Medivation 10-K 26 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Feb. 16, 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	MDVN
Entity Registrant Name	MEDIVATION, INC.
Entity Central Index Key	1,011,835
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		164,233,527
Entity Public Float			$ 7.7

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 225,853	$ 502,677
Receivable from collaboration partner	391,558	184,737
Deferred income tax assets		21,987
Prepaid expenses and other current assets	15,877	12,264
Restricted cash	930	203
Total current assets	634,218	721,868
Property and equipment, net	58,142	41,161
Intangible assets	644,299	101,000
Deferred income tax assets, non-current	57,011	15,176
Restricted cash, net of current	12,206	11,562
Goodwill	18,643	10,000
Other non-current assets	7,072	10,852
Total assets	1,431,591	911,619
Current liabilities:
Accounts payable, accrued expenses and other current liabilities	186,203	106,128
Contingent consideration	4,900	10,000
Deferred revenue		2,822
Current portion of build-to-suit lease obligation		698
Current portion of Convertible Notes, net of unamortized discount of $— and $1 at December 31, 2015 and 2014, respectively		4
Total current liabilities	266,103	119,652
Convertible Notes, net of unamortized discount of $— and $36,598 at December 31, 2015 and 2014, respectively		222,140
Contingent consideration	262,368	96,000
Build-to-suit lease obligation, excluding current portion	17,406	18,711
Other non-current liabilities	13,035	5,817
Total liabilities	$ 558,912	$ 462,320
Commitments and contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.01 par value per share; 1,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.01 par value per share; 340,000,000 shares authorized; 163,905,342 and 156,234,454 shares issued and outstanding at December 31, 2015 and 2014, respectively	$ 1,639	$ 1,562
Additional paid-in capital	684,841	505,446
Retained earnings (accumulated deficit)	186,199	(57,709)
Total stockholders’ equity	872,679	449,299
Total liabilities and stockholders’ equity	1,431,591	$ 911,619
Revolving Credit Facility [Member]
Current liabilities:
Borrowings under Credit Facility	$ 75,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Convertible Notes current, discount		$ 1
Convertible Notes, discount		$ 36,598
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	340,000,000	340,000,000
Common stock, shares issued	163,905,342	156,234,454
Common stock, shares outstanding	163,905,342	156,234,454

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Collaboration revenue	$ 943,258	$ 710,487	$ 272,942
Operating expenses:
Research and development expenses	232,100	189,570	118,952
Selling, general and administrative expenses	296,545	239,071	176,231
Total operating expenses	528,645	428,641	295,183
Income (loss) from operations	414,613	281,846	(22,241)
Other income (expense), net:
Loss on extinguishment of Convertible Notes	(21,087)
Interest expense	(12,483)	(21,690)	(20,249)
Other, net	275	38	(8)
Total other income (expense), net	(33,295)	(21,652)	(20,257)
Income (loss) before income tax (expense) benefit	381,318	260,194	(42,498)
Income tax (expense) benefit	(136,593)	16,258	(115)
Net income (loss)	$ 244,725	$ 276,452	$ (42,613)
Basic net income (loss) per common share	$ 1.53	$ 1.80	$ (0.28)
Diluted net income (loss) per common share	$ 1.47	$ 1.71	$ (0.28)
Weighted-average common shares used in the calculation of basic net income (loss) per common share	160,345	153,859	150,331
Weighted-average common shares used in the calculation of diluted net income (loss) per common share	169,324	170,001	150,331

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 244,725	$ 276,452	$ (42,613)
Other comprehensive income (loss):
Change in unrealized loss on available-for-sale securities, net	(10)		(33)
Amounts reclassified into earnings related to investments	10
Other comprehensive income (loss), net			(33)
Comprehensive income (loss)	$ 244,725	$ 276,452	$ (42,646)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ 244,725	$ 276,452	$ (42,613)
Adjustments for non-cash operating items:
Stock-based compensation	54,862	45,134	37,078
Impairment of intangible assets	30,000
Loss on extinguishment of Convertible Notes	21,087
Amortization of debt discount and debt issuance costs	8,613	14,898	13,456
Depreciation on property and equipment	7,023	5,239	3,449
Excess tax benefits from stock-based compensation	(100,243)	(16,965)
Changes in deferred income taxes	(8,270)	(3,827)
Change in fair value of contingent purchase consideration	(10,674)
Amortization of deferred revenue	(2,822)	(14,109)	(25,396)
Release of valuation allowance for deferred income taxes		(33,403)
Other non-cash items	52	1,124	(10)
Changes in operating assets and liabilities:
Receivable from collaboration partners	(206,821)	(77,527)	(71,752)
Prepaid expenses and other current assets	(4,556)	301	(3,953)
Other non-current assets	3,279	(401)	(7,353)
Accounts payable, accrued expenses and other current liabilities	145,997	41,965	27,852
Current taxes payable	30,459	1,970	37
Other non-current liabilities	7,228	(252)	996
Net cash provided by (used) in operating activities	219,939	240,599	(68,209)
Cash flows from investing activities:
Purchases of short-term investments	(90,381)		(144,926)
Sales or maturities of short-term investments	90,224		370,000
Purchases of property and equipment	(19,459)	(10,544)	(7,535)
Change in restricted cash	(1,371)	(1,866)	(713)
Net cash (used in) provided by investing activities	(430,987)	(17,410)	216,826
Cash flows from financing activities:
Principal repayment of Convertible Notes	(258,742)	(12)
Cash settlement of Convertible Notes conversion premium	(1,126)
Proceeds from borrowings under Revolving Credit Facility	150,000
Principal repayment of borrowings under Revolving Credit Facility	(75,000)
Financing transaction costs	(1,715)
Excess tax benefits from stock-based compensation	100,243	16,965
Proceeds from issuance of common stock under equity incentive and stock purchase plans	21,459	33,882	8,870
Reduction of build-to-suit lease obligation	(895)	(135)
Net cash (used in) provided by financing activities	(65,776)	50,700	8,870
Net (decrease) increase in cash and cash equivalents	(276,824)	273,889	157,487
Cash and cash equivalents at beginning of year	502,677	228,788	71,301
Cash and cash equivalents at end of year	225,853	502,677	228,788
Supplemental disclosures of cash flow information:
Interest	3,577	6,792	6,792
Income taxes, net of refunds	2,122	1,525	(127)
Non-cash investing and financing activities:
Reacquisition of Convertible Notes equity component upon conversion	324,177
Fair value of common stock issued for conversion of Convertible Notes	312,990
Derecognition of build-to-suit lease asset	3,241
Derecognition of build-to-suit lease obligations	3,176
Property and equipment expenditures incurred but not yet paid	5,828	242	$ 99
Interest capitalized during construction period for build-to-suit lease transactions	2,024	1,459
Accrued interest payable forfeited upon conversion of Convertible Notes	1,686
Amounts capitalized under build-to-suit lease transactions	44	18,085
BioMarin Pharmaceutical Inc. [Member]
Cash flows from investing activities:
Payments under Agreement	$ (410,000)
CureTech Ltd [Member]
Cash flows from investing activities:
Payments under Agreement		$ (5,000)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock [Member]		Additional Paid-In Capital [Member]	[1]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]
Balances at Dec. 31, 2012		$ 73,645	$ 1,495	[1]	$ 363,665		$ 33	$ (291,548)
Balance, Shares at Dec. 31, 2012	[1]		149,549,878
Common stock value issued under equity incentive and employee stock purchase plans		8,870	$ 20	[1]	8,850
Common stock shares issued under equity incentive and employee stock purchase plans	[1]		2,005,218
Common stock issued for warrant exercises, net of shares withheld for exercise price		0	$ 1	[1]	(1)		0	0
Common stock issued for warrant exercises, net of shares withheld for exercise price, Shares	[1]		50,944
Stock-based compensation expense		37,078			37,078
Change in comprehensive income		(33)					$ (33)
Net income (loss)		(42,613)						(42,613)
Balances at Dec. 31, 2013		76,947	$ 1,516	[1]	409,592			(334,161)
Balance, Shares at Dec. 31, 2013	[1]		151,606,040
Common stock value issued under equity incentive and employee stock purchase plans		33,882	$ 46	[1]	33,836
Common stock shares issued under equity incentive and employee stock purchase plans	[1]		4,628,414
Stock-based compensation expense		45,134			45,134
Excess tax benefits from stock-based compensation		16,965			16,965
Tax shortfalls from stock-based compensation		(77)			(77)
Repayment of Convertible Notes		(4)			(4)
Net income (loss)		276,452						276,452
Balances at Dec. 31, 2014		$ 449,299	$ 1,562	[1]	505,446			(57,709)
Balance, Shares at Dec. 31, 2014		156,234,454	156,234,454	[1]
Common stock value issued under equity incentive and employee stock purchase plans		$ 21,459	$ 21	[1]	21,438
Common stock shares issued under equity incentive and employee stock purchase plans	[1]		2,032,312
Stock-based compensation expense		54,862			54,862
Excess tax benefits from stock-based compensation		100,243			100,243
Tax shortfalls from stock-based compensation		(259)			(259)
Common stock issued for conversion of Convertible Notes, Amount		(11,183)	$ 56	[1]	(11,239)
Common stock issued for conversion of Convertible Notes, Shares	[1]		5,638,576
Tax impact of extinguishment of Convertible Notes		11,847			11,847
Reclassification of accrued interest on Convertible Notes upon conversion		1,686			1,686
Stock dividend					817			(817)
Change in comprehensive income		(10)
Net income (loss)		244,725						244,725
Balances at Dec. 31, 2015		$ 872,679	$ 1,639	[1]	$ 684,841			$ 186,199
Balance, Shares at Dec. 31, 2015		163,905,342	0	[1]
[1]	All share, par, and additional paid-in capital amounts have been retroactively adjusted to reflect the Company’s September 15, 2015, two-for-one forward stock split effected through a stock dividend. This stock split resulted in the issuance of approximately 81.7 million shares of the Company’s common stock.

Consolidated Statements of Sto8

Consolidated Statements of Stockholders' Equity (Parenthetical) shares in Millions	Sep. 15, 2015shares	Dec. 31, 2015shares
Stock dividend, common stock shares issued		81.7
Stock split of common stock	2
Common Stock [Member]
Stock dividend, common stock shares issued	81.7
Stock split of common stock	2	2

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	NOTE 1. DESCRIPTION OF BUSINESS Medivation, Inc. (the “Company” or “Medivation”) is a biopharmaceutical company focused on the development and commercialization of medically innovative therapies to treat serious diseases for which there are limited treatment options. It has one commercial product, XTANDI® (enzalutamide) capsules, or XTANDI, through the Company’s collaboration with Astellas Pharma, Inc., or Astellas. XTANDI has received marketing approval in the United States, Europe and numerous other countries worldwide for the treatment of patients with metastatic castration-resistant prostate cancer, or mCRPC, and in Japan for the treatment of patients with castration-resistant prostate cancer, or CRPC. The Company and Astellas are also conducting investigational studies of enzalutamide in prostate cancer, advanced breast cancer, and hepatocellular carcinoma. Under the Company’s collaboration agreement with Astellas, it shares equally with Astellas all profits (losses) related to U.S. net sales of XTANDI. The Company also receives royalties ranging from the low teens to the low twenties as a percentage of ex-U.S. XTANDI net sales. The collaboration also involved certain milestone payments from Astellas to the Company upon the achievement of defined development, regulatory and sales events, all of which have been achieved as of December 31, 2015. The Company seeks to become a more fully-integrated biopharmaceutical company through the continued commercialization of XTANDI, the acquisition or in-license and development and commercialization of other product opportunities, and through the advancement of its own proprietary research and development programs. The Company expects that its future growth may come from both internal research efforts and third-party business development activities. In the fourth quarter of 2015, the Company acquired all worldwide rights to talazoparib (which is referred to as MDV3800), an orally available poly-ADP ribose polymerase, or PARP, inhibitor from BioMarin Pharmaceutical Inc., or BioMarin. MDV3800 is currently in a Phase 3 clinical trial for the treatment of patients with germline BRCA, or gBRCA, mutated advanced breast cancer (i.e., advanced breast cancer in patients whose BRCA genes contain germline mutations). The Company is targeting a number of other indications in which to investigate MDV3800, including breast cancer (beyond gBRCA mutations), prostate cancer, small cell lung cancer, and ovarian cancer. In the fourth quarter of 2014, the Company licensed exclusive worldwide rights to pidilizumab (which is referred to as MDV9300), an antibody with immune-mediated anti-tumor effects for all potential indications from CureTech, Ltd., or CureTech. Under the license agreement, the Company is responsible for all development, regulatory, manufacturing, and commercialization activities for MDV9300. The Company initiated a Phase 2 clinical trial evaluating MDV9300 in patients with relapsed or refractory diffuse large B-cell lymphoma in the fourth quarter of 2015, which is on partial clinical hold pending its revision of certain investigator brochure, protocols and informed consent documents. The Company submitted the revised documents to the FDA in early February 2016 and the FDA has 30 days thereafter to notify the Company if the partial hold is lifted. The Company also plans to develop MDV9300 in other hematologic malignancies such as multiple myeloma. In addition to the above activities, the Company has various internal research and discovery efforts focused in oncology, neurology and other areas.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Significant Accounting Policies	NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (a) Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States, or U.S. GAAP, and include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The Company operates in one business segment. All tabular disclosures of dollar and share amounts are presented in thousands unless otherwise indicated. All per share amounts are presented at their actual amounts. The number of shares issuable under the Amended and Restated 2004 Equity Incentive Award Plan, or the Medivation Equity Incentive Plan, and the Medivation, Inc. 2013 Employee Stock Purchase Plan, or ESPP, disclosed in Note 11, “Stockholders’ Equity,” are presented at their actual amounts unless otherwise indicated. Amounts presented herein may not calculate or sum precisely due to rounding. Certain prior period amounts have been reclassified to conform to the current year presentation. There was no effect on net income (loss) or stockholders’ equity related to these reclassifications. (b) Use of Estimates The preparation of consolidated financial statements in accordance with U.S. GAAP requires that management make estimates and assumptions in certain circumstances that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. Although management believes that these estimates are reasonable, actual future results could differ materially from those estimates. In addition, had different estimates and assumptions been used, the consolidated financial statements could have differed materially from what is presented. Significant estimates and assumptions used by management principally relate to revenue recognition, including reliance on third-party information, estimating the performance periods of the Company’s deliverables under collaboration agreements, and estimating the various deductions from gross sales to calculate net sales of XTANDI. Additionally, significant estimates and assumptions used by management include those related to contingent purchase consideration, intangible assets, goodwill, the Convertible Notes, determining whether the Company is the primary beneficiary of any variable interest entities, (c) Capital Structure On June 15, 2015, the Company filed a Certificate of Amendment to its Amended and Restated Certificate of Incorporation, as amended, effecting an increase in the total number of authorized shares of capital stock of the Company from 171,000,000 to 341,000,000 and an increase in the total number of authorized shares of common stock of the Company from 170,000,000 to 340,000,000. On September 15, 2015, the Company effected a two-for-one forward stock split of its common stock in the form of a stock dividend. Stockholders of record as of August 13, 2015 received one additional share of the Company’s common stock, par value $0.01, for each share they held as of the record date. The Company issued approximately 81.7 million shares of its common stock as a result of the stock dividend. The par value of the Company’s common stock remained unchanged at $0.01 per share. During the year ended December 31, 2015, the Company settled $258.8 million aggregate principal amount of its 2.625% convertible senior notes due April 1, 2017, or the Convertible Notes, through a combination of $259.9 million in cash and 5,638,576 shares of its common stock. Upon settlement, the Convertible Notes were no longer outstanding, interest ceased to accrue thereon, and all rights of the holders of the Convertible Notes ceased to exist. Information regarding shares of common stock (except par value per share), par, additional paid-in capital, and net income (loss) per common share for all periods presented has been retroactively adjusted to reflect the effects of the stock split. The number of shares of the Company’s common stock issuable upon exercise of outstanding stock options and stock appreciation rights and vesting of other stock-based awards was proportionally increased, and the exercise price per share thereof, as applicable, was proportionally decreased, in accordance with the terms of the Medivation Equity Incentive Plan, as amended, and the ESPP. (d) Collaboration Agreement Payments The Company accounts for the various payment flows under its collaboration agreement with Astellas, or the Astellas Collaboration Agreement, as follows: Estimated Performance Periods The Astellas Collaboration Agreement contains multiple elements and deliverables, and required evaluation pursuant to Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, 605-25, “Revenue Recognition—Multiple-Element Arrangements.” The Company concluded that it had multiple deliverables under the Astellas Collaboration Agreement, including deliverables relating to grants of technology licenses, and performance of manufacturing, regulatory and clinical development activities in the United States. The period in which the Company performed its deliverables began in the fourth quarter of 2009 and concluded in the third quarter of 2015 upon substantial completion of the Company’s remaining performance obligations. The Company also concluded that its deliverables under the Astellas Collaboration Agreement should be accounted for as a single unit under ASC 605-25. Estimation of the performance periods of the Company’s deliverables requires the use of management’s judgment. Significant factors considered in management’s evaluation of the estimated performance periods include, but are not limited to, the Company’s experience, along with its collaboration partners’ experience, in conducting manufacturing, clinical development and regulatory activities. The Company reviews the estimated duration of its performance periods under its collaboration agreements on a quarterly basis and makes any appropriate adjustments on a prospective basis. Upfront Payments The Company received a non-refundable, upfront cash payment of $110.0 million under the Astellas Collaboration Agreement. The Company recognized the payment as collaboration revenue on a straight-line basis over the applicable estimated performance period. As of December 31, 2015, there was no deferred revenue related to payments received under the Astellas Collaboration Agreement. Milestone Payments The Company has been eligible to receive milestone payments under the Astellas Collaboration Agreement based on achievement of specified development, regulatory and commercial events. Management evaluated the nature of the events triggering these contingent payments, and concluded that these events fall into two categories: (a) events which involve the performance of the Company’s obligations under the Astellas Collaboration Agreement, and (b) events which do not involve the performance of the Company’s obligations under the Astellas Collaboration Agreement. The former category of milestone payments consist of those triggered by development and regulatory activities in the United States and by the acceptance for review of marketing applications in Europe and Japan. Management concluded that each of these payments, with one exception, constitute substantive milestone payments. This conclusion was based primarily on the facts that (i) each triggering event represented a specific outcome that could be achieved only through successful performance by the Company of one or more of its deliverables, (ii) achievement of each triggering event was subject to inherent risk and uncertainty and would result in additional payments becoming due to the Company, (iii) each of the milestone payments was non-refundable, (iv) substantial effort was required to complete each milestone, (v) the amount of each milestone payment was reasonable in relation to the value created in achieving the milestone, (vi) a substantial amount of time was expected to pass between the upfront payment and the potential milestone payments, and (vii) the milestone payments related solely to past performance. Based on the foregoing, the Company recognized any revenue from these milestone payments in the period in which the underlying triggering event occurs. The one exception is the milestone payment for initiation of the Phase 3 PREVAIL trial, an event which management deemed to be reasonably assured at the inception of the Astellas collaboration. This milestone payment was triggered in the third quarter of 2010, and the Company recognized it as collaboration revenue on a straight-line basis over the estimated remaining performance period of the Astellas Collaboration Agreement. The latter category of milestone payments consist of those triggered by potential marketing approvals in Europe and Japan, and commercial activities globally, all of which were areas in which the Company had no pertinent contractual responsibilities under the Astellas Collaboration Agreement. Management concluded that these payments constitute contingent revenues and thus recognized them as revenue in the period in which the contingency was met. As of December 31, 2015, the Company has earned all development and sales milestone payments under the Astellas Collaboration Agreement. Royalties and Profit (Loss) Sharing Payments Under the Astellas Collaboration Agreement, the Company shares equally profits (losses) on sales of products in the United States and receives royalties on sales of products outside the United States. The Company recognizes revenue from these events based on the revenue recognition criteria set forth in ASC 605-10-25-1, “Revenue Recognition.” Based on those criteria, the Company considers these payments to be contingent revenues, and recognizes them as revenue in the period in which the applicable contingency is resolved. Cost-Sharing Payments Under the Astellas Collaboration Agreement, the Company and Astellas share certain development and commercialization costs in the United States, including cost of goods sold and the royalty on net sales payable to The Regents of the University of California, or UCLA, under the Company’s license agreement with UCLA. The Company and Astellas make quarterly cost-sharing payments to one another in amounts necessary to ensure that each party bears its contractual share of the overall shared U.S. development and commercialization costs incurred. The Company’s policy is to account for cost-sharing payments to its collaboration partners as increases in expense in its consolidated statements of operations, while cost-sharing payments from its collaboration partners to the Company are accounted for as reductions in expense. Cost-sharing payments related to development activities and commercialization activities are recorded in research and development expenses, or R&D expenses, and selling, general and administrative expenses, or SG&A expenses, respectively. Reliance on Third-Party Information Under the Astellas Collaboration Agreement, Astellas records all XTANDI sales globally and has operational responsibility for certain development and commercialization activities in the United States for which the Company shares costs. Thus, Astellas has control over certain XTANDI-related financial information needed to prepare the Company’s financial statements and related disclosures, including information regarding gross sales, net sales, gross-to-net sales deductions, including estimates of potential future product returns, and shared U.S. development and commercialization costs incurred by Astellas. The Company is dependent on Astellas to provide it with such information in a timely and accurate manner for use in preparing the Company’s consolidated financial statements and disclosures. Certain of this information provided by Astellas is subject to estimates, including estimates used in determining gross-to-net revenue deductions such as payor mix, discounts (including legally mandated discounts to government entities), returns, chargebacks, rebates, and participation levels in patient assistance programs, and estimates regarding accrued development and commercialization costs incurred by Astellas. Under the Astellas Collaboration Agreement, the deductions from gross sales used to derive net sales of XTANDI are determined in a manner consistent with GAAP, consistently applied. Should Astellas fail to provide the Company with any such financial information in a timely manner, or should any such financial information provided by Astellas, or any of the estimates upon which such financial information was based, prove to be inaccurate, the Company could be required to record adjustments in future periods. (e) Research and Development Expenses and Accruals R&D expenses are charged to expense as incurred unless there is an alternative future use in other research and development projects or otherwise. R&D expenses are comprised of costs incurred in performing research and development activities, including personnel-related costs, share-based compensation, and facilities-related overhead, outside contracted services including clinical trial costs, manufacturing and process development costs for both clinical and preclinical materials, research costs, upfront and development milestone payments under license agreements and other consulting services. Non-refundable advance payment for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. In instances where the Company enters into agreements with third parties to provide research and development services, costs are expensed as services are performed. Amounts due under such arrangements may be either fixed fee or fee for service, and may include upfront payments, monthly payments, and payments upon the completion of milestones or receipt of deliverables. The Company’s accruals for clinical trials and other research and development activities are based on estimates of the services received and efforts expended pursuant to contracts with numerous clinical trial centers, contract research organizations and clinical manufacturing organizations. In the normal course of business the Company contracts with third parties to perform various research and development activities in the on-going development of its product candidates, including, without limitation, third-party clinical trial centers and contract research organizations that perform and administer the Company’s clinical trials on its behalf and clinical manufacturing organizations that manufacture clinical trial materials. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Payments under these agreements depend on factors such as the achievement of certain events, the successful enrollment of patients, and the completion of portions of the clinical trial or similar conditions. The objective of the Company’s accrual policy is to match the recording of expenses in its consolidated financial statements to the actual services received and efforts expended. As such, expense accruals related to clinical trials and other research and development activities are recognized based on the Company’s estimate of the degree of completion of the event or events specified in the specific agreement. The Company’s accrual estimates are dependent upon the timeliness and accuracy of data provided by third parties regarding the status and cost of studies, and may not match the actual services performed by the organizations. During the course of a clinical trial, the Company adjusts its rate of clinical trial expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued clinical trial expenses as of each balance sheet date based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. This could result in adjustment to the Company’s R&D expense in future periods. The Company has had no significant adjustments to previously recorded research and development amounts. (f) Promotional and Advertising Costs Promotional and advertising costs are classified as SG&A expenses and are expensed as incurred. Promotional and advertising expenses consist primarily of the costs of designing, producing and distributing materials promoting the Company and its products, including its corporate website. Under the Astellas Collaboration Agreement, the Company and its collaboration partners share certain commercialization costs, including certain promotional and advertising costs, in the United States. See Note 3, “Collaboration Agreement,” for additional information regarding cost-sharing with its collaboration partners. (g) Stock-Based Compensation The Company has outstanding stock options, restricted stock units, and stock appreciation rights pursuant to the terms of the Medivation Equity Incentive Plan, and eligible employees may purchase shares pursuant to the ESPP. The Company accounts for stock-based compensation awards to employees and directors and ESPP shares in accordance with ASC 718, “Stock Compensation,” and stock-based compensation awards to consultants in accordance with ASC 505-50, “Equity-Based Payments to Non-Employees.” Stock-based compensation expense associated with stock options is based on the estimated grant date fair value using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, option term, risk-free interest rate and dividend yield. The Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest. Stock-based compensation expense associated with restricted stock units is based on the fair value of the Company’s common stock on the grant date, which equals the closing market price of the Company’s common stock on the grant date. For restricted stock units, the Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest. The fair value of stock-settled and cash-settled stock appreciation rights is initially measured on the grant date using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, term, risk-free interest rate and dividend yield. Similar to stock options, compensation expense for stock-settled stock appreciation rights is recognized over the vesting period of the awards that are ultimately expected to vest based on the grant-date fair value. Cash-settled stock appreciation rights are liability-classified awards for which compensation expense and the liability are remeasured at each reporting date through the date of settlement based on the portion of the requisite service period rendered. Upon the conversion of cash-settled stock appreciation rights to stock-settled stock appreciation rights, the awards are remeasured using the then-current Black-Scholes assumptions and the remeasured liability is reclassified to additional paid-in capital. The Company accounts for the ESPP as a compensatory plan. The fair value of each purchase under the Company’s ESPP is estimated on the date of the beginning of the offering period using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, term, risk-free interest rate and dividend yield. The Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest. Equity awards to consultants are typically remeasured at fair value at each reporting date until the awards vest. The Company applies a forfeiture rate when determining stock-based compensation expense to account for an estimate of the granted awards not expected to vest. If actual forfeitures differ from the expected rate, the Company may be required to make additional adjustments to compensation expense in future periods. The Black-Scholes valuation model was developed for use in estimating the fair value of traded options that have no vesting restrictions and are fully transferable, characteristics not present in the Company’s stock options, stock appreciation rights, or ESPP shares. If the model permitted consideration of the unique characteristics of employee stock options, stock appreciation rights, and ESPP shares, the resulting estimate of fair value of the stock options, stock appreciation rights, and ESPP shares could be different. In addition, if the Company had made different assumptions and estimates for use in the Black-Scholes valuation model, the amount of recognized and to be recognized stock-based compensation expense could have been different. (h) Cash and Cash Equivalents Cash and cash equivalents are stated at cost, which approximates fair market value. Cash and cash equivalents consist of cash on deposit with banks, money market funds, and all highly liquid investments with a remaining maturity of three months or less at the time of purchase. (i) Short-Term Investments The Company considers all highly liquid investments with a remaining maturity at the time of acquisition of more than three months but no longer than 12 months to be short-term investments. The Company classifies its short-term investments as available-for-sale securities and reports them at fair value with related unrealized gains and losses included as a component of stockholders’ equity. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in other income (expense), net, on the consolidated statements of operations. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income (expense), net. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in other income (expense), net. For the year ended December 31, 2015, total realized gains and losses on sales of available-for-sale securities were not material. There were no realized gains or losses from sales of available-for-sale securities for the years ended December 31, 2014 and 2013. (j) Concentration of Credit Risk The Company is subject to credit risk from its portfolio of cash, cash equivalents and short-term investments. The goals of the Company’s investment policy, in order of priority, are (1) the safety and preservation of principal, (2) maintain liquidity sufficient to meet the requirements of the Company’s operations and strategic initiatives, and (3) deliver competitive after-tax returns relative to stated objectives and market conditions. Given this investment policy, the Company does not believe its exposure to credit risk with respect to the issuers of the securities in which it invests is material. The Company’s cash and cash equivalents are primarily invested in deposits and money market accounts with one major financial institution in the United States. Deposits in this financial institution may exceed the amount of insurance provided on such deposits. (k) Restricted Cash Restricted cash represents certificates of deposit held in the Company’s name with a major financial institution to secure the Company’s contingent obligations under irrevocable letters of credit issued to certain of its lessors. (l) Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation and amortization. Repairs and maintenance costs are expensed in the period incurred. Property and equipment is generally depreciated on a straight-line basis over the estimated useful lives of the assets as follows: Description Estimated Useful Life Furniture and fixtures 3-5 years Computer equipment and software 3-5 years Laboratory equipment 5 years Leasehold improvements are amortized over their estimated useful life or the related lease term, whichever is shorter. (m) Leases At the inception of a lease, the Company evaluates the lease agreement to determine whether the lease is an operating, capital or build-to-suit lease using the criteria in ASC 840, “Leases.” Certain lease agreements also require the Company to make additional payments for taxes, insurance, and other operating expenses incurred during the lease period, which are expensed as incurred. Operating Leases For operating leases, the Company recognizes rent expense on a straight-line basis over the lease term and records the difference between cash rent payments and the recognition of rent expense as a deferred liability. Where lease agreements contain rent escalation clauses, rent abatements and/or concessions, such as rent holidays and tenant improvement allowances, the Company applies them in the determination of straight-line expense over the lease term. Capital Leases Capital leases are recorded as an asset within property and equipment, net and as an obligation at an amount equal to the present value of the minimum lease payments during the lease term. The asset is generally amortized over its estimated useful life or the related lease term, whichever is shorter. Lease payments under capital leases are recognized as a reduction of the capital lease obligation and interest expense. The Company currently does not have any capital leases. Build-to-Suit Leases In certain lease arrangements, the Company is involved in the construction of the building. To the extent the Company is involved with the structural improvements of the construction project or takes construction risk prior to the commencement of a lease, ASC 840-40, “Leases – Sale-Leaseback Transactions (Subsection 05-5),” requires the Company to be considered the owner for accounting purposes of these types of projects during the construction period. Therefore, the Company records an asset in property and equipment, net on the consolidated balance sheets, including capitalized interest costs, for the replacement cost of the Company’s portion of the pre-existing building plus the amount of estimated structural construction costs incurred by the landlord and the Company as of the balance sheet date. The Company records a corresponding build-to-suit lease obligation on its consolidated balance sheets representing the amounts paid by the lessor. Once construction is complete, the Company considers the requirements for sale-leaseback accounting treatment, including evaluating whether all risks of ownership have been transferred back to the landlord, as evidenced by a lack of continuing involvement in the leased property. If the arrangement does not qualify for sale-leaseback accounting treatment, the building asset remains on the Company’s consolidated balance sheets at its historical cost, and such asset is depreciated over its estimated useful life. The Company bifurcates its lease payments into a portion allocated to the building and a portion allocated to the parcel of land on which the building has been built. The portion of the lease payments allocated to the land is treated for accounting purposes as operating lease payments, and therefore is recorded as rent expense in the consolidated statements of operations. The portion of the lease payments allocated to the building is further bifurcated into a portion allocated to interest expense and a portion allocated to reduce the build-to-suit lease obligation. The interest rate used for the build-to-suit lease obligation represents the Company’s estimated incremental borrowing rate at inception of the lease, adjusted to reduce any built in loss. The initial recording of these assets and liabilities is classified as non-cash investing and financing items, respectively, for purposes of the consolidated statements of cash flows. (n) Business Combinations Business combinations are accounted for under the acquisition method of accounting. The purchase price, including the fair value of any contingent consideration, is allocated between tangible and intangible assets acquired and liabilities assumed from the acquired business based on their estimated fair values, with the residual of the purchase price recorded as goodwill. Transaction costs are expensed as incurred. Contingent Consideration The Company determines the fair value of contingent consideration payable at the acquisition date using a probability-based income approach utilizing an appropriate discount rate. Each reporting period thereafter, the Company re-measures the contingent consideration and records increases or decreases in their fair value as non-cash adjustments in the consolidated statements of operations. Changes in the fair value of contingent consideration payable can result from adjustments to the estimated probability and assumed timing of achieving the underlying milestones, as well as from changes to the discount rates and periods. In-Process Research and Development In-process research and development, or IPR&D, represents the fair value assigned to incomplete research projects that the Company acquires through business combinations which, at the time of acquisition, have not reached technological feasibility. The amounts are capitalized and accounted for as indefinite-lived intangible assets, subject to impairment testing until completion or abandonment of the projects. Upon successful completion of each project, the Company will make a determination as to the then useful life of the intangible asset, generally determined by the period in which the substantial majority of the cash flows are expected to be generated, and begin amortization over that period. The Company tests IPR&D for impairment at least annually, or more frequently if impairment indicators exist, by first assessing qualitative factors to determine whether it is more likely than not that the fair value of the IPR&D is less than its carrying amount. If the Company concludes it is more likely than not that the fair value is less than the carrying amount, a quantitative test that compares the fair value of the IPR&D with its carrying value is performed. If the fair value is less than the carrying amount, a non-cash impairment change is recognized in the consolidated statements of operations. Goodwill Goodwill represents the excess of the consideration transferred over the fair value of net assets of businesses acquired. Goodwill is assigned to reporting units and tested at least annually for impairment or when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable, on an enterprise level by assessing qualitative factors or performing a quantitative analysis in determining whether it is more likely than not that its fair value exceeds the carrying value. Examples of qualitative factors include the Company’s share price, its financial performance compared to budgets, long-term financial plans, macroeconomic, industry and market conditions as well as the substantial excess of fair value over the carrying value of net assets. If the carrying value of goodwill exceeds its implied fair value, the excess is recorded as a non-cash impairment charge in the consolidated statement of operations. (o) Convertible Notes The debt and equity components of the Company’s Convertible Notes were bifurcated and accounted for separately based on the authoritative guidance in ASC 470-20, “Debt with Conversion and Other Options.” The debt component of the Convertible Notes, which excluded the associated equity conversion feature, was recorded at fair value on the issuance date. The equity component, representing the difference between the aggregate principal amount of the Convertible Notes and the fair value of the debt component, was recorded in additional paid-in capital on the consolidated balance sheet. The discounted carrying value of the Convertibl

Collaboration Agreement

Collaboration Agreement	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaboration Agreement	NOTE 3. COLLABORATION AGREEMENT (a) Collaboration Agreement with Astellas In October 2009, the Company entered into the Astellas Collaboration Agreement, pursuant to which it is collaborating with Astellas to develop and commercialize XTANDI globally for all indications, dosages and formulations of enzalutamide. Under the agreement, decision making and economic participation differs between the U.S. market and the ex-U.S. market. In the United States, decisions are generally made by consensus, pre-tax profits and losses are shared equally, and, subject to certain exceptions, development and commercialization costs (including cost of goods sold and the royalty on net sales payable to UCLA under the Company’s license agreement with UCLA) are also shared equally. The primary exceptions to equal cost sharing in the U.S. market are that each party is responsible for its own commercial full-time equivalent, or FTE, costs, and that development costs supporting marketing approvals in both the United States and either Europe or Japan are borne one-third by the Company and two-thirds by Astellas. The Company and Astellas are co-promoting XTANDI in the U.S. market, with each company providing half of the sales and medical affairs effort in support of the product. Both the Company and Astellas are entitled to receive a fee for each qualifying detail made by its respective sales representatives. Outside the United States, decisions are generally made by Astellas and all development and commercialization costs (including cost of goods sold and the royalty on net sales payable to UCLA) are borne by Astellas. Astellas retains all ex-U.S. profits and losses, and pays the Company a tiered royalty ranging from the low teens to the low twenties as a percentage of the aggregate net sales of XTANDI outside the United States, or ex-U.S. XTANDI net sales. Astellas has sole responsibility for promoting XTANDI outside the United States and for recording all XTANDI net sales both inside and outside the United States. Both the Company and Astellas have agreed not to commercialize certain other products having a similar mechanism of action (as defined by the Astellas Collaboration Agreement) as XTANDI for the treatment of prostate cancer for a specified time period, subject to certain exceptions. Under the Astellas Collaboration Agreement, Astellas paid the Company a non-refundable, upfront cash payment of $110.0 million in the fourth quarter of 2009. The Company was also eligible to receive up to $335.0 million in development milestone payments and up to $320.0 million in sales milestone payments. As of December 31, 2015, the Company has earned all development and sales milestone payments under the Astellas Collaboration Agreement. The Company and Astellas are each permitted to terminate the Astellas Collaboration Agreement for an uncured material breach by the other party or for the insolvency of the other party. Astellas has a right to terminate the Astellas Collaboration Agreement unilaterally by advance written notice to the Company. Following any termination of the Astellas Collaboration Agreement in its entirety, all rights to develop and commercialize XTANDI will revert to the Company, and Astellas will grant a license to the Company to enable it to continue such development and commercialization. In addition, except in the case of a termination by Astellas for the Company’s material breach, Astellas will supply XTANDI to the Company during a specified transition period. Unless terminated earlier by the Company or Astellas pursuant to the terms thereof, the Astellas Collaboration Agreement will remain in effect: (a) in the United States, until such time as Astellas notifies the Company that Astellas has permanently stopped selling products covered by the Astellas Collaboration Agreement in the United States; and (b) in each other country of the world, on a country-by-country basis, until such time as (i) products covered by the Astellas Collaboration Agreement cease to be protected by patents or regulatory exclusivity in such country and (ii) commercial sales of generic equivalent products have commenced in such country. (b) Collaboration Revenue Collaboration revenue was as follows: Years Ended December 31, 2015 2014 2013 Collaboration revenue: Related to U.S. XTANDI net sales $ 575,658 $ 339,902 $ 196,208 Related to ex-U.S. XTANDI net sales 119,778 49,476 6,338 Related to upfront and milestone payments 247,822 321,109 70,396 Total $ 943,258 $ 710,487 $ 272,942 The Company is required to pay UCLA ten percent of all Sublicensing Income, as defined in its license agreement with UCLA. The Company is currently involved in litigation with UCLA regarding certain terms of the license agreement and other matters, which are discussed in Note 15, “Commitments and Contingencies.” Collaboration Revenue Related to U.S. XTANDI Net Sales Under the Astellas Collaboration Agreement, Astellas records all U.S. XTANDI net sales. The Company and Astellas share equally all pre-tax profits and losses from U.S. XTANDI net sales. Subject to certain exceptions, the Company and Astellas also share equally all XTANDI development and commercialization costs attributable to the U.S. market, including cost of goods sold and the royalty on net sales payable to UCLA under the Company’s license agreement with UCLA. The primary exceptions to the 50/50 cost sharing are that each party is responsible for its own commercial FTE costs and that development costs supporting marketing approvals in both the United States and either Europe or Japan are borne one-third by the Company and two-thirds by Astellas. The Company recognizes collaboration revenue related to U.S. XTANDI net sales in the period in which such sales occur. Collaboration revenue related to U.S. XTANDI net sales consists of the Company’s share of pre-tax profits and losses from U.S. XTANDI net sales, plus reimbursement of the Company’s share of reimbursable U.S. development and commercialization costs. The Company’s collaboration revenue related to U.S. XTANDI net sales in any given period is equal to 50% of U.S. XTANDI net sales as reported by Astellas for the applicable period. Collaboration revenue related to U.S. XTANDI net sales was as follows: Years Ended December 31, 2015 2014 2013 U.S. XTANDI net sales (as reported by Astellas) $ 1,151,317 $ 679,805 $ 392,415 Shared U.S. development and commercialization costs (375,008 ) (323,730 ) (241,106 ) Pre-tax U.S. profit $ 776,309 $ 356,075 $ 151,309 Medivation’s share of pre-tax U.S. profit $ 388,154 $ 178,037 $ 75,655 Reimbursement of Medivation’s share of shared U.S. costs 187,504 161,865 120,553 Collaboration revenue related to U.S. XTANDI net sales $ 575,658 $ 339,902 $ 196,208 Collaboration Revenue Related to Ex-U.S. XTANDI Net Sales Under the Astellas Collaboration Agreement, Astellas records all ex-U.S. XTANDI net sales. Astellas is responsible for all development and commercialization costs for XTANDI outside the United States, including cost of goods sold and the royalty on net sales payable to UCLA under the Company’s license agreement with UCLA, and pays the Company a tiered royalty ranging from the low teens to the low twenties on net ex-U.S. XTANDI net sales. The Company recognizes collaboration revenue related to ex-U.S. XTANDI net sales in the period in which such sales occur. Collaboration revenue related to ex-U.S. XTANDI net sales consists of royalties from Astellas on those sales. Collaboration Revenue Related to Upfront and Milestone Payments Collaboration revenue related to upfront and milestone payments from Astellas was as follows: Years Ended December 31, 2015 2014 2013 Sales milestones earned $ 245,000 $ 50,000 $ 25,000 Development milestones earned — 257,000 20,000 Amortization of deferred upfront and development milestones 2,822 14,109 25,396 Total $ 247,822 $ 321,109 $ 70,396 As of December 31, 2015, the Company has earned all development and sales milestone payments under the Astellas Collaboration Agreement, including $245.0 million, $307.0 million, and $45.0 million in the years ended December 31, 2015, 2014, and 2013, respectively. Deferred revenue related to payments received under the Astellas Collaboration Agreement was $2.8 million at December 31, 2014. There was no deferred revenue related to payments received under the Astellas Collaboration Agreement at December 31, 2015. (c) Cost-Sharing Payments Under the Astellas Collaboration Agreement, the Company and Astellas share certain development and commercialization costs (including cost of goods sold and the royalty on net sales payable to UCLA under the Company’s license agreement with UCLA) in the United States. Development cost-sharing payments from Astellas were $60.8 million, $63.5 million and $46.6 million for the years ended December 31, 2015, 2014 and 2013, respectively. Commercialization cost-sharing payments to Astellas were $37.5 million, $36.1 million and $12.0 million for the years ended December 31, 2015, 2014 and 2013, respectively. Development cost-sharing payments from Astellas are recorded as reductions in R&D expenses. Commercialization cost-sharing payments to Astellas are recorded as increases in SG&A expenses. (d) Collaboration Receivable At December 31, 2015 and 2014, collaboration receivable from Astellas was $391.6 million and $184.7 million, respectively. The amounts receivable at December 31, 2015 and 2014 were received in the first quarter of 2016 and 2015, respectively.

Business Acquisition

Business Acquisition	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Business Acquisition	NOTE 4. BUSINESS ACQUISITIONS (a) Acquisition of MDV3800 from BioMarin In the fourth quarter of 2015, the Company completed an acquisition of all rights to MDV3800, a PARP inhibitor, from BioMarin pursuant to an Asset Purchase Agreement. The acquired MDV3800 assets include all patents, data, know-how, third-party agreements, regulatory materials and pre-commercial inventories. The Company also assumed certain costs for ongoing clinical trials of MDV3800, and commitments under certain agreements previously entered into or assumed by BioMarin and assigned to the Company. The parties entered into a Transition Services Agreement at the closing of the transaction to facilitate the transition of the research and development activities relating to MDV3800 from BioMarin to the Company, including responsibility for the ongoing clinical studies. The Company has concluded that the acquisition of MDV3800 from BioMarin is an acquisition of a business and will account for it in accordance with ASC 805-10, “Business Combinations.” The acquisition was completed on October 6, 2015, and results of operations related to MDV3800 since that date have been included in the consolidated statement of operations and were not significant. In connection with the acquisition, the Company paid BioMarin an upfront cash payment of $410.0 million during the fourth quarter of 2015. In addition, BioMarin is entitled to contingent payments totaling up to the achievement of defined regulatory and sales-based milestones, net sales of products that contain during the royalty term specified in the Agreement model using a discounted cash flow analysis for contingent regulatory and royalty payments and a Monte Carlo simulation model for the contingent sales milestone payments The following table presents the final allocation of the purchase consideration for the MDV3800 acquisition, including the contingent consideration payable, based on fair value: Purchase consideration: Cash $ 410,000 Acquisition-date fair value of contingent consideration 171,942 Total purchase consideration $ 581,942 Allocation of the purchase consideration: Assets: Identifiable intangible assets- IPR&D $ 573,299 Net identifiable assets acquired 573,299 Goodwill 8,643 Net assets acquired $ 581,942 Identifiable intangible assets totaled $573.3 million and consist entirely of IPR&D for MDV3800. As of the valuation date, the Company determined that MDV3800 was the only R&D project with substance, such that the project had undergone conceptual stages, and research, development, and preproduction had been started for the project. As such, no other intangible assets were identified in the transaction other than MDV3800 as separate and apart from goodwill. The Company utilized the multi-period excess earnings model of the “income method” to determine the fair value of the IPR&D as of the acquisition date. The excess of the consideration over the fair values assigned to the net assets acquired was $8.6 million, which represents the amount of goodwill resulting from the acquisition. The Company believes that the goodwill primarily represents benefits to it, such as the potential to diversify its product portfolio in the area of oncology, that do not qualify for separate recognition as acquired intangible assets. The amount of goodwill that is expected to be deductible for income tax purposes is $8.6 million. The Company recorded the goodwill on its consolidated balance sheet as of the acquisition date. Pro forma Financial Information The following unaudited pro forma financial information presents the combined results of operations of Medivation and MDV3800 as if the acquisition of MDV3800 had been completed on January 1, 2014, with adjustments to give effect to pro forma events that are directly attributable to the acquisition. The unaudited pro forma results do not reflect any operating efficiencies or potential cost savings which may result from the consolidation of the operations of Medivation and MDV3800. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Year Ended December 31, 2015 2014 Total revenues $ 943,258 $ 710,487 Net income $ 201,161 $ 230,271 (b) Acquisition of MDV9300 from CureTech In the fourth quarter of 2014, the Company entered into a License Agreement with Israel-based CureTech, pursuant to which it licensed exclusive worldwide rights to CureTech’s late-stage clinical molecule MDV9300, an antibody with immune-mediated anti-tumor effects. Under the License Agreement, the Company is responsible for all development, regulatory, manufacturing, and commercialization activities for MDV9300 for all indications, including oncology. The Company has concluded that the in-license transaction is an acquisition of a business and will account for it in accordance with ASC 805-10, “Business Combinations.” In connection with the acquisition, the Company made upfront cash payments to CureTech totaling $5.0 million during the fourth quarter of 2014. In addition, CureTech is entitled to contingent payments totaling up to $85.0 million upon attainment of certain development and regulatory milestones, up to $245.0 million upon the achievement of certain annual worldwide net sales thresholds, and tiered royalties ranging from 5% to 11% on annual worldwide net sales. CureTech is also entitled to a $5.0 million milestone payment upon completion of the Manufacturing Technology Transfer as described in Note 15, “Commitments and Contingencies.” The acquisition-date fair value of the contingent consideration payments totaled $106.0 million and was estimated by applying a probability-based income approach using an appropriate discount rate. The estimation was based on significant inputs that are not observable in the market, referred to as Level 3 inputs, as described in more detail in Note 14, “Fair Value Disclosures.” The following table presents the final allocation of the purchase consideration for the MDV9300 acquisition, including the contingent consideration payable, based on fair value: Purchase consideration: Cash $ 5,000 Acquisition-date fair value of contingent consideration 106,000 Total purchase consideration $ 111,000 Allocation of the purchase consideration: Assets: Identifiable intangible assets- IPR&D $ 101,000 Net identifiable assets acquired 101,000 Goodwill 10,000 Net assets acquired $ 111,000 Identifiable intangible assets totaled $101.0 million and consist entirely of IPR&D for MDV9300. As of the valuation date, the Company determined that MDV9300 was the only R&D project with substance, such that the project had undergone conceptual stages, and research, development, and preproduction had been started for the project. As such, no other intangible assets were identified in the transaction other than MDV9300 as separate and apart from goodwill. The Company utilized the multi-period excess earnings model of the “income method” to determine the fair value of the IPR&D as of the acquisition date. The excess of the consideration over the fair values assigned to the net assets acquired was $10.0 million, which represents the amount of goodwill resulting from the acquisition. The Company believes that the goodwill primarily represents benefits to it, such as the potential to diversify its product portfolio in the area of oncology, that do not qualify for separate recognition as acquired intangible assets. The amount of goodwill that is expected to be deductible for income tax purposes is $10.0 million. The Company recorded the goodwill on its consolidated balance sheet as of the acquisition date. Pro forma Financial Information The following unaudited pro forma financial information presents the combined results of operations of Medivation and MDV9300 as if the acquisition of MDV9300 had been completed on January 1, 2013, with adjustments to give effect to pro forma events that are directly attributable to the acquisition. The unaudited pro forma results do not reflect any operating efficiencies or potential cost savings which may result from the consolidation of the operations of Medivation and MDV9300. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Year Ended December 31, 2014 2013 Total revenues $ 710,487 $ 272,942 Net income (loss) $ 274,626 $ (45,685 )

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	NOTE 5. INTANGIBLE ASSETS AND GOODWILL Intangible assets consist of IPR&D acquired from business acquisitions. The Company accounts for IPR&D as indefinite-lived intangible assets until regulatory approval or discontinuation of the related R&D efforts. Upon obtaining regulatory approval, the Company reclassifies the IPR&D as a definite-lived intangible asset and determines the economic life for amortization purposes. The Company assesses the impairment of indefinite-lived intangible assets and goodwill on an annual basis or more frequently whenever events or changes in circumstances may indicate that the carrying value might not be recoverable. During the fourth quarter of 2015, the Company recorded a $30.0 million impairment charge related to its IPR&D asset for MDV9300 as a result of an extended clinical development timeline and other factors. In the fourth quarter, the Company concluded its testing that revealed MDV9300 is not an anti-PD-1 antibody and, after advising the FDA of this conclusion in early-January 2016, its IND was placed on partial clinical hold pending revision of all related study documentation characterizing MDV9300 as an anti-PD-1 antibody. While the Company believes the partial clinical hold does not relate to concerns regarding the safety or previously-observed efficacy of MDV9300, the Company extended its clinical study timelines which, in turn, gave rise to changes to the significant inputs to its IPR&D valuation including forecasted revenues and probabilities of success. The quantitative assessment resulted in a net impairment charge, which the Company recorded as a reduction in the IPR&D asset and an increase to R&D expense in the fourth quarter of 2015. The following table summarizes the Company’s indefinite-lived intangible assets: December 31, 2015 2014 Indefinite-lived intangible asset – MDV3800 $ 573,299 — Indefinite-lived intangible asset – MDV9300 71,000 101,000 Total $ 644,299 $ 101,000 The following table summarizes the changes in the carrying amount of goodwill: Year Ended December 31, 2015 Goodwill: Balance at beginning of period $ 10,000 Goodwill at acquisition date – MDV3800 8,643 Balance at end of period $ 18,643

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	NOTE 6. NET INCOME (LOSS) PER COMMON SHARE The computation of basic net income (loss) per common share is based on the weighted-average number of common shares outstanding during each period. The computation of diluted net income (loss) per common share is based on the weighted-average number of common shares outstanding during the period plus, when their effect is dilutive, incremental shares consisting of shares subject to stock options, restricted stock units, stock appreciation rights, ESPP shares, warrants, and shares issuable upon conversion of convertible debt. During the second quarter of 2015, the Company asserted its intent and ability to settle the outstanding Convertible Notes for a combination of cash and common stock. Under the “cash settlement” method, interest is not added back to the numerator, and only the contingently issuable shares related to the conversion spread are included in the denominator, if dilutive. Under such method, the settlement of the conversion spread has a dilutive effect when the average share price of the Company’s common stock during the period exceeds the conversion price. The computation of diluted net income per share for the year ended December 31, 2015 reflects the application of the “if-converted” method for the first quarter of 2015 and the “cash settlement” method for the second and third quarters of 2015 given the demonstrated and asserted redemption of the outstanding debt. The Company completed the settlement of all of its Convertible Notes during the third quarter of 2015 as described in Note 10, “Debt.” The calculation of diluted net income per common share for the year ended December 31, 2015 includes approximately 3.9 million contingently issuable shares related to the Convertible Notes. The Company used the “if-converted” method to compute the dilutive effect of the Convertible Notes for the calculation of diluted net income per common share for the year ended December 31, 2014. Under the “if-converted” method, interest expense, net of tax, related to the Convertible Notes is added back to net income, and the Convertible Notes are assumed to have been converted into common shares at the beginning of the period in periods in which there would have been a dilutive effect. The calculation of diluted net income per common share for the year ended December 31, 2014 includes approximately 10.1 million contingently issuable shares related to the Convertible Notes. In periods in which the Company reports a net loss, all common stock equivalents are deemed anti-dilutive such that basic net loss per common share and diluted net loss per common share are equal. For the years ended December 31, 2015 and 2014, employee stock-based awards to purchase approximately 1.4 million and 1.3 million shares of the Company’s common stock, respectively, were excluded from the computation of diluted net income per common share because their effect would have been anti-dilutive. For the year ended December 31, 2013, approximately 25.1 million potentially dilutive common shares were excluded from the diluted net loss per common share computation because such securities had an anti-dilutive effect on net loss per common share due to the Company’s net loss for that year. The following table reconciles the numerator and denominator used to calculate diluted net income (loss) per common share: Years Ended December 31, 2015 2014 2013 Numerator: Net income (loss) $ 244,725 $ 276,452 $ (42,613 ) Interest expense on convertible notes, net of tax 3,629 14,030 — Numerator for diluted net income (loss) per common share calculation $ 248,354 $ 290,482 $ (42,613 ) Denominator: Weighted-average common shares, basic 160,345 153,859 150,331 Dilutive effect of common stock equivalents 8,979 16,142 — Weighted-average common shares, diluted 169,324 170,001 150,331

Build-to-Suit Lease Obligation

Build-to-Suit Lease Obligation	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Build-to-Suit Lease Obligation	NOTE 7. BUILD-TO-SUIT LEASE OBLIGATION In the fourth quarter of 2013, the Company entered into a property lease for approximately 52,000 square feet of space located in San Francisco, California. In the second quarter of 2015, the Company entered into an amended lease agreement to reduce the amount of leased space at this property to approximately 44,000 square feet. The lease agreement expires in August 2024, and the Company has an option to extend the lease term for up to an additional five years. The Company is deemed, for accounting purposes only, to be the owner of the entire project including the building shell, even though it is not the legal owner. In connection with the Company’s accounting for this transaction, the Company capitalized $14.5 million as a build-to-suit property within property and equipment, net, and recognized a corresponding build-to-suit lease obligation for the same amount. The Company has also recognized, as an additional build-to-suit lease property and obligation, structural tenant improvements totaling $3.6 million for amounts paid by the landlord and $3.5 million for capitalized interest during the construction period through December 31, 2015. As a result of the amended agreement, the Company surrendered a portion of the property totaling approximately 8,000 square feet to the lessor. The Company has no continuing involvement with the portion of the property surrendered to the lessor. Accordingly, the Company derecognized a portion of the build-to-suit asset totaling $3.2 million and a portion of the build-to-suit lease obligation totaling $3.2 million during 2015 related to the portion of the property that was surrendered to the lessor. A portion of the monthly lease payment is allocated to land rent and recorded as an operating lease expense and the non-interest portion of the amortized lease payments to the landlord related to the rent of the building is applied to reduce the build-to-suit lease obligation. At December 31, 2015, the build-to-suit lease obligation totaling $17.4 million was classified as a non-current liability on the consolidated balance sheet. Expected reductions (increases) in the build-to-suit lease obligation are as follows: Years Ending December 31, Build-To-Suit Lease Obligation 2016 $ (8 ) 2017 58 2018 130 2019 208 2020 292 2021 and thereafter 16,726 Total $ 17,406 The amounts included in the table above represent the reductions (increases) in the build-to-suit lease obligation included on the Company’s consolidated balance sheet at December 31, 2015 related to each of the periods presented. The amount in the terminal period includes the amount to derecognize the build-to-suit lease obligation at the end of the lease term. The expected reductions (increases) in the build-to-suit lease obligation presented in the table above are impacted by the timing of the completion of the construction project. Actual expected lease payments under the build-to-suit lease obligation are included in Note 15, “Commitments and Contingencies.”

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property and Equipment, Net	NOTE 8. PROPERTY AND EQUIPMENT, NET Property and equipment, net, consisted of the following: December 31, 2015 2014 Build-to-suit property $ 18,371 $ 19,544 Leasehold improvements 19,074 15,051 Computer equipment and software 16,083 9,499 Furniture and fixtures 5,714 4,667 Construction in progress 14,440 1,360 Laboratory equipment 748 735 74,430 50,856 Less: Accumulated depreciation (16,288 ) (9,695 ) Total $ 58,142 $ 41,161

Accounts Payable, Accrued Expen

Accounts Payable, Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2015
Payables And Accruals [Abstract]
Accounts Payable, Accrued Expenses and Other Current Liabilities	NOTE 9. ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES Accounts payable, accrued expenses and other current liabilities consisted of the following: December 31, 2015 2014 Clinical and preclinical $ 48,975 $ 31,069 Taxes payable 32,565 2,106 Payroll and payroll-related 29,215 33,272 Accounts payable 22,696 10,492 Royalties payable 20,665 13,582 Other payable to licensor 17,500 5,000 Accrued professional services and other current liabilities 14,282 8,909 Interest payable 305 1,698 Total $ 186,203 $ 106,128 Accounts payable represents short-term liabilities for which the Company has received and processed a vendor invoice prior to the end of the reporting period. Accrued expenses and other current liabilities represent, among other things, compensation and related benefits to employees, royalties due to licensors of technologies, interest payable related to the Company’s Convertible Notes and Revolving Credit Facility, estimated amounts due to third-party vendors for services rendered prior to the end of the reporting period, invoices received from third-party vendors that have not yet been processed, taxes payable, and other accrued items.

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt	NOTE 10. DEBT (a) Revolving Credit Facility On September 4, 2015, the Company, as borrower, entered into a credit agreement (the “Original Credit Agreement”) with JPMorgan Chase Bank, N.A., as administrative agent, and the lenders from time to time party thereto providing for (i) a one-year $75.0 million revolving loan facility and (ii) an uncommitted accordion facility subject to the satisfaction of certain conditions. The revolving loan facility included a $20.0 million multicurrency sub-facility, a $10.0 million letter of credit sub-facility and a $100,000 swing line loan sub-facility. On September 17, 2015, the Company executed a borrowing of $75.0 million under this revolving credit facility. The interest rate for this borrowing was 2.3125% and was applied on an actual/360 day basis. On October 23, 2015, the Company entered into an amendment and restatement of the Original Credit Agreement (the “Credit Agreement”) with JPMorgan Chase Bank, N.A., as administrative agent, and the lenders from time to time party thereto (the “Lenders”), providing for (i) a five-year $300 million revolving loan facility (the “Revolving Credit Facility”); and (ii) an uncommitted accordion facility subject to the satisfaction of certain conditions (collectively, the “Senior Secured Credit Facility”). The Revolving Credit Facility includes a $50 million multicurrency sub-facility, a $20 million letter of credit sub-facility and a $10 million swing line loan sub-facility. Loans under the Revolving Credit Facility bear interest, at the Company’s option, at a rate equal to either (a) the LIBOR rate, plus an applicable margin ranging from 1.75% to 2.50% per annum, based upon the secured leverage ratio (as defined in the Credit Agreement) or (b) the prime lending rate, plus an applicable margin ranging from 0.75% to 1.50% per annum, based upon the senior secured net leverage ratio (as defined in the Credit Agreement). On October 23, 2015, the Company borrowed $75.0 million under the Revolving Credit Facility, which was used to repay the $75.0 million outstanding at September 30, 2015 under the Original Credit Agreement. The interest rate for this borrowing was 2.1250% and was applied on an actual/360 day basis. On January 25, 2016, the Company repaid the $75.0 million outstanding under the Revolving The obligations under the Credit Agreement and any swap obligations and banking services obligations owing to a lender (or an affiliate of a lender) thereunder are and will be guaranteed by the Company and each of the Company’s existing and subsequently acquired or organized direct and indirect domestic subsidiaries (other than certain immaterial domestic subsidiaries, certain Domestic Foreign Holding Companies, and certain domestic subsidiaries whose equity interests are owned directly or indirectly by certain foreign subsidiaries) (collectively, the “Loan Parties”). The obligations under the Credit Agreement and any such swap and banking services obligations are secured, subject to customary permitted liens and other agreed upon exceptions, by a perfected security interest in (i) all tangible and intangible assets of the Loan Parties, except for certain customary excluded assets, and (ii) all of the capital stock owned by the Loan Parties thereunder (limited, in the case of the stock of certain non-U.S. subsidiaries of the Company and Domestic Foreign Holding Companies, to 65% of the capital stock of such subsidiaries). The Credit Agreement contains customary representations and warranties and customary affirmative and negative covenants, including, among other things, restrictions on indebtedness, liens, investments, mergers, dispositions, prepayment of other indebtedness and dividends and other distributions. Under the terms of the Credit Agreement, the Company is required to comply with a maximum senior secured net leverage ratio and minimum interest coverage ratio covenants. At December 31, 2015, the Company was in compliance with these covenants. In accordance with ASU 2015-15, the Company deferred $1.7 million of debt issuance costs associated with the Revolving Credit Facility, including underwriting, legal and accounting fees, and will amortize this amount ratably over the five-year access period of the facility. Amortization of the debt issuance costs will be recorded as non-cash interest expense on the consolidated statement of operations. (b) Convertible Notes Due 2017 On March 19, 2012, the Company issued $258.8 million aggregate principal amount of the Convertible Notes. The Company was required to pay interest semi-annually in arrears on April 1 and October 1 of each year, at a rate of 2.625% per annum at a conversion rate of 39.0344 shares of common stock per $1,000 principal amount of the Convertible Notes, equivalent to a conversion price of approximately $25.62 per share of common stock The Convertible Notes were scheduled to mature on April 1, 2017, unless earlier converted, redeemed or repurchased in accordance with their terms. Upon a conversion of the Convertible Notes, the Company was required to pay or deliver, as the case may be, cash, shares of the Company’s common stock, or a combination of both, at the Company’s election. The debt and equity components of the Convertible Notes were bifurcated and accounted for separately based on the authoritative accounting guidance in ASC 470-20. The $258.8 million aggregate principal amount of Convertible Notes was bifurcated between the debt component ($187.1 million) and the equity component ($71.7 million). The amount allocated to the debt component was estimated based on the fair value of similar debt instruments that did not include an equity conversion feature. The Convertible Notes were recorded at an initial carrying value of $187.1 million, net of $71.7 million in debt discount, which was being accreted to the carrying value of the Convertible Notes as non-cash interest expense over the life of the Convertible Notes . During the year ended December 31, 2015, the Company settled $258.8 million aggregate principal amount of the Convertible Notes through a combination of $259.9 million in cash and 5,638,576 shares of its common stock. The Company recorded a non-cash loss on extinguishment of the Convertible Notes of $21.1 million for the year ended December 31, 2015, which was included in other income (expense), net, on the consolidated statements of operations. Forfeited accrued interest payable of $1.7 million was reclassified to additional paid-in capital during the year ended December 31, 2015. Upon settlement, the Convertible Notes were no longer outstanding, interest ceased to accrue thereon, and all rights of the holders of the Convertible Notes ceased to exist.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	NOTE 11. STOCKHOLDERS’ EQUITY (a) Stock Purchase Rights All shares of the Company’s common stock, if issued prior to the termination by the Company of its rights agreement, dated as of December 4, 2006, include stock purchase rights. The rights are exercisable only if a person or group acquires twenty percent or more of the Company’s common stock or announces a tender or exchange offer which would result in ownership of twenty percent or more of the Company’s common stock. Following the acquisition of twenty percent or more of the Company’s common stock, the holders of the rights, other than the acquiring person or group, may purchase Medivation common stock at half of its fair market value. In the event of a merger or other acquisition of the Company, the holders of the rights, other than the acquiring person or group, may purchase shares of the acquiring entity at half of their fair market value. The rights were not exercisable at December 31, 2015. (b) Medivation Equity Incentive Plan The Medivation Equity Incentive Plan, which is stockholder-approved, provides for the issuance of options and other stock-based awards, including restricted stock units and stock appreciation rights. The vesting of all outstanding awards under the Medivation Equity Incentive Plan will accelerate, and all such awards will become immediately exercisable, upon a “change of control” of Medivation, as defined in the Medivation Equity Incentive Plan. On June 16, 2015, the Company’s stockholders approved an amendment and restatement of the Medivation Equity Incentive Plan to increase the aggregate number of shares of common stock authorized for issuance under the Medivation Equity Incentive Plan from 21,150,000 to 23,850,000. As a result of the two-for-one stock split effected through a stock dividend described in Note 2, “Summary of Significant Accounting Policies,” the number of shares of common stock authorized for issuance under the Medivation Equity Incentive Plan was increased to 47,700,000 effective on September 15, 2015. As a result of the stock dividend, the number of shares of the Company’s common stock issuable upon exercise of outstanding stock options and vesting of other stock-based awards was proportionally increased, and the exercise price per share as applicable for options and stock appreciation rights was proportionally decreased, in accordance with the terms of the Medivation Equity Incentive Plan. As of December 31, 2015, approximately 8.7 million shares were available for issuance under the Medivation Equity Incentive Plan. Stock Options The terms of stock options granted under the Medivation Equity Incentive Plan cannot exceed ten years. Stock options generally have an exercise price equal to the fair market value of the Company’s common stock on the grant date, and generally vest over a period of four years, except for annual stock option grants to non-employee directors, which vest over a period of one year. The following table summarizes stock option activity for the year ended December 31, 2015, as adjusted to reflect the two-for-one forward stock split effected through a stock dividend on September 15, 2015: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value(1) (in millions) Outstanding at December 31, 2014 10,135,914 $ 16.76 Granted 1,822,724 $ 52.66 Exercised (1,446,047 ) $ 11.24 Forfeited/expired (404,422 ) $ 41.20 Outstanding at December 31, 2015 10,108,169 $ 23.05 6.01 $ 266.4 Vested and exercisable at December 31, 2015 7,043,757 $ 13.88 4.84 $ 242.9 (1) The aggregate intrinsic value is calculated as the pre-tax difference between the weighted-average exercise price of the underlying awards and the closing price per share of $48.34 of the Company’s common stock on December 31, 2015. The calculation excludes any awards with an exercise price higher than the closing price of the Company’s common stock on December 31, 2015. Additional information regarding stock options is set forth below (in thousands, except per share data): Years Ended December 31, 2015 2014 2013 Intrinsic value of options exercised $ 63,550 $ 145,842 $ 35,155 Grant-date fair value of options vested $ 26,542 $ 38,147 $ 22,278 Weighted-average grant-date fair value per share of options granted (split-adjusted) $ 25.08 $ 21.68 $ 15.20 Restricted Stock Units A restricted stock unit is an agreement to issue shares of the Company’s common stock at the time of vesting. Restricted stock units generally vest in three equal installments on approximately the first, second and third anniversaries of the grant date, except for annual restricted stock unit grants to non-employee directors, which vest on approximately the first anniversary of the grant date. The following table summarizes restricted stock unit activity for the year ended December 31, 2015, as adjusted to reflect the two-for-one forward stock split effected through a stock dividend on September 15, 2015: Number of Shares Weighted- Average Grant-Date Fair Value Unvested at December 31, 2014 967,160 $ 38.10 Granted 670,244 $ 52.34 Vested (404,906 ) $ 34.92 Forfeited (143,452 ) $ 45.45 Unvested at December 31, 2015 1,089,046 $ 47.08 The total fair value of restricted stock units that vested during the years ended December 31, 2015, 2014, and 2013 was $14.1 million, $7.0 million, and $11.8 million, respectively. Stock Appreciation Rights Stock appreciation rights give the holder the right, upon exercise, to receive the difference between the market price per share of the Company’s common stock at the time of exercise and the exercise price of the stock appreciation right. The exercise price of the stock appreciation right is equal to the market price of the Company’s common stock at the date of the grant. The following table summarizes stock appreciation rights activity for the year ended December 31, 2015, as adjusted to reflect the two-for-one forward stock split effected through a stock dividend on September 15, 2015: Number of Rights Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (1) (in millions) Outstanding at December 31, 2014 1,376,456 $ 12.03 Granted — — Exercised (61,172 ) $ 11.60 Forfeited (17,156 ) $ 11.60 Outstanding at December 31, 2015 1,298,128 $ 12.05 5.96 $ 47.1 Vested and exercisable at December 31, 2015 1,290,720 $ 12.05 5.96 $ 46.8 (1) The aggregate intrinsic value is calculated as the pre-tax difference between the weighted-average exercise price of the underlying awards and the closing price per share of $48.34 of the Company’s common stock on December 31, 2015. The calculation excludes any awards with an exercise price higher than the closing price of the Company’s common stock on December 31, 2015. Additional information regarding stock appreciation rights is set forth below: Years Ended December 31, 2015 2014 2013 Intrinsic value of stock appreciation rights exercised $ 3,034 $ 7,024 $ 1,090 Fair value of stock appreciation rights vested (based on remeasurement-date fair value) $ 5,730 $ 6,834 $ 9,955 No stock appreciation rights were granted during the years ended December 31, 2015, 2014 and 2013. (c) Medivation Employee Stock Purchase Plan The ESPP, which is stockholder approved, permits eligible employees to purchase shares of the Company’s common stock through payroll deductions at the lower of 85% of the fair market value of the common stock at the beginning or end of a purchase period. Eligible employee purchases are limited on an annual basis to $25,000 in accordance with Section 423 of the Internal Revenue Code. As a result of the stock dividend described in Note 2, “ (d) Stock-Based Compensation The Company estimates the fair value of stock options, stock appreciation rights, and ESPP shares using the Black-Scholes valuation model. The Company estimates expected volatility based on the historical price volatility of its common stock and implied volatility of its common stock inherent in the market price of publicly traded options in its common stock. The Company estimates the expected term of stock options and stock appreciation rights based on actual exercise experience and an assumption that unexercised options will remain outstanding for a period equal to the midpoint between the date the option vests in full and the contractual option termination date. The Company estimates the expected term of ESPP shares based on the duration of the applicable purchase period. The risk-free interest rate is based on the U.S. Treasury yield for a term consistent with the expected term of the awards at the time of grant. The Company uses a dividend yield of zero as it has no history or expectation of paying cash dividends on its common stock. The Black-Scholes assumptions used to estimate the fair value of stock options granted were as follows: Years Ended December 31, 2015 2014 2013 Expected volatility 50-64% 60-65% 64-75% Expected term (in years) 4.98-7.17 5.0-5.5 5.2-5.5 Risk-free interest rate 1.33-1.77% 1.56-1.79% 0.73-1.64% Expected dividend yield — — — No significant stock options were granted to consultants during the periods presented above. The Black-Scholes assumptions used to estimate the fair value of shares issued under the ESPP on the commencement date of the offering period were as follows: Years Ended December 31, 2015 2014 2013 Expected volatility 37-48% 43-53% 45 % Expected term (in years) 0.5 0.5 0.5 Risk-free interest rate 0.08-0.12% 0.04-0.06% 0.04 % Expected dividend yield — — — Stock-based compensation expense was as follows: Years Ended December 31, 2015 2014 2013 Stock-based compensation expense recognized as: R&D expenses $ 24,368 $ 17,913 $ 16,503 SG&A expenses 30,494 27,221 20,575 Total $ 54,862 $ 45,134 $ 37,078 Unrecognized stock-based compensation expense was approximately $87.2 million at December 31, 2015, and is expected to be recognized over a weighted-average period of approximately 2.5 years. (e) Warrants At December 31, 2015, an aggregate of 40,000 warrants to purchase shares of Medivation common stock at an exercise price of $3.47 per share were outstanding. These outstanding warrants expire in 2017. During the year ended December 31, 2013, an aggregate of 51,616 warrants to purchase shares of Medivation common stock at an exercise price of $0.39 per share were exercised.

Retirement Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2015
Postemployment Benefits [Abstract]
Retirement Plan	NOTE 12. RETIREMENT PLAN The Company has a defined contribution savings plan, which qualifies as a deferred salary arrangement under Section 401(k) of the Internal Revenue Code, or IRC. The 401(k) Plan is for the benefit of all participating employees and permits voluntary contributions by employees up to 100% of their annual pre-tax compensation limited by the Internal Revenue Service, or the IRS, imposed maximum contribution. The Company matches 100% of the first 3% of employee contributions and 50% of the next 2% of employee contributions. The Company’s contributions and the employee contributions are fully vested when contributed. The plan assets are held in trust and invested as directed by the plan participants. Employer matching contributions to the plan were $3.5 million, $2.7 million, and $1.9 million for the years ended December 31, 2015, 2014, and 2013, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 13. INCOME TAXES The Company’s income before income tax (expense) benefit was $381.3 million and $260.2 million for the years ended December 31, 2015 and 2014, respectively. The Company’s loss before income tax expense was $42.5 million for the year ended December 31, 2013. Since inception, the Company has only generated pre-tax income (losses) in the United States and has not generated any pre-tax income (losses) outside the United States. Income tax (expense) benefit for the periods presented consisted of the following: Years Ended December 31, 2015 2014 2013 Current: Federal $ (140,987 ) $ (19,476 ) $ (7 ) State (3,875 ) (1,496 ) (108 ) Total current (144,862 ) (20,972 ) (115 ) Deferred: Federal 8,179 36,917 — State 90 313 — Total deferred 8,269 37,230 — Total income tax (expense) benefit $ (136,593 ) $ 16,258 $ (115 ) During 2015 and 2014, the Company reduced its current Federal and state taxes payable by $100.2 million and $17.0 million, respectively, related to excess tax benefits from stock-based compensation, offsetting additional paid-in capital. In addition, for the year ended December 31, 2015, the Company recorded a credit to additional paid-in capital of $11.8 million related to certain tax impacts of the extinguishment of Convertible Notes. The Company had unrecorded state excess stock-based compensation tax benefits of $3.4 million (tax-effected) as of December 31, 2015. These amounts will be credited to additional paid-in capital when such amounts reduce cash taxes payable. A reconciliation of the statutory Federal income tax rate of 35% to the Company’s effective income tax rates is as follows: Years Ended December 31, 2015 2014 2013 Federal tax provision at statutory rate 35.0 % 35.0 % 35.0 % State taxes (net of Federal benefit) 0.6 % 0.4 % 1.4 % Stock-based compensation 0.1 % 0.1 % (0.2 %) Non-deductible officer compensation 0.2 % 0.1 % (1.8 %) Change in valuation allowance — (40.5 %) (52.1 %) Research and development credits (0.2 %) (1.5 %) 17.1 % Other 0.1 % 0.2 % 0.3 % Effective income tax rate 35.8 % (6.2 %) (0.3 %) The Company recorded income tax expense of $136.6 million for the year ended December 31, 2015. The Company recorded an income tax benefit of $16.3 million for the year ended December 31, 2014. For the year ended December 31, 2015, the provision for income taxes was higher than the tax computed at the U.S. Federal statutory rate primarily due to state income taxes and non-deductible stock-based compensation, net of Federal research and development credit. For the year ended December 31, 2014, the provision for income taxes was lower than the tax computed at the U.S. Federal statutory rate due primarily to utilization of net operating loss and tax credit carryforwards and the release of the valuation allowance on a portion of the Company’s net deferred tax assets. The income tax expense for the year ended December 31, 2013 was not significant. The increase in the effective tax rate for the year ended December 31, 2015 as compared to the year ended December 31, 2014 was primarily due to the release of the valuation allowance against federal and certain state deferred tax assets during the fourth quarter of 2014. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the tax basis of assets and liabilities. Significant components of the Company’s deferred tax assets for Federal and state income taxes are follows: December 31, 2015 2014 Deferred tax assets: Deferred revenue $ — $ 1,005 Net operating loss carryforward 8,257 9,100 Stock-based compensation 35,482 26,000 Tax credits 8,076 12,098 Intangible assets 9,833 5,259 Accruals and reserves 19,156 15,247 Total deferred tax assets 80,804 68,709 Less: valuation allowance (16,827 ) (16,023 ) Total net deferred tax assets 63,977 52,686 Deferred tax liabilities Depreciation (3,168 ) (2,741 ) Convertible Notes — (12,792 ) Contingent consideration (3,798 ) — Total deferred tax liabilities (6,966 ) (15,533 ) Net deferred tax assets $ 57,011 $ 37,153 Recorded as: Net current deferred tax assets $ — $ 21,987 Net non-current deferred tax assets 57,011 15,176 Net non-current deferred tax liabilities (included in “Other non-current liabilities”) — (10 ) Net deferred tax assets $ 57,011 $ 37,153 As of December 31, 2015, all deferred tax assets and liabilities are classified as non-current on the Company’s balance sheet in accordance with the early adoption of ASU 2015-17. See additional discussion in Note 2, “Summary of Significant Accounting Policies”. As of December 31, 2015, the Company had no Federal net operating loss carryforwards for tax return purposes as the Company fully utilized all of its tax attributes during 2015. Also, as of December 31, 2015, the Company had state net operating loss carryforwards for tax return purposes of approximately $216.3 million, which will expire at various dates between the years 2017 and 2033, if not utilized. The Company has fully utilized all of its Federal research and development credit and Orphan Drug credit carryforwards and alternative minimum tax credits as of December 31, 2015 for tax return purposes. In addition, the Company has California research and development credit carryforwards for tax purposes of approximately $16.6 million as of December 31, 2015. The California research credits do not expire. On December 18, 2015, the Consolidated Appropriations Act of 2016 was signed, permanently renewing the Federal research and development tax credit retroactive to January 1, 2015. ASC 740-10-45-15, “Income Taxes,” requires that the effects of a change in tax laws or rates be recognized in the period that includes the enactment date; consequently, the Company recognized the benefit of the Federal research and development credit during the fourth quarter of 2015. Federal and state tax laws impose substantial restrictions on the utilization of net operating loss and credit carryforwards in the event of an “ownership change” for tax purposes, as defined in IRC Section 382. The Company completed Section 382 studies through September 30, 2015, and concluded that ownership changes occurred in 2004, 2007 and 2010. The ownership changes did not result in a reduction of its net operating loss or in its research and development credits expiring unused. If additional ownership changes occur, the utilization of net operating loss and credit carryforwards could be significantly reduced. The valuation allowance increased by $0.8 million in 2015, decreased by $104.8 million in 2014 and increased by $22.1 million in 2013. The Company records a valuation allowance to reduce deferred tax assets to reflect the net amount that is more likely than not to be realized. Based upon the weight of available evidence at December 31, 2014, the Company determined that it was more likely than not that a portion of its deferred tax assets would be realizable and consequently released the valuation allowance against Federal and certain state net deferred tax assets and recorded a discrete tax benefit of $33.4 million during the fourth quarter of 2014. The decision to reverse a portion of the valuation allowance was made after management considered all available evidence, both positive and negative, including but not limited to the historical operating results, income or loss in recent periods, cumulative income in recent years, forecasted earnings, forecasted future taxable income, and significant risk and uncertainty related to forecasts. The release of the valuation allowance resulted in the recognition of certain deferred net tax assets and a decrease to income tax expense. The following table summarizes activity related to the Company’s gross unrecognized tax positions: December 31, 2015 2014 2013 Balance as of beginning of year $ 12,367 $ 5,955 $ 4,602 Additions based on tax positions related to the current year 2,898 6,439 702 Additions based on tax position related to prior year 135 — 660 Decreases based on tax positions related to prior year (1,324 ) (27 ) (9 ) Balance as of end of year $ 14,076 $ 12,367 $ 5,955 Approximately $7.7 million of the total gross unrecognized tax benefits at December 31, 2015, if recognized, would affect the effective tax rate. The Company does not anticipate a material change in unrecognized tax benefits during the next twelve months. Interest and/or penalties related to income tax matters are recognized as a component of income tax expense as incurred. The interest expense related to uncertain tax positions in the income tax expense line of the Company’s consolidated statements of operations was not significant during 2015, 2014, and 2013. Interest related to income tax matters accrued as of December 31, 2015 and 2014 was not significant. As a result of the Company’s net operating loss and tax credit carryforwards, all of its tax years are subject to Federal and state examination. The Company’s Federal income tax returns were audited by the Internal Revenue Service for tax years 2008 and 2012 and resulted in no material adjustments. The Company’s 2009 and 2010 California income tax returns are currently under audit by the California tax authorities. The Company believes that it has adequately provided for any reasonable foreseeable outcomes related to its Federal and California income tax returns. The future effective tax rate is subject to volatility and may be materially impacted by various internal and external factors. These factors may include, but are not limited to, the amount of income tax benefits and charges from: interpretations of existing tax laws; changes in tax laws and rates; future levels of research and development expenditures; changes in the mix of earnings in countries with differing statutory tax rates in which the Company may conduct business; changes in the valuation of deferred tax assets and liabilities; state income taxes; the tax impact of stock-based compensation; accounting for uncertain tax positions; closure of statute of limitations or settlement of tax audits; changes in estimates of prior years’ items; tax costs for acquisition-related items; changes in accounting standards; non-deductible officers’ compensation; limitations on the utilization of net operating losses and tax credits due to changes in ownership; and overall levels of income before taxes.

Fair Value Disclosures

Fair Value Disclosures	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Disclosures	NOTE 14. FAIR VALUE DISCLOSURES The Company follows ASC 820-10, “Fair Value Measurements and Disclosures,” which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows: · Level 1—Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. · Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life. · Level 3—Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Unobservable inputs are used when little or no market data are available. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. The following table presents the Company’s financial assets and liabilities that are measured at fair value on a recurring basis: Fair value measurements using: Fair Value Level 1 Level 2 Level 3 December 31, 2015: Current liabilities: Contingent consideration $ 4,900 — — $ 4,900 Long-term liabilities: Contingent consideration $ 262,368 — — $ 262,368 December 31, 2014: Cash equivalents: Money market funds $ 189,031 $ 189,031 — — Current liabilities: Contingent consideration $ 10,000 — — $ 10,000 Long-term liabilities: Contingent consideration $ 96,000 — — $ 96,000 The Company classifies money market funds, which are based on quoted market prices in active markets with no valuation adjustments, as Level 1 assets within the valuation hierarchy. The Company estimates the fair values of Level 2 assets by taking into consideration valuations obtained from third-party pricing sources. These pricing sources utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly, or indirectly, to estimate fair value. These inputs include market pricing based on real-time trade data for the same or similar assets, issuer credit spreads, benchmark yields, and other observable inputs. The Company validates the prices provided by its third-party pricing sources by understanding the models used, obtaining market values from other pricing sources, and/or analyzing pricing data in certain instances. In connection with the acquisitions of MDV9300 and MDV3800 During the year ended December 31, 2015, the Company recorded fair value adjustments of $2.6 million and $7.7 million as a decrease to R&D expenses and SG&A expenses, respectively, related to the CureTech contingent consideration liability. Since the date of the fourth quarter acquisition of MDV3800 The aggregate remaining, undiscounted amount of contingent consideration that the Company could potentially be required to pay to CureTech and BioMarin under each respective transaction is included in Note 4, “Business Acquisitions.” Contingent consideration may change significantly as development progresses and additional data is obtained that will affect the Company’s assumptions regarding probabilities of successful achievement of related milestones used to estimate the fair value of the liability and the timing in which they are expected to be achieved. Updates to these assumptions could have a significant impact on our results of operations. For example, a significant increase in the probability of achieving a milestone would result in a significantly higher fair value measurement, while a significant increase in the expected timing of achieving the milestone would result in a significantly lower fair value measurement. There were no transfers between Level 1 and Level 2 financial instruments during the year ended December 31, 2015. The following table includes a roll-forward of the fair value of Level 3 financial instruments for the year ended December 31, 2015: Year Ended December 31, 2015 Contingent consideration (current and long-term): Balance at beginning of period $ 106,000 Amounts acquired or issued 171,942 Net change in fair value (10,674 ) Settlements — Transfers in and/or out of Level 3 — Balance at end of period $ 267,268 The following table presents the total balance of the Company’s other financial instruments that are not measured at fair value on a recurring basis. Fair value measurements using: Total Balance Level 1 Level 2 Level 3 December 31, 2015: Assets: Bank deposits (included in “Cash and cash equivalents”) $ 225,853 $ 225,853 — — Liabilities: Borrowings under Revolving Credit Facility $ 75,000 $ 75,000 — — December 31, 2014: Assets: Bank deposits (included in “Cash and cash equivalents”) $ 313,646 $ 313,646 — — Liabilities: Convertible Notes $ 359,219 — $ 359,219 — Due to their short-term maturities, the Company believes that the fair value of its bank deposits, receivable from collaboration partner, accounts payable and accrued expenses, short-term borrowings under the Revolving Credit Facility, and other current assets and liabilities approximate their carrying value. The estimated fair value of the Company’s Convertible Notes, including the equity component, was $496.8 million at December 31, 2014 and was determined using recent trading prices of the Convertible Notes. The fair value of the Convertible Notes included in the table above at December 31, 2014 represents only the liability component of the Convertible Notes, because the equity component is included in stockholders’ equity on the consolidated balance sheet. The Company settled its remaining Convertible Notes in the third quarter of 2015 as discussed further in Note 10, “Debt.”

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 15. COMMITMENTS AND CONTINGENCIES (a) Leases The Company leases approximately 158,000 square feet of office space, including 143,000 square feet of office space at its corporate headquarters, pursuant to operating lease agreements expiring at various dates through December 2019. The Company has the option to extend the lease term of its corporate headquarters for an additional five years. Future operating lease obligations as of December 31, 2015, are as follows: Years Ending December 31, Operating Leases 2016 $ 9,343 2017 9,542 2018 9,743 2019 5,065 2020 — 2021 and thereafter — Total $ 33,693 The Company is considered the “accounting owner” for a build-to-suit property and has recorded a build-to-suit lease obligation on its consolidated balance sheets. Additional information regarding the build-to-suit lease obligation is included in Note 7, “Build-To-Suit Lease Obligation.” Expected future lease payments under the build-to-suit lease as of December 31, 2015 are as follows: Years Ending December 31, Expected Payments Under Build-To-Suit Lease Obligation 2016 $ 2,178 2017 2,244 2018 2,311 2019 2,380 2020 2,452 2021 and thereafter 9,627 Total minimum lease payments $ 21,192 Rent expense for the years ended December 31, 2015, 2014, and 2013 was $10.3 million, $8.1 million, and $5.2 million, respectively. In addition to the amounts included in the tables above, certain lease agreements also require the Company to make additional payments during the lease term for taxes, insurance, and other operating expenses. (b) License Agreement with UCLA Under an August 2005 license agreement with UCLA, the Company’s subsidiary Medivation Prostate Therapeutics, Inc., or MPT, holds an exclusive worldwide license under several UCLA patents and patent applications covering XTANDI and related compounds. Under the Astellas Collaboration Agreement, the Company granted Astellas a sublicense under the patent rights licensed to it by UCLA. The Company is required to pay UCLA (a) an annual maintenance fee, (b) $2.8 million in aggregate milestone payments upon achievement of certain development and regulatory milestone events with respect to XTANDI (all of which has been paid as of December 31, 2015), (c) ten percent of all Sublicensing Income, as defined in the agreement, which the Company earns under the Astellas Collaboration Agreement, and (d) a four percent royalty on global net sales of XTANDI, as defined. Under the terms of the Astellas Collaboration Agreement, the Company shares this royalty obligation equally with Astellas with respect to sales in the United States, and Astellas is responsible for this entire royalty obligation with respect to sales outside of the United States. The Company is currently involved in litigation with UCLA, which are discussed in the section titled “Litigation” below. UCLA may terminate the agreement if the Company does not meet a general obligation to diligently proceed with the development, manufacturing and sale of licensed products, or if it commits any other uncured material breach of the agreement. The Company may terminate the agreement at any time upon advance written notice to UCLA. If neither party terminates the agreement early, the agreement will continue in force until the expiration of the last-to-expire patent on a country-by-country basis. (c) Clinical Manufacturing Agreements Manufacturing Services and Supply Agreements Contemporaneous with the execution of the License Agreement with CureTech, the Company entered into a Manufacturing Services and Supply Agreement, or MSA, with CureTech pursuant to which CureTech will provide clinical trial supply of MDV9300 over a three-year period. In accordance with the terms of the MSA, as amended, the Company paid CureTech upfront and setup fees of $3.0 million during the fourth quarter of 2014, $0.2 million during the second quarter of 2015 and $0.1 million during the third quarter of 2015. The Company is required to pay CureTech a one-time milestone payment of $5.0 million upon the completion of the Manufacturing Technology Transfer, as defined. In accordance with the terms of the MSA, the Company is also responsible for providing Manufacturing Funding totaling up to $19.3 million for clinical trial materials of MDV9300 over the three-year term of the MSA, of which $9.0 million has been paid through December 31, 2015. The Manufacturing Funding is contingent upon the successful achievement of the requirements set forth in the Manufacturing Plan, and any such amounts may be reduced or eliminated by the Company under the terms of the MSA. Development and Manufacturing Services Agreement During the fourth quarter of 2014, the Company entered into a Development and Manufacturing Services Agreement with a third party clinical manufacturing organization. The term of the agreement is for the longer of (i) a period of five (5) years or (ii) through the completion of the Services, as defined. Under the current statement of work under this agreement, as amended, the Company intends to transfer the current manufacturing process of MDV9300 from CureTech to this third party, further scale up and production of Phase 3 clinical trial material of MDV9300 from this entity’s manufacturing facility. The estimated total consideration payable under the current statement of work, as amended, is approximately $15.2 million, of which approximately $5.1 million has been paid through December 31, 2015. (f) Litigation The Company is party to legal proceedings, investigations, and claims in the ordinary course of its business, including the matters described below. The Company records accruals for outstanding legal matters when it believes that it is both probable that a liability has been incurred and the amount of such liability can be reasonably estimated. The Company evaluates, on a quarterly basis, developments in significant legal matters that could affect the amount of any accrual and developments that would make a loss contingency both probable and reasonably estimable. To the extent new information is obtained and the Company’s views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in the Company’s accrued liabilities would be recorded in the period in which such determination is made. In addition, in accordance with the relevant authoritative guidance, for matters for which the likelihood of material loss is at least reasonably possible, the Company provides disclosure of the possible loss or range of loss; however, if a reasonable estimate cannot be made, the Company will provide disclosure to that effect. Gain contingencies, if any, are recorded when they are realized. In May 2011, the Company filed a lawsuit in San Francisco Superior Court against the Regents of the University of California, or the Regents, and one of its professors, alleging breach of contract and fraud claims, among others. The Company’s allegations in this lawsuit include that it has exclusive commercial rights to apalutamide, an investigational drug originally known as ARN-509 (previously also referred to as JNJ-56021927, or JNJ-927), which is currently being developed by Aragon Pharmaceuticals, or Aragon. In August 2013, Johnson & Johnson and Aragon completed a transaction in which Johnson & Johnson acquired all apalutamide assets owned by Aragon. The Company sought remedies including a declaration that it is the proper licensee of apalutamide, contractual remedies conferring to it exclusive patent license rights regarding apalutamide, and other equitable and monetary relief. On August 7, 2012, the Regents filed a cross-complaint against the Company seeking declaratory relief that the Regents are entitled to ten percent of any sales milestone payments under the Astellas Collaboration Agreement. On December 20, 2012, and January 25, 2013, the Court granted summary judgment motions filed by defendants Regents and Aragon, resulting in dismissal of all claims against Regents and Aragon, but denied such motions filed by the remaining Regents professor. On April 15, 2013, the Company filed a Notice of Appeal seeking appeal of the judgment in favor of Aragon, which is now wholly-owned by Johnson & Johnson. The bench trial of the Regent’s cross-complaint against the Company was conducted in July 2013, and on January 15, 2014, the Court entered a judgment in the cross-complaint in favor of Regents. The Company appealed this judgment on February 13, 2014 along with the December 2012 summary judgment order in favor of Regents. The jury trial of the Company’s breach of contract and fraud claims against the remaining Regents professor was conducted in October and November 2013. On November 15, 2013, the jury rendered a verdict in the case, finding in favor of Medivation on one of the breach of contract claims, and in favor of the Regents professor on the fraud claims. The Company appealed the resulting judgment on the fraud claims. All appeals from this matter were consolidated, and oral arguments were heard on February 23, 2016. A decision of the appellate court is required to be rendered within 90 days of the oral argument. On April 11, 2014, the Regents filed a complaint against the Company in which UCLA alleges that the “Operating Profits” Medivation has received (and will continue to receive) from Astellas, as a result of the Astellas Collaboration Agreement, constitute Sublicensing Income under the license agreement between Medivation and the Regents and that Medivation and its subsidiary, MPT, have failed to pay the Regents ten percent of such Operating Profits. The Company denies the Regents’ allegations and is vigorously defending the litigation. The Company is currently awaiting a trial date to be set by the Courts. While the Company believes it has meritorious positions with respect to the claims above and intends to advance its positions in these lawsuits vigorously, including on appeal, the process of resolving matters through litigation or other means is inherently uncertain, and it is not possible to predict the ultimate resolution of any such proceeding. The actual costs of defending the Company’s position may be significant, and the Company may not prevail.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	NOTE 16. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) The following table presents the unaudited quarterly results of operations of the Company for the years ended December 31, 2015 and 2014, respectively. The unaudited financial information is prepared on the same basis as the audited consolidated financial statements. The Company’s operating results for any quarter are not necessarily indicative of results for any future quarters or for a full year. All share and per share amounts have been retroactively adjusted to reflect the Company’s September 15, 2015, two-for-one forward stock split effected through a stock dividend. Quarters Ended March 31, June 30, September 30, December 31, 2015: Collaboration revenue $ 129,188 $ 175,657 $ 260,665 $ 377,748 Operating expenses $ (128,615 ) $ (122,002 ) $ (121,680 ) $ (156,348 ) Income from operations $ 573 $ 53,655 $ 138,985 $ 221,400 Net income (loss) $ (3,118 ) $ 25,826 $ 79,510 $ 142,507 Basic net income (loss) per common share $ (0.02 ) $ 0.16 $ 0.49 $ 0.87 Diluted net income (loss) per common share $ (0.02 ) $ 0.15 $ 0.47 $ 0.85 Weighted-average common shares used in the calculation of basic net income (loss) per common share 156,637 158,505 162,390 163,746 Weighted-average common shares used in the calculation of diluted net income (loss) per common share 156,637 168,690 168,070 168,368 2014: Collaboration revenue $ 87,189 $ 148,090 $ 200,478 $ 274,730 Operating expenses $ (95,654 ) $ (93,139 ) $ (108,595 ) $ (131,253 ) Income (loss) from operations $ (8,465 ) $ 54,951 $ 91,883 $ 143,477 Net income (loss) $ (13,665 ) $ 47,919 $ 77,993 $ 164,205 Basic net income (loss) per common share $ (0.09 ) $ 0.31 $ 0.51 $ 1.06 Diluted net income (loss) per common share $ (0.09 ) $ 0.30 $ 0.48 $ 0.98 Weighted-average common shares used in the calculation of basic net income (loss) per common share 152,489 153,153 154,112 155,644 Weighted-average common shares used in the calculation of diluted net income (loss) per common share 152,489 160,983 162,446 171,513 Net income (loss) per common share amounts for the 2015 and 2014 quarters and full years have been computed separately. Accordingly, quarterly amounts may not add to the annual amounts because of differences in the weighted average shares outstanding during each quarter due to the effect of potentially dilutive securities only in the periods in which such effect would be dilutive.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation and Principles of Consolidation	(a) Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States, or U.S. GAAP, and include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The Company operates in one business segment. All tabular disclosures of dollar and share amounts are presented in thousands unless otherwise indicated. All per share amounts are presented at their actual amounts. The number of shares issuable under the Amended and Restated 2004 Equity Incentive Award Plan, or the Medivation Equity Incentive Plan, and the Medivation, Inc. 2013 Employee Stock Purchase Plan, or ESPP, disclosed in Note 11, “Stockholders’ Equity,” are presented at their actual amounts unless otherwise indicated. Amounts presented herein may not calculate or sum precisely due to rounding. Certain prior period amounts have been reclassified to conform to the current year presentation. There was no effect on net income (loss) or stockholders’ equity related to these reclassifications.
Use of Estimates	(b) Use of Estimates The preparation of consolidated financial statements in accordance with U.S. GAAP requires that management make estimates and assumptions in certain circumstances that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management bases its estimates on historical experience and on assumptions believed to be reasonable under the circumstances. Although management believes that these estimates are reasonable, actual future results could differ materially from those estimates. In addition, had different estimates and assumptions been used, the consolidated financial statements could have differed materially from what is presented. Significant estimates and assumptions used by management principally relate to revenue recognition, including reliance on third-party information, estimating the performance periods of the Company’s deliverables under collaboration agreements, and estimating the various deductions from gross sales to calculate net sales of XTANDI. Additionally, significant estimates and assumptions used by management include those related to contingent purchase consideration, intangible assets, goodwill, the Convertible Notes, determining whether the Company is the primary beneficiary of any variable interest entities,
Capital Structure	(c) Capital Structure On June 15, 2015, the Company filed a Certificate of Amendment to its Amended and Restated Certificate of Incorporation, as amended, effecting an increase in the total number of authorized shares of capital stock of the Company from 171,000,000 to 341,000,000 and an increase in the total number of authorized shares of common stock of the Company from 170,000,000 to 340,000,000. On September 15, 2015, the Company effected a two-for-one forward stock split of its common stock in the form of a stock dividend. Stockholders of record as of August 13, 2015 received one additional share of the Company’s common stock, par value $0.01, for each share they held as of the record date. The Company issued approximately 81.7 million shares of its common stock as a result of the stock dividend. The par value of the Company’s common stock remained unchanged at $0.01 per share. During the year ended December 31, 2015, the Company settled $258.8 million aggregate principal amount of its 2.625% convertible senior notes due April 1, 2017, or the Convertible Notes, through a combination of $259.9 million in cash and 5,638,576 shares of its common stock. Upon settlement, the Convertible Notes were no longer outstanding, interest ceased to accrue thereon, and all rights of the holders of the Convertible Notes ceased to exist. Information regarding shares of common stock (except par value per share), par, additional paid-in capital, and net income (loss) per common share for all periods presented has been retroactively adjusted to reflect the effects of the stock split. The number of shares of the Company’s common stock issuable upon exercise of outstanding stock options and stock appreciation rights and vesting of other stock-based awards was proportionally increased, and the exercise price per share thereof, as applicable, was proportionally decreased, in accordance with the terms of the Medivation Equity Incentive Plan, as amended, and the ESPP.
Collaboration Agreement Payments	(d) Collaboration Agreement Payments The Company accounts for the various payment flows under its collaboration agreement with Astellas, or the Astellas Collaboration Agreement, as follows: Estimated Performance Periods The Astellas Collaboration Agreement contains multiple elements and deliverables, and required evaluation pursuant to Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, 605-25, “Revenue Recognition—Multiple-Element Arrangements.” The Company concluded that it had multiple deliverables under the Astellas Collaboration Agreement, including deliverables relating to grants of technology licenses, and performance of manufacturing, regulatory and clinical development activities in the United States. The period in which the Company performed its deliverables began in the fourth quarter of 2009 and concluded in the third quarter of 2015 upon substantial completion of the Company’s remaining performance obligations. The Company also concluded that its deliverables under the Astellas Collaboration Agreement should be accounted for as a single unit under ASC 605-25. Estimation of the performance periods of the Company’s deliverables requires the use of management’s judgment. Significant factors considered in management’s evaluation of the estimated performance periods include, but are not limited to, the Company’s experience, along with its collaboration partners’ experience, in conducting manufacturing, clinical development and regulatory activities. The Company reviews the estimated duration of its performance periods under its collaboration agreements on a quarterly basis and makes any appropriate adjustments on a prospective basis. Upfront Payments The Company received a non-refundable, upfront cash payment of $110.0 million under the Astellas Collaboration Agreement. The Company recognized the payment as collaboration revenue on a straight-line basis over the applicable estimated performance period. As of December 31, 2015, there was no deferred revenue related to payments received under the Astellas Collaboration Agreement. Milestone Payments The Company has been eligible to receive milestone payments under the Astellas Collaboration Agreement based on achievement of specified development, regulatory and commercial events. Management evaluated the nature of the events triggering these contingent payments, and concluded that these events fall into two categories: (a) events which involve the performance of the Company’s obligations under the Astellas Collaboration Agreement, and (b) events which do not involve the performance of the Company’s obligations under the Astellas Collaboration Agreement. The former category of milestone payments consist of those triggered by development and regulatory activities in the United States and by the acceptance for review of marketing applications in Europe and Japan. Management concluded that each of these payments, with one exception, constitute substantive milestone payments. This conclusion was based primarily on the facts that (i) each triggering event represented a specific outcome that could be achieved only through successful performance by the Company of one or more of its deliverables, (ii) achievement of each triggering event was subject to inherent risk and uncertainty and would result in additional payments becoming due to the Company, (iii) each of the milestone payments was non-refundable, (iv) substantial effort was required to complete each milestone, (v) the amount of each milestone payment was reasonable in relation to the value created in achieving the milestone, (vi) a substantial amount of time was expected to pass between the upfront payment and the potential milestone payments, and (vii) the milestone payments related solely to past performance. Based on the foregoing, the Company recognized any revenue from these milestone payments in the period in which the underlying triggering event occurs. The one exception is the milestone payment for initiation of the Phase 3 PREVAIL trial, an event which management deemed to be reasonably assured at the inception of the Astellas collaboration. This milestone payment was triggered in the third quarter of 2010, and the Company recognized it as collaboration revenue on a straight-line basis over the estimated remaining performance period of the Astellas Collaboration Agreement. The latter category of milestone payments consist of those triggered by potential marketing approvals in Europe and Japan, and commercial activities globally, all of which were areas in which the Company had no pertinent contractual responsibilities under the Astellas Collaboration Agreement. Management concluded that these payments constitute contingent revenues and thus recognized them as revenue in the period in which the contingency was met. As of December 31, 2015, the Company has earned all development and sales milestone payments under the Astellas Collaboration Agreement. Royalties and Profit (Loss) Sharing Payments Under the Astellas Collaboration Agreement, the Company shares equally profits (losses) on sales of products in the United States and receives royalties on sales of products outside the United States. The Company recognizes revenue from these events based on the revenue recognition criteria set forth in ASC 605-10-25-1, “Revenue Recognition.” Based on those criteria, the Company considers these payments to be contingent revenues, and recognizes them as revenue in the period in which the applicable contingency is resolved. Cost-Sharing Payments Under the Astellas Collaboration Agreement, the Company and Astellas share certain development and commercialization costs in the United States, including cost of goods sold and the royalty on net sales payable to The Regents of the University of California, or UCLA, under the Company’s license agreement with UCLA. The Company and Astellas make quarterly cost-sharing payments to one another in amounts necessary to ensure that each party bears its contractual share of the overall shared U.S. development and commercialization costs incurred. The Company’s policy is to account for cost-sharing payments to its collaboration partners as increases in expense in its consolidated statements of operations, while cost-sharing payments from its collaboration partners to the Company are accounted for as reductions in expense. Cost-sharing payments related to development activities and commercialization activities are recorded in research and development expenses, or R&D expenses, and selling, general and administrative expenses, or SG&A expenses, respectively. Reliance on Third-Party Information Under the Astellas Collaboration Agreement, Astellas records all XTANDI sales globally and has operational responsibility for certain development and commercialization activities in the United States for which the Company shares costs. Thus, Astellas has control over certain XTANDI-related financial information needed to prepare the Company’s financial statements and related disclosures, including information regarding gross sales, net sales, gross-to-net sales deductions, including estimates of potential future product returns, and shared U.S. development and commercialization costs incurred by Astellas. The Company is dependent on Astellas to provide it with such information in a timely and accurate manner for use in preparing the Company’s consolidated financial statements and disclosures. Certain of this information provided by Astellas is subject to estimates, including estimates used in determining gross-to-net revenue deductions such as payor mix, discounts (including legally mandated discounts to government entities), returns, chargebacks, rebates, and participation levels in patient assistance programs, and estimates regarding accrued development and commercialization costs incurred by Astellas. Under the Astellas Collaboration Agreement, the deductions from gross sales used to derive net sales of XTANDI are determined in a manner consistent with GAAP, consistently applied. Should Astellas fail to provide the Company with any such financial information in a timely manner, or should any such financial information provided by Astellas, or any of the estimates upon which such financial information was based, prove to be inaccurate, the Company could be required to record adjustments in future periods.
Research and Development Expenses and Accruals	(e) Research and Development Expenses and Accruals R&D expenses are charged to expense as incurred unless there is an alternative future use in other research and development projects or otherwise. R&D expenses are comprised of costs incurred in performing research and development activities, including personnel-related costs, share-based compensation, and facilities-related overhead, outside contracted services including clinical trial costs, manufacturing and process development costs for both clinical and preclinical materials, research costs, upfront and development milestone payments under license agreements and other consulting services. Non-refundable advance payment for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. In instances where the Company enters into agreements with third parties to provide research and development services, costs are expensed as services are performed. Amounts due under such arrangements may be either fixed fee or fee for service, and may include upfront payments, monthly payments, and payments upon the completion of milestones or receipt of deliverables. The Company’s accruals for clinical trials and other research and development activities are based on estimates of the services received and efforts expended pursuant to contracts with numerous clinical trial centers, contract research organizations and clinical manufacturing organizations. In the normal course of business the Company contracts with third parties to perform various research and development activities in the on-going development of its product candidates, including, without limitation, third-party clinical trial centers and contract research organizations that perform and administer the Company’s clinical trials on its behalf and clinical manufacturing organizations that manufacture clinical trial materials. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Payments under these agreements depend on factors such as the achievement of certain events, the successful enrollment of patients, and the completion of portions of the clinical trial or similar conditions. The objective of the Company’s accrual policy is to match the recording of expenses in its consolidated financial statements to the actual services received and efforts expended. As such, expense accruals related to clinical trials and other research and development activities are recognized based on the Company’s estimate of the degree of completion of the event or events specified in the specific agreement. The Company’s accrual estimates are dependent upon the timeliness and accuracy of data provided by third parties regarding the status and cost of studies, and may not match the actual services performed by the organizations. During the course of a clinical trial, the Company adjusts its rate of clinical trial expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued clinical trial expenses as of each balance sheet date based on facts and circumstances known at that time. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in the Company reporting amounts that are too high or too low for any particular period. This could result in adjustment to the Company’s R&D expense in future periods. The Company has had no significant adjustments to previously recorded research and development amounts.
Promotional and Advertising Costs	(f) Promotional and Advertising Costs Promotional and advertising costs are classified as SG&A expenses and are expensed as incurred. Promotional and advertising expenses consist primarily of the costs of designing, producing and distributing materials promoting the Company and its products, including its corporate website. Under the Astellas Collaboration Agreement, the Company and its collaboration partners share certain commercialization costs, including certain promotional and advertising costs, in the United States. See Note 3, “Collaboration Agreement,” for additional information regarding cost-sharing with its collaboration partners.
Stock-Based Compensation	(g) Stock-Based Compensation The Company has outstanding stock options, restricted stock units, and stock appreciation rights pursuant to the terms of the Medivation Equity Incentive Plan, and eligible employees may purchase shares pursuant to the ESPP. The Company accounts for stock-based compensation awards to employees and directors and ESPP shares in accordance with ASC 718, “Stock Compensation,” and stock-based compensation awards to consultants in accordance with ASC 505-50, “Equity-Based Payments to Non-Employees.” Stock-based compensation expense associated with stock options is based on the estimated grant date fair value using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, option term, risk-free interest rate and dividend yield. The Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest. Stock-based compensation expense associated with restricted stock units is based on the fair value of the Company’s common stock on the grant date, which equals the closing market price of the Company’s common stock on the grant date. For restricted stock units, the Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest. The fair value of stock-settled and cash-settled stock appreciation rights is initially measured on the grant date using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, term, risk-free interest rate and dividend yield. Similar to stock options, compensation expense for stock-settled stock appreciation rights is recognized over the vesting period of the awards that are ultimately expected to vest based on the grant-date fair value. Cash-settled stock appreciation rights are liability-classified awards for which compensation expense and the liability are remeasured at each reporting date through the date of settlement based on the portion of the requisite service period rendered. Upon the conversion of cash-settled stock appreciation rights to stock-settled stock appreciation rights, the awards are remeasured using the then-current Black-Scholes assumptions and the remeasured liability is reclassified to additional paid-in capital. The Company accounts for the ESPP as a compensatory plan. The fair value of each purchase under the Company’s ESPP is estimated on the date of the beginning of the offering period using the Black-Scholes valuation model, which requires the use of subjective assumptions related to the expected stock price volatility, term, risk-free interest rate and dividend yield. The Company recognizes compensation expense over the vesting period of the awards that are ultimately expected to vest. Equity awards to consultants are typically remeasured at fair value at each reporting date until the awards vest. The Company applies a forfeiture rate when determining stock-based compensation expense to account for an estimate of the granted awards not expected to vest. If actual forfeitures differ from the expected rate, the Company may be required to make additional adjustments to compensation expense in future periods. The Black-Scholes valuation model was developed for use in estimating the fair value of traded options that have no vesting restrictions and are fully transferable, characteristics not present in the Company’s stock options, stock appreciation rights, or ESPP shares. If the model permitted consideration of the unique characteristics of employee stock options, stock appreciation rights, and ESPP shares, the resulting estimate of fair value of the stock options, stock appreciation rights, and ESPP shares could be different. In addition, if the Company had made different assumptions and estimates for use in the Black-Scholes valuation model, the amount of recognized and to be recognized stock-based compensation expense could have been different.
Cash and Cash Equivalents	(h) Cash and Cash Equivalents Cash and cash equivalents are stated at cost, which approximates fair market value. Cash and cash equivalents consist of cash on deposit with banks, money market funds, and all highly liquid investments with a remaining maturity of three months or less at the time of purchase.
Short-Term Investments	(i) Short-Term Investments The Company considers all highly liquid investments with a remaining maturity at the time of acquisition of more than three months but no longer than 12 months to be short-term investments. The Company classifies its short-term investments as available-for-sale securities and reports them at fair value with related unrealized gains and losses included as a component of stockholders’ equity. The amortized cost of debt securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in other income (expense), net, on the consolidated statements of operations. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income (expense), net. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in other income (expense), net. For the year ended December 31, 2015, total realized gains and losses on sales of available-for-sale securities were not material. There were no realized gains or losses from sales of available-for-sale securities for the years ended December 31, 2014 and 2013.
Concentration of Credit Risk	(j) Concentration of Credit Risk The Company is subject to credit risk from its portfolio of cash, cash equivalents and short-term investments. The goals of the Company’s investment policy, in order of priority, are (1) the safety and preservation of principal, (2) maintain liquidity sufficient to meet the requirements of the Company’s operations and strategic initiatives, and (3) deliver competitive after-tax returns relative to stated objectives and market conditions. Given this investment policy, the Company does not believe its exposure to credit risk with respect to the issuers of the securities in which it invests is material. The Company’s cash and cash equivalents are primarily invested in deposits and money market accounts with one major financial institution in the United States. Deposits in this financial institution may exceed the amount of insurance provided on such deposits.
Restricted Cash	(k) Restricted Cash Restricted cash represents certificates of deposit held in the Company’s name with a major financial institution to secure the Company’s contingent obligations under irrevocable letters of credit issued to certain of its lessors.
Property and Equipment	(l) Property and Equipment Property and equipment are recorded at cost, less accumulated depreciation and amortization. Repairs and maintenance costs are expensed in the period incurred. Property and equipment is generally depreciated on a straight-line basis over the estimated useful lives of the assets as follows: Description Estimated Useful Life Furniture and fixtures 3-5 years Computer equipment and software 3-5 years Laboratory equipment 5 years Leasehold improvements are amortized over their estimated useful life or the related lease term, whichever is shorter.
Leases	(m) Leases At the inception of a lease, the Company evaluates the lease agreement to determine whether the lease is an operating, capital or build-to-suit lease using the criteria in ASC 840, “Leases.” Certain lease agreements also require the Company to make additional payments for taxes, insurance, and other operating expenses incurred during the lease period, which are expensed as incurred. Operating Leases For operating leases, the Company recognizes rent expense on a straight-line basis over the lease term and records the difference between cash rent payments and the recognition of rent expense as a deferred liability. Where lease agreements contain rent escalation clauses, rent abatements and/or concessions, such as rent holidays and tenant improvement allowances, the Company applies them in the determination of straight-line expense over the lease term. Capital Leases Capital leases are recorded as an asset within property and equipment, net and as an obligation at an amount equal to the present value of the minimum lease payments during the lease term. The asset is generally amortized over its estimated useful life or the related lease term, whichever is shorter. Lease payments under capital leases are recognized as a reduction of the capital lease obligation and interest expense. The Company currently does not have any capital leases. Build-to-Suit Leases In certain lease arrangements, the Company is involved in the construction of the building. To the extent the Company is involved with the structural improvements of the construction project or takes construction risk prior to the commencement of a lease, ASC 840-40, “Leases – Sale-Leaseback Transactions (Subsection 05-5),” requires the Company to be considered the owner for accounting purposes of these types of projects during the construction period. Therefore, the Company records an asset in property and equipment, net on the consolidated balance sheets, including capitalized interest costs, for the replacement cost of the Company’s portion of the pre-existing building plus the amount of estimated structural construction costs incurred by the landlord and the Company as of the balance sheet date. The Company records a corresponding build-to-suit lease obligation on its consolidated balance sheets representing the amounts paid by the lessor. Once construction is complete, the Company considers the requirements for sale-leaseback accounting treatment, including evaluating whether all risks of ownership have been transferred back to the landlord, as evidenced by a lack of continuing involvement in the leased property. If the arrangement does not qualify for sale-leaseback accounting treatment, the building asset remains on the Company’s consolidated balance sheets at its historical cost, and such asset is depreciated over its estimated useful life. The Company bifurcates its lease payments into a portion allocated to the building and a portion allocated to the parcel of land on which the building has been built. The portion of the lease payments allocated to the land is treated for accounting purposes as operating lease payments, and therefore is recorded as rent expense in the consolidated statements of operations. The portion of the lease payments allocated to the building is further bifurcated into a portion allocated to interest expense and a portion allocated to reduce the build-to-suit lease obligation. The interest rate used for the build-to-suit lease obligation represents the Company’s estimated incremental borrowing rate at inception of the lease, adjusted to reduce any built in loss. The initial recording of these assets and liabilities is classified as non-cash investing and financing items, respectively, for purposes of the consolidated statements of cash flows.
Business Combinations	(n) Business Combinations Business combinations are accounted for under the acquisition method of accounting. The purchase price, including the fair value of any contingent consideration, is allocated between tangible and intangible assets acquired and liabilities assumed from the acquired business based on their estimated fair values, with the residual of the purchase price recorded as goodwill. Transaction costs are expensed as incurred. Contingent Consideration The Company determines the fair value of contingent consideration payable at the acquisition date using a probability-based income approach utilizing an appropriate discount rate. Each reporting period thereafter, the Company re-measures the contingent consideration and records increases or decreases in their fair value as non-cash adjustments in the consolidated statements of operations. Changes in the fair value of contingent consideration payable can result from adjustments to the estimated probability and assumed timing of achieving the underlying milestones, as well as from changes to the discount rates and periods. In-Process Research and Development In-process research and development, or IPR&D, represents the fair value assigned to incomplete research projects that the Company acquires through business combinations which, at the time of acquisition, have not reached technological feasibility. The amounts are capitalized and accounted for as indefinite-lived intangible assets, subject to impairment testing until completion or abandonment of the projects. Upon successful completion of each project, the Company will make a determination as to the then useful life of the intangible asset, generally determined by the period in which the substantial majority of the cash flows are expected to be generated, and begin amortization over that period. The Company tests IPR&D for impairment at least annually, or more frequently if impairment indicators exist, by first assessing qualitative factors to determine whether it is more likely than not that the fair value of the IPR&D is less than its carrying amount. If the Company concludes it is more likely than not that the fair value is less than the carrying amount, a quantitative test that compares the fair value of the IPR&D with its carrying value is performed. If the fair value is less than the carrying amount, a non-cash impairment change is recognized in the consolidated statements of operations. Goodwill Goodwill represents the excess of the consideration transferred over the fair value of net assets of businesses acquired. Goodwill is assigned to reporting units and tested at least annually for impairment or when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable, on an enterprise level by assessing qualitative factors or performing a quantitative analysis in determining whether it is more likely than not that its fair value exceeds the carrying value. Examples of qualitative factors include the Company’s share price, its financial performance compared to budgets, long-term financial plans, macroeconomic, industry and market conditions as well as the substantial excess of fair value over the carrying value of net assets. If the carrying value of goodwill exceeds its implied fair value, the excess is recorded as a non-cash impairment charge in the consolidated statement of operations.
Convertible Notes	(o) Convertible Notes The debt and equity components of the Company’s Convertible Notes were bifurcated and accounted for separately based on the authoritative guidance in ASC 470-20, “Debt with Conversion and Other Options.” The debt component of the Convertible Notes, which excluded the associated equity conversion feature, was recorded at fair value on the issuance date. The equity component, representing the difference between the aggregate principal amount of the Convertible Notes and the fair value of the debt component, was recorded in additional paid-in capital on the consolidated balance sheet. The discounted carrying value of the Convertible Notes resulting from the bifurcation was subsequently accreted to its principal amount through the recognition of non-cash interest expense. Costs related to the issuance of the Convertible Notes, consisting primarily of investment banking, legal and other professional fees were allocated to the debt and equity components of the Company’s Convertible Notes in proportion to the allocation of the principal. Amounts allocated to the debt component were capitalized and amortized as non-cash interest expense using the effective yield method over the five-year contract term of the Convertible Notes. Amounts allocated to the equity component were recorded against additional paid-in capital. During the year ended December 31, 2015, all of the Company’s Convertible Notes were settled.
Fair Value of Financial Instruments	(p) Fair Value of Financial Instruments The estimated fair value of the Company’s cash equivalents is based on quoted market prices. The estimated fair value of contingent consideration is determined utilizing a model that considers the probability of achieving each milestone and an appropriate discount rate. The estimated fair value of the Company’s Convertible Notes was determined using recent trading prices of the Convertible Notes. Other financial instruments, including bank deposits, receivable from collaboration partner, accounts payable, accrued expenses, borrowings under the Revolving Credit Facility, and other current liabilities are carried at cost, which the Company believes approximates fair value because of the short-term maturities of these instruments.
Litigation	(q) Litigation The Company is party to legal proceedings, investigations, and claims in the ordinary course of its business. The Company records accruals for outstanding legal matters when it believes that it is both probable that a liability has been incurred and the amount of such liability can be reasonably estimated. The Company evaluates, on a quarterly basis, developments in significant legal matters that could affect the amount of any accrual and developments that would make a loss contingency both probable and reasonably estimable. To the extent new information is obtained and the Company’s views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in the Company’s accrued liabilities would be recorded in the period in which such determination is made. In addition, in accordance with the relevant authoritative guidance, for matters for which the likelihood of material loss is at least reasonably possible, the Company provides disclosure of the possible loss or range of loss; however, if a reasonable estimate cannot be made, the Company will provide disclosure to that effect. Gain contingencies, if any, are recorded when they are realized.
Income Taxes	(r) Income Taxes The Company accounts for income taxes using an asset and liability approach in accordance with the guidance provided by ASC 740-10, “Accounting for Income Taxes.” ASC 740-10 requires the recognition of taxes payable or refundable for the current year and deferred tax assets and liabilities for the future tax consequences of events that have been recognized in the consolidated financial statements or tax returns. The measurement of current and deferred tax assets and liabilities is based on provisions of the enacted tax law; the effects of future changes in tax laws or rates are not anticipated. The measurement of deferred tax assets is reduced, if necessary, by the amount of any tax benefits that, based on available evidence, is not expected to be realized. The Company records a valuation allowance to reduce its deferred tax assets to reflect the net amount that it believes is more likely than not to be realized. Realization of the deferred tax assets is dependent upon the generation of future taxable income, the amount and timing of which are uncertain. Based upon the weight of available evidence at December 31, 2014, the Company determined that it was more likely than not that a portion of its deferred tax assets would be realizable and consequently released the valuation allowance against Federal and certain state net deferred tax assets and recorded a discrete tax benefit of $33.4 million during the fourth quarter of 2014. The decision to reverse a portion of the valuation allowance was made after management considered all available evidence, both positive and negative, including but not limited to the Company’s historical operating results, income or loss in recent periods, cumulative income in recent years, forecasted earnings, forecasted future taxable income, and significant risk and uncertainty related to forecasts. The release of the valuation allowance resulted in the recognition of certain deferred tax assets and a decrease to income tax expense. Significant judgment in required in evaluating the Company’s uncertain income tax positions based on the guidance in ASC 740-10-25, “Accounting for Uncertainty in Income Taxes.” The Company recognizes a tax benefit from an uncertain tax position only if it is more likely than not that the position will be sustained upon examination by tax authorities. The tax benefit recognized in the financial statements on a particular tax position is measured on the largest benefit that is more likely than not to be realized. The Company evaluates uncertain tax positions on a quarterly basis and adjusts the liability for changes in facts and circumstances, such as new regulations or interpretations by the taxing authorities, new information obtained during a tax examination, significant amendment to an existing tax law, or resolution of an examination. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will impact the income tax provision in the period in which such determination is made. The resolution of the Company’s uncertain income tax positions is dependent on uncontrollable factors such as law changes, new case law, and the willingness of the income tax authorities to settle, including the timing thereof and other factors. Although The Company does not anticipate significant changes to its uncertain income tax positions in the next twelve months, items outside of the Company’s control could cause the uncertain income tax positions to change in the future, which would be recorded in the consolidated statements of operations. Interest and/or penalties related to income tax matters are recognized as a component of income tax expense as incurred.
New Accounting Pronouncements	(s) New Accounting Pronouncements In November 2015, the FASB issued Accounting Standards Update, or ASU, 2015-17, “Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes.” ASU 2015-17 requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. The amended guidance is effective for fiscal years beginning after December 15, 2016, including interim periods within that reporting period, and may be applied either prospectively to all deferred tax liabilities and assets or retrospectively to all periods presented. Earlier application is permitted for all entities as of the beginning of an interim or annual reporting period. The Company adopted the amended guidance prospectively as of October 1, 2015. Prior periods were not retrospectively adjusted. The adoption of ASU 2015-17 resulted in a reclassification of current deferred tax assets to non-current on the Company’s consolidated balance sheet as of December 31, 2015. See Note 13, “Income Taxes,” for additional information regarding the adoption of ASU 2015-17. In September 2015, the FASB issued ASU 2015-16, “Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments.” ASU 2015-16 requires that the acquirer recognize adjustments to provisional amounts recognized in a business combination that are identified during the measurement period in the reporting period in which the adjustment amounts are determined and record, in the same period’s financial statements, the effect on earnings of changes in depreciation, amortization, or other income effects, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date. The amended guidance eliminates the requirement to retrospectively account for adjustments made to provisional amounts during the measurement period. The amended guidance is effective for fiscal years beginning after December 15, 2015, including interim periods within that reporting period, and should be applied prospectively to provisional amounts that occur after the effective date. The Company does not currently expect that the adoption of ASU 2015-16 will have a material impact on its consolidated financial statements and related disclosures. In August 2015, the FASB issued ASU 2015-15, “Interest – Imputation of Interest (Subtopic 835-30): Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line of Credit Arrangements.” The amended guidance, which became effective immediately upon issuance, clarifies that entities are permitted to defer and present such debt issuance costs as an asset to be amortized ratably over the term of the line of credit arrangement, regardless of whether there are any outstanding borrowings on the line of credit arrangement. The adoption of ASU 2015-15 did not have a material impact on the Company’s consolidated financial statements and related disclosures. In April 2015, the FASB issued ASU 2015-03, “Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs,” which requires that debt issuance costs related to a recognized debt liability be presented on the balance sheet as a direct deduction from the carrying amount of the debt liability, consistent with debt discounts. The ASU requires retrospective adoption and is effective for fiscal years beginning after December 15, 2015, including interim periods within that reporting period. Early adoption is permitted. The Company does not currently expect that the adoption of ASU 2015-03 will have a material impact on its consolidated financial statements and related disclosures. In February 2015, the FASB issued ASU 2015-02, “Consolidation (Topic 820): Amendments to the Consolidation Analysis.” The amended guidance provides a revised consolidation model for all reporting entities to use in evaluating whether they should consolidate certain legal entities. All legal entities will be subject to reevaluation under this revised consolidation model. The revised consolidation model, among other things, (i) modifies the evaluation of whether limited partnerships and similar legal entities are voting interest entities, (ii) eliminates the presumption that a general partner should consolidate a limited partnership, and (iii) modifies the consolidation analysis of reporting entities that are involved with voting interest entities through fee arrangements and related party relationships. The amended guidance is effective for fiscal years beginning after December 15, 2015, including interim periods within that reporting period. The Company does not currently expect that the adoption of ASU 2015-02 will have a material impact on its consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” (Topic 606), a comprehensive new revenue recognition standard that will supersede the existing revenue recognition guidance. The new accounting guidance creates a framework by which an entity will allocate the transaction price to separate performance obligations and recognize revenue when (or as) each performance obligation is satisfied. Under the new standard, entities will be required to use judgment and make estimates, including identifying performance obligations in a contract, estimating the amount of variable consideration to include in the transaction price, allocating the transaction price to each separate performance obligation and determining when an entity satisfies its performance obligations. The standard allows for either “full retrospective” adoption, meaning that the standard is applied to all of the periods presented with a cumulative catch-up as of the earliest period presented, or “modified retrospective” adoption, meaning the standard is applied only to the most current period presented in the financial statements with a cumulative catch-up as of the current period. In August 2015, the effective date of the new revenue standard was delayed by one year to December 15, 2017 for annual reporting periods beginning after that date. The FASB also agreed to permit early adoption of the standard, but not before the original effective date of December 15, 2016. The Company has not yet selected a transition method and is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures.
Out-of-Period Adjustment	(t) Out-of-Period Adjustment In the first quarter of 2013, the Company recorded an out-of-period correcting adjustment that increased operating expenses and net loss by $3.6 million for the three months ended March 31, 2013. Management concluded that the adjustment is not material to the full year 2013 results or any previously reported financial statements.
Net Income (Loss) Per Common Share	The computation of basic net income (loss) per common share is based on the weighted-average number of common shares outstanding during each period. The computation of diluted net income (loss) per common share is based on the weighted-average number of common shares outstanding during the period plus, when their effect is dilutive, incremental shares consisting of shares subject to stock options, restricted stock units, stock appreciation rights, ESPP shares, warrants, and shares issuable upon conversion of convertible debt.
Fair Value Disclosures	The Company follows ASC 820-10, “Fair Value Measurements and Disclosures,” which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows: · Level 1—Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. · Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life. · Level 3—Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Unobservable inputs are used when little or no market data are available. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Estimated Useful Lives of Property and Equipment	Property and equipment is generally depreciated on a straight-line basis over the estimated useful lives of the assets as follows: Description Estimated Useful Life Furniture and fixtures 3-5 years Computer equipment and software 3-5 years Laboratory equipment 5 years

Collaboration Agreement (Tables

Collaboration Agreement (Tables)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Collaboration Revenue	Collaboration revenue was as follows: Years Ended December 31, 2015 2014 2013 Collaboration revenue: Related to U.S. XTANDI net sales $ 575,658 $ 339,902 $ 196,208 Related to ex-U.S. XTANDI net sales 119,778 49,476 6,338 Related to upfront and milestone payments 247,822 321,109 70,396 Total $ 943,258 $ 710,487 $ 272,942
Schedule of Collaboration Revenue Related to U.S. XTANDI Net Sales	Collaboration revenue related to U.S. XTANDI net sales was as follows: Years Ended December 31, 2015 2014 2013 U.S. XTANDI net sales (as reported by Astellas) $ 1,151,317 $ 679,805 $ 392,415 Shared U.S. development and commercialization costs (375,008 ) (323,730 ) (241,106 ) Pre-tax U.S. profit $ 776,309 $ 356,075 $ 151,309 Medivation’s share of pre-tax U.S. profit $ 388,154 $ 178,037 $ 75,655 Reimbursement of Medivation’s share of shared U.S. costs 187,504 161,865 120,553 Collaboration revenue related to U.S. XTANDI net sales $ 575,658 $ 339,902 $ 196,208
Schedule of Collaboration Revenue Related to Upfront and Milestone Payments	Collaboration revenue related to upfront and milestone payments from Astellas was as follows: Years Ended December 31, 2015 2014 2013 Sales milestones earned $ 245,000 $ 50,000 $ 25,000 Development milestones earned — 257,000 20,000 Amortization of deferred upfront and development milestones 2,822 14,109 25,396 Total $ 247,822 $ 321,109 $ 70,396

Business Acquisition (Tables)

Business Acquisition (Tables)	12 Months Ended
	Dec. 31, 2015
MDV3800 [Member]
Summary of Final Allocation of Purchase Consideration, Including Contingent Consideration Payable, Based on Fair Value	The following table presents the final allocation of the purchase consideration for the MDV3800 acquisition, including the contingent consideration payable, based on fair value: Purchase consideration: Cash $ 410,000 Acquisition-date fair value of contingent consideration 171,942 Total purchase consideration $ 581,942 Allocation of the purchase consideration: Assets: Identifiable intangible assets- IPR&D $ 573,299 Net identifiable assets acquired 573,299 Goodwill 8,643 Net assets acquired $ 581,942
Summary of Pro Forma Financial Information	The following unaudited pro forma financial information presents the combined results of operations of Medivation and MDV3800 as if the acquisition of MDV3800 had been completed on January 1, 2014, with adjustments to give effect to pro forma events that are directly attributable to the acquisition. The unaudited pro forma results do not reflect any operating efficiencies or potential cost savings which may result from the consolidation of the operations of Medivation and MDV3800. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Year Ended December 31, 2015 2014 Total revenues $ 943,258 $ 710,487 Net income $ 201,161 $ 230,271
MDV9300 [Member]
Summary of Final Allocation of Purchase Consideration, Including Contingent Consideration Payable, Based on Fair Value	The following table presents the final allocation of the purchase consideration for the MDV9300 acquisition, including the contingent consideration payable, based on fair value: Purchase consideration: Cash $ 5,000 Acquisition-date fair value of contingent consideration 106,000 Total purchase consideration $ 111,000 Allocation of the purchase consideration: Assets: Identifiable intangible assets- IPR&D $ 101,000 Net identifiable assets acquired 101,000 Goodwill 10,000 Net assets acquired $ 111,000
Summary of Pro Forma Financial Information	The following unaudited pro forma financial information presents the combined results of operations of Medivation and MDV9300 as if the acquisition of MDV9300 had been completed on January 1, 2013, with adjustments to give effect to pro forma events that are directly attributable to the acquisition. The unaudited pro forma results do not reflect any operating efficiencies or potential cost savings which may result from the consolidation of the operations of Medivation and MDV9300. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of what the actual results of operations of the combined company would have been if the acquisition had occurred at the beginning of the period presented, nor are they indicative of future results of operations: Year Ended December 31, 2014 2013 Total revenues $ 710,487 $ 272,942 Net income (loss) $ 274,626 $ (45,685 )

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Indefinite-lived Intangible Assets	The following table summarizes the Company’s indefinite-lived intangible assets: December 31, 2015 2014 Indefinite-lived intangible asset – MDV3800 $ 573,299 — Indefinite-lived intangible asset – MDV9300 71,000 101,000 Total $ 644,299 $ 101,000
Summary of Changes in the Carrying Amount of Goodwill	The following table summarizes the changes in the carrying amount of goodwill: Year Ended December 31, 2015 Goodwill: Balance at beginning of period $ 10,000 Goodwill at acquisition date – MDV3800 8,643 Balance at end of period $ 18,643

Net Income (Loss) Per Common 30

Net Income (Loss) Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Calculation of Diluted Net Income (Loss) Per Common Share	The following table reconciles the numerator and denominator used to calculate diluted net income (loss) per common share: Years Ended December 31, 2015 2014 2013 Numerator: Net income (loss) $ 244,725 $ 276,452 $ (42,613 ) Interest expense on convertible notes, net of tax 3,629 14,030 — Numerator for diluted net income (loss) per common share calculation $ 248,354 $ 290,482 $ (42,613 ) Denominator: Weighted-average common shares, basic 160,345 153,859 150,331 Dilutive effect of common stock equivalents 8,979 16,142 — Weighted-average common shares, diluted 169,324 170,001 150,331

Build-to-Suit Lease Obligation

Build-to-Suit Lease Obligation (Tables)	12 Months Ended
	Dec. 31, 2015
Leases [Abstract]
Schedule of Expected Reductions (Increases) in Build-to-Suit Lease Obligation	Expected reductions (increases) in the build-to-suit lease obligation are as follows: Years Ending December 31, Build-To-Suit Lease Obligation 2016 $ (8 ) 2017 58 2018 130 2019 208 2020 292 2021 and thereafter 16,726 Total $ 17,406

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net, consisted of the following: December 31, 2015 2014 Build-to-suit property $ 18,371 $ 19,544 Leasehold improvements 19,074 15,051 Computer equipment and software 16,083 9,499 Furniture and fixtures 5,714 4,667 Construction in progress 14,440 1,360 Laboratory equipment 748 735 74,430 50,856 Less: Accumulated depreciation (16,288 ) (9,695 ) Total $ 58,142 $ 41,161

Accounts Payable, Accrued Exp33

Accounts Payable, Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Payables And Accruals [Abstract]
Components of Accounts Payable, Accrued Expenses and Other Current Liabilities	Accounts payable, accrued expenses and other current liabilities consisted of the following: December 31, 2015 2014 Clinical and preclinical $ 48,975 $ 31,069 Taxes payable 32,565 2,106 Payroll and payroll-related 29,215 33,272 Accounts payable 22,696 10,492 Royalties payable 20,665 13,582 Other payable to licensor 17,500 5,000 Accrued professional services and other current liabilities 14,282 8,909 Interest payable 305 1,698 Total $ 186,203 $ 106,128

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Stock Option Activity	The following table summarizes stock option activity for the year ended December 31, 2015 Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value(1) (in millions) Outstanding at December 31, 2014 10,135,914 $ 16.76 Granted 1,822,724 $ 52.66 Exercised (1,446,047 ) $ 11.24 Forfeited/expired (404,422 ) $ 41.20 Outstanding at December 31, 2015 10,108,169 $ 23.05 6.01 $ 266.4 Vested and exercisable at December 31, 2015 7,043,757 $ 13.88 4.84 $ 242.9 (1) The aggregate intrinsic value is calculated as the pre-tax difference between the weighted-average exercise price of the underlying awards and the closing price per share of $48.34 of the Company’s common stock on December 31, 2015. The calculation excludes any awards with an exercise price higher than the closing price of the Company’s common stock on December 31, 2015.
Schedule of Value of Options Vested and Exercised	Additional information regarding stock options is set forth below (in thousands, except per share data): Years Ended December 31, 2015 2014 2013 Intrinsic value of options exercised $ 63,550 $ 145,842 $ 35,155 Grant-date fair value of options vested $ 26,542 $ 38,147 $ 22,278 Weighted-average grant-date fair value per share of options granted (split-adjusted) $ 25.08 $ 21.68 $ 15.20
Summary of Restricted Stock Units	The following table summarizes restricted stock unit activity for the year ended December 31, 2015 Number of Shares Weighted- Average Grant-Date Fair Value Unvested at December 31, 2014 967,160 $ 38.10 Granted 670,244 $ 52.34 Vested (404,906 ) $ 34.92 Forfeited (143,452 ) $ 45.45 Unvested at December 31, 2015 1,089,046 $ 47.08
Summary of Stock Appreciation Rights Activity	The following table summarizes stock appreciation rights activity for the year ended December 31, 2015 Number of Rights Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (1) (in millions) Outstanding at December 31, 2014 1,376,456 $ 12.03 Granted — — Exercised (61,172 ) $ 11.60 Forfeited (17,156 ) $ 11.60 Outstanding at December 31, 2015 1,298,128 $ 12.05 5.96 $ 47.1 Vested and exercisable at December 31, 2015 1,290,720 $ 12.05 5.96 $ 46.8 (1) The aggregate intrinsic value is calculated as the pre-tax difference between the weighted-average exercise price of the underlying awards and the closing price per share of $48.34 of the Company’s common stock on December 31, 2015. The calculation excludes any awards with an exercise price higher than the closing price of the Company’s common stock on December 31, 2015.
Schedule of Additional Information Regarding Stock Appreciation Rights	Additional information regarding stock appreciation rights is set forth below: Years Ended December 31, 2015 2014 2013 Intrinsic value of stock appreciation rights exercised $ 3,034 $ 7,024 $ 1,090 Fair value of stock appreciation rights vested (based on remeasurement-date fair value) $ 5,730 $ 6,834 $ 9,955
Schedule of Black-Scholes Assumptions Used for Stock Options	The Black-Scholes assumptions used to estimate the fair value of stock options granted were as follows: Years Ended December 31, 2015 2014 2013 Expected volatility 50-64% 60-65% 64-75% Expected term (in years) 4.98-7.17 5.0-5.5 5.2-5.5 Risk-free interest rate 1.33-1.77% 1.56-1.79% 0.73-1.64% Expected dividend yield — — —
Schedule of Black-Scholes Assumptions Used to Estimate Fair Value of Shares Issued under ESPP	The Black-Scholes assumptions used to estimate the fair value of shares issued under the ESPP on the commencement date of the offering period were as follows: Years Ended December 31, 2015 2014 2013 Expected volatility 37-48% 43-53% 45 % Expected term (in years) 0.5 0.5 0.5 Risk-free interest rate 0.08-0.12% 0.04-0.06% 0.04 % Expected dividend yield — — —
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense was as follows: Years Ended December 31, 2015 2014 2013 Stock-based compensation expense recognized as: R&D expenses $ 24,368 $ 17,913 $ 16,503 SG&A expenses 30,494 27,221 20,575 Total $ 54,862 $ 45,134 $ 37,078

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense	Income tax (expense) benefit for the periods presented consisted of the following: Years Ended December 31, 2015 2014 2013 Current: Federal $ (140,987 ) $ (19,476 ) $ (7 ) State (3,875 ) (1,496 ) (108 ) Total current (144,862 ) (20,972 ) (115 ) Deferred: Federal 8,179 36,917 — State 90 313 — Total deferred 8,269 37,230 — Total income tax (expense) benefit $ (136,593 ) $ 16,258 $ (115 )
Schedule of Reconciliation of Statutory Federal Income Tax Rate	A reconciliation of the statutory Federal income tax rate of 35% to the Company’s effective income tax rates is as follows: Years Ended December 31, 2015 2014 2013 Federal tax provision at statutory rate 35.0 % 35.0 % 35.0 % State taxes (net of Federal benefit) 0.6 % 0.4 % 1.4 % Stock-based compensation 0.1 % 0.1 % (0.2 %) Non-deductible officer compensation 0.2 % 0.1 % (1.8 %) Change in valuation allowance — (40.5 %) (52.1 %) Research and development credits (0.2 %) (1.5 %) 17.1 % Other 0.1 % 0.2 % 0.3 % Effective income tax rate 35.8 % (6.2 %) (0.3 %)
Schedule of Company's Deferred Tax Assets	Significant components of the Company’s deferred tax assets for Federal and state income taxes are follows: December 31, 2015 2014 Deferred tax assets: Deferred revenue $ — $ 1,005 Net operating loss carryforward 8,257 9,100 Stock-based compensation 35,482 26,000 Tax credits 8,076 12,098 Intangible assets 9,833 5,259 Accruals and reserves 19,156 15,247 Total deferred tax assets 80,804 68,709 Less: valuation allowance (16,827 ) (16,023 ) Total net deferred tax assets 63,977 52,686 Deferred tax liabilities Depreciation (3,168 ) (2,741 ) Convertible Notes — (12,792 ) Contingent consideration (3,798 ) — Total deferred tax liabilities (6,966 ) (15,533 ) Net deferred tax assets $ 57,011 $ 37,153 Recorded as: Net current deferred tax assets $ — $ 21,987 Net non-current deferred tax assets 57,011 15,176 Net non-current deferred tax liabilities (included in “Other non-current liabilities”) — (10 ) Net deferred tax assets $ 57,011 $ 37,153
Schedule of Gross Unrecognized Tax Positions	The following table summarizes activity related to the Company’s gross unrecognized tax positions: December 31, 2015 2014 2013 Balance as of beginning of year $ 12,367 $ 5,955 $ 4,602 Additions based on tax positions related to the current year 2,898 6,439 702 Additions based on tax position related to prior year 135 — 660 Decreases based on tax positions related to prior year (1,324 ) (27 ) (9 ) Balance as of end of year $ 14,076 $ 12,367 $ 5,955

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents the Company’s financial assets and liabilities that are measured at fair value on a recurring basis: Fair value measurements using: Fair Value Level 1 Level 2 Level 3 December 31, 2015: Current liabilities: Contingent consideration $ 4,900 — — $ 4,900 Long-term liabilities: Contingent consideration $ 262,368 — — $ 262,368 December 31, 2014: Cash equivalents: Money market funds $ 189,031 $ 189,031 — — Current liabilities: Contingent consideration $ 10,000 — — $ 10,000 Long-term liabilities: Contingent consideration $ 96,000 — — $ 96,000
Schedule of Roll-forward of Fair Value of Level 3 Instruments	The following table includes a roll-forward of the fair value of Level 3 financial instruments for the year ended December 31, 2015: Year Ended December 31, 2015 Contingent consideration (current and long-term): Balance at beginning of period $ 106,000 Amounts acquired or issued 171,942 Net change in fair value (10,674 ) Settlements — Transfers in and/or out of Level 3 — Balance at end of period $ 267,268
Fair Value of Other Financial Instruments Not Measured on Recurring Basis	The following table presents the total balance of the Company’s other financial instruments that are not measured at fair value on a recurring basis. Fair value measurements using: Total Balance Level 1 Level 2 Level 3 December 31, 2015: Assets: Bank deposits (included in “Cash and cash equivalents”) $ 225,853 $ 225,853 — — Liabilities: Borrowings under Revolving Credit Facility $ 75,000 $ 75,000 — — December 31, 2014: Assets: Bank deposits (included in “Cash and cash equivalents”) $ 313,646 $ 313,646 — — Liabilities: Convertible Notes $ 359,219 — $ 359,219 —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Operating Lease Obligations	Future operating lease obligations as of December 31, 2015, are as follows: Years Ending December 31, Operating Leases 2016 $ 9,343 2017 9,542 2018 9,743 2019 5,065 2020 — 2021 and thereafter — Total $ 33,693
Schedule of Future Lease Cash Payments under Build to Suit Lease	Expected future lease payments under the build-to-suit lease as of December 31, 2015 are as follows: Years Ending December 31, Expected Payments Under Build-To-Suit Lease Obligation 2016 $ 2,178 2017 2,244 2018 2,311 2019 2,380 2020 2,452 2021 and thereafter 9,627 Total minimum lease payments $ 21,192

Selected Quarterly Financial 38

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	The following table presents the unaudited quarterly results of operations of the Company for the years ended December 31, 2015 and 2014, respectively. The unaudited financial information is prepared on the same basis as the audited consolidated financial statements. The Company’s operating results for any quarter are not necessarily indicative of results for any future quarters or for a full year. All share and per share amounts have been retroactively adjusted to reflect the Company’s September 15, 2015, two-for-one forward stock split effected through a stock dividend. Quarters Ended March 31, June 30, September 30, December 31, 2015: Collaboration revenue $ 129,188 $ 175,657 $ 260,665 $ 377,748 Operating expenses $ (128,615 ) $ (122,002 ) $ (121,680 ) $ (156,348 ) Income from operations $ 573 $ 53,655 $ 138,985 $ 221,400 Net income (loss) $ (3,118 ) $ 25,826 $ 79,510 $ 142,507 Basic net income (loss) per common share $ (0.02 ) $ 0.16 $ 0.49 $ 0.87 Diluted net income (loss) per common share $ (0.02 ) $ 0.15 $ 0.47 $ 0.85 Weighted-average common shares used in the calculation of basic net income (loss) per common share 156,637 158,505 162,390 163,746 Weighted-average common shares used in the calculation of diluted net income (loss) per common share 156,637 168,690 168,070 168,368 2014: Collaboration revenue $ 87,189 $ 148,090 $ 200,478 $ 274,730 Operating expenses $ (95,654 ) $ (93,139 ) $ (108,595 ) $ (131,253 ) Income (loss) from operations $ (8,465 ) $ 54,951 $ 91,883 $ 143,477 Net income (loss) $ (13,665 ) $ 47,919 $ 77,993 $ 164,205 Basic net income (loss) per common share $ (0.09 ) $ 0.31 $ 0.51 $ 1.06 Diluted net income (loss) per common share $ (0.09 ) $ 0.30 $ 0.48 $ 0.98 Weighted-average common shares used in the calculation of basic net income (loss) per common share 152,489 153,153 154,112 155,644 Weighted-average common shares used in the calculation of diluted net income (loss) per common share 152,489 160,983 162,446 171,513

Description of Business - Addit

Description of Business - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Product
XTANDI [Member]
Organization And Description Of Business [Line Items]
Number of commercial products	1
Collaborative agreement [Member] | Astellas Pharma Inc. [Member]
Organization And Description Of Business [Line Items]
Range of percentage rates for royalties received on ex-U.S. net sales, as defined by collaboration agreement	Low teens to the low twenties

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Additional Information (Detail)	Sep. 15, 2015$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Mar. 31, 2013USD ($)	Dec. 31, 2009USD ($)	Dec. 31, 2015USD ($)SegmentReportingUnit$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)	Jun. 30, 2015USD ($)	Jun. 15, 2015shares
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Number of operating business segment | Segment					1
Shares of common stock authorized | shares		340,000,000			340,000,000	340,000,000
Stock split of common stock	2
Stock dividend, common stock shares issued | shares					81,700,000
Common stock, par value | $ / shares		$ 0.01			$ 0.01	$ 0.01
Repayment of convertible notes in cash					$ 258,742,000	$ 12,000
Deferred revenue		$ 2,822,000				2,822,000
Realized gains or losses from sales of available-for-sale securities						0	$ 0
Number of reporting unit | ReportingUnit					1
Contract term of the Convertible Notes, years					5 years
Discrete tax benefit		33,400,000
Out-of-period adjustment					In the first quarter of 2013, the Company recorded an out-of-period correcting adjustment that increased operating expenses and net loss by $3.6 million for the three months ended March 31, 2013. Management concluded that the adjustment is not material to the full year 2013 results or any previously reported financial statements.
Amount of net loss increased due to out-of-period adjustment			$ 3,600,000
Cash And Cash Equivalents
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Highly liquid investments maximum maturity period					3 months
Short-Term Investments [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Highly liquid investments maximum maturity period					12 months
Collaborative agreement [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Deferred revenue		$ 2,800,000			$ 0	$ 2,800,000
Astellas [Member] | Collaborative agreement [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Nonrefundable upfront payment received under collaboration arrangement				$ 110,000,000
Deferred revenue					$ 0
2.625% Convertible Senior Notes Due 2017 [Member] | Senior Notes [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Aggregate principal amount of convertible notes settled								$ 258,800,000
Debt instrument interest rate								2.625%
Debt instrument maturity date					Apr. 1, 2017
Repayment of convertible notes in cash					$ 259,900,000
Common stock, shares issued on redemption of convertible notes | shares					5,638,576
Common Stock [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Stock split of common stock	2				2
Common stock split, description					On September 15, 2015, the Company effected a two-for-one forward stock split of its common stock in the form of a stock dividend. Stockholders of record as of August 13, 2015 received one additional share of the Company’s common stock, par value $0.01, for each share they held as of the record date.
Stock dividend, common stock shares issued | shares	81,700,000
Common stock, par value | $ / shares	$ 0.01
Stock dividend, effective date of stock split					Sep. 15, 2015
Common stock dividend, record date					Aug. 13, 2015
Pre-Amended and Restated Certificate of Incorporation [Member] | Capital stock [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Shares of capital stock authorized | shares									171,000,000
Pre-Amended and Restated Certificate of Incorporation [Member] | Common Stock [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Shares of common stock authorized | shares									170,000,000
Post-Amended and Restated Certificate of Incorporation [Member] | Capital stock [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Shares of capital stock authorized | shares									341,000,000
Post-Amended and Restated Certificate of Incorporation [Member] | Common Stock [Member]
Schedule Of Summary Of Significant Accounting Policies [Line Items]
Shares of common stock authorized | shares									340,000,000

Summary of Significant Accoun41

Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2015
Furniture and fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Estimated Useful Life, years	3 years
Furniture and fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Estimated Useful Life, years	5 years
Computer equipment and software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Estimated Useful Life, years	3 years
Computer equipment and software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Estimated Useful Life, years	5 years
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Estimated Useful Life, years	5 years

Collaboration Agreement - Colla

Collaboration Agreement - Collaboration Agreements with Astellas - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2015
Collaborative agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Co-promotion of sales and medical affairs percentage		50.00%
Astellas Pharma Inc. [Member] | Up-front cash payment arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable, upfront cash payment	$ 110,000,000
Astellas Pharma Inc. [Member] | Development milestone payments [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Eligible to receive milestone payments		$ 335,000,000
Astellas Pharma Inc. [Member] | Sales milestone payments [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Eligible to receive milestone payments		$ 320,000,000
Astellas Pharma Inc. [Member] | Collaborative agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Range of percentage rates for royalties received on ex-U.S. net sales, as defined by collaboration agreement		Low teens to the low twenties

Collaboration Agreement - Sched

Collaboration Agreement - Schedule of Collaboration Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	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
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue	$ 377,748	$ 260,665	$ 175,657	$ 129,188	$ 274,730	$ 200,478	$ 148,090	$ 87,189	$ 943,258	$ 710,487	$ 272,942
Collaborative agreement [Member] | XTANDI [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Related to upfront and milestone payments									247,822	321,109	70,396
Collaboration revenue									943,258	710,487	272,942
Collaborative agreement [Member] | U.S. [Member] | XTANDI [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Related to XTANDI net sales									575,658	339,902	196,208
Collaborative agreement [Member] | ex-U.S. [Member] | XTANDI [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Related to XTANDI net sales									$ 119,778	$ 49,476	$ 6,338

Collaboration Agreement - Col44

Collaboration Agreement - Collaboration Revenue and Collaboration Receivables - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of sublicensing income	10.00%
Collaboration revenue percentage of U.S. XTANDI net sales	50.00%	50.00%	50.00%
Deferred revenue, Current		$ 2,822,000
Collaboration receivable	$ 391,558,000	184,737,000
Collaborative agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue, Current	0	2,800,000
Collaboration receivable	391,600,000	184,700,000
Collaborative agreement [Member] | Development and sales milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development and sales milestone earned	245,000,000	307,000,000	$ 45,000,000
Astellas Pharma Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development cost-sharing payments	60,800,000	63,500,000	46,600,000
Commercialization cost-sharing payments	$ 37,500,000	$ 36,100,000	$ 12,000,000
Development cost-sharing payments [Member] | Collaborative agreement [Member] | Medivation Inc [Member] | U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	50.00%
Development cost-sharing payments [Member] | Collaborative agreement [Member] | Medivation Inc [Member] | ex-U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	33.33%
Commercial cost sharing-payments [Member] | Astellas Pharma Inc. [Member] | Collaborative agreement [Member] | U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	50.00%
Commercial cost sharing-payments [Member] | Astellas Pharma Inc. [Member] | Collaborative agreement [Member] | ex-U.S. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Share of XTANDI development and commercialization costs	66.67%

Collaboration Agreement - Sch45

Collaboration Agreement - Schedule of Collaboration Revenue Related to U.S. XTANDI Net Sales (Detail) - U.S. [Member] - XTANDI [Member] - Collaborative agreement [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue related to U.S. XTANDI net sales	$ 575,658	$ 339,902	$ 196,208
Astellas Pharma Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
U.S. XTANDI net sales (as reported by Astellas)	1,151,317	679,805	392,415
Shared U.S. development and commercialization costs	(375,008)	(323,730)	(241,106)
Pre-tax U.S. profit	776,309	356,075	151,309
Medivation [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Medivation’s share of pre-tax U.S. profit	388,154	178,037	75,655
Reimbursement of Medivation’s share of shared U.S. costs	$ 187,504	$ 161,865	$ 120,553

Collaboration Agreement - Sch46

Collaboration Agreement - Schedule of Collaboration Revenue Related to Upfront and Milestone Payments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amortization of deferred upfront and development milestones	$ 2,822	$ 14,109	$ 25,396
Astellas Pharma Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total collaboration revenue attributable to upfront and milestone payments	247,822	321,109	70,396
Astellas Pharma Inc. [Member] | Sales milestones earned [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development and sales milestone earned	245,000	50,000	25,000
Astellas Pharma Inc. [Member] | Development milestones earned [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Development and sales milestone earned		257,000	20,000
Astellas Pharma Inc. [Member] | Amortization of deferred upfront and development milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Amortization of deferred upfront and development milestones	$ 2,822	$ 14,109	$ 25,396

Business Acquisition - Addition

Business Acquisition - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
Business Acquisition [Line Items]
Business combination, goodwill	$ 18,643	$ 10,000	$ 18,643
MDV3800 [Member]
Business Acquisition [Line Items]
Business acquisition upfront cash payments	410,000		410,000
Acquisition-date fair value of contingent consideration payments	171,942		171,942
Business combination, identifiable intangible asset	573,299		573,299
Business combination, goodwill	8,643		8,643
Business combination, Goodwill expected to be deductible for tax purposes	8,600		8,600
MDV9300 [Member]
Business Acquisition [Line Items]
Business acquisition upfront cash payments		5,000	5,000
Acquisition-date fair value of contingent consideration payments	106,000	$ 106,000	106,000
Business combination, identifiable intangible asset	101,000		101,000
Business combination, goodwill	10,000		10,000
Business combination, Goodwill expected to be deductible for tax purposes	$ 10,000		10,000
Milestone payment			$ 5,000
MDV9300 [Member] | Minimum [Member]
Business Acquisition [Line Items]
Percentage of royalty	5.00%		5.00%
MDV9300 [Member] | Maximum [Member]
Business Acquisition [Line Items]
Percentage of royalty	11.00%		11.00%
Defined Regulatory and Sales-Based Milestones [Member] | MDV3800 [Member]
Business Acquisition [Line Items]
Business acquisition maximum contingent consideration	$ 160,000		$ 160,000
Sales Milestones [Member] | MDV9300 [Member]
Business Acquisition [Line Items]
Business acquisition maximum contingent consideration	245,000		245,000
Development Milestones [Member] | MDV9300 [Member]
Business Acquisition [Line Items]
Business acquisition maximum contingent consideration	$ 85,000		$ 85,000

Business Acquisition - Summary

Business Acquisition - Summary of Final Allocation of Purchase Consideration, Including Contingent Consideration Payable, Based on Fair Value (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
Assets:
Goodwill	$ 18,643	$ 10,000	$ 18,643
MDV3800 [Member]
Purchase consideration:
Cash	410,000		410,000
Acquisition-date fair value of contingent consideration	171,942		171,942
Total purchase consideration			581,942
Assets:
Identifiable intangible assets- IPR&D	573,299		573,299
Net identifiable assets acquired	573,299		573,299
Goodwill	8,643		8,643
Net assets acquired	581,942		581,942
MDV9300 [Member]
Purchase consideration:
Cash		5,000	5,000
Acquisition-date fair value of contingent consideration	106,000	$ 106,000	106,000
Total purchase consideration			111,000
Assets:
Identifiable intangible assets- IPR&D	101,000		101,000
Net identifiable assets acquired	101,000		101,000
Goodwill	10,000		10,000
Net assets acquired	$ 111,000		$ 111,000

Business Acquisition - Summar49

Business Acquisition - Summary of Pro Forma Financial Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
MDV3800 [Member]
Business Acquisition [Line Items]
Total revenues	$ 943,258	$ 710,487
Net income (loss)	$ 201,161	230,271
MDV9300 [Member]
Business Acquisition [Line Items]
Total revenues		710,487	$ 272,942
Net income (loss)		$ 274,626	$ (45,685)

Intangible Assets and Goodwil50

Intangible Assets and Goodwill - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015
Acquired Indefinite Lived Intangible Assets [Line Items]
Impairment charges		$ 30,000
MDV9300 [Member]
Acquired Indefinite Lived Intangible Assets [Line Items]
Impairment charges	$ 30,000

Intangible Assets and Goodwil51

Intangible Assets and Goodwill - Summary of Indefinite-lived Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Acquired Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible asset	$ 644,299	$ 101,000
MDV3800 [Member]
Acquired Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible asset	573,299
MDV9300 [Member]
Acquired Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible asset	$ 71,000	$ 101,000

Intangible Assets and Goodwil52

Intangible Assets and Goodwill - Summary of Changes in the Carrying Amount of Goodwill (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Goodwill:
Beginning Balance	$ 10,000
Ending Balance	18,643
MDV3800 [Member]
Goodwill:
Goodwill at acquisition date	8,643
Ending Balance	$ 8,643

Net Income (Loss) Per Common 53

Net Income (Loss) Per Common Share - Additional Information (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Calculation of diluted net income per common share includes contingently issuable shares related to convertible notes	3.9	10.1
Dilutive common shares excluded from net loss per common share computations	1.4	1.3	25.1

Net Income (Loss) Per Common 54

Net Income (Loss) Per Common Share - Calculation of Diluted Net Income (Loss) Per Common Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	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
Numerator:
Net income (loss)	$ 142,507	$ 79,510	$ 25,826	$ (3,118)	$ 164,205	$ 77,993	$ 47,919	$ (13,665)	$ 244,725	$ 276,452	$ (42,613)
Interest expense on convertible notes, net of tax									3,629	14,030
Numerator for diluted net income (loss) per common share calculation									$ 248,354	$ 290,482	$ (42,613)
Denominator:
Weighted-average common shares used in the calculation of basic net income (loss) per common share	163,746	162,390	158,505	156,637	155,644	154,112	153,153	152,489	160,345	153,859	150,331
Dilutive effect of common stock equivalents									8,979	16,142
Weighted-average common shares, diluted	168,368	168,070	168,690	156,637	171,513	162,446	160,983	152,489	169,324	170,001	150,331

Build-to-Suit Lease Obligatio55

Build-to-Suit Lease Obligation - Additional Information (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)ft²	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)	Dec. 31, 2013ft²
Build To Suit Lease Obligation [Line Items]
Build to suit lease | ft²		158,000
Amounts capitalized under build-to-suit lease transactions		$ 44	$ 18,085
Area of property surrendered | ft²		8,000
Derecognized portion of build-to-suit asset	$ 3,200	$ 3,241
Derecognized portion of build-to-suit lease obligation	$ 3,200	3,176
Build-to-suit lease obligation non-current liability		$ 17,406	$ 18,711
Laboratory Space [Member]
Build To Suit Lease Obligation [Line Items]
Build to suit lease | ft²	44,000			52,000
Lease expiry period		August 2,024
Build to suit lease extension term	5 years
Build-to-suit Lease Property and Equipment [Member]
Build To Suit Lease Obligation [Line Items]
Amounts capitalized under build-to-suit lease transactions		$ 14,500
Tenant Improvements [Member]
Build To Suit Lease Obligation [Line Items]
Amounts capitalized under build-to-suit lease transactions		3,600
Capitalized Interest Cost [Member]
Build To Suit Lease Obligation [Line Items]
Amounts capitalized under build-to-suit lease transactions		$ 3,500

Build-to-Suit Lease Obligatio56

Build-to-Suit Lease Obligation - Schedule of Expected Reductions (Increases) in Build-to-Suit Lease Obligation (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Leases [Abstract]
Build-to-Suit Lease Obligation, 2016	$ (8)
Build-to-Suit Lease Obligation, 2017	58
Build-to-Suit Lease Obligation, 2018	130
Build-to-Suit Lease Obligation, 2019	208
Build-to-Suit Lease Obligation, 2020	292
Build-to-Suit Lease Obligation, 2021 and thereafter	16,726
Total minimum payments	$ 17,406

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 74,430	$ 50,856
Less: Accumulated depreciation	(16,288)	(9,695)
Total	58,142	41,161
Build-to-suit property [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	18,371	19,544
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	19,074	15,051
Computer equipment and software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	16,083	9,499
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,714	4,667
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	14,440	1,360
Laboratory equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 748	$ 735

Accounts Payable, Accrued Exp58

Accounts Payable, Accrued Expenses and Other Current Liabilities - Components of Accounts Payable, Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Clinical and preclinical	$ 48,975	$ 31,069
Taxes payable	32,565	2,106
Payroll and payroll-related	29,215	33,272
Accounts payable	22,696	10,492
Royalties payable	20,665	13,582
Other payable to licensor	17,500	5,000
Accrued professional services and other current liabilities	14,282	8,909
Interest payable	305	1,698
Total	$ 186,203	$ 106,128

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Jan. 25, 2016	Oct. 23, 2015	Sep. 17, 2015	Sep. 04, 2015	Dec. 31, 2015	Dec. 31, 2014	Mar. 19, 2012
Debt Instrument [Line Items]
Debt instrument term					5 years
Proceeds from borrowings under Revolving Credit Facility					$ 150,000,000
Line of credit facility, interest rate description					The interest rate for this borrowing was 2.1250% and was applied on an actual/360 day basis.
Repayment of outstanding credit facility					$ 75,000,000
Debt issuance costs					1,715,000
Principal settlement amount					258,742,000	$ 12,000
Non-cash loss on extinguishment of Convertible Notes					$ 21,087,000
Convertible Notes Due 2017 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Convertible Notes, aggregate principal amount							$ 258,800,000
Convertible Notes, payment terms					The Company was required to pay interest semi-annually in arrears on April 1 and October 1 of each year, at a rate of 2.625% per annum.
Aggregate principal amount of convertible notes settled					$ 258,800,000
Principal settlement amount					$ 259,900,000
Common stock, shares issued on redemption of convertible notes					5,638,576
Non-cash loss on extinguishment of Convertible Notes					$ 21,100,000
Forfeited accrued interest payable reclassified to additional paid-in capital					$ 1,700,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument term		5 years		1 year	5 years
Line of credit facility, maximum borrowing capacity		$ 300,000,000		$ 75,000,000
Proceeds from borrowings under Revolving Credit Facility		$ 75,000,000	$ 75,000,000
Line of credit facility, interest rate		2.125%	2.3125%
Line of credit facility, interest rate description					The interest rate for this borrowing was 2.3125% and was applied on an actual/360 day basis.
Repayment of outstanding credit facility		$ 75,000,000
Interest rate spread on base rate, description					(a) the LIBOR rate, plus an applicable margin ranging from 1.75% to 2.50% per annum, based upon the secured leverage ratio (as defined in the Credit Agreement) or (b) the prime lending rate, plus an applicable margin ranging from 0.75% to 1.50% per annum, based upon the senior secured net leverage ratio (as defined in the Credit Agreement).
Debt issuance costs					$ 1,700,000
Revolving Credit Facility [Member] | LIBOR [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate				1.75%
Revolving Credit Facility [Member] | LIBOR [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate				2.50%
Revolving Credit Facility [Member] | Prime Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate				0.75%
Revolving Credit Facility [Member] | Prime Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Interest rate spread on base rate				1.50%
Revolving Credit Facility [Member] | Subsequent Event
Debt Instrument [Line Items]
Repayment of outstanding credit facility	$ 75,000,000
Revolving Credit Facility [Member] | Multicurrency Sub-facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		50,000,000		$ 20,000,000
Revolving Credit Facility [Member] | Letter of Credit Sub-Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		20,000,000		10,000,000
Revolving Credit Facility [Member] | Swing Line Loan Sub-facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 10,000,000		$ 100,000
Credit Agreement [Member]
Debt Instrument [Line Items]
Obligations under credit agreement, description					(i) all tangible and intangible assets of the Loan Parties, except for certain customary excluded assets, and (ii) all of the capital stock owned by the Loan Parties thereunder (limited, in the case of the stock of certain non-U.S. subsidiaries of the Company and Domestic Foreign Holding Companies, to 65% of the capital stock of such subsidiaries).
Percentage of capital stock					65.00%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	Sep. 15, 2015shares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)$ / sharesshares	Sep. 14, 2015shares	Jun. 16, 2015shares	Mar. 31, 2015shares	Dec. 04, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage before exercise								20.00%
Stock split of common stock	2
Number of shares available for issuance		8,700,000
Total fair value of restricted stock units vested | $		$ 14,100,000	$ 7,000,000	$ 11,800,000
Employees share purchase plan, fair market value of common stock at beginning of offering period		85.00%
Employees share purchase plan, fair market value of common stock at end of purchase period		85.00%
Eligible employee purchases | $		$ 25,000
Shares reserved for issuance		97,662
Shares issued in period		312,086
Employee withholdings for ESPP shares | $		$ 1,700,000
Expected dividend yield		0.00%
Unrecognized stock-based compensation expense | $		$ 87,200,000
Unrecognized stock-based compensation expense, weighted-average period for recognition		2 years 6 months
Warrants to purchase aggregate shares of common stock, Exercised				51,616
Common stock, Exercise price per share | $ / shares				$ 0.39
Warrants to purchase aggregate shares of common stock, Outstanding		40,000
Common stock, Exercise price per share, Outstanding | $ / shares		$ 3.47
Warrants expiration date		2,017
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payments award, expiration term		10 years
Share-based payment awards, vesting period		4 years
Stock options granted		0	0	0
Stock appreciation rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of restricted stock units vested | $		$ 5,730,000	$ 6,834,000	$ 9,955,000
Stock appreciation rights granted		0	0	0
Annual non-employee directors grants [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment awards, vesting period		1 year
Annual non-employee directors grants [Member] | Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment awards, vesting period, descriptions		Restricted stock units generally vest in three equal installments on approximately the first, second and third anniversaries of the grant date, except for annual restricted stock unit grants to non-employee directors, which vest on approximately the first anniversary of the grant date.
Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance	47,700,000					23,850,000	21,150,000
Stock split of common stock	2
Equity Incentive Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		1,822,724
Equity Incentive Plan [Member] | Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock appreciation rights granted		670,244
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance	6,000,000				3,000,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity (Detail) - Stock options [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Granted	0	0	0
Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding at December 31, 2014	10,135,914
Number of Options, Granted	1,822,724
Number of Options, Exercised	(1,446,047)
Number of Options, Forfeited/expired	(404,422)
Number of Options, Outstanding at December 31, 2015	10,108,169	10,135,914
Number of Options, Vested and exercisable at December 31, 2015	7,043,757
Weighted Average Exercise Price, Outstanding at December 31, 2014	$ 16.76
Weighted Average Exercise Price, Granted	52.66
Weighted Average Exercise Price, Exercised	11.24
Weighted Average Exercise Price, Forfeited/expired	41.20
Outstanding at December 31, 2015	23.05	$ 16.76
Vested and exercisable at December 31, 2015	$ 13.88
Weighted Average Remaining Contractual Term (in years), Outstanding at December 31, 2015	6 years 4 days
Weighted Average Remaining Contractual Term (in years), Vested and exercisable at December 31, 2015	4 years 10 months 2 days
Aggregate Intrinsic Value, Outstanding at December 31, 2015	$ 266.4
Aggregate Intrinsic Value, Vested and exercisable at December 31, 2015	$ 242.9

Stockholders' Equity - Summar62

Stockholders' Equity - Summary of Stock Option Activity (Parenthetical) (Detail)	Dec. 31, 2015$ / shares
Equity Incentive Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing stock price of common stock	$ 48.34

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Value of Options Vested and Exercised (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stockholders Equity Note [Abstract]
Intrinsic value of options exercised	$ 63,550	$ 145,842	$ 35,155
Grant-date fair value of options vested	$ 26,542	$ 38,147	$ 22,278
Weighted-average grant-date fair value per share of options granted (split-adjusted)	$ 25.08	$ 21.68	$ 15.20

Stockholders' Equity - Summar64

Stockholders' Equity - Summary of Restricted Stock Units (Detail) - Equity Incentive Plan [Member] - Restricted stock units [Member]	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Unvested at December 31, 2014 | shares	967,160
Number of Shares, Granted | shares	670,244
Number of Shares, Vested | shares	(404,906)
Number of Shares, Forfeited | shares	(143,452)
Number of Shares, Unvested at December 31, 2015 | shares	1,089,046
Weighted-Average Grant-Date Fair Value, Unvested at December 31, 2014 | $ / shares	$ 38.10
Weighted-Average Grant-Date Fair Value, Granted | $ / shares	52.34
Weighted-Average Grant-Date Fair Value, Vested | $ / shares	34.92
Weighted-Average Grant-Date Fair Value, Forfeited | $ / shares	45.45
Weighted-Average Grant-Date Fair Value, Unvested at December 31, 2015 | $ / shares	$ 47.08

Stockholders' Equity - Summar65

Stockholders' Equity - Summary of Stock Appreciation Rights Activity (Detail) - Stock appreciation rights [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock appreciation rights, Granted	0	0	0
Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock appreciation rights, Outstanding at December 31, 2014	1,376,456
Number of stock appreciation rights, Exercised	(61,172)
Number of stock appreciation rights, Forfeited	(17,156)
Number of stock appreciation rights, Outstanding at December 31, 2015	1,298,128	1,376,456
Number of stock appreciation rights, Vested and exercisable at December 31, 2015	1,290,720
Weighted Average Exercise Price, Outstanding at December 31, 2014	$ 12.03
Weighted Average Exercise Price, Exercised	11.60
Weighted Average Exercise Price, Forfeited	11.60
Weighted Average Exercise Price, Outstanding at December 31, 2015	12.05	$ 12.03
Weighted Average Exercise Price, Vested and exercisable at December 31, 2015	$ 12.05
Weighted Average Remaining Contractual Term (in years), Outstanding at December 31, 2015	5 years 11 months 16 days
Weighted Average Remaining Contractual Term (in years), Vested and exercisable at December 31, 2015	5 years 11 months 16 days
Aggregate Intrinsic Value, Outstanding at December 31, 2015	$ 47.1
Aggregate Intrinsic Value, Vested and exercisable at December 31, 2015	$ 46.8

Stockholders' Equity - Summar66

Stockholders' Equity - Summary of Stock Appreciation Rights Activity (Parenthetical) (Detail)	Dec. 31, 2015$ / shares
Equity Incentive Plan [Member] | Stock appreciation rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing stock price of common stock	$ 48.34

Stockholders' Equity - Schedu67

Stockholders' Equity - Schedule of Additional Information Regarding Stock Appreciation Rights (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]
Fair value of stock appreciation rights vested (based on remeasurement-date fair value)	$ 14,100	$ 7,000	$ 11,800
Stock appreciation rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of stock appreciation rights exercised	3,034	7,024	1,090
Fair value of stock appreciation rights vested (based on remeasurement-date fair value)	$ 5,730	$ 6,834	$ 9,955

Stockholders' Equity - Schedu68

Stockholders' Equity - Schedule of Black-Scholes Assumptions Used for Stock Options (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%
Equity Incentive Plan [Member] | Stock options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	50.00%	60.00%	64.00%
Expected term (in years)	4 years 11 months 23 days	5 years	5 years 2 months 12 days
Risk-free interest rate	1.33%	1.56%	0.73%
Equity Incentive Plan [Member] | Stock options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	64.00%	65.00%	75.00%
Expected term (in years)	7 years 2 months 1 day	5 years 6 months	5 years 6 months
Risk-free interest rate	1.77%	1.79%	1.64%

Stockholders' Equity - Schedu69

Stockholders' Equity - Schedule of Black-Scholes Assumptions Used to Estimate Fair Value of Shares Issued under ESPP (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			45.00%
Expected term (in years)	6 months	6 months	6 months
Risk-free interest rate			0.04%
ESPP [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	37.00%	43.00%
Risk-free interest rate	0.08%	0.04%
ESPP [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	48.00%	53.00%
Risk-free interest rate	0.12%	0.06%

Stockholders' Equity - Schedu70

Stockholders' Equity - Schedule of Stock-Based Compensation Expense (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, Compensation Cost [Line Items]
Share-based compensation	$ 54,862	$ 45,134	$ 37,078
R&D expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	24,368	17,913	16,503
SG&A expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 30,494	$ 27,221	$ 20,575

Retirement Plan - Additional In

Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Maximum defined contribution plan employees contributions, percentage	100.00%
Percentage of participant contributions considered for first condition of plan	100.00%
Description of percentage of employees eligible earnings subject to match	The Company matches 100% of the first 3% of employee contributions and 50% of the next 2% of employee contributions.
Percentage of participant salary under first condition of plan	3.00%
Percentage of participant contributions considered for second condition of plan	50.00%
Percentage of participant salary under second condition of plan	2.00%
Employer matching contributions to the plan	$ 3.5	$ 2.7	$ 1.9

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Income (loss) before income tax (expense)		$ 381,318	$ 260,194	$ (42,498)
Excess tax benefits from stock-based compensation		100,243	$ 16,965
Tax impact of extinguishment of Convertible Notes		11,847
Unrecorded excess stock-based compensation tax benefits		$ 3,400
Federal tax provision at statutory rate		35.00%	35.00%	35.00%
Income tax (expense) benefit		$ (136,593)	$ 16,258	$ (115)
Valuation allowance increased (decreased)		800	(104,800)	$ 22,100
Release of valuation allowance for deferred income taxes	$ 33,400		$ 33,403
Gross unrecognized tax that would decrease effective tax rate, if recognized		7,700
California credit carryforwards [Member]
Income Taxes [Line Items]
Research and development credit and orphan drug credit		16,600
Federal [Member]
Income Taxes [Line Items]
Operating loss carryforwards		0
State [Member]
Income Taxes [Line Items]
Operating loss carryforwards		$ 216,300
Operating loss carryforwards, expiration dates		at various dates between the years 2017 and 2033

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current Federal	$ (140,987)	$ (19,476)	$ (7)
Current State	(3,875)	(1,496)	(108)
Total current	(144,862)	(20,972)	(115)
Deferred Federal	8,179	36,917
Deferred State	90	313
Total deferred	8,269	37,230
Total income tax (expense) benefit	$ (136,593)	$ 16,258	$ (115)

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
Federal tax provision at statutory rate	35.00%	35.00%	35.00%
State taxes (net of Federal benefit)	0.60%	0.40%	1.40%
Stock-based compensation	0.10%	0.10%	(0.20%)
Non-deductible officer compensation	0.20%	0.10%	(1.80%)
Change in valuation allowance		(40.50%)	(52.10%)
Research and development credits	(0.20%)	(1.50%)	17.10%
Other	0.10%	0.20%	0.30%
Effective income tax rate	35.80%	(6.20%)	(0.30%)

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Company's Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Components Of Deferred Tax Assets And Liabilities [Abstract]
Deferred revenue		$ 1,005
Net operating loss carryforward	$ 8,257	9,100
Stock-based compensation	35,482	26,000
Tax credits	8,076	12,098
Intangible assets	9,833	5,259
Accruals and reserves	19,156	15,247
Total deferred tax assets	80,804	68,709
Less: valuation allowance	(16,827)	(16,023)
Total net deferred tax assets	63,977	52,686
Depreciation	(3,168)	(2,741)
Convertible Notes		(12,792)
Contingent consideration	(3,798)
Total deferred tax liabilities	(6,966)	(15,533)
Net deferred tax assets	57,011	37,153
Net current deferred tax assets		21,987
Net non-current deferred tax assets	$ 57,011	15,176
Net non-current deferred tax liabilities (included in “Other non-current liabilities”)		$ (10)

Income Taxes - Schedule of Gros

Income Taxes - Schedule of Gross Unrecognized Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance as of beginning of year	$ 12,367	$ 5,955	$ 4,602
Additions based on tax positions related to the current year	2,898	6,439	702
Additions based on tax position related to prior year	135		660
Decreases based on tax positions related to prior year	(1,324)	(27)	(9)
Balance as of end of year	$ 14,076	$ 12,367	$ 5,955

Fair Value Disclosures - Financ

Fair Value Disclosures - Financial 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]
Contingent consideration, current liabilities	$ 4,900	$ 10,000
Contingent consideration, long-term liabilities	262,368	96,000
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, current liabilities	4,900	10,000
Contingent consideration, long-term liabilities	262,368	96,000
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration, current liabilities	4,900	10,000
Contingent consideration, long-term liabilities	$ 262,368	96,000
Money market funds [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		189,031
Money market funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		$ 189,031

Fair Value Disclosures - Additi

Fair Value Disclosures - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Change in fair value of contingent consideration liability	$ (10,674,000)
Fair value of liabilities transferred from Level 1 to Level 2	0
Fair value of liabilities transferred from Level 2 to Level 1	0
Fair value of assets transferred from Level 1 to Level 2	0
Fair value of assets transferred from Level 2 to Level 1	0
Fair value, measurements, nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated fair value of the debt		$ 496,800,000
R&D expense [Member] | MDV9300 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Change in fair value of contingent consideration liability	2,600,000
SG&A expense [Member] | MDV9300 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Change in fair value of contingent consideration liability	$ 7,700,000

Fair Value Disclosures - Schedu

Fair Value Disclosures - Schedule of Roll-forward of Fair Value of Level 3 Instruments (Detail) - Level 3 [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 106,000
Amounts acquired or issued	171,942
Net change in fair value	(10,674)
Settlements	0
Transfers in and/or out of Level 3	0
Balance at end of period	$ 267,268

Fair Value Disclosures - Fair V

Fair Value Disclosures - Fair Value of Other Financial Instruments Not Measured 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]
Convertible Notes		$ 222,140
Fair value, measurements, nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bank deposits (included in “Cash and cash equivalents”)	$ 225,853	313,646
Fair value, measurements, nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Notes		359,219
Fair value, measurements, nonrecurring [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bank deposits (included in “Cash and cash equivalents”)	225,853	313,646
Convertible Notes		$ 359,219
Revolving Credit Facility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Borrowings under Revolving Credit Facility	75,000
Revolving Credit Facility [Member] | Fair value, measurements, nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Borrowings under Revolving Credit Facility	75,000
Revolving Credit Facility [Member] | Fair value, measurements, nonrecurring [Member] | Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Borrowings under Revolving Credit Facility	$ 75,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended			12 Months Ended
	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)ft²	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Commitments And Contingencies [Line Items]
Operating lease office space, in square feet | ft²				158,000
Lease expiry period				2019-12
Rent expense				$ 10,300,000	$ 8,100,000	$ 5,200,000
Percentage of sublicensing income				10.00%
Total consideration under current statement of work			$ 15,200,000
Partial payment consideration under current statement of work				$ 5,100,000
MDV9300 [Member]
Commitments And Contingencies [Line Items]
Manufacturing services and supply agreement period				3 years
Upfront and setup fees	$ 100,000	$ 200,000	$ 3,000,000
Potential payment upon completion of Manufacturing Technology Transfer				$ 5,000,000
Funding for clinical trial materials				$ 19,300,000
Funding period for clinical materials				3 years
Clinical trial materials amount paid				$ 9,000,000
Development milestone payments [Member]
Commitments And Contingencies [Line Items]
Aggregate milestone payments upon achievement of certain development and regulatory milestone events				$ 2,800,000
Percentage of sublicensing income				10.00%
Royalty percentage on sales				4.00%
Corporate Headquarters [Member]
Commitments And Contingencies [Line Items]
Operating lease office space, in square feet | ft²				143,000
Optional lease extension term				5 years

Commitments and Contingencies82

Commitments and Contingencies - Schedule of Future Operating Lease Obligations (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
Operating Leases, 2016	$ 9,343
Operating Leases, 2017	9,542
Operating Leases, 2018	9,743
Operating Leases, 2019	5,065
Operating Leases, Future Minimum Lease Payments	$ 33,693

Commitments and Contingencies83

Commitments and Contingencies - Schedule of Future Lease Cash Payments under the Build to Suit Lease (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
Build-To-Suit Lease, 2016	$ 2,178
Build-To-Suit Lease, 2017	2,244
Build-To-Suit Lease, 2018	2,311
Build-To-Suit Lease, 2019	2,380
Build-To-Suit Lease, 2020	2,452
Build-To-Suit Lease, 2021 and thereafter	9,627
Build-To-Suit Lease, Future Minimum Payments	$ 21,192

Selected Quarterly Financial 84

Selected Quarterly Financial Data - Additional Information (Detail)	Sep. 15, 2015
Income Statement [Abstract]
Stock split of common stock	2

Selected Quarterly Financial 85

Selected Quarterly Financial Data - Selected Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	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 Statement [Abstract]
Collaboration revenue	$ 377,748	$ 260,665	$ 175,657	$ 129,188	$ 274,730	$ 200,478	$ 148,090	$ 87,189	$ 943,258	$ 710,487	$ 272,942
Operating expenses	(156,348)	(121,680)	(122,002)	(128,615)	(131,253)	(108,595)	(93,139)	(95,654)	(528,645)	(428,641)	(295,183)
Income (loss) from operations	221,400	138,985	53,655	573	143,477	91,883	54,951	(8,465)	414,613	281,846	(22,241)
Net income (loss)	$ 142,507	$ 79,510	$ 25,826	$ (3,118)	$ 164,205	$ 77,993	$ 47,919	$ (13,665)	$ 244,725	$ 276,452	$ (42,613)
Basic net income (loss) per common share	$ 0.87	$ 0.49	$ 0.16	$ (0.02)	$ 1.06	$ 0.51	$ 0.31	$ (0.09)	$ 1.53	$ 1.80	$ (0.28)
Diluted net income (loss) per common share	$ 0.85	$ 0.47	$ 0.15	$ (0.02)	$ 0.98	$ 0.48	$ 0.30	$ (0.09)	$ 1.47	$ 1.71	$ (0.28)
Weighted-average common shares used in the calculation of basic net income (loss) per common share	163,746	162,390	158,505	156,637	155,644	154,112	153,153	152,489	160,345	153,859	150,331
Weighted-average common shares used in the calculation of diluted net income (loss) per common share	168,368	168,070	168,690	156,637	171,513	162,446	160,983	152,489	169,324	170,001	150,331