or credit carryforward prior to expiration. It is possible that a change in ownership will occur in the future, which will limit the NOL amounts generated since the last estimated change. The Company’s federal and state income taxes for the period from inception to December 31, 2015 remain open to an audit. Our foreign subsidiaries are also subject to tax audits by tax authorities in the jurisdictions where they operate for the periods from December 31, 2010 to December 31, 2015. Tax positions are initially recognized in the financial statements when it is more likely than not that the position will be sustained upon examination by the tax authorities. Such tax positions must initially and subsequently be measured at the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with the tax authority assuming full knowledge of the position and relevant facts. The Company has not identified any significant uncertain tax positions that require recognition in our financial statements. Our evaluation was performed from inception through December 31, 2015. In December 2014, the Company converted a non-U.S. entity into a U.S. entity for U.S. income tax purposes. As a result of this election, the subsidiary was treated as a flow through entity for U.S. federal tax purposes. The election generated deferred tax assets, calculated as the difference between the subsidiary’s tax basis and the underlying financial statement basis of the assets. The Company may be assessed interest and penalties related to the settlement of tax positions and such amounts will be recognized within income tax expense when assessed. To date, no interest and penalties have been recognized by the Company.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	15. Employee Benefit Plan We maintain a retirement plan, which is qualified under section 401(k) of the Internal Revenue Code for its U.S. employees. The plan allows eligible employees to defer, at the employee’s discretion, pretax compensation up to the IRS annual limits. The Company matches contributions up to 4% of the eligible employee’s compensation or the maximum amount permitted by law. Total expense for contributions made to U.S. employees was approximately $824 thousand, $425 thousand and $368 thousand for the years ended December 31, 2015, 2014 and 2013, respectively. The Company’s international employees participate in retirement plans governed by the local laws in effect for the country in which they reside. The Company made matching contributions to international employees of approximately $171 thousand, $106 thousand and $81 thousand for the years ended December 31, 2015, 2014 and 2013, respectively.

Quarterly Information (Unaudite

Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Information (Unaudited)	16. Quarterly Information (Unaudited) The results of operations on a quarterly basis for the years ended December 31, 2015 and 2014 were as follows (in thousands): March 31, June 30, Sept. 30, Dec. 31, March 31, June 30, Sept. 30, Dec. 31, 2015 2015 2015 (1) 2015 2014 2014 2014 2014 Revenues: License and milestone revenue $ — $ — $ — $ — $ 13,625 $ — $ — $ — Operating expenses: Research and development 56,750 60,368 76,138 75,995 24,151 28,440 34,965 50,149 General and administrative 6,751 7,204 8,331 8,238 5,320 5,265 5,267 5,605 Acquired in-process research and development — — 12,000 — 8,406 400 — — Impairment of intangible asset — — — 89,557 3,409 — — — Change in fair value of contingent purchase consideration 724 764 783 (26,882 ) 822 861 888 (1,864 ) Total expenses 64,225 68,336 97,252 146,908 42,108 34,966 41,120 53,890 Operating loss (64,225 ) (68,336 ) (97,252 ) (146,908 ) (28,483 ) (34,966 ) (41,120 ) (53,890 ) Other income (expense): Interest expense (2,075 ) (2,097 ) (2,099 ) (2,101 ) — — (511 ) (2,093 ) Foreign currency gains (losses) 3,247 (1,142 ) (101 ) 736 (60 ) 316 2,323 1,001 Other income (expense) 11 62 179 164 (46 ) (46 ) (42 ) (106 ) Other income (expense), net 1,183 (3,177 ) (2,021 ) (1,201 ) (106 ) 270 1,770 (1,198 ) Loss before income taxes (63,042 ) (71,513 ) (99,273 ) (148,109 ) (28,589 ) (34,696 ) (39,350 ) (55,088 ) Income tax (expense) benefit (102 ) (18 ) 628 28,568 (2,129 ) (68 ) (292 ) 181 Net loss $ (63,144 ) $ (71,531 ) $ (98,645 ) $ (119,541 ) $ (30,718 ) $ (34,764 ) $ (39,642 ) $ (54,907 ) Basic and diluted net loss per common share $ (1.86 ) $ (2.10 ) $ (2.62 ) $ (3.12 ) $ (0.91 ) $ (1.03 ) $ (1.17 ) $ (1.62 ) Basic and diluted weighted average common shares outstanding 34,011 34,088 37,613 38,321 33,820 33,872 33,921 33,941 (1) In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	17. Subsequent Events The Company evaluated events after the balance sheet date of December 31, 2015 and up to the date the Company filed this Annual Report and determined that no subsequent activity required disclosure.

Nature of Business (Policies)

Nature of Business (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Liquidity	Liquidity The Company has incurred significant net losses since inception and has relied on its ability to fund its operations through debt and equity financings. Management expects operating losses and negative cash flows to continue for the foreseeable future. As the Company continues to incur losses, transition to profitability is dependent upon the successful development, approval and commercialization of its product candidates and achieving a level of revenues adequate to support the Company’s cost structure. The Company may never achieve profitability, and unless and until it does, the Company will continue to need to raise additional cash. Management intends to fund future operations through additional private or public debt or equity offerings and may seek additional capital through arrangements with strategic partners or from other sources. Based on current estimates, management believes that existing working capital at December 31, 2015 is sufficient to meet the cash requirements to fund planned operations through the next 12 months, although there can be no assurance that this can, in fact, be accomplished.
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain reclassifications have been made to prior year amounts to conform to the current year presentation. These reclassifications had no effect on the Company’s previously reported results of operations, financial position or cash flows.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, expenses and revenue and related disclosures. On an ongoing basis, management evaluates its estimates, including estimates related to contingent purchase consideration, the allocation of purchase consideration, intangible asset impairment, clinical trial accruals and share-based compensation expense. The Company bases its estimates on historical experience and other market-specific or other relevant assumptions that it believes to be reasonable under the circumstances. Actual results may differ from those estimates or assumptions.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Cash, cash equivalents, available-for-sale securities and contingent purchase consideration are carried at fair value (see Note 5). Financial instruments, including other current assets and accounts payable, are carried at cost, which approximates fair value given their short-term nature.
Cash, Cash Equivalents and Available-for-Sale Securities	Cash, Cash Equivalents and Available-for-Sale Securities The Company considers all highly liquid investments with original maturities at the date of purchase of three months or less to be cash equivalents. Cash and cash equivalents include bank demand deposits and money market funds that invest primarily in certificate of deposits, commercial paper and U.S. government and U.S. government agency obligations. Marketable securities are considered to be available-for-sale securities and consist of U.S. treasury securities. Available-for-sale securities are reported at fair value on the Consolidated Balance Sheets and unrealized gains and losses are included in accumulated other comprehensive income (loss) on the Consolidated Balance Sheets. Realized gains and losses, amortization of premiums and discounts and interest and dividends earned are included in other income (expense) on the Consolidated Statements of Operations. The cost of investments for purposes of computing realized and unrealized gains and losses is based on the specific identification method. Investments with maturities beyond one year are classified as short-term based on management’s intent to fund current operations with these securities or to make them available for current operations. A decline in the market value of a security below its cost that is deemed to be other than temporary is charged to earnings and results in the establishment of a new cost basis for the security. Factors evaluated to determine if an investment is other-than-temporarily impaired include significant deterioration in earnings performance, credit rating, asset quality or business prospects of the issuer; adverse changes in the general market conditions in which the issuer operates; and the Company’s intent and ability to hold the security until an anticipated recovery in value occurs.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Equipment purchased for use in manufacturing and clinical trials is evaluated to determine whether the equipment is solely beneficial for a drug candidate in the development stage or whether it has an alternative use. Equipment with an alternative use is capitalized. Leasehold improvements are amortized over the economic life of the asset or the lease term, whichever is shorter. Maintenance and repairs are expensed as incurred. The estimated useful lives of our capitalized assets are as follows: Estimated Useful Life Computer hardware and software 3 to 5 years Leasehold improvements 6 years Laboratory, manufacturing and office equipment 5 to 7 years Furniture and fixtures 10 years
Long-Lived Assets	Long-Lived Assets The Company reviews long-lived assets for impairment when events or changes in circumstances indicate that the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the assets’ book value to future net undiscounted cash flows that the assets are expected to generate. If the carrying value of the assets exceed their future net undiscounted cash flows, an impairment charge is recognized for the amount by which the carrying value of the assets exceeds the fair value of the assets.
Intangible Assets	Intangible Assets Intangible acquired in-process research and development (“IPR&D”) assets were established as part of the acquisition of Ethical Oncology Science, S.p.A. (“EOS”) (see Note 3) and are not amortized. Amortization of these assets will commence upon completion of the related research and development activities. IPR&D intangible assets are evaluated for impairment at least annually in the fourth quarter or more frequently if impairment indicators exist and any reduction in fair value would be recorded as impairment of intangible asset on the Consolidated Statements of Operations. During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge to the IPR&D intangible assets (see Note 7).
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of net assets acquired in a business combination accounted for under the acquisition method of accounting and is not amortized, but is subject to impairment testing at least annually in the fourth quarter or when a triggering event is identified that could indicate a potential impairment. We are organized as a single reporting unit and perform impairment testing by comparing the carrying value of the reporting unit to the fair value of the Company.
Other Current Assets	Other Current Assets Other current assets are comprised of the following (in thousands): December 31, 2015 2014 Receivable from partners $ 3,241 $ 1,991 Prepaid insurance 1,231 1,190 Receivable from landlord 1,153 — Prepaid expenses - other 1,023 1,168 Receivable - other 889 281 Other 199 100 Total $ 7,736 $ 4,730
Other Accrued Expenses	Other Accrued Expenses Other accrued expenses are comprised of the following (in thousands): December 31, 2015 2014 Accrued personnel costs $ 8,250 $ 4,726 Accrued interest payable 2,096 2,236 Accrued expenses - other 959 636 Total $ 11,305 $ 7,598
Valuation of Contingent Consideration Resulting from a Business Combination	Valuation of Contingent Consideration Resulting from a Business Combination Subsequent to the acquisition date, we re-measure contingent consideration arrangements at fair value each reporting period and record changes in fair value to change in fair value of contingent purchase consideration and foreign currency gains (losses) for changes in the foreign currency translation rate on the Consolidated Statements of Operations. Changes in fair value are primarily attributed to new information about the IPR&D assets, including changes in timeline and likelihood of success, and the passage of time. In the absence of new information, changes in fair value reflect only the passage of time. During the fourth quarter of 2015, the Company recorded a $26.9 million reduction in the fair value of the contingent purchase consideration liability (see Note 5).
Research and Development Expense	Research and Development Expense Research and development costs are charged to expense as incurred and include, but are not limited to, salary and benefits, share-based compensation, clinical trial activities, drug development and manufacturing, companion diagnostic development and third-party service fees, including clinical research organizations and investigative sites. During 2015, we completed the hiring of our U.S. sales and marketing and medical affairs organizations in preparation for the potential commercial launch of rociletinib. These costs are also included in research and development expense. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations or information provided to us by our vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred and are reflected on the Consolidated Balance Sheets as prepaid or accrued research and development expenses.
Acquired In-Process Research and Development Expense	Acquired In-Process Research and Development Expense The Company has acquired and expects to continue to acquire the rights to develop and commercialize new drug candidates. The upfront payments to acquire a new drug compound, as well as subsequent milestone payments, are immediately expensed as acquired in-process research and development provided that the drug has not achieved regulatory approval for marketing and, absent obtaining such approval, has no alternative future use.
Share-Based Compensation Expense	Share-Based Compensation Expense Share-based compensation is recognized as expense for all share-based awards made to employees and directors and is based on estimated fair values. The Company determines equity-based compensation at the grant date using the Black-Scholes option pricing model. The value of the award that is ultimately expected to vest is recognized as expense on a straight-line basis over the requisite service period. Any changes to the estimated forfeiture rates are accounted for prospectively.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents and available-for-sale securities. The Company maintains its cash and cash equivalent balances in the form of money market accounts with financial institutions that management believes are creditworthy. Available-for-sale securities are invested in accordance with the Company’s investment policy. The investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company has no financial instruments with off-balance sheet risk of accounting loss.
Foreign Currency	Foreign Currency The assets and liabilities of the Company’s foreign operations are translated into U.S. dollars at current exchange rates and the results of operations are translated at the average exchange rates for the reported periods. The resulting translation adjustments are included in accumulated other comprehensive loss on the Consolidated Balance Sheets. Transactions denominated in currencies other than the functional currency are recorded based on exchange rates at the time such transactions arise. Transaction gains and losses are recorded to foreign currency gains (losses) on the Consolidated Statements of Operations. As of December 31, 2015 and 2014, approximately 3% and 7%, respectively, of the Company’s total liabilities were denominated in currencies other than the functional currency.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Tax benefits are recognized when it is more likely than not that a tax position will be sustained during an audit. Deferred tax assets are reduced by a valuation allowance if current evidence indicates that it is considered more likely than not that these benefits will not be realized.
Revenue Recognition	Revenue Recognition Revenue is recognized from license milestone payments when the following criteria have been met: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred or services have been rendered; (3) the price is fixed or determinable; and (4) collectability is reasonably assured. We exercise judgment in determining that collectability is reasonably assured or that services have been delivered in accordance with the arrangement. We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. We assess collectability based primarily on the customer's payment history and creditworthiness of the customer. Payments that are contingent upon the achievement of a substantive milestone will be recognized in the period in which the milestone is achieved.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In April 2015, the FASB issued ASU No. 2015-03, “Interest – Imputation of Interest (Subtopic 835-30) – Simplifying the Presentation of Debt Issuance Costs.” ASU No. 2015-03 requires debt issuance costs to be presented as a deduction from the corresponding debt liability rather than as an asset. This update is effective for fiscal years beginning after December 15, 2015, including interim periods within those years. Early adoption is permitted. Upon adoption, the guidance must be applied retrospectively to all periods presented in the financial statements. The Company elected to early adopt this standard effective December 31, 2015. Adoption of the standard resulted in the reclassification of the Company’s debt issuance costs from other assets to convertible senior notes on its Consolidated Balance Sheets. In November 2015, the FASB issued ASU No. 2015-17, “Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes.” ASU No. 2015-17 requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. This update is effective for fiscal years beginning after December 15, 2016, including interim periods within those years. Early adoption is permitted. Upon adoption, the guidance may be applied either prospectively, for all deferred tax assets and liabilities, or retrospectively to all periods presented in the financial statements. The Company elected to early adopt this standard effective December 31, 2015. Adoption of this standard was applied retrospectively and resulted in no change to the Company’s Consolidated Balance Sheets.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 specifies the accounting for revenue from contracts with customers and establishes disclosure requirements relating to the nature, timing and uncertainty of revenue and cash flows arising from an entity’s contracts with customers. In August 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” which delayed the effective date of the standard to annual and interim periods beginning after December 15, 2017. Early application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods. ASU 2014-09 allows for either full retrospective or modified retrospective adoption. The Company is currently evaluating its planned method of adoption and the impact the standard may have on its consolidated financial statements and related disclosures. In August 2014, the FASB issued ASU No. 2014-15, “Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern,” which requires management to evaluate whether there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern and to provide disclosures when certain criteria are met. The guidance is effective for annual periods beginning in 2016 and interim reporting periods starting in the first quarter of 2017. Early application is permitted. The Company is currently evaluating the impact the standard may have on its disclosures. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842),” which requires lessees to recognize assets and liabilities for the rights and obligations created by most leases on their balance sheet. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted. ASU 2016-02 requires modified retrospective adoption for all leases existing at, or entered into after, the date of initial application, with an option to use certain transition relief. The Company is currently evaluating the impact the standard may have on its consolidated financial statements and related disclosures.
Fair Value Measurements	Fair value is defined as the exchange price that would be received to sell an asset or paid to transfer a liability (at exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The three levels of inputs that may be used to measure fair value include: Level 1: Quoted prices in active markets for identical assets or liabilities. The Company’s Level 1 assets consist of money market investments. The Company does not have Level 1 liabilities. Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities in active markets or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 assets consist of U.S. treasury securities. The Company does not have Level 2 liabilities. Level 3: Unobservable inputs that are supported by little or no market activity. The Company does not have Level 3 assets. The contingent purchase consideration related to the undeveloped lucitanib product rights acquired with the purchase of EOS is a Level 3 liability. The fair value of this liability is based on unobservable inputs and includes valuations for which there is little, if any, market activity. See Note 3 for further discussion of the valuation methodology.
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Accumulated other comprehensive loss consists of changes in foreign currency translation adjustments, which includes changes in a subsidiary’s functional currency, and unrealized gains and losses on available-for-sale securities.
Lucitanib	Reimbursements are recorded as a reduction to research and development expense on the Consolidated Statements of Operations.
Net Loss Per Common Share	Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common share equivalents outstanding using the treasury-stock method for the stock options and the if-converted method for the Notes. As a result of our net losses for the periods presented, all potentially dilutive common share equivalents were considered anti-dilutive and were excluded from the computation of diluted net loss per share.
Income Tax Positions	Tax positions are initially recognized in the financial statements when it is more likely than not that the position will be sustained upon examination by the tax authorities. Such tax positions must initially and subsequently be measured at the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with the tax authority assuming full knowledge of the position and relevant facts. The Company has not identified any significant uncertain tax positions that require recognition in our financial statements. Our evaluation was performed from inception through December 31, 2015.

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Estimated Useful Lives of Property and Equipment	The estimated useful lives of our capitalized assets are as follows: Estimated Useful Life Computer hardware and software 3 to 5 years Leasehold improvements 6 years Laboratory, manufacturing and office equipment 5 to 7 years Furniture and fixtures 10 years
Other Current Assets	Other current assets are comprised of the following (in thousands): December 31, 2015 2014 Receivable from partners $ 3,241 $ 1,991 Prepaid insurance 1,231 1,190 Receivable from landlord 1,153 — Prepaid expenses - other 1,023 1,168 Receivable - other 889 281 Other 199 100 Total $ 7,736 $ 4,730
Other Accrued Expenses	Other accrued expenses are comprised of the following (in thousands): December 31, 2015 2014 Accrued personnel costs $ 8,250 $ 4,726 Accrued interest payable 2,096 2,236 Accrued expenses - other 959 636 Total $ 11,305 $ 7,598

EOS Acquisition (Tables)

EOS Acquisition (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Summary of Contingent Payment Obligation	A summary of the contingent payment obligations is as follows (in thousands and payment currency): Amount Initial approval of an NDA for lucitanib in the U.S. $ 65,000 Obligations associated with the receipt of milestone payments from Servier: Initial filing of a MAA for lucitanib in the E.U. € 15,000 Initial approval of a MAA for lucitanib in the E.U. € 45,000 Initial achievement of lucitanib net sales in Servier licensed territory of €500 million in any four consecutive quarters € 55,000 Total € 115,000

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property and Equipment	Property and equipment consisted of the following (in thousands): December 31, 2015 2014 Laboratory, manufacturing and office equipment $ 2,556 $ 2,452 Leasehold improvements 1,861 260 Furniture and fixtures 1,487 667 Computer hardware and software 833 414 Total property and equipment 6,737 3,793 Less: accumulated depreciation (1,791 ) (1,075 ) Total property and equipment, net $ 4,946 $ 2,718

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table identifies the Company’s assets and liabilities that were measured at fair value on a recurring basis (in thousands): Balance Level 1 Level 2 Level 3 December 31, 2015 Assets: Money market $ 251,037 $ 251,037 $ — $ — U.S. treasury securities 249,832 — 249,832 — Total assets at fair value $ 500,869 $ 251,037 $ 249,832 $ — Liabilities: Contingent purchase consideration $ 24,661 $ — $ — $ 24,661 Total liabilities at fair value $ 24,661 $ — $ — $ 24,661 December 31, 2014 Assets: Money market $ 447,994 $ 447,994 $ — $ — Total assets at fair value $ 447,994 $ 447,994 $ — $ — Liabilities: Contingent purchase consideration $ 52,453 $ — $ — $ 52,453 Total liabilities at fair value $ 52,453 $ — $ — $ 52,453
Roll-forward of Fair Value of Level 3 Instruments (significant unobservable inputs)	The following table rolls forward the fair value of Level 3 instruments (significant unobservable inputs) (in thousands): Year Ended December 31, 2015 Liabilities: Balance at beginning of period $ 52,453 Change in fair value (a) (24,611 ) Change in foreign currency gains and losses (3,181 ) Balance at end of period $ 24,661 (a) The decrease in the fair value of the contingent purchase consideration was due to a change in the estimated probability-weighted future milestone payments discounted using an estimated borrowing rate ranging from 8.5% to 8.6%, as well as the timing of such payments, for the lucitanib program.

Available-for-Sale Securities (

Available-for-Sale Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Available For Sale Securities [Abstract]
Summary of Available-for-Sale Securities	As of December 31, 2015, available-for-sale securities consisted of the following (in thousands): Gross Gross Aggregate Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. treasury securities $ 250,215 $ — $ (383 ) $ 249,832
Summary of Fair Value and Gross Unrealized Losses of Available-for-Sale Securities in a Continuous Unrealized Loss Position	As of December 31, 2015, the fair value and gross unrealized losses of available-for-sale securities that have been in a continuous unrealized loss position for less than 12 months were as follows (in thousands): Aggregate Gross Fair Unrealized Value Losses U.S. treasury securities $ 249,832 $ (383 )
Summary of Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity	As of December 31, 2015, the amortized cost and fair value of available-for-sale securities by contractual maturity were (in thousands): Amortized Fair Cost Value Due in one year or less $ 200,147 $ 199,912 Due in one year to two years 50,068 49,920 Total $ 250,215 $ 249,832

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of IPR&D Assets and Goodwill	IPR&D assets and goodwill were established as part of the purchase accounting of EOS (see Note 3) and consisted of the following (in thousands): December 31, 2015 2014 IPR&D assets: Balance at beginning of period $ 212,900 $ 244,518 Impairment of intangible asset (a) (89,557 ) (3,409 ) Change in foreign currency gains and losses (21,843 ) (28,209 ) Balance at end of period $ 101,500 $ 212,900 Goodwill: Balance at beginning of period $ 66,055 $ 74,811 Change in foreign currency gains and losses (6,728 ) (8,756 ) Balance at end of period $ 59,327 $ 66,055 (a) During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge due to the Company’s and its development partner’s decision to terminate the development of lucitanib for lung cancer, as well as updates to the probability-weighted discounted cash flow assumptions for the breast cancer indication.

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Total Interest Expense Recognized Related to Notes	The following table sets forth total interest expense recognized related to the Notes during the years ended December 31, 2015 and 2014 (in thousands): Year Ended December 31, 2015 2014 Contractual interest expense $ 7,167 $ 2,236 Amortization of debt issuance costs 1,205 368 Total interest expense $ 8,372 $ 2,604

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Component of Other Comprehensive Income (Loss)	The accumulated balances related to each component of other comprehensive income (loss) are summarized as follows (in thousands): Total Foreign Accumulated Currency Other Translation Unrealized Comprehensive Adjustments Losses Income (Loss) Balance December 31, 2013 $ 4,696 $ — $ 4,696 Period change (29,144 ) — (29,144 ) Balance December 31, 2014 (24,448 ) — (24,448 ) Period change (22,629 ) (383 ) (23,012 ) Balance December 31, 2015 $ (47,077 ) $ (383 ) $ (47,460 )

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation Expense Recognized in Accompanying Statements of Operations	Share-based compensation expense for the years ended December 31, 2015, 2014 and 2013, respectively, was recognized in the accompanying Consolidated Statements of Operations as follows (in thousands): Year Ended December 31, 2015 2014 2013 Research and development (a) $ 27,321 $ 11,474 $ 4,289 General and administrative 13,036 10,043 5,216 Total share-based compensation expense $ 40,357 $ 21,517 $ 9,505 (a) During the third quarter of 2015, the Company recognized $2.9 million in share-based compensation expense associated with a modification to the terms of a former executive’s stock option agreement.
Summary of Stock Options Activity	The following table summarizes the activity relating to the Company’s options to purchase common stock: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (Thousands) Outstanding at December 31, 2014 4,159,362 $ 37.69 Granted (a) 1,600,593 80.04 Exercised (295,759 ) 18.52 Forfeited (103,939 ) 56.93 Outstanding at December 31, 2015 5,360,257 $ 51.53 7.1 $ 33,927 Vested and expected to vest at December 31, 2015 5,030,757 $ 50.22 7.0 $ 33,678 Exercisable at December 31, 2015 2,608,239 $ 34.56 6.0 $ 29,607 (a) Includes 120,000 performance-based stock options granted to executives of the Company in the first quarter of 2015. Fifty percent of the grant vests contingent on approval by the FDA to commercially distribute, sell or market rociletinib and 50% of the grant vests contingent on approval by the FDA to commercially distribute, sell or market rucaparib. Stock compensation expense will be recognized when the condition for vesting is probable of being met.
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award	The following table summarizes information about our stock options as of and for the years ended December 31, 2015, 2014 and 2013: Year Ended December 31, 2015 2014 2013 Weighted-average grant date fair value per share $ 52.70 $ 38.47 $ 18.59 Intrinsic value of options exercised $ 19,976,769 $ 2,906,304 $ 6,114,436 Cash received from stock option exercises $ 5,478,211 $ 682,678 $ 1,393,053
Weighted-Average Assumptions	The fair value of each share-based award is estimated on the grant date using the Black-Scholes option pricing model based upon the weighted-average assumptions provided in the following table: Year Ended December 31, 2015 2014 2013 Dividend yield — — — Volatility (a) 72 % 70 % 69 % Risk-free interest rate (b) 1.77 % 1.92 % 1.16 % Expected term (years) (c) 6.1 6.2 6.2 (a) Volatility : The expected volatility was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans. (b) Risk-free interest rate: The rate is based on the yield on the grant date of a zero-coupon U.S. Treasury bond whose maturity period approximates the option’s expected term. (c) Expected term: The expected term of the award was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans.
Reserved Shares of Common Stock for Future Issuance	As of December 31, 2015, the Company reserved shares of common stock for future issuance as follows: Options Outstanding Available for Grant or Future Issuance Total Shares of Common Stock Reserved 2009 Equity Incentive Plan 494,031 — 494,031 2011 Stock Incentive Plan 4,866,226 1,181,722 6,047,948 2011 Employee Stock Purchase Plan — 376,231 376,231 Total 5,360,257 1,557,953 6,918,210
Weighted-Average Assumptions Used to Estimate Fair Value of Purchase Awards Granted	The fair value of purchase awards granted to our employees during the years ended December 31, 2015, 2014 and 2013, respectively, was estimated using the Black-Scholes option pricing model based upon the weighted-average assumptions provided in the following table: Year Ended December 31, 2015 2014 2013 Dividend yield — — — Volatility (a) 71 % 71 % 72 % Risk-free interest rate (b) 0.11 % 0.07 % 0.09 % Expected term (years) (c) 0.5 0.5 0.5 (a) Volatility : The expected volatility was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans. (b) Risk-free interest rate: The rate is based on the U.S. Treasury yield in effect at the time of grant with terms similar to the contractual term of the purchase right. (c) Expected term: The expected life of the award represents the six-month offering period for the Purchase Plan.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Rental Commitments	Future minimum rental commitments, by fiscal year and in the aggregate, for the Company’s operating leases are provided below (in thousands): December 31, 2015 2016 $ 1,795 2017 1,746 2018 1,783 2019 1,837 2020 1,891 Thereafter 2,547 Total future minimum lease payments $ 11,599

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Shares Outstanding Excluded from Calculation of Diluted Net Loss Per Share	The shares outstanding at the end of the respective periods presented in the table below were excluded from the calculation of diluted net loss per share due to their anti-dilutive effect (in thousands): Year ended December 31, 2015 2014 2013 Common shares under option 2,031 2,973 2,344 Convertible senior notes 4,646 4,646 — Total potential dilutive shares 6,677 7,619 2,344

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income (Loss) Before Income Taxes	The geographical components of income (loss) before income taxes consisted of the following (in thousands): Year ended December 31, 2015 2014 2013 Domestic $ (290,342 ) $ (165,220 ) $ (84,534 ) Foreign (91,595 ) 7,497 54 Total loss before income taxes $ (381,937 ) $ (157,723 ) $ (84,480 )
Current and Deferred Foreign Tax Expenses	The income tax provision consists of the following current and deferred foreign tax expenses (in thousands). No U.S. tax expense was recognized in the 2015 and 2014 and the 2013 tax provisions are not significant. Year ended December 31, 2015 2014 Foreign: Current expense $ — $ 1,547 Deferred (benefit) expense (29,076 ) 761 Total income tax (benefit) expense $ (29,076 ) $ 2,308
Reconciliation of Statutory Income Tax Rate to Effective Income Tax Rate	A reconciliation of the U.S. statutory income tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2015 2014 2013 Federal income tax benefit at statutory rate (34.0 )% (34.0 )% (34.0 )% State income tax benefit, net of federal benefit (3.0 ) (3.5 ) (3.0 ) Tax credits (13.6 ) (20.5 ) (15.5 ) Change in tax status of foreign subsidiary — (13.5 ) — Limitation on future foreign tax credits (5.0 ) — — Other 0.4 1.0 2.1 Change in valuation allowance 47.6 72.0 50.5 Effective income tax rate (7.6 )% 1.5 % 0.1 %
Components of Deferred Tax Assets and Liabilities	The components of the Company’s deferred tax assets and liabilities are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating loss carryforward $ 189,663 $ 111,309 Tax credit carryforwards 179,865 101,469 Intangible assets 26,766 — Deductible foreign taxes 10,836 22,729 Share-based compensation expense 23,844 10,777 Foreign currency translation 17,471 9,092 Product acquisition costs 10,470 6,866 Accrued liabilities and other 4,147 2,051 Total deferred tax assets 463,062 264,293 Valuation allowance (449,080 ) (259,004 ) Deferred tax assets, net of valuation allowance 13,982 5,289 Deferred tax liabilities: Intangible assets (31,871 ) (70,084 ) Contingent purchase consideration (11,142 ) (843 ) Prepaid expenses and other (2,102 ) (1,213 ) Total deferred tax liabilities (45,115 ) (72,140 ) Net deferred tax liability $ (31,133 ) $ (66,851 )

Quarterly Information (Unaudi39

Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Results of Operations on Quarterly Basis	The results of operations on a quarterly basis for the years ended December 31, 2015 and 2014 were as follows (in thousands): March 31, June 30, Sept. 30, Dec. 31, March 31, June 30, Sept. 30, Dec. 31, 2015 2015 2015 (1) 2015 2014 2014 2014 2014 Revenues: License and milestone revenue $ — $ — $ — $ — $ 13,625 $ — $ — $ — Operating expenses: Research and development 56,750 60,368 76,138 75,995 24,151 28,440 34,965 50,149 General and administrative 6,751 7,204 8,331 8,238 5,320 5,265 5,267 5,605 Acquired in-process research and development — — 12,000 — 8,406 400 — — Impairment of intangible asset — — — 89,557 3,409 — — — Change in fair value of contingent purchase consideration 724 764 783 (26,882 ) 822 861 888 (1,864 ) Total expenses 64,225 68,336 97,252 146,908 42,108 34,966 41,120 53,890 Operating loss (64,225 ) (68,336 ) (97,252 ) (146,908 ) (28,483 ) (34,966 ) (41,120 ) (53,890 ) Other income (expense): Interest expense (2,075 ) (2,097 ) (2,099 ) (2,101 ) — — (511 ) (2,093 ) Foreign currency gains (losses) 3,247 (1,142 ) (101 ) 736 (60 ) 316 2,323 1,001 Other income (expense) 11 62 179 164 (46 ) (46 ) (42 ) (106 ) Other income (expense), net 1,183 (3,177 ) (2,021 ) (1,201 ) (106 ) 270 1,770 (1,198 ) Loss before income taxes (63,042 ) (71,513 ) (99,273 ) (148,109 ) (28,589 ) (34,696 ) (39,350 ) (55,088 ) Income tax (expense) benefit (102 ) (18 ) 628 28,568 (2,129 ) (68 ) (292 ) 181 Net loss $ (63,144 ) $ (71,531 ) $ (98,645 ) $ (119,541 ) $ (30,718 ) $ (34,764 ) $ (39,642 ) $ (54,907 ) Basic and diluted net loss per common share $ (1.86 ) $ (2.10 ) $ (2.62 ) $ (3.12 ) $ (0.91 ) $ (1.03 ) $ (1.17 ) $ (1.62 ) Basic and diluted weighted average common shares outstanding 34,011 34,088 37,613 38,321 33,820 33,872 33,921 33,941 (1) In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Nature of Business - Additional

Nature of Business - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Segment
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of operating segments	1

Estimated Useful Lives of Prope

Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2015
Computer Hardware and Software | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	3 years
Computer Hardware and Software | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	5 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	6 years
Laboratory, Manufacturing, and Office Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	5 years
Laboratory, Manufacturing, and Office Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	7 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	10 years

Summary of Significant Accoun42

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014
Schedule Of Significant Accounting Policies [Line Items]
Impairment of intangible asset	$ 89,557	$ 3,409	$ 89,557		$ 3,409
Reduction in fair value of contingent purchase consideration liability	(26,900)
Total liabilities denominated in currencies other than functional currency			3.00%		7.00%
Convertible Senior Unsecured Notes
Schedule Of Significant Accounting Policies [Line Items]
Debt issuance costs	7,600		$ 7,600		$ 8,800
In Process Research and Development
Schedule Of Significant Accounting Policies [Line Items]
Impairment of intangible asset	$ 89,557		$ 89,557	[1]	$ 3,409	[1]
[1]	During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge due to the Company’s and its development partner’s decision to terminate the development of lucitanib for lung cancer, as well as updates to the probability-weighted discounted cash flow assumptions for the breast cancer indication.During the first quarter of 2014, the Company recorded a $3.4 million reduction in the intangible assets driven by lower expected future milestone revenue from the lucitanib development activities due to the receipt of a lucitanib milestone payment from Servier (see Note 12 - Lucitanib).These reductions were included in impairment of intangible asset on the Consolidated Statements of Operations.

Other Current Assets (Detail)

Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Receivable from partners	$ 3,241	$ 1,991
Prepaid insurance	1,231	1,190
Receivable from landlord	1,153
Prepaid expenses - other	1,023	1,168
Receivable - other	889	281
Other	199	100
Other current assets	$ 7,736	$ 4,730

Other Accrued Expenses (Detail)

Other Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Accrued personnel costs	$ 8,250	$ 4,726
Accrued interest payable	2,096	2,236
Accrued expenses - other	959	636
Other accrued expenses	$ 11,305	$ 7,598

EOS Acquisition - Additional In

EOS Acquisition - Additional Information (Detail) € in Thousands, $ in Thousands	Nov. 19, 2013USD ($)	Nov. 30, 2013USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2015USD ($)		Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)	Nov. 19, 2013EUR (€)
Business Acquisition [Line Items]
Fair value of contingent consideration									$ 55,754
Impairment of intangible asset			$ 89,557	$ 3,409	$ 89,557		$ 3,409
Reduction in fair value of contingent purchase consideration liability			(26,900)
In Process Research and Development
Business Acquisition [Line Items]
Impairment of intangible asset			$ 89,557		$ 89,557	[1]	$ 3,409	[1]
Ethical Oncology Science, S.p.A.
Business Acquisition [Line Items]
Business acquisition cash payments made on acquisition	$ 11,800
Business acquisition, common stock issued at acquisition date		$ 173,700							173,654
Fair value of contingent consideration	54,727
Future maximum contingent milestone payments	190,500
Ethical Oncology Science, S.p.A. | Regulatory Milestones
Business Acquisition [Line Items]
Fair value of contingent consideration	$ 52,500
Estimated borrowing rate, Minimum	5.20%
Estimated borrowing rate, Maximum	5.80%
Ethical Oncology Science, S.p.A. | Sales Milestone
Business Acquisition [Line Items]
Net cash flows risk-adjusted discount rate	18.70%
Fair value of contingent consideration	$ 2,200
Future maximum contingent milestone payments | €										€ 55,000
Ethical Oncology Science, S.p.A. | Regulatory and Sales Milestones
Business Acquisition [Line Items]
Future minimum potential contingent milestone payments	0									0
Future maximum contingent milestone payments	65,000									€ 115,000
Ethical Oncology Science, S.p.A. | Value Of Servier Sublicensed Product Rights
Business Acquisition [Line Items]
Fair value of the IPR&D intangible product rights	56,100
Ethical Oncology Science, S.p.A. | Value Of US Japan Product Rights
Business Acquisition [Line Items]
Fair value of the IPR&D intangible product rights	$ 183,800
Net cash flows risk-adjusted discount rate	18.90%
Ethical Oncology Science, S.p.A. | Common Stock
Business Acquisition [Line Items]
Business acquisition, common stock issued at acquisition date	$ 173,700								$ 4
[1]	During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge due to the Company’s and its development partner’s decision to terminate the development of lucitanib for lung cancer, as well as updates to the probability-weighted discounted cash flow assumptions for the breast cancer indication.During the first quarter of 2014, the Company recorded a $3.4 million reduction in the intangible assets driven by lower expected future milestone revenue from the lucitanib development activities due to the receipt of a lucitanib milestone payment from Servier (see Note 12 - Lucitanib).These reductions were included in impairment of intangible asset on the Consolidated Statements of Operations.

Summary of Contingent Payment O

Summary of Contingent Payment Obligation (Detail) - Nov. 19, 2013 - Ethical Oncology Science, S.p.A. € in Thousands, $ in Thousands	USD ($)	EUR (€)
Business Acquisition Contingent Consideration [Line Items]
Future potential cash consideration payments | $	$ 190,500
New Drug Application Initial Approval for lucitanib in the U.S.
Business Acquisition Contingent Consideration [Line Items]
Future potential cash consideration payments | $	65,000
Regulatory Milestones Marketing Authorization Application Initial filing for lucitanib in the E.U.
Business Acquisition Contingent Consideration [Line Items]
Future potential cash consideration payments		€ 15,000
Regulatory Milestones Initial Approval of Marketing Authorization Application for lucitanib in the E.U
Business Acquisition Contingent Consideration [Line Items]
Future potential cash consideration payments		45,000
Sales Milestone
Business Acquisition Contingent Consideration [Line Items]
Future potential cash consideration payments		55,000
Regulatory and Sales Milestones
Business Acquisition Contingent Consideration [Line Items]
Future potential cash consideration payments	$ 65,000	€ 115,000

Summary of Contingent Payment47

Summary of Contingent Payment Obligation (Parenthetical) (Detail) € in Millions	Nov. 19, 2013EUR (€)
Sales Milestone | Ethical Oncology Science, S.p.A.
Business Acquisition Contingent Consideration [Line Items]
Aggregate net sales in Servier licensed territory in any four consecutive quarters	€ 500

Property and Equipment (Detail)

Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 6,737	$ 3,793
Less: accumulated depreciation	(1,791)	(1,075)
Property and equipment, net	4,946	2,718
Laboratory, Manufacturing, and Office Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,556	2,452
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,861	260
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,487	667
Computer Hardware and Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 833	$ 414

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment [Abstract]
Depreciation expense on property and equipment	$ 761	$ 444	$ 250

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	$ 500,869	$ 447,994
Contingent purchase consideration, fair value	24,661	52,453
Liabilities at fair value	24,661	52,453
Money Market
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	251,037	447,994
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	249,832
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	251,037	447,994
Fair Value, Inputs, Level 1 | Money Market
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	251,037	447,994
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	249,832
Fair Value, Inputs, Level 2 | U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets at fair value	249,832
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent purchase consideration, fair value	24,661	52,453
Liabilities at fair value	$ 24,661	$ 52,453

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 09, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers between level 1 and level 2, assets	$ 0
Transfers between level 2 and level 1, assets	0
Transfers between level 1 and level 2, liabilities	0
Transfers between level 2 and level 1, liabilities	0
Transfer of assets into level 3	0
Transfer of assets out of level 3	0
Transfer of liabilities into level 3	0
Transfer of liabilities out of level 3	0
Convertible senior notes	279,885,000	$ 278,680,000
Convertible Senior Unsecured Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Convertible senior notes	287,500,000		$ 287,500,000
Convertible Senior Unsecured Notes | Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Convertible senior notes, fair value	$ 248,700,000

Roll-forward of Fair Value of L

Roll-forward of Fair Value of Level 3 Instruments (significant unobservable inputs) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Change in fair value	$ (26,900)
Fair Value, Inputs, Level 3
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance at beginning of period		$ 52,453
Change in fair value		(24,611)
Change in foreign currency gains and losses		(3,181)
Balance at end of period	$ 24,661	$ 24,661

Roll-forward of Fair Value of53

Roll-forward of Fair Value of Level 3 Instruments (significant unobservable inputs) (Parenthetical) (Detail) - Fair Value, Inputs, Level 3 - Regulatory Milestones	12 Months Ended
	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated borrowing rate, Minimum	8.50%
Estimated borrowing rate, Maximum	8.60%

Available-for-Sale Securities -

Available-for-Sale Securities - Summary of Available-for-Sale Securities (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 250,215
Aggregate Fair Value	249,832
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	250,215
Gross Unrealized Losses	(383)
Aggregate Fair Value	$ 249,832

Summary of Fair Value and Gross

Summary of Fair Value and Gross Unrealized Losses of Available-for-Sale Securities in a Continuous Unrealized Loss Position (Detail) - U.S. Treasury Securities $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Fair Value	$ 249,832
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses	$ (383)

Available-for-Sale Securities56

Available-for-Sale Securities - Summary of Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Available For Sale Securities Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 200,147
Amortized Cost, Due in one year to two years	50,068
Amortized Cost	250,215
Fair Value, Due in one year or less	199,912
Fair Value, Due in one year to two years	49,920
Aggregate Fair Value	$ 249,832

Summary of IPR&D Assets and Goo

Summary of IPR&D Assets and Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014
IPR&D assets:
Balance at beginning of period			$ 212,900
Impairment of intangible asset	$ (89,557)	$ (3,409)	(89,557)		$ (3,409)
Balance at end of period	101,500		101,500		212,900
Goodwill:
Balance at beginning of period			66,055
Balance at end of period	59,327		59,327		66,055
In Process Research and Development
IPR&D assets:
Balance at beginning of period		244,518	212,900		244,518
Impairment of intangible asset	(89,557)		(89,557)	[1]	(3,409)	[1]
Change in foreign currency gains and losses			(21,843)		(28,209)
Balance at end of period	101,500		101,500		212,900
Ethical Oncology Science, S.p.A.
Goodwill:
Balance at beginning of period		$ 74,811	66,055		74,811
Change in foreign currency gains and losses			(6,728)		(8,756)
Balance at end of period	$ 59,327		$ 59,327		$ 66,055
[1]	During the fourth quarter of 2015, the Company recorded an $89.6 million impairment charge due to the Company’s and its development partner’s decision to terminate the development of lucitanib for lung cancer, as well as updates to the probability-weighted discounted cash flow assumptions for the breast cancer indication.During the first quarter of 2014, the Company recorded a $3.4 million reduction in the intangible assets driven by lower expected future milestone revenue from the lucitanib development activities due to the receipt of a lucitanib milestone payment from Servier (see Note 12 - Lucitanib).These reductions were included in impairment of intangible asset on the Consolidated Statements of Operations.

Summary of IPR&D Assets and G58

Summary of IPR&D Assets and Goodwill (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Impairment of intangible asset	$ 89,557	$ 3,409	$ 89,557	$ 3,409

Intangible Assets and Goodwil59

Intangible Assets and Goodwill - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)
Ethical Oncology Science, S.p.A.
Intangible Assets And Goodwill [Line Items]
Impairment of goodwill	$ 0

Convertible Senior Notes - Addi

Convertible Senior Notes - Additional Information (Detail) $ / shares in Units, $ in Thousands	Sep. 09, 2014USD ($)TD$ / shares	Dec. 31, 2015USD ($)TD	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Convertible senior notes, aggregate principal amount		$ 279,885	$ 278,680
Net proceeds from convertible senior notes			278,313
Convertible Senior Unsecured Notes
Debt Instrument [Line Items]
Convertible senior notes, aggregate principal amount	$ 287,500	$ 287,500
Convertible senior notes, interest rate	2.50%
Net proceeds from convertible senior notes	$ 278,300
Convertible senior notes, frequency of periodic payment		semi-annually
Convertible senior notes, maturity date		Sep. 15, 2021
Convertible senior notes, initial conversion price per share | $ / shares	$ 61.88
Common stock initial conversion rate per $1,000 in principal amount	16.1616
Last reported sale price of common stock	150.00%
Debt instrument, conversion in effect for number of trading days | TD	20
Debt instrument conversion, consecutive trading day period	30 days
Debt instrument redemption price percentage to principal amount	100.00%
Debt instrument redemption description		On or after September 15, 2018, we may redeem the Notes, at our option, in whole or in part, if the last reported sale price of our common stock has been at least 150% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending not more than two trading days preceding the date on which we provide written notice of redemption at a redemption price equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the Notes.
Debt instrument, redemption period start date		Sep. 15, 2018
Debt instrument, trading days preceding redemption notice, maximum | TD		2
Debt instrument repurchase percentage		100.00%
Debt issuance costs		$ 9,200
Debt instrument term		7 years
Unamortized debt issuance costs		$ 7,600	$ 8,800
Convertible Senior Unsecured Notes | Semi Annual Payment, First payment date
Debt Instrument [Line Items]
Interest payment date on senior notes		--03-15
Convertible Senior Unsecured Notes | Semi Annual Payment, Second payment date
Debt Instrument [Line Items]
Interest payment date on senior notes		--09-15

Schedule of Total Interest Expe

Schedule of Total Interest Expense Recognized Related to Notes (Detail) - USD ($) $ in Thousands	3 Months Ended							12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	[1]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Contractual interest expense								$ 7,167	$ 2,236
Amortization of debt issuance costs								1,205	368
Total interest expense	$ 2,101	$ 2,099		$ 2,097	$ 2,075	$ 2,093	$ 511	$ 8,372	$ 2,604
[1]	In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Jul. 31, 2015	Nov. 30, 2013	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2013
Class Of Stock [Line Items]
Common stock, shares issued	4,054,487		3,819,444
Sale of stock, price per share	$ 78		$ 72
Proceeds from the sale of common stock, net of issuance costs	$ 298,500		$ 259,100	$ 298,509	$ 259,071
Ethical Oncology Science, S.p.A.
Class Of Stock [Line Items]
Issuance of common stock related to EOS acquisition , shares		3,713,731
Issuance of common stock related to EOS acquisition		$ 173,700			$ 173,654

Component of Other Comprehensiv

Component of Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ (24,448)	$ 4,696
Period change	(23,012)	(29,144)	$ 4,643
Ending balance	(47,460)	(24,448)	4,696
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(24,448)	4,696
Period change	(22,629)	(29,144)
Ending balance	(47,077)	$ (24,448)	$ 4,696
Unrealized Losses
Accumulated Other Comprehensive Income Loss [Line Items]
Period change	(383)
Ending balance	$ (383)

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Aug. 31, 2011	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense, tax benefit recognized		$ 0	$ 0	$ 0
Pretax intrinsic value, closing stock price		$ 35
Unrecognized stock-based compensation expense related to non-vested options		$ 88,600,000
Unrecognized stock-based compensation expense related to non-vested options, weighted-average remaining vesting period		2 years 8 months 12 days
Stock-based compensation expense		$ 40,357,000	$ 21,517,000	9,505,000
2009 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized		1,317,125
Stock options expiration period		10 years
Shares of common stock remaining for future grant		191,496
2011 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized		6,262,641			1,250,000
Stock options vesting period		4 years
Stock options expiration period		10 years
Shares of common stock remaining for future grant		376,231
Increase in amount of shares reserved for issuance as percentage of outstanding shares of common stock	1.00%
Increase in amount of shares reserved for issuance	344,828
Employee stock purchase plan offering period	6 months
Purchase plan participating employees compensation withheld and applied to purchase of common stock	10.00%
Share based compensation arrangement by share based payment award purchase price of common stock percent	85.00%
Purchase Plan termination date	Aug. 24, 2021
Common stock shares sold to employees		32,021	13,633
weighted-average estimated grant date fair value of purchase awards under Purchase Plan		$ 26.80	$ 17.31
Stock-based compensation expense		$ 858,000	$ 236,000	$ 169,000
2011 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock additional shares authorized		4,821,145
Minimum | Board Of Directors | 2009 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period		1 year
Minimum | Board Of Directors | 2011 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period		1 year
Maximum | Board Of Directors | 2009 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period		3 years
Maximum | Board Of Directors | 2011 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period		3 years
Employee Stock | 2009 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options vesting period		4 years

Share-Based Compensation Expens

Share-Based Compensation Expense Recognized in Accompanying Statements of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 40,357	$ 21,517	$ 9,505
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	27,321	11,474	4,289
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 13,036	$ 10,043	$ 5,216

Share-Based Compensation Expe66

Share-Based Compensation Expense Recognized in Accompanying Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense		$ 40,357	$ 21,517	$ 9,505
Stock Option [Member] | Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 2,900

Summary of Stock Options Activi

Summary of Stock Options Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning Balance, Number of Options Outstanding | shares	4,159,362
Number of Options, Granted | shares	1,600,593
Number of Options, Exercised | shares	(295,759)
Number of Options, Forfeited | shares	(103,939)
Ending Balance, Number of Options Outstanding | shares	5,360,257
Number of Option, Vested and expected to vest at December 31, 2015 | shares	5,030,757
Number of Options, Exercisable at December 31, 2015 | shares	2,608,239
Beginning Balance, Weighted Average Exercise Price | $ / shares	$ 37.69
Granted, Weighted Average Exercise Price | $ / shares	80.04
Exercised, Weighted Average Exercise Price | $ / shares	18.52
Forfeited, Weighted Average Exercise Price | $ / shares	56.93
Ending Balance, Weighted Average Exercise Price | $ / shares	51.53
Vested and expected to vest, Weighted Average Exercise Price | $ / shares	50.22
Exercisable, Weighted Average Exercise Price | $ / shares	$ 34.56
Outstanding, Weighted Average Remaining Contractual Term (Years)	7 years 1 month 6 days
Vested and expected to vest, Weighted Average Remaining Contractual Term (Years)	7 years
Exercisable, Weighted Average Remaining Contractual Term (Years)	6 years
Outstanding, Aggregate Intrinsic Value | $	$ 33,927
Vested and expected to vest, Aggregate Intrinsic Value | $	33,678
Exercisable, Aggregate Intrinsic Value | $	$ 29,607

Summary of Stock Options Acti68

Summary of Stock Options Activity (Parenthetical) (Detail) (Performance Shares) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Granted		1,600,593
Performance Shares | Contingent on FDA Approval to Commercially Distribute, Sell or Market Rociletinib
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of grant vest contingent on approval		50.00%
Performance Shares | Contingent on FDA Approval to Commercially Distribute, Sell or Market Rucaparib
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of grant vest contingent on approval		50.00%
Performance Shares | Executive Officer [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Options, Granted	120,000

Schedule of Share-Based Compens

Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted-average grant date fair value per share	$ 52.70	$ 38.47	$ 18.59
Intrinsic value of options exercised	$ 19,976,769	$ 2,906,304	$ 6,114,436
Cash received from stock option exercises	$ 5,478,211	$ 682,678	$ 1,393,053

Weighted-Average Assumptions (D

Weighted-Average Assumptions (Detail)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Volatility	[1]	72.00%	70.00%	69.00%
Risk-free interest rate	[2]	1.77%	1.92%	1.16%
Expected term (years)	[3]	6 years 1 month 6 days	6 years 2 months 12 days	6 years 2 months 12 days
[1]	Volatility: The expected volatility was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans.
[2]	Risk-free interest rate: The rate is based on the yield on the grant date of a zero-coupon U.S. Treasury bond whose maturity period approximates the option’s expected term.
[3]	Expected term: The expected term of the award was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans

Reserved Shares of Common Stock

Reserved Shares of Common Stock for Future Issuance (Detail) - shares	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding	5,360,257	4,159,362
Available for Grant or Future Issuance	1,557,953
Total Shares of Common Stock Reserved	6,918,210
2009 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding	494,031
Total Shares of Common Stock Reserved	494,031
2011 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options Outstanding	4,866,226
Available for Grant or Future Issuance	1,181,722
Total Shares of Common Stock Reserved	6,047,948
2011 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Available for Grant or Future Issuance	376,231
Total Shares of Common Stock Reserved	376,231

Weighted-Average Assumptions Us

Weighted-Average Assumptions Used to Estimate Fair Value of Purchase Awards Granted (Detail)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	[1]	72.00%	70.00%	69.00%
Risk-free interest rate	[2]	1.77%	1.92%	1.16%
Expected term (years)	[3]	6 years 1 month 6 days	6 years 2 months 12 days	6 years 2 months 12 days
Employee Stock Purchase Plans
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Volatility	[1]	71.00%	71.00%	72.00%
Risk-free interest rate	[4]	0.11%	0.07%	0.09%
Expected term (years)	[5]	6 months	6 months	6 months
[1]	Volatility: The expected volatility was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans.
[2]	Risk-free interest rate: The rate is based on the yield on the grant date of a zero-coupon U.S. Treasury bond whose maturity period approximates the option’s expected term.
[3]	Expected term: The expected term of the award was estimated using peer data of companies in the biopharmaceutical industry with similar equity plans
[4]	Risk-free interest rate: The rate is based on the U.S. Treasury yield in effect at the time of grant with terms similar to the contractual term of the purchase right.
[5]	Expected term: The expected life of the award represents the six-month offering period for the Purchase Plan

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 28, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Operating lease agreements expiration year		2,023
Operating lease term		7 years
Leasehold improvement expenditures		$ 1,100,000
Rental expenses		2,400,000	$ 1,400,000	$ 1,100,000
Purchase commitment		16,100,000
Contractual agreement quarterly forecasts required period	24 months
Contractual agreement obligated forecast period	12 months
Purchases occurred under agreement		$ 6,000,000	$ 3,300,000	$ 6,400,000

Future Minimum Rental Commitmen

Future Minimum Rental Commitments (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,016	$ 1,795
2,017	1,746
2,018	1,783
2,019	1,837
2,020	1,891
Thereafter	2,547
Total future minimum lease payments	$ 11,599

License Agreements - Additional

License Agreements - Additional Information (Detail)	1 Months Ended							3 Months Ended										12 Months Ended
	Apr. 30, 2014USD ($)	Jan. 31, 2013USD ($)	Sep. 30, 2012EUR (€)	Apr. 30, 2012USD ($)	Jun. 30, 2011USD ($)	May. 31, 2010USD ($)	Oct. 31, 2008	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)		Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Mar. 31, 2012USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Research And Development Arrangement Contract To Perform For Others [Line Items]
Acquired in process research and development costs									$ 12,000,000	[1]					$ 400,000	$ 8,406,000		$ 12,000,000	$ 8,806,000	$ 250,000
Development cost receivable								$ 3,241,000					$ 1,991,000					3,241,000	1,991,000
Research and development								75,995,000	76,138,000	[1]	$ 60,368,000	$ 56,750,000	50,149,000	$ 34,965,000	$ 28,440,000	24,151,000		269,251,000	137,705,000	66,545,000
License Agreements Lucitanib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment | €			€ 45,000,000
Additional payments receivable on attaining the sales target | €			250,000,000
Sublicense agreement consideration																13,600,000
Additional payments receivable on milestone achievements | €			90,000,000
Initial global development costs reimbursable | €			€ 80,000,000
Development cost receivable								3,200,000					$ 2,000,000					3,200,000	2,000,000
Research and development																		13,700,000	9,500,000	1,400,000
Reduction in research and development expense for reimbursable development costs due from Servier																		11,800,000	$ 10,000,000	$ 1,300,000
License Agreements Licensor Celgene Avilomics Research Inc | Name of drug product in licensed by the entity Rociletinib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Sales milestone payments																		120,000,000
License Agreements Licensor Celgene Avilomics Research Inc | Name of drug product in licensed by the entity Rociletinib | Minimum
Research And Development Arrangement Contract To Perform For Others [Line Items]
Additional payments receivable on attaining the sales target								$ 500,000,000										500,000,000
License Agreements Licensor Pfizer | Rucaparib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Acquired in process research and development costs	$ 400,000
License Agreement Terms | License Agreements Licensor Celgene Avilomics Research Inc | Name of drug product in licensed by the entity Rociletinib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment						$ 2,000,000
Future expected regulatory and development payment																		98,000,000
License Agreement Terms | License Agreements Licensor Celgene Avilomics Research Inc | Name of drug product in licensed by the entity Rociletinib | FDA [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Future expected regulatory and development payment																		15,000,000
License Agreement Terms | License Agreements Licensor Celgene Avilomics Research Inc | Name of drug product in licensed by the entity Rociletinib | EMA [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Future expected regulatory and development payment																		15,000,000
License Agreement Terms | License Agreements Licensor Gatekeeper | Name of drug product in licensed by the entity Rociletinib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment		$ 250,000
License Agreement Terms | License Agreements Licensor Pfizer | Rucaparib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment					$ 7,000,000
Future expected development, regulatory and sales milestone payments																		258,500,000
License Agreement Terms | License Agreements Licensor Pfizer | Rucaparib | First approval of NDA by FDA
Research And Development Arrangement Contract To Perform For Others [Line Items]
Future expected development, regulatory and sales milestone payments																		$ 20,750,000
License Agreement Terms | License Agreements Licensor Astra Zeneca U K Ltd | Rucaparib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Upfront payment				$ 250,000
Future expected regulatory payment				$ 700,000
License Agreement Terms | Advenchen Laboratories LLC | License Agreements Lucitanib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Acquired in process research and development costs																3,400,000
Percentage of Non-Royalty Consideration Payable on Sublicense Agreements							25.00%
Regulatory Milestone Payment | License Agreement Terms | License Agreements Licensor Celgene Avilomics Research Inc | Name of drug product in licensed by the entity Rociletinib
Research And Development Arrangement Contract To Perform For Others [Line Items]
Acquired in process research and development costs									$ 12,000,000							$ 5,000,000	$ 4,000,000
[1]	In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Shares Outstanding Excluded fro

Shares Outstanding Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	6,677	7,619	2,344
Common shares under option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	2,031	2,973	2,344
Convertible senior notes
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total potential dilutive shares	4,646	4,646

Income (Loss) Before Income Tax

Income (Loss) Before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	[1]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Domestic										$ (290,342)	$ (165,220)	$ (84,534)
Foreign										(91,595)	7,497	54
Loss before income taxes	$ (148,109)	$ (99,273)		$ (71,513)	$ (63,042)	$ (55,088)	$ (39,350)	$ (34,696)	$ (28,589)	$ (381,937)	$ (157,723)	$ (84,480)
[1]	In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Current and Deferred Foreign Ta

Current and Deferred Foreign Tax Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	[1]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current expense											$ 1,547
Deferred (benefit) expense										$ (29,076)	761
Total income tax (benefit) expense	$ (28,568)	$ (628)		$ 18	$ 102	$ (181)	$ 292	$ 68	$ 2,129	$ (29,076)	$ 2,308	$ 52
[1]	In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Reconciliation of Statutory Inc

Reconciliation of Statutory Income Tax Rate to Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal income tax benefit at statutory rate	(34.00%)	(34.00%)	(34.00%)
State income tax benefit, net of federal benefit	(3.00%)	(3.50%)	(3.00%)
Tax credits	(13.60%)	(20.50%)	(15.50%)
Change in tax status of foreign subsidiary		(13.50%)
Limitation on future foreign tax credits	(5.00%)
Other	0.40%	1.00%	2.10%
Change in valuation allowance	47.60%	72.00%	50.50%
Effective income tax rate	(7.60%)	1.50%	0.10%

Components of Deferred Tax Asse

Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating loss carryforward	$ 189,663	$ 111,309
Tax credit carryforwards	179,865	101,469
Intangible assets	26,766
Deductible foreign taxes	10,836	22,729
Share-based compensation expense	23,844	10,777
Foreign currency translation	17,471	9,092
Product acquisition costs	10,470	6,866
Accrued liabilities and other	4,147	2,051
Total deferred tax assets	463,062	264,293
Valuation allowance	(449,080)	(259,004)
Deferred tax assets, net of valuation allowance	13,982	5,289
Deferred tax liabilities:
Intangible assets	(31,871)	(70,084)
Contingent purchase consideration	(11,142)	(843)
Prepaid expenses and other	(2,102)	(1,213)
Total deferred tax liabilities	(45,115)	(72,140)
Net deferred tax liability	$ (31,133)	$ (66,851)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Increase to valuation allowance	$ 190.1	$ 122.7
Net operating loss, stock based compensation expense	16.7
Research and development and orphan drug tax credit carryforwards	177.7
U.S. federal
Income Taxes [Line Items]
Net operating loss carryforwards	504.8
State
Income Taxes [Line Items]
Net operating loss carryforwards	728.1
Foreign Country
Income Taxes [Line Items]
Net operating loss carryforwards	$ 2.7
Minimum
Income Taxes [Line Items]
Net operating loss carryforwards expiration year	2,029
Tax credit carryforwards expiration year	2,029
Maximum
Income Taxes [Line Items]
Net operating loss carryforwards expiration year	2,035
Tax credit carryforwards expiration year	2,035

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, employer's contribution percentage	4.00%
Domestic Defined Contribution Plan
Defined Benefit Plan Disclosure [Line Items]
Matching contributions to employees	$ 824	$ 425	$ 368
Foreign Defined Contribution Plan
Defined Benefit Plan Disclosure [Line Items]
Matching contributions to employees	$ 171	$ 106	$ 81

Results of Operations on Quarte

Results of Operations on Quarterly Basis (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	[1]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
License and milestone revenue									$ 13,625		$ 13,625
Operating expenses:
Research and development	$ 75,995	$ 76,138		$ 60,368	$ 56,750	$ 50,149	$ 34,965	$ 28,440	24,151	$ 269,251	137,705	$ 66,545
General and administrative	8,238	8,331		7,204	6,751	5,605	5,267	5,265	5,320	30,524	21,457	16,567
Acquired in-process research and development		12,000						400	8,406	12,000	8,806	250
Impairment of intangible asset	89,557								3,409	89,557	3,409
Change in fair value of contingent purchase consideration	(26,882)	783		764	724	(1,864)	888	861	822	(24,611)	707	405
Total expenses	146,908	97,252		68,336	64,225	53,890	41,120	34,966	42,108	376,721	172,084	83,767
Operating loss	(146,908)	(97,252)		(68,336)	(64,225)	(53,890)	(41,120)	(34,966)	(28,483)	(376,721)	(158,459)	(83,767)
Other income (expense):
Interest expense	(2,101)	(2,099)		(2,097)	(2,075)	(2,093)	(511)			(8,372)	(2,604)
Foreign currency gains (losses)	736	(101)		(1,142)	3,247	1,001	2,323	316	(60)	2,740	3,580	(535)
Other income (expense)	164	179		62	11	(106)	(42)	(46)	(46)	416	(240)	(178)
Other income (expense), net	(1,201)	(2,021)		(3,177)	1,183	(1,198)	1,770	270	(106)	(5,216)	736	(713)
Loss before income taxes	(148,109)	(99,273)		(71,513)	(63,042)	(55,088)	(39,350)	(34,696)	(28,589)	(381,937)	(157,723)	(84,480)
Income tax benefit (expense)	28,568	628		(18)	(102)	181	(292)	(68)	(2,129)	29,076	(2,308)	(52)
Net loss	$ (119,541)	$ (98,645)		$ (71,531)	$ (63,144)	$ (54,907)	$ (39,642)	$ (34,764)	$ (30,718)	$ (352,861)	$ (160,031)	$ (84,532)
Basic and diluted net loss per common share	$ (3.12)	$ (2.62)		$ (2.10)	$ (1.86)	$ (1.62)	$ (1.17)	$ (1.03)	$ (0.91)	$ (9.79)	$ (4.72)	$ (2.95)
Basic and diluted weighted average common shares outstanding	38,321	37,613		34,088	34,011	33,941	33,921	33,872	33,820	36,026	33,889	28,672
[1]	In July 2015, the Company sold 4,054,487 shares of its common stock in a public offering at $78.00 per share. The net proceeds to the Company from the offering were $298.5 million after deducting underwriting discounts and commissions and offering expenses.

Results of Operations on Quar84

Results of Operations on Quarterly Basis (Parenthetical) (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Jul. 31, 2015	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Common stock, shares issued	4,054,487	3,819,444
Sale of stock, price per share	$ 78	$ 72
Proceeds from the sale of common stock, net of issuance costs	$ 298,500	$ 259,100	$ 298,509	$ 259,071