Portola Pharmaceuticals (PTLA) 10-Q 7 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	PTLA
Entity Registrant Name	PORTOLA PHARMACEUTICALS INC
Entity Central Index Key	1,269,021
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		56,543,918

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	[1]	$ 98,661	$ 186,488
Short-term investments	[1]	175,936	257,713
Restricted cash (SRX Cardio)	[1]	1,930	341
Receivables from collaborators	[1]	5,000	1,000
Prepaid research and development	[1]	15,575	16,976
Prepaid expenses and other current assets	[1]	4,596	3,059
Total current assets	[1]	301,698	465,577
Property and equipment, net	[1]	6,384	6,243
Intangible asset	[1]	3,151	3,151
Long-term investments	[1]		15,960
Prepaid and other long-term assets	[1]	6,316	11,993
Total assets	[1]	317,549	502,924
Current liabilities:
Accounts payable	[1]	8,993	10,279
Accrued compensation and employee benefits	[1]	3,517	5,459
Accrued research and development	[1]	15,433	24,195
Accrued and other liabilities	[1]	2,339	2,826
Deferred revenue, current portion	[1]	17,148	8,387
Total current liabilities	[1]	47,430	51,146
Deferred revenue, long-term	[1]	26,557	18,629
Other long-term liabilities	[1]	2,261	2,826
Total liabilities	[1]	76,248	72,601
Stockholders’ equity:
Preferred stock, $0.001 par value, 5,000,000 shares authorized; no shares issued and outstanding	[1]
Common stock, $0.001 par value, 100,000,000 shares authorized at September 30, 2016 and December 31, 2015; 56,543,428 and 56,359,515 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	[1]	57	57
Additional paid-in capital	[1]	1,100,924	1,076,791
Accumulated deficit	[1]	(864,504)	(649,302)
Accumulated other comprehensive income/(loss)	[1]	44	(150)
Total stockholders’ equity	[1]	236,521	427,396
Noncontrolling interest (SRX Cardio)	[1]	4,780	2,927
Total stockholders' equity	[1]	241,301	430,323
Total liabilities and stockholders’ equity	[1]	$ 317,549	$ 502,924
[1]	Amounts include the assets and liabilities of SRX Cardio, LLC, a consolidated variable interest entity (“VIE”). Portola's interests and obligations with respect to the VIE's assets and liabilities are limited to those accorded to Portola in its agreement with the VIE. See Note 7, “Asset Acquisition and License Agreements,” to these condensed consolidated financial statements.

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	56,543,428	56,359,515
Common stock, shares outstanding	56,543,428	56,359,515

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Collaboration and license revenue	$ 9,322	$ 2,912	$ 21,811	$ 7,656
Operating expenses:
Research and development	87,209	48,405	190,822	140,563
Selling, general and administrative	13,556	10,071	45,374	27,987
Total operating expenses	100,765	58,476	236,196	168,550
Loss from operations	(91,443)	(55,564)	(214,385)	(160,894)
Interest and other income, net	407	406	1,036	495
Net loss	(91,036)	(55,158)	(213,349)	(160,399)
Net income attributable to noncontrolling interest (SRX Cardio)	(1,853)		(1,853)
Net loss attributable to Portola	$ (92,889)	$ (55,158)	$ (215,202)	$ (160,399)
Net loss per share attributable to Portola common stockholders:
Basic and diluted	$ (1.64)	$ (1.05)	$ (3.81)	$ (3.12)
Shares used to compute net loss per share attributable to Portola common stockholders:
Basic and diluted	56,508,426	52,576,005	56,459,418	51,428,117

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (91,036)	$ (55,158)	$ (213,349)	$ (160,399)
Other comprehensive income:
Unrealized gain (loss) on available-for-sale securities, net of tax	(49)	111	194	259
Comprehensive loss	(91,085)	(55,047)	(213,155)	(160,140)
Comprehensive income attributable to noncontrolling interest (SRX Cardio)	(1,853)		(1,853)
Total comprehensive loss attributable to Portola	$ (92,938)	$ (55,047)	$ (215,008)	$ (160,140)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016		Sep. 30, 2015
Operating activities
Net loss	$ (213,349)		$ (160,399)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization	1,423		942
Amortization of premium on investment securities	962		2,548
Stock-based compensation expense	22,464		16,032
Gain on retirement of equipment			(11)
Changes in operating assets and liabilities:
Receivables from collaborators	(4,000)		57
Prepaid research and development	1,401		(17,753)
Prepaid expenses and other current assets	(1,537)		3,000
Prepaid and other long-term assets	5,677		2,625
Accounts payable	(1,286)		(5,332)
Accrued compensation and employee benefits	(1,942)		383
Accrued research and development	(8,762)		11,197
Accrued and other liabilities	(249)		2,276
Deferred revenue	16,689		(7,154)
Other long-term liabilities	(565)		1,522
Net cash used in operating activities	(183,074)		(150,067)
Investing activities
Purchases of property and equipment	(1,564)		(3,150)
Increase in restricted cash (SRX Cardio)	(1,589)
Proceeds from sales of equipment			11
Purchases of investments	(197,650)		(187,166)
Proceeds from maturities of investments	294,619		241,422
Net cash provided by investing activities	93,816		51,117
Financing activities
Proceeds from public offering of common stock, net of underwriters discount			108,772
Payment of public offering cost	(242)		(358)
Proceeds from issuance of common stock pursuant to equity award plans	1,673		10,744
Net cash provided by financing activities	1,431		119,158
Net (decrease) increase in cash and cash equivalents	(87,827)		20,208
Cash and cash equivalents at beginning of period	186,488	[1]	57,514
Cash and cash equivalents at end of period	$ 98,661	[1]	$ 77,722
[1]	Amounts include the assets and liabilities of SRX Cardio, LLC, a consolidated variable interest entity (“VIE”). Portola's interests and obligations with respect to the VIE's assets and liabilities are limited to those accorded to Portola in its agreement with the VIE. See Note 7, “Asset Acquisition and License Agreements,” to these condensed consolidated financial statements.

Organization

Organization	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	1. Organization Portola Pharmaceuticals, Inc. ® Our two late stage development programs address significant unmet medical needs in the area of thrombosis, or blood clots. Our lead compound, betrixaban, is a U.S. Food and Drug Administration, or FDA, designated Fast-Track novel oral once-daily inhibitor of Factor Xa. Our second compound, andexanet alfa, an FDA-designated breakthrough therapy and orphan drug, is a recombinant protein designed to reverse anticoagulant activity in patients treated with a Factor Xa inhibitor. Our third compound, cerdulatinib, is being developed for hematologic, or blood, cancers and inflammatory disorders. Cerdulatinib is an orally available dual kinase inhibitor that inhibits spleen tyrosine kinase, or Syk, and janus kinases, or JAK, enzymes that regulate important signaling pathways. We also have an early stage program of highly selective Syk inhibitors, one of which is partnered with Ora, Inc., or Ora, and another early stage program to develop a drug in the field of hypercholesterolemia.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Consolidation and Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the amounts of Portola and its wholly-owned subsidiaries and a Development Partner that is a variable interest entity (a “VIE”) for which Portola is deemed, under applicable accounting guidance, to be the primary beneficiary as of September 30, 2016. The unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”), and follow the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These condensed consolidated financial statements have been prepared on the same basis as our annual consolidated financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments that are necessary for a fair statement of our financial information. The results of operations for the three and nine months ended September 30, 2016 are not necessarily indicative of the results to be expected for the year ending December 31, 2016 or for any other interim period or for any other future year. The condensed consolidated balance sheet as of December 31, 2015 has been derived from audited financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2015 included in our Annual Report on Form 10-K filed February 29, 2016 with the SEC. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities and the reported amounts of revenues and expenses in the condensed consolidated financial statements and the accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, fair value of assets and liabilities, income taxes, in-process research and development, the consolidation of VIEs and deconsolidation of VIEs and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates. Variable Interest Entities We review agreements we enter into with third party entities, pursuant to which we may have a variable interest in that entity, in order to determine if the entity is a VIE. If the entity is a VIE, we assess whether or not we are the primary beneficiary of that entity. In determining whether we are the primary beneficiary of an entity, we apply a qualitative approach that determines whether we have both (1) the power to direct the economically significant activities of the entity and (2) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity. If we determine we are the primary beneficiary of a VIE, we consolidate the operations and financial position of the VIE into our consolidated financial statements. Our determination about whether we should consolidate such VIEs is made continuously as changes to existing relationships or future transactions may result in a consolidation or deconsolidation event. In-process Research and Development Asset In-process research and development asset relates to our consolidated VIE and is considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts which generally occurs if and when regulatory approval to market a product is obtained, Cash and Cash Equivalents Cash and cash equivalents consist of cash and other highly liquid investments with original maturities of three months or less from the date of purchase. Investments in Marketable Securities All investments in marketable securities have been classified as “available-for-sale” and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of our investments in debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Unrealized gains and losses are excluded from earnings and were reported as a component of accumulated comprehensive income (loss). Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest and other income, net. The cost of securities sold is based on the specific-identification method. Interest on marketable securities is included in interest and other income, net. Collaboration Collaboration customers who accounted for 10% or more of total collaboration and license revenues were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Daiichi Sankyo, Inc. 41 % 40 % 39 % 45 % Bayer Pharma, AG and Janssen Pharmaceuticals, Inc. 36 % 45 % 34 % 38 % Bristol-Myers Squibb Company and Pfizer Inc. 19 % 13 % 22 % 15 % Revenue Recognition We generate revenue from collaboration and license agreements for the development and commercialization of our products. Collaboration and license agreements may include non-refundable or partially refundable upfront license fees, partial or complete reimbursement of research and development costs, contingent consideration payments based on the achievement of defined collaboration objectives and royalties on sales of commercialized products. Our performance obligations under our collaborations may include the transfer of intellectual property rights (licenses), obligations to provide research and development services and related clinical drug supply, obligations to provide regulatory approval services and obligations to participate on certain development and/or commercialization committees with the collaborators. If we determine that multiple deliverables exist, the consideration is allocated to one or more units of accounting based upon the best estimate of the selling price of each deliverable. The selling price used for each deliverable will be based on vendor-specific objective evidence, if available, third-party evidence if vendor-specific objective evidence is not available, or estimated selling price if neither vendor-specific or third-party evidence is available. In order to account for multiple element arrangements, we identify the deliverables at the inception of the arrangement and each deliverable within a multiple deliverable revenue arrangement is accounted for as a separate unit of accounting if both of the following criteria are met: (1) the delivered item or items have value to the customer on a standalone basis and (2) for an arrangement that includes a general right of return relative to the delivered items, delivery or performance of the undelivered items is considered probable and substantially in our control. A delivered item or items that do not qualify as a separate unit of accounting within the arrangement shall be combined with the other applicable undelivered items within the arrangement. For a combined unit of accounting, non-refundable upfront payments are recognized in a manner consistent with the final deliverable, which has generally been ratably over the period we provide research and development services. Amounts received in advance of performance are recorded as deferred revenue in our condensed consolidated balance sheet and are recognized as collaboration revenue. We regularly review the estimated periods of performance related to our collaborations based on the progress made under each arrangement. Our estimates of our performance period may change over the course of the collaboration term. Such a change could have a material impact on the amount of revenue we record in future periods. Payments that are contingent upon achievement of a substantive milestone are recognized in their entirety in the period in which the milestone is achieved. A milestone is defined as an event that can only be achieved based on our performance and there is substantive uncertainty about whether the event will be achieved at the inception of the arrangement. Events that are contingent only on the passage of time or only on counterparty performance are not considered milestones subject to this guidance. Further, the amounts received must relate solely to prior performance, be reasonable relative to all of the deliverables and payment terms within the agreement and commensurate with our performance to achieve the milestone after commencement of the agreement. Payments contingent upon achievement of events that are not considered substantive milestones are allocated to the respective arrangements unit of accounting when received and recognized as revenue based on the revenue recognition policy for that unit of accounting. Amounts received from our collaboration and license agreements are recognized as revenue if the collaboration arrangement involves the sale of services associated with the development and commercialization of our products at amounts that exceed our cost. Under certain collaboration arrangements we receive reimbursement for a portion of our research and development costs. Such funding is recognized as a reduction in research and development expense when we engage in a research and development project jointly with another entity, with both entities participating in project activities and sharing costs and potential benefits of the arrangement. Amounts related to research and development and regulatory approval funding are recognized as the related services or activities are performed, in accordance with the contract terms. Payments may be made to or by us based on the number of full-time equivalent researchers assigned to the collaboration project and the related research and development expenses incurred. Net Loss per Share Attributable to Portola Common Stockholders Basic net loss per share attributable to Portola Common Stockholders is calculated by dividing the net loss attributable to Portola Common Stockholders by the weighted-average number of shares of Common Stock outstanding for the period. Diluted net loss per share attributable to Portola Common Stockholders is computed by giving effect to all potential dilutive Common Stock equivalents outstanding for the period. Diluted net loss per share attributable to Portola Common Stockholders is the same as basic net loss per share attributable to Portola Common Stockholders, since the effects of potentially dilutive securities are antidilutive. Recent Accounting Pronouncements In October 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-16, Income Taxes (topic 740) however, existing disclosure requirements might be applicable when accounting for the current and deferred income taxes for an intra-entity transfer of an asset. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those fiscal years and early adoption is permitted. We are currently evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230) We are currently evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. In April 2016, the FASB issued ASU 2016-10, Identifying Performance Obligations and Licensing . This ASU addresses certain implementation issues that have surfaced since the issuance of ASU No. 2014-09 in May 2014. The ASU provides guidance in identifying performance obligations and determining the appropriate accounting for licensing arrangements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, and for interim periods therein. Early adoption is permitted. We are currently evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU No. 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net). for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern Substantial doubt about an entity’s ability to continue as a going concern exists when relevant conditions and events, considered in the aggregate, indicate that it is probable that the entity will be unable to meet its obligations as they become due within one year after the date that the financial statements are issued (or available to be issued).

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Financial assets and liabilities are recorded at fair value. The carrying amounts of certain of our financial instruments, including cash and cash equivalents, restricted cash, short-term investments, receivables from collaborations, prepaid research and development, prepaid expenses and other current assets accounts payable, accrued research and development, accrued compensation and employee benefits, accrued and other liabilities and deferred revenue, approximate their fair value due to their short maturities. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value, and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies 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 market 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. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. In certain cases where there is limited activity or less transparency around inputs to valuation, securities are classified as Level 3. The Company’s noncontrolling interest includes the fair value of the contingent milestone and royalty payments, which is valued based on Level 3 inputs. Please refer to Note 7, " Asset Acquisition and License Agreements ," for further information. The following table sets forth the fair value of our financial assets, allocated into Level 1, Level 2 and Level 3, that were measured on a recurring basis (in thousands): September 30, 2016 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 3,003 $ — $ — $ 3,003 Corporate notes and commercial paper — 162,819 — 162,819 U.S. government agency securities — 77,236 — 77,236 Total financial assets $ 3,003 $ 240,055 $ — $ 243,058 December 31, 2015 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 22,074 $ — $ — $ 22,074 Corporate notes and commercial paper — 242,033 — 242,033 U.S. government agency securities — 180,876 — 180,876 Total financial assets $ 22,074 $ 422,909 $ — $ 444,983 We estimate the fair values of our corporate notes and commercial paper and U.S government agency securities by taking into consideration valuations obtained from third-party pricing services. The pricing services 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 reported trades of and broker/dealer quotes on the same or similar securities; issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs. There were no transfers between Level 1 and Level 2 during the periods presented.

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Financial Instruments	4. Financial Instruments Cash equivalents and investments, all of which are classified as available-for-sale securities, consisted of the following (in thousands): September 30, 2016 December 31, 2015 Estimated Estimated Unrealized Unrealized Fair Unrealized Unrealized Fair Cost Gain (Loss) Value Cost Gain (Loss) Value Money market funds $ 3,003 $ — $ — $ 3,003 $ 22,074 $ — $ — $ 22,074 Corporate notes and commercial paper 162,822 6 (9 ) 162,819 242,089 3 (59 ) 242,033 U.S. government agency securities 77,189 47 — 77,236 180,970 1 (95 ) 180,876 $ 243,014 $ 53 $ (9 ) $ 243,058 $ 445,133 $ 4 $ (154 ) $ 444,983 Classified as: Cash equivalents $ 67,122 $ 171,310 Short-term investments 175,936 257,713 Long-term investments — 15,960 Total cash equivalents and investments $ 243,058 $ 444,983 At September 30, 2016, the remaining contractual maturities of available-for-sale securities were less than one year and at December 31, 2015 the remaining contractual maturities of available-for-sale securities were less than two years. There have been no significant realized losses on available-for-sale securities for the periods presented.

Collaboration and License Agree

Collaboration and License Agreements	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaboration and License Agreements	5. Collaboration and License Agreements Summary of Collaboration-Related Revenue We have recognized revenue from our collaboration and license agreements as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 BMS and Pfizer $ 1,798 $ 388 $ 4,785 $ 1,152 Daiichi Sankyo 3,810 1,154 8,491 3,424 Bayer and Janssen 3,316 1,316 7,431 2,922 Bayer 398 — 1,052 — Lee’s Pharmaceutical — 54 52 158 Total collaboration and license revenue $ 9,322 $ 2,912 $ 21,811 $ 7,656 Bristol-Myers Squibb Company (“BMS”) and Pfizer Inc. (“Pfizer”) In January 2014, we entered into a collaboration agreement with BMS and Pfizer to further study andexanet alfa as a reversal agent for their jointly owned FDA approved oral Factor Xa inhibitor, apixaban, through Phase 3 studies. We initiated Phase 3 studies in the first half of 2014. We are responsible for the cost of conducting this clinical study. Pursuant to our agreement with BMS and Pfizer we are obligated to provide research, development and regulatory approval services and participate in the Joint Collaboration Committee (“JCC”) We identified the following non-cancellable performance deliverables under the January 2014 agreement: 1) the obligation to provide research and development services, which include manufacturing and supplying andexanet alfa and providing various reports, 2) the obligation to provide regulatory approval services, and 3) the obligation to participate in the JCC. We considered the provisions of the multiple-elements arrangement guidance and determined that none of the deliverables have standalone value; all of these obligations will be delivered throughout the estimated period of performance and will be accounted for as a single unit of accounting. The non-contingent upfront consideration under this agreement of $6.5 million is being recognized as collaboration revenue on a straight-line basis over the estimated period of performance. In the third quarter of 2014, we revised the remaining estimated period of performance from the first quarter of 2017 to the first quarter of 2018 to reflect a modification to our clinical development and regulatory plans. The contingent upfront consideration of $6.5 million will be recognized if and when the refundable nature of these amounts lapses based upon the achievement of specified regulatory and/or clinical events. The contingent milestone payments under the January 2014 agreement are not considered substantive because a portion may be refunded upon certain events. The non-contingent portion of the milestone payment will be recognized as collaboration revenue on a straight-line basis over the estimated period of performance, which is now through the first quarter of 2018. The contingent portion of the milestone payments will be recognized if and when the refundable nature of these amounts lapse based upon the achievement of specified regulatory and/or clinical events. During the three months ended September 30, 2016, we received no payments. During the nine months ended September 30, 2016, we received two contingent milestone payments totaling $3.5 million related to the achievement of two of these milestones. The non-contingent portion of these milestones is being recognized in collaboration revenue on a straight-line basis over the estimated remaining period of performance and the contingent portion of these milestones are included in deferred revenue, long term in the condensed consolidated balance sheet. One of the contingent payments totaling $3.0 million remained eligible for achievement as of September 30, 2016. During the three and nine months ended September 30, 2016 and 2015, we recognized $603,000 and $1.6 million and $388,000 and $1.2 million in collaboration revenue under this agreement, respectively. The deferred revenue balance under this agreement as of September 30, 2016 was $11.8 million. In February 2016, we entered into a collaboration and license agreement with BMS and Pfizer whereby BMS and Pfizer obtained exclusive rights to develop and commercialize andexanet alfa in Japan. BMS and Pfizer are responsible for all development, regulatory and commercial activities in Japan and we will reimburse BMS and Pfizer for expenses they incur for research and development activities specific to Factor Xa inhibitors other than apixaban. Pursuant to this agreement, we are obligated to provide certain research and development activities outside of Japan, provide clinical drug supply and related manufacturing services and to participate on various committees in exchange for a non-refundable upfront fee of $15.0 million. We are also eligible to receive, contingent payments totaling up to $20.0 million which may be earned upon achievement of certain regulatory events and up to $70.0 million which may be earned upon achievement of specified annual net sales volumes in Japan. We are also entitled to receive royalties ranging from 5% to15% on net sales of andexanet alfa in Japan. We concluded that the January 2014 and February 2016 agreements should each be accounted for as standalone agreements. We identified the following non-cancellable performance deliverables under the February 2016 agreement: 1) grant of intellectual property license, 2) the obligation to provide research and development services, 3) the obligation to manufacture and provide clinical supply of andexanet alfa, and 4) the obligation to participate in various committees. The February 2016 agreement also contains an obligation to manufacture and provide commercial supply of andexanet alfa which we concluded was a contingent deliverable because andexanet alfa is not yet a commercially approved product and is currently subject to additional clinical studies prior to commercial approval in Japan. We considered the provisions of the multiple-elements arrangement guidance and determined that none of the deliverables have standalone value because of our required expertise associated with the manufacturing process of andexanet alfa and the interdependency of the remaining deliverables on the clinical supply of andexanet alfa. We evaluated the timing of delivery for each of the deliverables and concluded that our obligation to participate on the various committees would be the last delivered element under the arrangement and therefore would be the basis for revenue recognition for the combined unit of accounting. The total upfront consideration under this agreement is being recognized as collaboration revenue on a straight-line basis over the estimated performance period through the first quarter of 2019. We have determined that the future contingent payments meet the definition of a milestone and that such milestones are substantive in that the consideration is reasonable relative to all of the deliverables and payment terms within the agreement are commensurate with our performance to achieve the milestone after commencement of the agreement. Accordingly, revenue for the achievement of the milestone will be recognized in the period when the milestone is achieved and collectability is reasonably assured. As of September 30, 2016, no amounts had been recognized as collaboration revenue for any of these milestones and all the contingent payments remained eligible for achievement as of September 30, 2016. During the Daiichi Sankyo, Inc. (“Daiichi Sankyo”) In June 2013, we entered into an agreement with Daiichi Sankyo to include subjects dosed with edoxaban, their Factor Xa inhibitor product, in one of our Phase 2 proof-of-concept studies of andexanet alfa. We are responsible for the cost of conducting this clinical study. Under the terms of the agreement, Daiichi Sankyo provided us with an upfront fee of $6.0 million, $3.0 million of which was subject to refund if Daiichi Sankyo decided to terminate the agreement. We are obligated to participate in a JCC with Daiichi Sankyo to oversee the collaboration activities under the agreement. We identified the following performance deliverables under the agreement: 1) the obligation to provide research and development services, which includes supplying andexanet alfa and providing a final written report, and 2) the obligation to participate in the JCC. We considered the provisions of the multiple-element arrangement guidance and accounted for the research and development services and our participation in the JCC as a single unit of accounting. We originally estimated the non-contingent consideration under this agreement of $3.0 million would be recorded as collaboration revenue on a straight-line basis over the estimated non-contingent performance period through the second quarter of 2014. In December 2013, the JCC agreed to forego certain preclinical studies that were planned in the original study design at the inception of the agreement. As a result of this change, we updated our non-contingent performance period to be through the first quarter of 2014.The recognition of contingent consideration under this agreement of $3.0 million commenced upon resolution of the contingency in the first quarter of 2014 and was recognized as collaboration revenue through the fourth quarter of 2015. During the three and nine months ended September 30, 2015, we recognized $264,000 and $782,000, in collaboration revenue associated with the contingent and non-contingent elements of this arrangement. There was no deferred revenue balance under this agreement as of September 30, 2016. In July 2014, we entered into an agreement with Daiichi Sankyo to study the safety and efficacy of andexanet alfa as a reversal agent to their oral Factor Xa inhibitor, edoxaban, in our Phase 3 and Phase 4 studies. We are responsible for the cost of conducting these clinical studies. Pursuant to our agreement with Daiichi Sankyo we are obligated to provide research, development and regulatory services and to participate in a JCC in exchange for an upfront nonrefundable fee of $15.0 million, up to two contingent payments totaling $5.0 million which are payable upon the initiation of our Phase 3 study and achievement of certain events associated with scaling up our manufacturing process to support a commercial launch, and up to four payments totaling $20.0 million payable upon acceptance of filing and regulatory approval of andexanet alfa as a reversal agent to edoxaban by the FDA and European Medicines Agency (“EMA”). We identified the following non-cancellable performance deliverables under the agreement: 1) the obligation to provide research and development services, which include manufacturing and supplying andexanet alfa and providing various reports, 2) the obligation to provide regulatory approval services, and 3) the obligation to participate in the JCC. We considered the provisions of the multiple-element arrangement guidance and determined that none of the deliverables had standalone value, all of these obligations will be delivered throughout the estimated period of performance and will be accounted as a single unit of accounting. The total upfront consideration under this agreement is being recognized as collaboration revenue on a straight-line basis over the estimated performance period through the third quarter of 2018. We have determined all but one of the future contingent payments meet the definition of a milestone and that such milestones are substantive in that the consideration is reasonable relative to all of the deliverables and the payment terms within the agreement are commensurate with our performance to achieve the milestone after commencement of the agreement. Accordingly, revenue for the achievement of these milestones will be recognized in the period when the milestone is achieved and collectability is reasonably assured. For the three and nine months ended September 30, 2016, we recognized $2.5 million and $5.0 million in collaboration revenue associated with achievement of milestones, respectively. Amounts for the contingent payment not considered to be a substantive milestone will be deferred when received and recognized as collaboration revenue on a straight-line basis over the remaining performance period. All remaining contingent payments remained eligible for achievement as of September 30, 2016. During the three and nine months ended September 30, 2016 and 2015, we recognized $3.4 million and $7.7 million and $890,000 and $2.6 million in collaboration revenue under this agreement, respectively. The deferred revenue balance under this agreement as of September 30, 2016 was $7.1 million. In March 2016, we entered into an agreement with Daiichi Sankyo to perform an ethnic sensitivity study (“ESS-Study”) of Japanese ethnicity, perform any further studies requested by the Japanese regulatory authorities and to deliver services in connection with our collaboration agreement to commercialize andexanet alfa in Japan with BMS and Pfizer. Daiichi Sankyo will reimburse us for 33% of our costs and expenses incurred to conduct the ESS-Study and between 33% and 100% of costs and expenses we incur for other studies that involve edoxaban under the terms of the arrangement. Pursuant to our agreement with Daiichi Sankyo, we are obligated to provide research and development services, clinical drug supply and related manufacturing services, regulatory approval services and to participate in a JCC in exchange for an upfront nonrefundable fee of $5.0 million. We are eligible to receive, up to two contingent payments totaling $10.0 million payable upon the initial and final regulatory approval for andexanet alfa as a reversal agent to edoxaban in Japan. The $10.0 million contingent payments will be reduced to $7.0 million if the Japanese regulatory approval is attained based only upon the ESS-study results. We concluded that the July 2014 and March 2016 agreements should each be accounted for as standalone agreements. We identified the following non-cancellable performance deliverables under the March 2016 agreement: 1) the obligation to provide research and development services 2) the obligation to provide regulatory approval services, 3) the obligation to manufacture and provide clinical supply of andexanet alfa, and 4) the obligation to participate in the JCC. We considered the provisions of the multiple-element arrangement guidance and determined that none of the deliverables have standalone value and accordingly will be accounted for as a single unit of accounting. The total upfront consideration received under this agreement is being recognized as collaboration revenue on a straight-line basis over the estimated performance period associated with our participation in the JCC through the first quarter of 2019. We have determined that the future contingent payments meet the definition of a milestone and that such milestones are substantive in that the consideration is reasonable relative to all of the deliverable and payment term within the agreement are commensurate with our performance to achieve the milestones after commencement of the agreement. Accordingly, revenue for the achievement of these milestones will be recognized in the period when the milestones are achieved and collectability is reasonably assured. As of September 30, 2016, no amounts had been recognized as collaboration revenue for any of these milestones and the contingent payments remained eligible for achievement as of September 30, 2016. During the three and nine months ended September 30, 2016 we recognized $410,000 and $840,000 in collaboration revenue under this agreement, respectively. The deferred revenue balance under this agreement as of September 30, 2016 was $4.2 million. Bayer Pharma, AG (“Bayer”) and Janssen Pharmaceuticals, Inc. (“Janssen”) In February 2013, we entered into a three-way agreement with Bayer and Janssen to include subjects dosed with rivaroxaban, their Factor Xa inhibitor product, in one of our Phase 2 proof-of-concept studies of andexanet alfa. We are responsible for the cost of conducting this clinical study. Under the terms of the agreement, Bayer and Janssen have each provided us with an upfront and non-refundable fee of $2.5 million, for an aggregate fee of $5.0 million. The agreement also provides for additional non-refundable payments to us from Bayer and Janssen of $250,000 each for an aggregate of $500,000 following the delivery of the final written study report of our Phase 2 proof-of-concept studies of andexanet alfa. Also, we are obligated to participate on a JCC with Bayer and Janssen to oversee the collaboration activities under the agreement. We identified the following performance deliverables under the agreement: 1) the obligation to provide research and development services, which includes supplying andexanet alfa and providing a final written report, and 2) the obligation to participate in a JCC. We considered the provisions of the multiple-element arrangement guidance and determined that that none of the deliverables had standalone value and therefore they were accounted for as a single unit of accounting. The total upfront consideration under this agreement was recognized as collaboration revenue on a straight-line basis over the estimated performance period through the fourth quarter of 2014 and $500,000 was recognized in the third quarter of 2015 following the delivery of the final written study report of our Phase 2 proof-of-concept studies of andexanet alfa. In January 2014, we entered into a three-way agreement with Bayer and Janssen to study the safety and efficacy of andexanet alfa as a reversal agent to their oral Factor Xa inhibitor, rivaroxaban, in our Phase 3 studies. We are responsible for the cost of conducting this clinical study. Pursuant to our agreement with Bayer and Janssen we are obligated to provide research, development and regulatory services and to participate in a JCC in exchange for an upfront nonrefundable fee of $10.0 million. We are also eligible to receive, up to three contingent payments totaling $7.0 million payable upon achievement of certain events associated with scaling up our manufacturing process to support a commercial launch, and up to three payments totaling $8.0 million payable upon initiation of our Phase 3 study and regulatory approval of andexanet alfa as a reversal agent to rivaroxaban by the FDA and EMA. We identified the following non-cancellable performance deliverables under the agreement: 1) the obligation to provide research and development services, which include manufacturing and supplying andexanet alfa and providing various reports, 2) the obligation to provide regulatory approval services, and 3) the obligation to participate in the JCC. We considered the provisions of the multiple-element arrangement guidance and determined that none of the deliverables have standalone value; all of these obligations will be delivered throughout the estimated period of performance and accounted for as a single unit of accounting. The total upfront consideration under this agreement is being recognized as collaboration revenue on a straight-line basis over the estimated period of performance period. In the third quarter of 2014 we updated our estimated period of performance from the first quarter of 2017 to the first quarter of 2018 to reflect a modification to our clinical development and regulatory plans. We have determined all but one of the future contingent payments meet the definition of a milestone and that such milestones are substantive in that the consideration is reasonable relative to all of the deliverables and the payment terms within the agreement and commensurate with our performance to achieve the milestone after commencement of the agreement. Accordingly, revenue for the achievement of these milestones will be recognized in the period when the milestone is achieved and collectability is reasonably assured. For the three and nine months ended September 30, 2016, we recognized $2.5 million and $5.0 million in collaboration revenue associated with achievement of a milestone, respectively. The contingent payment of $3.0 million, not considered to be a substantive milestone, was received in the third quarter of 2014 and is being recognized as collaboration revenue on a straight-line basis over the estimated performance period through the first quarter of 2018. All remaining contingent payments remained eligible for achievement as of September 30, 2016. During the three and nine months ended September 30, 2016 and 2015, we recognized $3.3 million and $7.4 million and $816,000 and $2.4 million in collaboration revenue including milestone payment under this agreement, respectively. The deferred revenue balance under this agreement as of September 30, 2016 was $4.9 million. Bayer Pharma, AG (“Bayer”) In February 2016, we entered into an agreement with Bayer to perform an ESS-Study of Japanese ethnicity, perform any further studies requested by the Japanese regulatory authorities and to deliver services, in connection with our collaboration agreement to commercialize andexanet alfa in Japan with BMS and Pfizer. Bayer will reimburse us 33% of our costs and expenses incurred to conduct the ESS-Study and between 33% and 100% of costs and expenses we incur for other studies that involve rivaroxaban under the terms of the arrangement. Pursuant to our agreement with Bayer we are obligated to provide research and development services, provide clinical drug supply and related manufacturing services, provide regulatory approval services and to participate in a JCC in exchange for an upfront nonrefundable fee of $5.0 million. We are also eligible to receive, one contingent payment of $10.0 million which is payable upon the initial regulatory approval for andexanet alfa for rivaroxaban in Japan. The $10.0 million contingent payment will be reduced to $7.0 million if Japanese regulatory approval is attained based only upon the ESS-study results. We concluded that the January 2014 agreement with Bayer and Janssen and February 2016 agreement with Bayer should each be accounted for as standalone agreements. We identified the following non-cancellable performance deliverables under the February 2016 agreement: 1) the obligation to provide research and development services 2) the obligation to provide regulatory approval services, 3) the obligation to manufacture and provide clinical supply of andexanet alfa, and 4) the obligation to participate in the JCC. We considered the provisions of the multiple-element arrangement guidance and determined that none of the deliverables had standalone value, all of these obligations will be delivered throughout the estimated period of performance and accounted for as a single unit of accounting. The total upfront consideration under this agreement is being recognized as collaboration revenue on a straight-line basis over the estimated performance period through the first quarter of 2019. We have determined that the future contingent payment meets the definition of a milestone and that such milestone is substantive in that the consideration is reasonable relative to all of the deliverables and payment terms within the agreement are commensurate with our performance to achieve the milestone after commencement of the agreement. Accordingly, revenue for the achievement of the milestone will be recognized in the period when the milestone is achieved and collectability is reasonably assured. As of September 30, 2016, no amounts had been recognized as collaboration revenue for any of this milestone and the contingent payment remained eligible for achievement as of September 30, 2016. During the three and nine months ended September 30, 2016we recognized $398,000 and $1.1 million in collaboration revenue under this agreement. The deferred revenue balance under this agreement as of September 30, 2016 was $3.9 million. Ora, Inc. (“Ora”) In May 2015, we entered into a license and collaboration agreement with Ora pursuant to which we granted Ora an exclusive license to co-develop and co-commercialize one of our specific Syk inhibitors, PRT2761. Ora has the primary responsibility for conducting the research and development and regulatory activities under this agreement. We are obligated to provide assistance in accordance with the agreed- upon development plan as well as participate on various committees. Under the terms of this risk and cost sharing agreement, each party will incur its own share of development costs. Third-party related development costs will be shared by Ora and us at approximately 60% and 40%, respectively, until an End of Phase 2 meeting with the FDA, and equally thereafter. We are entitled to receive either 50% of the profits, if any, generated by future sales of the products developed under the agreement or royalty payments on such sales, should we opt out of the agreement. We may opt out of the agreement any time prior to 90 days after an End of Phase 2 meeting with the FDA. The timing of the exercise of our opt out rights would impact future royalties we would be entitled to receive from Ora. Each party may also buy out the rights and interests in the licensed compound by paying the greater of $6.0 million or two times the actual aggregate development cost incurred by both parties before or 90 days after an End of Phase 2 meeting with the FDA. All costs we incur in connection with this agreement will be recognized as research and development expenses. During the three and nine months ended September 30, 2016, we incurred $28,000 and $467,000 of costs related to this agreement, respectively.

Purchase Commitments

Purchase Commitments	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Purchase Commitments	6. Purchase Commitments Commercial Supply Agreement In July 2014, we entered into an agreement with CMC ICOS Biologics, Inc. (“CMC Biologics”), a subsidiary of CMC Biologics S.à.r.l., a privately-held contract manufacturing organization, pursuant to which CMC Biologics will manufacture clinical and commercial supply of andexanet alfa. Under the agreement, we are required to purchase an aggregate fixed number of batches of andexanet alfa from CMC Biologics beginning in 2015 through 2021. The fixed commitment to purchase batches is divided between two manufacturing lines at CMC Biologics: (i) the 2,500 liter manufacturing line which has been used since inception of the program to supply clinical drug product, referred to as “Line A/B”; and (ii) the 6x2,000 liter manufacturing line referred to as “Line C” which was intended to satisfy the drug product requirements of our initial commercial launch. Total batch commitments under the agreement can be increased or decreased based on the achievement of milestones relating to the regulatory approval process for andexanet alfa, expansion of existing manufacturing capacity and operational qualification of CMC Biologics’ manufacturing facilities. We made an upfront payment to CMC Biologics in the amount of $10.0 million in July 2014 and a reservation payment to CMC Biologics of $4.6 million in November 2014. Both payments were intended to be credited against our future purchases of batches under the agreement. Total fixed commitments under the agreement for the purchases of clinical and commercial batches, not taking into account possible price and batch adjustments per the terms of the agreement, are approximately $276.1 million. The term of the agreement is seven years and may be early terminated by either party for the other party’s uncured material breach or insolvency. We may also terminate the agreement if CMC Biologics is unable to add additional manufacturing capacity on a timely basis, if certain manufacturing-related regulatory events do not occur before certain deadlines, or if the batch yield is below a certain threshold, in which case we are not obligated to pay CMC Biologics a termination payment and CMC Biologics will be obligated to refund the uncredited amounts of the upfront payment and reservation payment. In addition, we may terminate the agreement unilaterally if we discontinue the development and commercialization of andexanet alfa for regulatory, safety, efficacy or other commercial reasons, or if the projected market demand or gross margin of andexanet alfa is below a minimum threshold. The termination provisions will obligate us to pay CMC Biologics a termination fee between $5.0 million and $30.0 million, depending on the date of termination. The termination fee is highest from 2015 through 2017, and then decreases through 2021. Any remaining upfront payments or reservation payments we have made, not yet credited against the purchase of batches, at the time of termination will be applied against the termination fee. In February 2016, we filed a Biologics License Application (“BLA”) based on the Line A/B manufacturing process. On August 17 2016, we received a Complete Response Letter, or CRL from the FDA that focused primarily on Line A/B manufacturing. Since the amount of drug substance yielded by Line A/B will support only a limited launch, our intent was to seek approval for Line C subsequent to the approval of Line A/B in an effort to bridge the supply gap until the commercial scale generation 2 process manufactured at Lonza was approved. Given the time and effort required to address the deficiencies raised in the CRL and re-submit the BLA, we made the corporate decision to suspend manufacturing activities on Line C in order to focus on getting AndexXa approved using Line A/B and then transition commercial manufacturing to generation 2 as quickly as possible. Given the uncertainty about whether we will consume the services originally contracted regarding Line C, we can no longer assert recoverability of the carrying amounts of the (i) unamortized upfront and reservation payments of $12.3 million recorded as $8.9 million in prepaid and other long-term assets and $3.4 million in prepaid research and development; (ii) unamortized payments made for the purchase of batches of $13.3 million recorded in prepaid research and development; nor (iii) other miscellaneous receivables of $1.7 million recorded in prepaid and other current assets. Accordingly, we have recorded a charge of $27.3 million in research and development expense in our condensed consolidated statement of operations for the period ended September 30, 2016. Under the consolidation guidance, we determined that CMC Biologics is and continues to be a VIE, but that we are not CMC Biologics’ primary beneficiary and therefore consolidation of CMC Biologics by us is not required. As of September 30, 2016, we have not provided financial or other support to CMC Biologics that was not previously contractually required. We have recorded $1.3 million of prepaid and other current assets, $352,000 of prepaid research and development, $367,000 of accounts payable and $1.8 million of accrued research and development in the condensed consolidated balance sheet as of September 30, 2016. These assets represent our maximum exposure to loss under this agreement at September 30, 2016.We are currently not able to quantify our total exposure to losses associated with the fixed pricing terms of this agreement and the potential losses associated with our inability to resolve manufacturing issues with CMC. Betrixaban Manufacturing Agreement In April 2016, we entered into a Manufacturing Agreement (“the Hovione Agreement”) with Hovione, Limited, (“Hovione”), pursuant to which Hovione will manufacture active pharmaceutical ingredient (“API”) for betrixaban at commercial scale and perform process validation during the term of the agreement. Pursuant to the Hovione Hovione Hovione Hovione Hovione Hovione

Asset Acquisition and License A

Asset Acquisition and License Agreements	9 Months Ended
	Sep. 30, 2016
Research And Development [Abstract]
Asset Acquisition and License Agreements	7. Asset Acquisition and License Agreements Agreement with Early Development Stage Company, SRX Cardio, LLC In December 2015, we entered into an option agreement with SRX Cardio, LLC (“SRX Cardio”) to explore a novel approach to develop a drug in the field of hypercholesterolemia. This agreement provided us an option to enter into an exclusive license agreement as well as responsibility to lead and fund the development effort during the option period. In September 2016, we exercised our right to enter into an exclusive license agreement. Pursuant to the terms of the agreement, we made an upfront payment of $2.2 million to acquire the license and are obligated to pay up to $152.5 million in research and development milestones and royalties in the range of 2% to 6% of net sales. We may terminate the license agreement upon 90 days notice for convenience and the agreement may also be terminated by either party for a material breach by the other party. We determined that SRX Cardio is and continues to be a variable interest entity and that we hold a variable interest in SRX Cardio’s intellectual property assets and the related potential future product candidates these assets may produce. Due to the absence of other significant development programs at SRX Cardio, we concluded that the variable interest was in the entity as a whole. Given the stage of development, we concluded that SRX Cardio is not considered a business as they lack the processes required to generate outputs. We concluded that the responsibilities assigned to us under the option agreement and as continued via the exclusive license agreement provided us control over those activities most significant to SRX Cardio, and therefore we are considered to be the primary beneficiary of SRX Cardio. Accordingly, SRX Cardio is subject to consolidation and we have consolidated the financial statements of SRX Cardio since inception of the agreement on December 1, 2015 by (a) eliminating all intercompany balances and transactions; and (b) allocating loss attributable to the noncontrolling interest in SRX Cardio to net loss attributable to noncontrolling interest in our consolidated statement of operations and reflecting noncontrolling interest on our consolidated balance sheet. Our interest in SRX Cardio is limited to the development of the intellectual property asset. The upfront payments of $500,000 and $2.2 million and the obligation to fund the development plan represent our maximum exposure to loss under the agreement. We did not acquire any equity interest in SRX Cardio, any interest in SRX Cardio's cash and cash equivalents or any control over their activities that do not relate to the exclusive license agreement. SRX Cardio does not have any right to the Company's assets except as provided in the exclusive license agreement . At the inception of the agreement, the identifiable assets, assumed liabilities and non-controlling interest of SRX Cardio were recorded at their estimated fair value upon the initial consolidation of SRX Cardio, including the in-process research and development intangible asset. We estimated the fair value of these indefinite lived intangible assets to be $3.2 million and the noncontrolling interest to be $2.9 million. The fair value was estimated using present-value models on potential contingent milestones and royalty payments, based on assumptions regarding the probability of achieving the development milestones, estimate of time to develop the drug candidate, estimates of future cash flows from potential product sales and assumptions regarding the appropriate discount rate. There were no material changes to the amounts recorded upon execution of the license agreement. We will evaluate the fair value of contingent milestones and royalties payments at each reporting period. As of September 30, 2016, we have not provided financial or other support to SRX Cardio that was not previously contracted or required. We recorded SRX Cardio’s $1.9 million of cash as restricted cash because (a) we do not have any interest in or control over SRX Cardio's cash and (b) the agreement does not provide for these assets to be used for the development of the intellectual property assets developed pursuant to this agreement.

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	8. Stock Based Compensation In January 2013, our Board of Directors adopted our 2013 Equity Incentive Plan (the “2013 Plan”), which became effective upon of the closing of our initial public offering in May 2013. On January 1, 2016, the number of shares available for issuance under the 2013 Plan automatically increased by a number of shares equal to 5% of the total common stock outstanding at December 31, 2015. As of September 30, 2016 there were 12,205,425 shares reserved under the 2013 Plan for the future issuance of equity awards. Stock Options The following table summarizes stock option activity under our 2013 Plan and related information during the nine months ended September 30, 2016: Shares Subject Weighted- Outstanding Average Exercise Options Price Per Share Balance at December 31, 2015 4,731,483 $ 24.19 Options granted 1,586,286 29.37 Options exercised (53,255 ) 7.34 Options canceled (376,365 ) 29.66 Balance at September 30, 2016 5,888,149 $ 25.39 Performance Stock Options (“PSOs”) In May 2016, the Compensation Committee of our Board of Directors approved the commencement of granting performance stock option awards to our executive and senior officers. PSOs represent a contingent right to purchase our Common Stock upon achievement of specified conditions. The PSOs granted in May 2016 will vest upon the achievement of certain regulatory and manufacturing goals related to our lead programs. As of September 30, 2016, there was $3.2 million of unrecognized compensation costs related to these PSOs, which could be recognized over an estimated weighted-average period of 1.4 years. The following table summarizes PSO activity under our 2013 Plan and related information during the nine months ended September 30, 2016: Shares Subject Weighted- Outstanding Average Exercise Options Price Per Share Balance at December 31, 2015 — $ — Options granted 271,122 23.76 Options exercised — — Options canceled — — Balance at September 30, 2016 271,122 $ 23.76 The estimated grant date fair values of the employee stock options were calculated using the Black Scholes valuation model, based on the following assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Risk-free interest rate Stock options 1.03% - 1.33% 1.77% 1.01% - 1.60% 1.65% Performance stock options 1.34% - 1.50% — 1.34% - 1.50% — Expected life Stock options 5.0 years - 6.1 years 6.0 years 5.0 years - 6.1 years 6.0 years Performance stock options 5.4 years - 6.4 years — 5.4 years - 6.4 years — Expected volatility Stock options 63% to 65% 65% 62% - 66% 65% Performance stock options 65% to 66% — 65% to 66% — Dividend yield Stock options — — — — Performance stock options — — — — Restricted Stock Units (“RSUs”) In January 2015, the Compensation Committee of our Board of Directors approved the commencement of granting restricted stock units, to our employees. RSUs are share awards that entitle the holder to receive freely tradable shares of our Common Stock upon vesting. The following table summarizes RSU activity, under our 2013 Plan and related information: Shares Subject to Weighted- Outstanding Average grant date RSUs fair value per share Balance at December 31, 2015 167,750 $ 30.86 RSUs granted 495,806 28.01 RSUs released (55,195 ) 30.88 RSUs canceled (49,284 ) 30.07 Balance at September 30, 2016 559,077 $ 28.40 Performance Stock Units In January 2015, the Compensation Committee of our Board of Directors approved the commencement of granting performance stock units to our employees. PSUs are share awards that entitle the holder to receive freely tradable shares of our Common Stock upon achievement of specified conditions. In January 2016, the Compensation Committee of our Board of Directors approved a program to award up to 102,906 PSUs to the management team based on the achievement of certain commercial and regulatory goals related to andexanet alfa and betrixaban, respectively. As of September 30, 2016, there was $3.4 million of unrecognized compensation costs related to these PSUs, which could be recognized over an estimated weighted-average period of 0.9 years. The following table summarizes PSU activity, under our 2013 Plan and related information: Shares Subject to Weighted- Outstanding Average grant date PSUs fair value per share Balance at December 31, 2015 205,261 $ 29.33 PSUs granted 102,906 33.49 PSUs released (13,170 ) 50.00 PSUs canceled (8,945 ) 49.34 Balance at September 30, 2016 286,052 $ 29.25 The table below sets forth the functional classification of stock-based compensation expense, net of estimated forfeitures, for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Research and development $ 3,465 $ 3,252 $ 9,561 $ 8,004 Selling, general and administrative 4,307 2,849 12,903 8,028 Total stock-based compensation $ 7,772 $ 6,101 $ 22,464 $ 16,032

Net Loss per Share Attributable

Net Loss per Share Attributable to Portola Common Stockholders	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Portola Common Stockholders	9. Net Loss per Share Attributable to Portola Common Stockholders Basic net loss per share attributable to Portola Common Stockholders has been computed by dividing the net loss attributable to Portola Common Stockholders by the weighted-average number of shares of Common Stock outstanding during the period. Diluted net loss per share attributable to Portola Common Stockholders is calculated by dividing net loss attributable to Portola Common Stockholders by the weighted average number of shares of Common Stock and potential dilutive securities outstanding during the period. The following common stock equivalent shares were excluded from the computation of diluted net loss per share attributable to Portola Common Stockholders for the three and nine months ended September 30, 2016 and 2015 because including them would have been anti-dilutive: 2016 2015 Stock options to purchase common stock 5,888,149 4,712,354 Performance stock options 271,122 — Common stock warrants 1,500 1,500 Restricted stock units 559,077 191,773 Performance stock units 286,052 165,000 Employee stock purchase plan 10,019 4,327

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	10. Subsequent Events In October 2016, we amended our Phase 3 and Phase 4 clinical collaboration agreement with Daiichi Sankyo dated July 2014 to include additional activities and obligations. Under the amended collaboration agreement, we will be responsible to expand our andexanet alfa Phase 4 clinical study to clinical sites in Germany with the highest expected enrollment of edoxaban patients. Daiichi Sankyo will assist us in this expansion by identifying sites and assisting us with communication. We will also be responsible for expanding our operations with third party vendors to support opening of these new sites and ongoing operations. Further, we will be responsible to supply andexanet alfa to these additional sites. Under the terms of the amendment, we will receive an upfront payment of $15.0 million and are eligible to receive additional clinical milestone payments totaling up to $10.0 million. One of the substantive milestones from the original Phase 3 and Phase 4 clinical collaboration agreement totaling $2.5 million relating to FDA and EMA acceptance of scaled commercial materials has been deleted in its entirety by this amendment. Upon FDA or EMA approval of andexanet alfa, we are obligated to pay a royalty of 1% of net global commercial sales to Daiichi Sankyo until a total aggregate payment of $8.0 million is reached.

Summary of Significant Accoun17

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Consolidation and Basis of Presentation	Consolidation and Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the amounts of Portola and its wholly-owned subsidiaries and a Development Partner that is a variable interest entity (a “VIE”) for which Portola is deemed, under applicable accounting guidance, to be the primary beneficiary as of September 30, 2016. The unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”), and follow the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These condensed consolidated financial statements have been prepared on the same basis as our annual consolidated financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments that are necessary for a fair statement of our financial information. The results of operations for the three and nine months ended September 30, 2016 are not necessarily indicative of the results to be expected for the year ending December 31, 2016 or for any other interim period or for any other future year. The condensed consolidated balance sheet as of December 31, 2015 has been derived from audited financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2015 included in our Annual Report on Form 10-K filed February 29, 2016 with the SEC.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities and the reported amounts of revenues and expenses in the condensed consolidated financial statements and the accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, fair value of assets and liabilities, income taxes, in-process research and development, the consolidation of VIEs and deconsolidation of VIEs and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates.
Variable Interest Entities	Variable Interest Entities We review agreements we enter into with third party entities, pursuant to which we may have a variable interest in that entity, in order to determine if the entity is a VIE. If the entity is a VIE, we assess whether or not we are the primary beneficiary of that entity. In determining whether we are the primary beneficiary of an entity, we apply a qualitative approach that determines whether we have both (1) the power to direct the economically significant activities of the entity and (2) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity. If we determine we are the primary beneficiary of a VIE, we consolidate the operations and financial position of the VIE into our consolidated financial statements. Our determination about whether we should consolidate such VIEs is made continuously as changes to existing relationships or future transactions may result in a consolidation or deconsolidation event.
In-process Research and Development Asset	In-process Research and Development Asset In-process research and development asset relates to our consolidated VIE and is considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts which generally occurs if and when regulatory approval to market a product is obtained,
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash and other highly liquid investments with original maturities of three months or less from the date of purchase.
Investments in Marketable Securities	Investments in Marketable Securities All investments in marketable securities have been classified as “available-for-sale” and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of our investments in debt securities at the time of purchase and reevaluates such designation as of each balance sheet date. Unrealized gains and losses are excluded from earnings and were reported as a component of accumulated comprehensive income (loss). Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in interest and other income, net. The cost of securities sold is based on the specific-identification method. Interest on marketable securities is included in interest and other income, net.
Collaboration Customer Concentration	Collaboration Collaboration customers who accounted for 10% or more of total collaboration and license revenues were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Daiichi Sankyo, Inc. 41 % 40 % 39 % 45 % Bayer Pharma, AG and Janssen Pharmaceuticals, Inc. 36 % 45 % 34 % 38 % Bristol-Myers Squibb Company and Pfizer Inc. 19 % 13 % 22 % 15 %
Revenue Recognition	Revenue Recognition We generate revenue from collaboration and license agreements for the development and commercialization of our products. Collaboration and license agreements may include non-refundable or partially refundable upfront license fees, partial or complete reimbursement of research and development costs, contingent consideration payments based on the achievement of defined collaboration objectives and royalties on sales of commercialized products. Our performance obligations under our collaborations may include the transfer of intellectual property rights (licenses), obligations to provide research and development services and related clinical drug supply, obligations to provide regulatory approval services and obligations to participate on certain development and/or commercialization committees with the collaborators. If we determine that multiple deliverables exist, the consideration is allocated to one or more units of accounting based upon the best estimate of the selling price of each deliverable. The selling price used for each deliverable will be based on vendor-specific objective evidence, if available, third-party evidence if vendor-specific objective evidence is not available, or estimated selling price if neither vendor-specific or third-party evidence is available. In order to account for multiple element arrangements, we identify the deliverables at the inception of the arrangement and each deliverable within a multiple deliverable revenue arrangement is accounted for as a separate unit of accounting if both of the following criteria are met: (1) the delivered item or items have value to the customer on a standalone basis and (2) for an arrangement that includes a general right of return relative to the delivered items, delivery or performance of the undelivered items is considered probable and substantially in our control. A delivered item or items that do not qualify as a separate unit of accounting within the arrangement shall be combined with the other applicable undelivered items within the arrangement. For a combined unit of accounting, non-refundable upfront payments are recognized in a manner consistent with the final deliverable, which has generally been ratably over the period we provide research and development services. Amounts received in advance of performance are recorded as deferred revenue in our condensed consolidated balance sheet and are recognized as collaboration revenue. We regularly review the estimated periods of performance related to our collaborations based on the progress made under each arrangement. Our estimates of our performance period may change over the course of the collaboration term. Such a change could have a material impact on the amount of revenue we record in future periods. Payments that are contingent upon achievement of a substantive milestone are recognized in their entirety in the period in which the milestone is achieved. A milestone is defined as an event that can only be achieved based on our performance and there is substantive uncertainty about whether the event will be achieved at the inception of the arrangement. Events that are contingent only on the passage of time or only on counterparty performance are not considered milestones subject to this guidance. Further, the amounts received must relate solely to prior performance, be reasonable relative to all of the deliverables and payment terms within the agreement and commensurate with our performance to achieve the milestone after commencement of the agreement. Payments contingent upon achievement of events that are not considered substantive milestones are allocated to the respective arrangements unit of accounting when received and recognized as revenue based on the revenue recognition policy for that unit of accounting. Amounts received from our collaboration and license agreements are recognized as revenue if the collaboration arrangement involves the sale of services associated with the development and commercialization of our products at amounts that exceed our cost. Under certain collaboration arrangements we receive reimbursement for a portion of our research and development costs. Such funding is recognized as a reduction in research and development expense when we engage in a research and development project jointly with another entity, with both entities participating in project activities and sharing costs and potential benefits of the arrangement. Amounts related to research and development and regulatory approval funding are recognized as the related services or activities are performed, in accordance with the contract terms. Payments may be made to or by us based on the number of full-time equivalent researchers assigned to the collaboration project and the related research and development expenses incurred.
Net Loss per Share Attributable to Portola Common Stockholders	Net Loss per Share Attributable to Portola Common Stockholders Basic net loss per share attributable to Portola Common Stockholders is calculated by dividing the net loss attributable to Portola Common Stockholders by the weighted-average number of shares of Common Stock outstanding for the period. Diluted net loss per share attributable to Portola Common Stockholders is computed by giving effect to all potential dilutive Common Stock equivalents outstanding for the period. Diluted net loss per share attributable to Portola Common Stockholders is the same as basic net loss per share attributable to Portola Common Stockholders, since the effects of potentially dilutive securities are antidilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In October 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2016-16, Income Taxes (topic 740) however, existing disclosure requirements might be applicable when accounting for the current and deferred income taxes for an intra-entity transfer of an asset. The ASU is effective for annual reporting periods beginning after December 15, 2017, including interim periods within those fiscal years and early adoption is permitted. We are currently evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230) We are currently evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. In April 2016, the FASB issued ASU 2016-10, Identifying Performance Obligations and Licensing . This ASU addresses certain implementation issues that have surfaced since the issuance of ASU No. 2014-09 in May 2014. The ASU provides guidance in identifying performance obligations and determining the appropriate accounting for licensing arrangements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, and for interim periods therein. Early adoption is permitted. We are currently evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU No. 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net). for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern Substantial doubt about an entity’s ability to continue as a going concern exists when relevant conditions and events, considered in the aggregate, indicate that it is probable that the entity will be unable to meet its obligations as they become due within one year after the date that the financial statements are issued (or available to be issued).

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Percentage of Revenue from Significant Collaboration Customers	Collaboration customers who accounted for 10% or more of total collaboration and license revenues were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Daiichi Sankyo, Inc. 41 % 40 % 39 % 45 % Bayer Pharma, AG and Janssen Pharmaceuticals, Inc. 36 % 45 % 34 % 38 % Bristol-Myers Squibb Company and Pfizer Inc. 19 % 13 % 22 % 15 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets Measured on Recurring Basis	The following table sets forth the fair value of our financial assets, allocated into Level 1, Level 2 and Level 3, that were measured on a recurring basis (in thousands): September 30, 2016 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 3,003 $ — $ — $ 3,003 Corporate notes and commercial paper — 162,819 — 162,819 U.S. government agency securities — 77,236 — 77,236 Total financial assets $ 3,003 $ 240,055 $ — $ 243,058 December 31, 2015 Level 1 Level 2 Level 3 Total Financial Assets: Money market funds $ 22,074 $ — $ — $ 22,074 Corporate notes and commercial paper — 242,033 — 242,033 U.S. government agency securities — 180,876 — 180,876 Total financial assets $ 22,074 $ 422,909 $ — $ 444,983

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Investments Debt And Equity Securities [Abstract]
Cash Equivalents and Investments Classified as Available-for-sale Securities	Cash equivalents and investments, all of which are classified as available-for-sale securities, consisted of the following (in thousands): September 30, 2016 December 31, 2015 Estimated Estimated Unrealized Unrealized Fair Unrealized Unrealized Fair Cost Gain (Loss) Value Cost Gain (Loss) Value Money market funds $ 3,003 $ — $ — $ 3,003 $ 22,074 $ — $ — $ 22,074 Corporate notes and commercial paper 162,822 6 (9 ) 162,819 242,089 3 (59 ) 242,033 U.S. government agency securities 77,189 47 — 77,236 180,970 1 (95 ) 180,876 $ 243,014 $ 53 $ (9 ) $ 243,058 $ 445,133 $ 4 $ (154 ) $ 444,983 Classified as: Cash equivalents $ 67,122 $ 171,310 Short-term investments 175,936 257,713 Long-term investments — 15,960 Total cash equivalents and investments $ 243,058 $ 444,983

Collaboration and License Agr21

Collaboration and License Agreements (Tables)	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Revenue from Collaboration and License Agreements	We have recognized revenue from our collaboration and license agreements as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 BMS and Pfizer $ 1,798 $ 388 $ 4,785 $ 1,152 Daiichi Sankyo 3,810 1,154 8,491 3,424 Bayer and Janssen 3,316 1,316 7,431 2,922 Bayer 398 — 1,052 — Lee’s Pharmaceutical — 54 52 158 Total collaboration and license revenue $ 9,322 $ 2,912 $ 21,811 $ 7,656

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes stock option activity under our 2013 Plan and related information during the nine months ended September 30, 2016: Shares Subject Weighted- Outstanding Average Exercise Options Price Per Share Balance at December 31, 2015 4,731,483 $ 24.19 Options granted 1,586,286 29.37 Options exercised (53,255 ) 7.34 Options canceled (376,365 ) 29.66 Balance at September 30, 2016 5,888,149 $ 25.39
Summary of PSO Activity	The following table summarizes PSO activity under our 2013 Plan and related information during the nine months ended September 30, 2016: Shares Subject Weighted- Outstanding Average Exercise Options Price Per Share Balance at December 31, 2015 — $ — Options granted 271,122 23.76 Options exercised — — Options canceled — — Balance at September 30, 2016 271,122 $ 23.76
Fair Values of Employee Stock Options	The estimated grant date fair values of the employee stock options were calculated using the Black Scholes valuation model, based on the following assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Risk-free interest rate Stock options 1.03% - 1.33% 1.77% 1.01% - 1.60% 1.65% Performance stock options 1.34% - 1.50% — 1.34% - 1.50% — Expected life Stock options 5.0 years - 6.1 years 6.0 years 5.0 years - 6.1 years 6.0 years Performance stock options 5.4 years - 6.4 years — 5.4 years - 6.4 years — Expected volatility Stock options 63% to 65% 65% 62% - 66% 65% Performance stock options 65% to 66% — 65% to 66% — Dividend yield Stock options — — — — Performance stock options — — — —
Summary of RSU Activity	The following table summarizes RSU activity, under our 2013 Plan and related information: Shares Subject to Weighted- Outstanding Average grant date RSUs fair value per share Balance at December 31, 2015 167,750 $ 30.86 RSUs granted 495,806 28.01 RSUs released (55,195 ) 30.88 RSUs canceled (49,284 ) 30.07 Balance at September 30, 2016 559,077 $ 28.40
Summary of PSU Activity	The following table summarizes PSU activity, under our 2013 Plan and related information: Shares Subject to Weighted- Outstanding Average grant date PSUs fair value per share Balance at December 31, 2015 205,261 $ 29.33 PSUs granted 102,906 33.49 PSUs released (13,170 ) 50.00 PSUs canceled (8,945 ) 49.34 Balance at September 30, 2016 286,052 $ 29.25
Classification of Stock-Based Compensation Expense	The table below sets forth the functional classification of stock-based compensation expense, net of estimated forfeitures, for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Research and development $ 3,465 $ 3,252 $ 9,561 $ 8,004 Selling, general and administrative 4,307 2,849 12,903 8,028 Total stock-based compensation $ 7,772 $ 6,101 $ 22,464 $ 16,032

Net Loss per Share Attributab23

Net Loss per Share Attributable to Portola Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Common Stock Equivalent Shares Excluded from Computation of Diluted Net Loss	The following common stock equivalent shares were excluded from the computation of diluted net loss per share attributable to Portola Common Stockholders for the three and nine months ended September 30, 2016 and 2015 because including them would have been anti-dilutive: 2016 2015 Stock options to purchase common stock 5,888,149 4,712,354 Performance stock options 271,122 — Common stock warrants 1,500 1,500 Restricted stock units 559,077 191,773 Performance stock units 286,052 165,000 Employee stock purchase plan 10,019 4,327

Organization - Additional Infor

Organization - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016Segment
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Number of operating segment	1

Revenue Accounted for 10% or Mo

Revenue Accounted for 10% or More of Total Collaboration and License Revenues (Detail) - Customer Concentration Risk - Sales Revenue, Net	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Daiichi Sankyo, Inc ("Daiichi")
Concentration Risk [Line Items]
Concentration risk percentage	41.00%	40.00%	39.00%	45.00%
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")
Concentration Risk [Line Items]
Concentration risk percentage	36.00%	45.00%	34.00%	38.00%
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")
Concentration Risk [Line Items]
Concentration risk percentage	19.00%	13.00%	22.00%	15.00%

Fair Value of Financial Assets,

Fair Value of Financial Assets, Allocated into Level 1, Level 2, and Level 3 Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financial Assets:
Total financial assets	$ 243,058	$ 444,983
Fair Value, Inputs, Level 1
Financial Assets:
Total financial assets	3,003	22,074
Fair Value, Inputs, Level 2
Financial Assets:
Total financial assets	240,055	422,909
Money market funds
Financial Assets:
Total financial assets	3,003	22,074
Money market funds | Fair Value, Inputs, Level 1
Financial Assets:
Total financial assets	3,003	22,074
Corporate notes and commercial paper
Financial Assets:
Total financial assets	162,819	242,033
Corporate notes and commercial paper | Fair Value, Inputs, Level 2
Financial Assets:
Total financial assets	162,819	242,033
U.S. government agency securities
Financial Assets:
Total financial assets	77,236	180,876
U.S. government agency securities | Fair Value, Inputs, Level 2
Financial Assets:
Total financial assets	$ 77,236	$ 180,876

Fair Values Measurements - Addi

Fair Values Measurements - Additional Information (Detail) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair value assets transfers from level 1 to level 2	$ 0	$ 0
Fair value assets transfers from level 2 to level 1	$ 0	$ 0

Cash Equivalents and Investment

Cash Equivalents and Investments Classified as Available-for-sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Cost	$ 243,014	$ 445,133
Unrealized Gains	53	4
Unrealized (Losses)	(9)	(154)
Estimated Fair Value	243,058	444,983
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Cost	3,003	22,074
Estimated Fair Value	3,003	22,074
Corporate notes and commercial paper
Schedule Of Available For Sale Securities [Line Items]
Cost	162,822	242,089
Unrealized Gains	6	3
Unrealized (Losses)	(9)	(59)
Estimated Fair Value	162,819	242,033
U.S. government agency securities
Schedule Of Available For Sale Securities [Line Items]
Cost	77,189	180,970
Unrealized Gains	47	1
Unrealized (Losses)		(95)
Estimated Fair Value	77,236	180,876
Cash equivalents
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value	67,122	171,310
Short-term investments
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value	$ 175,936	257,713
Long-term investments
Schedule Of Available For Sale Securities [Line Items]
Estimated Fair Value		$ 15,960

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Investments Debt And Equity Securities [Abstract]
Available For Sale Securities Contractual Maturity	1 year	2 years
Available-for-sale Securities, Gross Realized Losses	$ 0	$ 0

Summary of Revenue from Collabo

Summary of Revenue from Collaboration and License Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue	$ 9,322	$ 2,912	$ 21,811	$ 7,656
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue	1,798	388	4,785	1,152
Daiichi Sankyo, Inc ("Daiichi")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue	3,810	1,154	8,491	3,424
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue	3,316	1,316	7,431	2,922
Bayer Pharma AG
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue	$ 398		1,052
Lee’s Pharmaceutical (HK) Ltd (“Lee’s”)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue		$ 54	$ 52	$ 158

Collaboration and License Agr31

Collaboration and License Agreements - Additional Information (Detail) - USD ($)	1 Months Ended						3 Months Ended				9 Months Ended		24 Months Ended
	Mar. 31, 2016	Feb. 29, 2016	Jul. 31, 2014	Jan. 31, 2014	Jun. 30, 2013	Feb. 28, 2013	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							$ 9,322,000	$ 2,912,000			$ 21,811,000	$ 7,656,000
Research and development							87,209,000	48,405,000			190,822,000	140,563,000
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee				$ 13,000,000
Milestone Payments of Development and Regulatory Event				$ 12,000,000
Percentage of consideration received under agreement				50.00%
Non-contingent consideration being recognized as revenue over estimated period of performance											6,500,000
Contingent consideration to be recognized after resolution of contingency											6,500,000
Milestone payments of regulatory and clinical event							0				3,500,000
Contingent payment receivable upon achievement											3,000,000
Collaboration and license revenue							1,798,000	388,000			4,785,000	1,152,000
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | January 2014 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							603,000	388,000			1,600,000	1,200,000
Deferred revenue							11,800,000				11,800,000
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | February 2016 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							1,200,000				3,200,000
Deferred revenue							11,800,000				$ 11,800,000
Non-refundable upfront fee		$ 15,000,000
Contingent payment receivable upon achievement of regulatory events		20,000,000
Contingent payment receivable upon achievement of annual net sales volumes		70,000,000
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | February 2016 Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of royalties entitle to receive under agreement											5.00%
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer") | February 2016 Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of royalties entitle to receive under agreement											15.00%
Daiichi Sankyo, Inc ("Daiichi")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee			$ 15,000,000
Milestone Payments of Development and Regulatory Event			20,000,000
Contingent consideration to be recognized after resolution of contingency													$ 3,000,000
Contingent payment receivable upon achievement			$ 5,000,000
Collaboration and license revenue							3,810,000	1,154,000			$ 8,491,000	3,424,000
Deferred revenue							0				0
Collaborative arrangement upfront payment to be received					$ 6,000,000
Upfront fee subject to refund					$ 3,000,000
Non-contingent consideration being recognized as collaboration revenue over estimated period of performance										$ 3,000,000
Contingent and non-contingent consideration to be recognized after resolution of contingency								264,000				782,000
Daiichi Sankyo, Inc ("Daiichi") | Collaborative Agreement to Study Safety and Efficacy of Andexanet Alfa
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							3,400,000	890,000			7,700,000	2,600,000
Deferred revenue							7,100,000				7,100,000
Daiichi Sankyo, Inc ("Daiichi") | Collaborative Agreement to Study Safety and Efficacy of Andexanet Alfa | Future Contingent Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							2,500,000				5,000,000
Daiichi Sankyo, Inc ("Daiichi") | March 2016 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							410,000				840,000
Deferred revenue							4,200,000				4,200,000
Daiichi Sankyo, Inc ("Daiichi") | March 2016 Agreement | Future Contingent Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue											0
Daiichi Sankyo, Inc ("Daiichi") | March 2016 Agreement | ESS-Study
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement of costs and expenses percentage	33.00%
Daiichi Sankyo, Inc ("Daiichi") | March 2016 Agreement | Minimum | Edoxaban
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement of costs and expenses percentage	33.00%
Daiichi Sankyo, Inc ("Daiichi") | March 2016 Agreement | Maximum | Edoxaban
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement of costs and expenses percentage	100.00%
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee	$ 5,000,000			$ 10,000,000		$ 5,000,000
Milestone Payments of Development and Regulatory Event				8,000,000
Contingent payment receivable upon achievement	10,000,000			$ 7,000,000
Collaboration and license revenue							3,316,000	1,316,000			7,431,000	2,922,000
Reduced contingent payment receivable upon achievement	$ 7,000,000
Additional non-refundable fee						500,000
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") | January 2014 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							3,300,000	816,000			7,400,000	$ 2,400,000
Deferred revenue							4,900,000				4,900,000
Contingent Payments Received									$ 3,000,000
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") | January 2014 Agreement | Future Contingent Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							2,500,000				5,000,000
Bayer Pharma, AG ('Bayer") and Janssen Pharmaceuticals, Inc. ("Janssen") | February 2013 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative Arrangement Payment Received								$ 500,000
Bayer Pharma AG
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee		5,000,000				2,500,000
Contingent payment receivable upon achievement		10,000,000
Collaboration and license revenue							398,000				1,052,000
Reduced contingent payment receivable upon achievement		$ 7,000,000
Additional non-refundable fee						250,000
Bayer Pharma AG | February 2016 Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue							398,000				1,100,000
Deferred revenue							3,900,000				3,900,000
Bayer Pharma AG | February 2016 Agreement | Future Contingent Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration and license revenue											$ 0
Bayer Pharma AG | February 2016 Agreement | ESS-Study
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement of costs and expenses percentage		33.00%
Bayer Pharma AG | February 2016 Agreement | Minimum | Rivaroxaban
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement of costs and expenses percentage		33.00%
Bayer Pharma AG | February 2016 Agreement | Maximum | Rivaroxaban
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursement of costs and expenses percentage		100.00%
Janssen Pharmaceuticals, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee						2,500,000
Additional non-refundable fee						$ 250,000
Ora, Inc. (“Ora”)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development costs, percent											60.00%
Percentage of profits entitle to receive under agreement											50.00%
Notice period for agreement termination											90 days
Rights to buy compound interests and licensed agreements											Each party may also buy out the rights and interests in the licensed compound by paying the greater of $6.0 million or two times the actual aggregate development cost incurred by both parties before or 90 days after an End of Phase 2 meeting with the FDA.
Research and development							$ 28,000				$ 467,000
Ora, Inc. (“Ora”) | PORTOLA PHARMACEUTICALS INC
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development costs, percent											40.00%

Purchase Commitments - Addition

Purchase Commitments - Additional Information (Detail)		1 Months Ended		9 Months Ended
		Apr. 30, 2016USD ($)	Jul. 31, 2014USD ($)	Sep. 30, 2016USD ($)ManufacturingLinel	Dec. 31, 2015USD ($)	Nov. 01, 2014USD ($)
Long Term Purchase Commitment [Line Items]
Prepaid and other long-term assets	[1]			$ 6,316,000	$ 11,993,000
Prepaid research and development	[1]			15,575,000	16,976,000
Prepaid expenses and other current assets	[1]			4,596,000	3,059,000
Accounts payables	[1]			8,993,000	10,279,000
Accrued research and development	[1]			$ 15,433,000	$ 24,195,000
CMC ICOS Biologics Inc
Long Term Purchase Commitment [Line Items]
Commercial supply agreement upfront payment			$ 10,000,000
Commercial supply (manufacturing services) agreement reservation payment						$ 4,600,000
Number of manufacturing lines | ManufacturingLine				2
Commercial agreement fixed commitment amount			276,100,000
Term of commercial supply agreement				7 years
Commercial supply agreement unamortized upfront and reservation payment				$ 12,300,000
Prepaid research and development				352,000
Purchases of batches recorded in prepaid research and development				13,300,000
Prepaid expenses and other current assets				1,300,000
Accounts payables				367,000
Accrued research and development				1,800,000
CMC ICOS Biologics Inc | Other Miscellaneous Receivables
Long Term Purchase Commitment [Line Items]
Prepaid expenses and other current assets				1,700,000
CMC ICOS Biologics Inc | Research and Development Expense
Long Term Purchase Commitment [Line Items]
Charge				27,300,000
CMC ICOS Biologics Inc | Unamortized Upfront and Reservation Payment
Long Term Purchase Commitment [Line Items]
Prepaid and other long-term assets				8,900,000
Prepaid research and development				$ 3,400,000
CMC ICOS Biologics Inc | Minimum
Long Term Purchase Commitment [Line Items]
Termination fees payment under obligation			5,000,000
CMC ICOS Biologics Inc | Maximum
Long Term Purchase Commitment [Line Items]
Termination fees payment under obligation			$ 30,000,000
CMC ICOS Biologics Inc | Line A/B
Long Term Purchase Commitment [Line Items]
Purchase commitment, description				(i) the 2,500 liter manufacturing line which has been used since inception of the program to supply clinical drug product, referred to as “Line A/B”
Purchase commitment volume | l				2,500
CMC ICOS Biologics Inc | Line C
Long Term Purchase Commitment [Line Items]
Purchase commitment, description				(ii) the 6x2,000 liter manufacturing line referred to as “Line C” which was intended to satisfy the drug product requirements of our initial commercial launch.
Purchase commitment volume | l				12,000
Hovione, Limited
Long Term Purchase Commitment [Line Items]
Prepaid and other long-term assets		$ 6,000,000
Prepaid research and development		12,700,000
Commercial agreement advance payment amount		18,700,000
Hovione, Limited | Maximum
Long Term Purchase Commitment [Line Items]
Cancellable additional purchase commitments		$ 24,100,000
[1]	Amounts include the assets and liabilities of SRX Cardio, LLC, a consolidated variable interest entity (“VIE”). Portola's interests and obligations with respect to the VIE's assets and liabilities are limited to those accorded to Portola in its agreement with the VIE. See Note 7, “Asset Acquisition and License Agreements,” to these condensed consolidated financial statements.

Asset Acquisition and License33

Asset Acquisition and License Agreements - Additional Information (Detail) - USD ($)		1 Months Ended		3 Months Ended	9 Months Ended
		Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2016	Sep. 30, 2016	Dec. 01, 2015
Asset Acquisition [Line Items]
Restricted cash (SRX Cardio)	[1]	$ 1,930,000	$ 341,000	$ 1,930,000	$ 1,930,000
Net income attributable to noncontrolling interest (SRX Cardio)				1,853,000	$ 1,853,000
SRX Cardio
Asset Acquisition [Line Items]
Variable interest entity, Terms of arrangements					Accordingly, SRX Cardio is subject to consolidation and we have consolidated the financial statements of SRX Cardio since inception of the agreement on December 1, 2015 by (a) eliminating all intercompany balances and transactions; and (b) allocating loss attributable to the noncontrolling interest in SRX Cardio to net loss attributable to noncontrolling interest in our consolidated statement of operations and reflecting noncontrolling interest on our consolidated balance sheet.
Variable interest entity, Upfront payment		2,200,000	$ 500,000
Fair value of indefinite lived intangible assets						$ 3,200,000
Noncontrolling interest in variable Interest entity						$ 2,900,000
Restricted cash (SRX Cardio)		$ 1,900,000		1,900,000	$ 1,900,000
SRX Cardio | License Agreement
Asset Acquisition [Line Items]
Notice period for agreement termination		90 days
SRX Cardio | License Agreement | Maximum
Asset Acquisition [Line Items]
Research and development milestone payment obligation		$ 152,500,000		$ 152,500,000	$ 152,500,000
Percentage of royalties on net sales, obligated to pay		6.00%
SRX Cardio | License Agreement | Minimum
Asset Acquisition [Line Items]
Percentage of royalties on net sales, obligated to pay		2.00%
[1]	Amounts include the assets and liabilities of SRX Cardio, LLC, a consolidated variable interest entity (“VIE”). Portola's interests and obligations with respect to the VIE's assets and liabilities are limited to those accorded to Portola in its agreement with the VIE. See Note 7, “Asset Acquisition and License Agreements,” to these condensed consolidated financial statements.

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Jan. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage increase in number of common stock outstanding		5.00%
Shares reserved for future issuance	12,205,425
Performance Stock Options (PSOs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized share based compensation could be recognized over the remaining vesting period	$ 3.2
Unamortized share based compensation recognition period	1 year 4 months 24 days
Performance Stock Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized share based compensation could be recognized over the remaining vesting period	$ 3.4
Unamortized share based compensation recognition period	10 months 24 days
Performance Stock Units (PSUs) | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance-based RSUs awarded based on achievement of development goals, available for grant			102,906

Summary of Stock Option Activit

Summary of Stock Option Activity (Detail) - Employee Stock Option	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Shares Subject to Outstanding Stock Options
Beginning balance | shares	4,731,483
Options granted | shares	1,586,286
Options exercised | shares	(53,255)
Options canceled | shares	(376,365)
Ending balance | shares	5,888,149
Weighted-Average Exercise Price Per Share
Beginning balance | $ / shares	$ 24.19
Options granted | $ / shares	29.37
Options exercised | $ / shares	7.34
Options canceled | $ / shares	29.66
Ending balance | $ / shares	$ 25.39

Summary of PSO Activity (Detail

Summary of PSO Activity (Detail) - Performance Stock Options (PSOs)	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Shares Subject to Outstanding Stock Options
Options granted | shares	271,122
Ending balance | shares	271,122
Weighted-Average Exercise Price Per Share
Options granted | $ / shares	$ 23.76
Ending balance | $ / shares	$ 23.76

Estimated Grant Date Fair Value

Estimated Grant Date Fair Values of Employee Stock Options (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate		1.77%		1.65%
Risk-free interest rate, minimum	1.03%		1.01%
Risk-free interest rate, maximum	1.33%		1.60%
Expected life		6 years		6 years
Expected volatility		65.00%		65.00%
Expected volatility, minimum	63.00%		62.00%
Expected volatility, maximum	65.00%		66.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Employee Stock Option | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	5 years		5 years
Employee Stock Option | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	6 years 1 month 6 days		6 years 1 month 6 days
Performance Stock Options (PSOs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	1.34%		1.34%
Risk-free interest rate, maximum	1.50%		1.50%
Expected volatility, minimum	65.00%		65.00%
Expected volatility, maximum	66.00%		66.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Performance Stock Options (PSOs) | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	5 years 4 months 24 days		5 years 4 months 24 days
Performance Stock Options (PSOs) | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	6 years 4 months 24 days		6 years 4 months 24 days

Summary of RSU Activity (Detail

Summary of RSU Activity (Detail) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Shares Subject to Outstanding Options
Beginning balance | shares	167,750
RSUs granted | shares	495,806
RSUs released | shares	(55,195)
RSUs canceled | shares	(49,284)
Ending balance | shares	559,077
Weighted-Average grant date fair value per share
Beginning balance | $ / shares	$ 30.86
RSUs granted | $ / shares	28.01
RSUs released | $ / shares	30.88
RSUs canceled | $ / shares	30.07
Ending balance | $ / shares	$ 28.40

Summary of PSU Activity (Detail

Summary of PSU Activity (Detail) - Performance Stock Units (PSUs)	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Shares Subject to Outstanding Options
Beginning balance | shares	205,261
RSUs granted | shares	102,906
RSUs released | shares	(13,170)
RSUs canceled | shares	(8,945)
Ending balance | shares	286,052
Weighted-Average grant date fair value per share
Beginning balance | $ / shares	$ 29.33
RSUs granted | $ / shares	33.49
RSUs released | $ / shares	50
RSUs canceled | $ / shares	49.34
Ending balance | $ / shares	$ 29.25

Classification of Stock-Based C

Classification of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 7,772	$ 6,101	$ 22,464	$ 16,032
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	3,465	3,252	9,561	8,004
Selling, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 4,307	$ 2,849	$ 12,903	$ 8,028

Common Stock Equivalent Shares

Common Stock Equivalent Shares Excluded from Computation of Diluted Net Loss per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	5,888,149	4,712,354	5,888,149	4,712,354
Performance stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	271,122		271,122
Common stock warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	1,500	1,500	1,500	1,500
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	559,077	191,773	559,077	191,773
Performance Stock Units (PSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	286,052	165,000	286,052	165,000
Employee stock purchase plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from computation of diluted net loss per share	10,019	4,327	10,019	4,327

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Daiichi Sankyo, Inc ("Daiichi") - USD ($)	1 Months Ended
	Oct. 31, 2016	Jun. 30, 2013
Subsequent Event [Line Items]
Collaborative arrangement upfront payment to be received		$ 6,000,000
Subsequent Event
Subsequent Event [Line Items]
Collaborative arrangement upfront payment to be received	$ 15,000,000
Subsequent Event | FDA and EMA
Subsequent Event [Line Items]
Aggregate amount in substantive milestones of clinical collaboration agreement deleted related to scaled commercial materials	$ 2,500,000
Percentage of royalty obligated to pay of net global commercial sales	1.00%
Aggregate payment reached for royalty obligation	$ 8,000,000
Maximum | Subsequent Event
Subsequent Event [Line Items]
Additional potential clinical milestone payments receivable	$ 10,000,000