Zogenix (ZGNX) 10-Q 9 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	ZGNX
Entity Registrant Name	ZOGENIX, INC.
Entity Central Index Key	1,375,151
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		35,223,373

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 271,953	$ 293,503
Prepaid expenses	8,547	5,994
Other current assets	827	5,206
Total current assets	281,327	304,703
Property and equipment, net	287	245
Intangible assets	102,500	102,500
Goodwill	6,234	6,234
Other assets	1,509	3,931
Total assets	391,857	417,613
Current liabilities:
Accounts payable	2,866	3,356
Accrued expenses	16,024	10,499
Accrued compensation	3,691	6,616
Common stock warrant liabilities	495	512
Total current liabilities	23,076	20,983
Contingent consideration	76,900	76,900
Deferred income taxes	17,425	17,425
Other long-term liabilities	684	784
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.001 par value; 50,000 shares authorized; 34,973 and 34,808 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	35	35
Additional paid-in capital	875,957	873,526
Accumulated deficit	(602,220)	(572,040)
Total stockholders’ equity	273,772	301,521
Total liabilities and stockholders’ equity	$ 391,857	$ 417,613

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	50,000,000	50,000,000
Common Stock, Shares, Issued	34,973,000	34,808,000
Common Stock, Shares, Outstanding	34,973,000	34,808,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Contract manufacturing revenue	$ 0	$ 2,696
Costs and expenses:
Cost of contract manufacturing	0	2,487
Research and development	22,980	13,341
Selling, general and administrative	8,070	6,554
Asset impairment charges	0	813
Change in fair value of contingent consideration	0	600
Total costs and expenses	31,050	23,795
Loss from operations	(31,050)	(21,099)
Other income (expense):
Interest income	833	94
Interest expense	(6)	(671)
Change in fair value of common stock warrant liabilities	17	587
Other income (expense)	26	(20)
Total other income (expense)	870	(10)
Loss from continuing operations before income taxes	(30,180)	(21,109)
Income tax expense	0	(17)
Net loss from continuing operations	(30,180)	(21,126)
Loss from discontinued operations, net of taxes	0	(181)
Net loss	$ (30,180)	$ (21,307)
Net loss per share, basic and diluted:
Continuing operations (in dollars per share)	$ (0.87)	$ (0.85)
Discontinued operations (in dollars per share)	0	(0.01)
Total (in dollars per share)	$ (0.87)	$ (0.86)
Weighted average shares outstanding, basic and diluted (shares)	34,841	24,813
Statements of Comprehensive Income (Loss)
Comprehensive loss	$ (30,180)	$ (21,307)

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (30,180)	$ (21,307)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	1,912	1,673
Depreciation and amortization	23	213
Amortization of debt issuance costs and debt discount	0	252
Asset impairment charges	0	813
Change in fair value of common stock warrant liabilities	(17)	(587)
Change in fair value of contingent consideration	0	600
Changes in operating assets and liabilities:
Trade accounts receivable	0	11,550
Inventory	0	(2,052)
Prepaid expenses and other assets	2,588	226
Accounts payable, accrued expenses and other liabilities	891	(2,525)
Deferred revenue	0	(273)
Net cash used in operating activities	(24,783)	(11,417)
Investing activities:
Purchases of property and equipment	(65)	(26)
Net cash used in investing activities	(65)	(26)
Financing activities:
Proceeds from issuance of common stock under equity incentive plans	3,590	0
Taxes paid related to net share settlement of equity awards	(292)	0
Net cash provided by financing activities	3,298	0
Net decrease in cash and cash equivalents	(21,550)	(11,443)
Cash and cash equivalents, beginning of the period	293,503	91,551
Cash and cash equivalents, end of the period	$ 271,953	$ 80,108

Organization, Basis of Presenta

Organization, Basis of Presentation and Liquidity	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Basis of Presentation and Going Concern	Organization and Basis of Presentation Zogenix, Inc. and its wholly-owned subsidiaries (the “Company”) is a pharmaceutical company developing and commercializing innovative central nervous system (“CNS”) therapies for people living with serious and life-threatening rare CNS disorders and medical conditions. The Company’s current primary area of therapeutic focus is rare, or “orphan” childhood-onset epilepsy disorders and its lead product candidate is ZX008. ZX008 is currently being developed for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut Syndrome. The Company operates in one business segment—the research, development and commercialization of pharmaceutical products and its headquarters are located in Emeryville, California. Basis of Presentation The accompanying condensed consolidated financial statements include the accounts of Zogenix, Inc. and its wholly-owned subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation. The condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, the condensed consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. Certain reclassifications have been made to the prior period amounts to conform to the current year presentation. Previously reported “Interest expense, net” have been reclassified to present interest income and interest expense separately in the accompanying condensed consolidated statements of operations and comprehensive loss. The results of operations for any interim period are not necessarily indicative of results of operations for any future period. Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 , which was filed with the SEC on March 6, 2018 . Future Funding Requirements Excluding gains from two discrete business divestitures, the Company has incurred significant net losses and negative cash flows from operating activities since inception resulting in an accumulated deficit of $602.2 million at March 31, 2018 . The Company expects to continue to incur significant operating losses and negative cash flows from operations to advance its product candidates through development and commercialization. Additionally, upon acceptance of the Company’s regulatory submissions for ZX008 by the U.S. Food and Drug Administration (“FDA”) or the European Medicines Agency (“EMA”), if at all, each a milestone event, the Company will owe milestone payments under an existing agreement in connection with the Company’s prior acquisition of ZX008. To date, the Company has relied primarily on the proceeds from equity offerings to finance its operations. Until such time, if ever, the Company can generate a sufficient amount of revenue to finance its cash requirements, the Company may need to continue to rely on additional financing to achieve its business objectives. However, if such financing is not available at adequate levels when needed, the Company may be required to significantly delay, scale back or discontinue one or more of the product development programs or commercialization efforts or other aspects of its business plans, and its operating results and financial condition would be adversely affected.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results may differ from those estimates. Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies during the three months ended March 31, 2018 , as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Accounting Pronouncements Recently Adopted Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606) and subsequent amendments to the initial guidance (collectively, “Topic 606”) amended the existing accounting standards for revenue recognition. The core principle of Topic 606 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. The Company adopted Topic 606 effective January 1, 2018 using the modified retrospective approach. The adoption of Topic 606 did not have a material impact on the Company’s condensed consolidated financial statements as the Company does not have any contracts with customers ASU 2016-15, Statement of Cash Flows (Topic 230) provides guidance on eight specific cash flow issues, thereby reducing the diversity in practice in how certain transactions are classified in the statement of cash flows. The amendments in this ASU are applied using a retrospective transition method to each period presented. The Company adopted ASU 2016-15 effective January 1, 2018. The adoption of this accounting standards update did not have a material impact on the Company’s condensed consolidated financial statements. ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business narrows the definition of a business and provides additional guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This accounting standards update is required to be applied prospectively to transactions occurring after the date of adoption. The impact of the adoption on the Company's financial position and results of operations will be dependent upon future acquisitions or disposals, if any. The Company adopted ASU 2017-09 effective January 1, 2018. ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting provides guidance on determining changes to the terms and conditions of share-based payment awards and require an entity to apply modification accounting under Topic 718 unless all of the following conditions are met: (1) the fair value of the modified award is the same as the fair value of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; and (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The amendments should be applied prospectively to an award modified on or after the adoption date. The Company adopted ASU 2017-09 effective January 1, 2018. The adoption of this accounting standards update did not have a material impact on the Company’s condensed consolidated financial statements. On December 22, 2017, the U.S. federal government enacted the Tax Cuts and Jobs Act (“the Act”). The Tax Act contains, among other things, significant changes to corporate taxation, including reduction of the corporate tax rate from a top marginal rate of 35% to a flat rate of 21% for tax years beginning after December 31, 2017, limitation of the deduction for net operating losses to 80% of current year taxable income and elimination of net operating loss carrybacks, implementing a territorial tax system, and requiring a mandatory one-time tax on U.S. owned undistributed foreign earnings and profits known as the transition tax. In December 2017, SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) to address the accounting implications of recently enacted U.S. federal tax reform. SAB 118 allows companies to record provisional amounts during a measurement period not to extend beyond one year of the enactment date to address ongoing guidance and tax interpretations that are expected over the next 12 months. The Company has adopted SAB 118 and currently considers its accounting of the impact of U.S. federal tax reform to be incomplete but continues to make a reasonable estimate of the effects on our existing deferred tax assets. The Company expects to complete the remainder of the analysis within the measurement period in accordance with SAB 118. Adjustments, if any, are not expected to impact the condensed consolidated statement of operations and comprehensive loss due to the full valuation allowance on the Company’s deferred tax assets. Accounting Pronouncements Issued But Not Yet Effective ASU 2016-02, Leases (Topic 842) requires the recognition of assets and liabilities arising from lease transactions on the balance sheet and the disclosure of key information about leasing arrangements. Accordingly, the lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. Both the asset and the liability will initially be measured at the present value of the future minimum lease payments over the lease term. Subsequent measurement, including the presentation of expenses and cash flows, will depend on the classification of the lease as either a finance or an operating lease. Initial costs directly attributable to negotiating and arranging the lease will be included in the asset. Lessees will also be required to provide additional qualitative and quantitative disclosures regarding the amount, timing and uncertainty of cash flows arising from leases. The new standard is effective for fiscal years beginning after December 15, 2018, and interim periods therein. Early adoption is permitted. As currently issued, entities are required to use a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. There are additional optional practical expedients that an entity may elect to apply. In January 2018, the FASB issued an exposure draft of the proposed ASU, Leases (Topic 842): Targeted Improvements . The proposed ASU provides an alternative transition method of adoption, permitting the recognition of a cumulative-effect adjustment to retained earnings on the date of adoption. We intend to adopt the standard on the effective date but have not yet selected a transition method. We are in the process of inventorying and scoping our population of leased assets in order to assess the impact Topic 842. Topic 842 is expected to impact the Company’s condensed consolidated financial statements as the Company has certain operating lease arrangements for which the Company is the lessee. Management is currently evaluating the impact of the adoption of Topic 842 will have on the Company’s financial position and results of operations. While the Company is currently evaluating the impact of the adoption of this standard on its financial statements, the Company anticipates the recognition of additional assets and corresponding liabilities on its condensed consolidated balance sheet related to leases. ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment simplifies how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under the amendments in ASU 2017-04, an entity should recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The updated guidance requires a prospective adoption. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the timing and impact of adopting this accounting standard update on its condensed consolidated financial statements and related disclosures.

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The carrying amount of the Company’s financial instruments, including cash and cash equivalents, other current assets, accounts payable, accrued expenses and accrued compensation approximate their fair value due to their short maturities. Authoritative guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The fair value of cash equivalents was determined based on Level 1 inputs utilizing quoted prices in active markets. The fair value of the Company’s common stock warrant liabilities and contingent consideration liabilities were determined based on Level 3 inputs using valuation models with significant unobservable inputs. Assets and liabilities measured at fair value on a recurring basis at March 31, 2018 and December 31, 2017 were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total March 31, 2018 Assets Cash equivalents (1) $ 256,615 $ — $ — $ 256,615 Liabilities Common stock warrant liabilities (2) $ — $ — $ 495 $ 495 Contingent consideration liabilities (3) $ — $ — $ 76,900 $ 76,900 December 31, 2017 Assets Cash equivalents (1) $ 289,782 $ — $ — $ 289,782 Liabilities Common stock warrant liabilities (2) $ — $ — $ 512 $ 512 Contingent consideration liabilities (3) $ — $ — $ 76,900 $ 76,900 (1) Cash equivalents are comprised of money market fund shares and are included as a component of cash and cash equivalents on the condensed consolidated balance sheets. (2) Represents the fair value of common stock warrants outstanding that may require cash settlement under certain circumstances. The Company estimated the fair value of the warrant liabilities using the Black-Scholes valuation model. As of December 31, 2017 and March 31, 2018 , common stock warrant liabilities relate to warrants issued in July 2011 in connection with a debt financing arrangement. The warrants entitle the holder to purchase up to 28,125 shares of common stock at an exercise price of $72.00 per share. The warrants will expire in July 2021. (3) In connection with a prior acquisition, the Company may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approval or sales-based milestone events. The Company estimated the fair value of the contingent consideration liabilities on the acquisition date using a probability-weighted income approach, which reflects the probability and timing of future payments. This fair value measurement is based on significant Level 3 inputs such as the anticipated timelines and probability of achieving development, regulatory approval or sales-based milestone events and projected revenues. The resulting probability-weighted cash flows are discounted at risk-adjusted rates. Subsequent to the acquisition date, at each reporting period prior to settlement, the Company revalues these liabilities by performing a review of the assumptions listed above and record increases or decreases in the fair value of these contingent consideration liabilities. In the absence of any significant changes in key assumptions, the quarterly determination of fair values of these contingent consideration liabilities would primarily reflect the passage of time. Significant judgment is used in determining Level 3 inputs and fair value measurements as of the acquisition date and for each subsequent reporting period. Updates to assumptions could have a significant impact on the Company’s results of operations in any given period and actual results may differ from estimates. For example, significant increases in the probability of achieving a milestone or projected revenues would result in a significantly higher fair value measurement while significant decreases in the estimated probability of achieving a milestone or projected revenues would result in a significantly lower fair value measurement. Significant increases in the discount rate or in the anticipated timelines would result in a significantly lower fair value measurement while significant decreases in the discount rate or anticipated timelines would result in a significantly higher fair value measurement. The potential contingent consideration payments required upon achievement of development, regulatory approval and sales-based milestones related to the Company’s acquisition of ZX008 range from zero if none of the milestones are achieved to a maximum of $95.0 million (undiscounted). There were no transfers between levels during the periods presented. The following table provides a reconciliation of liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2018 and 2017 (in thousands): Change in Fair Value March 31, December 31, 2016 Change in Fair Value March 31, 2017 Contingent consideration liabilities $ 76,900 $ — $ 76,900 $ 52,800 $ 600 $ 53,400 Common stock warrant liabilities 512 (17 ) 495 809 (587 ) 222 The changes in fair value of the liabilities shown in the table above are recorded through change in fair value of contingent consideration liabilities within operating expense and the change in fair value of common stock warrant liabilities within other income (expense) in the condensed consolidated statements of operations.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company has two noncancelable operating leases consisting of administrative and research and development office space for its Emeryville, California headquarters and former headquarters in San Diego, California that expire in November 2022 and March 2020, respectively. The former headquarters has been subleased to an unrelated third party for the remainder of the Company’s original lease term. Future minimum lease payments under our non-cancellable operating leases at March 31, 2018 , net of sublease income, were as follows (in thousands): Gross Lease Payments Sublease Income Net Lease Payments 2018 (remaining 9 months) $ 1,424 $ (379 ) $ 1,045 2019 1,955 (576 ) 1,379 2020 1,234 (148 ) 1,086 2021 1,004 — 1,004 2022 946 — 946 Total $ 6,563 $ (1,103 ) $ 5,460 Legal Matters The Company is not currently involved in any material legal proceedings. The Company may become involved in various legal proceedings and claims that arise in the ordinary course of business. Such matters are subject to uncertainty and there can be no assurance that such legal proceedings will not have a material adverse effect on its business, results of operations, financial position or cash flows.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company has adopted certain equity incentive and stock purchase plans as described in the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . In March 2018, our board of directors approved an amendment and restatement of our non-employee director compensation policy, pursuant to which any non-employee director who is first elected to the board of directors is granted an option to purchase 20,000 shares of our common stock on the date of his or her initial election to the board of directors. In addition, on the date of each annual meeting of our stockholders, commencing with the 2018 annual meeting, each non-employee director is eligible to receive an option to purchase 15,000 shares of common stock. Prior to March 2018, under our non-employee director compensation policy, any non-employee director who was first elected to the board of directors was granted an option to purchase 30,000 shares of our common stock on the date of his or her initial election to the board of directors. In addition, on the date of each annual meeting of our stockholders, each non-employee director was eligible to receive an option to purchase 20,000 shares of common stock. Equity Incentive Awards Activity Stock Options The following is a summary of stock option activity for the three months ended March 31, 2018 (in thousands, except per share data): Shares (in thousands) Weighted- Average Exercise Price per Share Outstanding at December 31, 2017 3,392 $ 14.41 Granted 490 42.37 Exercised (102 ) 19.09 Canceled (7 ) 19.00 Outstanding at March 31, 2018 3,773 $ 17.90 Restricted Stock Units The following is a summary of restricted stock unit activity for the three months ended March 31, 2018 (in thousands, except per share data): Shares (in thousands) Weighted- Average Fair Value per Share at Grant Date Outstanding as of December 31, 2017 259 $ 10.43 Granted 131 42.65 Vested (97 ) 10.38 Canceled — — Outstanding as of March 31, 2018 293 $ 24.84 As of March 31, 2018 , outstanding restricted stock units included 162,000 granted in March 2017 with performance-based conditions to employees and executives. The restricted stock units vest upon the approval of the Company’s new drug application for ZX008 by the FDA, provided such approval occurs within five years following the grant date. Due to the uncertainties associated with the FDA approval process, approval is not yet probable, as such term is used for accounting purposes, prior to the occurrence of the event. Accordingly, no compensation expense has been recognized to date for these performance-based awards. Valuation of Equity Awards The estimated grant date fair value of the stock options was estimated using the Black-Scholes option pricing model, based on the following assumptions: Three Months Ended March 31, 2018 2017 Risk free interest rate 2.3% to 2.7% 2.1% to 2.3% Expected term 6.0 to 6.1 years 6.0 to 6.1 years Expected volatility 84.2% to 85.2% 76.4% to 76.6% Expected dividend yield —% —% The fair value of restricted stock units granted is determined based on the price of the Company’s common stock on the date of grant. Stock-Based Compensation Expense The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations (in thousands): Three Months Ended March 31, 2018 2017 Cost of contract manufacturing $ — $ 77 Research and development 681 517 Selling, general and administrative 1,231 1,079 Total $ 1,912 $ 1,673

Net Loss Per Share (Notes)

Net Loss Per Share (Notes)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss Per Share Basic net loss from continuing operations per share is calculated by dividing net loss from continuing operations by the weighted average number of shares outstanding for the period. Diluted net loss from continuing operations per share is calculated by dividing net loss from continuing operations by the weighted average number of shares of common stock and potential dilutive common stock equivalents outstanding during the period if the effect is dilutive. The Company’s potentially dilutive shares of common stock include outstanding stock options, restricted stock units and warrants to purchase common stock. A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except per share amounts): Three Months Ended March 31, 2018 2017 Numerator: Net loss from continuing operations $ (30,180 ) $ (21,126 ) Denominator: Shares used in per share calculation 34,841 24,813 Net loss from continuing operations per share, basic and diluted $ (0.87 ) $ (0.85 ) The following table presents the potential shares of common stock outstanding that were excluded from the computation of diluted net loss from continuing operations per share for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Ended March 31, 2018 2017 Shares subject to outstanding common stock options 3,478 3,490 Shares subject to outstanding restricted stock units 266 137 Shares subject to outstanding warrants to purchase common stock 38 1,975 Total 3,782 5,602

Other

Other	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Other	Other The Company carries out extensive research and development activities that may benefit from the UK’s small and medium-sized enterprise research and development tax credit regime, whereby the Company may either receive an enhanced UK tax deduction on its research and development activities or a refundable cash credit. As of March 31, 2018, the Company has only filed a claim for a refundable cash credit for its 2015 tax year of up to $3.1 million . The Company has not recorded a receivable for this refundable cash credit at March 31, 2018 as collectability was not yet deemed probable or reasonably assured.

Summary of Significant Accoun13

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results may differ from those estimates.
Recent Accounting Pronouncements	Accounting Pronouncements Recently Adopted Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606) and subsequent amendments to the initial guidance (collectively, “Topic 606”) amended the existing accounting standards for revenue recognition. The core principle of Topic 606 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. The Company adopted Topic 606 effective January 1, 2018 using the modified retrospective approach. The adoption of Topic 606 did not have a material impact on the Company’s condensed consolidated financial statements as the Company does not have any contracts with customers ASU 2016-15, Statement of Cash Flows (Topic 230) provides guidance on eight specific cash flow issues, thereby reducing the diversity in practice in how certain transactions are classified in the statement of cash flows. The amendments in this ASU are applied using a retrospective transition method to each period presented. The Company adopted ASU 2016-15 effective January 1, 2018. The adoption of this accounting standards update did not have a material impact on the Company’s condensed consolidated financial statements. ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business narrows the definition of a business and provides additional guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This accounting standards update is required to be applied prospectively to transactions occurring after the date of adoption. The impact of the adoption on the Company's financial position and results of operations will be dependent upon future acquisitions or disposals, if any. The Company adopted ASU 2017-09 effective January 1, 2018. ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting provides guidance on determining changes to the terms and conditions of share-based payment awards and require an entity to apply modification accounting under Topic 718 unless all of the following conditions are met: (1) the fair value of the modified award is the same as the fair value of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; and (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The amendments should be applied prospectively to an award modified on or after the adoption date. The Company adopted ASU 2017-09 effective January 1, 2018. The adoption of this accounting standards update did not have a material impact on the Company’s condensed consolidated financial statements. On December 22, 2017, the U.S. federal government enacted the Tax Cuts and Jobs Act (“the Act”). The Tax Act contains, among other things, significant changes to corporate taxation, including reduction of the corporate tax rate from a top marginal rate of 35% to a flat rate of 21% for tax years beginning after December 31, 2017, limitation of the deduction for net operating losses to 80% of current year taxable income and elimination of net operating loss carrybacks, implementing a territorial tax system, and requiring a mandatory one-time tax on U.S. owned undistributed foreign earnings and profits known as the transition tax. In December 2017, SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) to address the accounting implications of recently enacted U.S. federal tax reform. SAB 118 allows companies to record provisional amounts during a measurement period not to extend beyond one year of the enactment date to address ongoing guidance and tax interpretations that are expected over the next 12 months. The Company has adopted SAB 118 and currently considers its accounting of the impact of U.S. federal tax reform to be incomplete but continues to make a reasonable estimate of the effects on our existing deferred tax assets. The Company expects to complete the remainder of the analysis within the measurement period in accordance with SAB 118. Adjustments, if any, are not expected to impact the condensed consolidated statement of operations and comprehensive loss due to the full valuation allowance on the Company’s deferred tax assets. Accounting Pronouncements Issued But Not Yet Effective ASU 2016-02, Leases (Topic 842) requires the recognition of assets and liabilities arising from lease transactions on the balance sheet and the disclosure of key information about leasing arrangements. Accordingly, the lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. Both the asset and the liability will initially be measured at the present value of the future minimum lease payments over the lease term. Subsequent measurement, including the presentation of expenses and cash flows, will depend on the classification of the lease as either a finance or an operating lease. Initial costs directly attributable to negotiating and arranging the lease will be included in the asset. Lessees will also be required to provide additional qualitative and quantitative disclosures regarding the amount, timing and uncertainty of cash flows arising from leases. The new standard is effective for fiscal years beginning after December 15, 2018, and interim periods therein. Early adoption is permitted. As currently issued, entities are required to use a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. There are additional optional practical expedients that an entity may elect to apply. In January 2018, the FASB issued an exposure draft of the proposed ASU, Leases (Topic 842): Targeted Improvements . The proposed ASU provides an alternative transition method of adoption, permitting the recognition of a cumulative-effect adjustment to retained earnings on the date of adoption. We intend to adopt the standard on the effective date but have not yet selected a transition method. We are in the process of inventorying and scoping our population of leased assets in order to assess the impact Topic 842. Topic 842 is expected to impact the Company’s condensed consolidated financial statements as the Company has certain operating lease arrangements for which the Company is the lessee. Management is currently evaluating the impact of the adoption of Topic 842 will have on the Company’s financial position and results of operations. While the Company is currently evaluating the impact of the adoption of this standard on its financial statements, the Company anticipates the recognition of additional assets and corresponding liabilities on its condensed consolidated balance sheet related to leases. ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment simplifies how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Under the amendments in ASU 2017-04, an entity should recognize an impairment charge for the amount by which the carrying amount of a reporting unit exceeds its fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The updated guidance requires a prospective adoption. ASU 2017-04 is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the timing and impact of adopting this accounting standard update on its condensed consolidated financial statements and related disclosures.
Fair Value Measurements	The carrying amount of the Company’s financial instruments, including cash and cash equivalents, other current assets, accounts payable, accrued expenses and accrued compensation approximate their fair value due to their short maturities. Authoritative guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The fair value of cash equivalents was determined based on Level 1 inputs utilizing quoted prices in active markets. The fair value of the Company’s common stock warrant liabilities and contingent consideration liabilities were determined based on Level 3 inputs using valuation models with significant unobservable inputs.
Stock-based Compensation	The Company has adopted certain equity incentive and stock purchase plans as described in the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 .
Net Loss per Share	Basic net loss from continuing operations per share is calculated by dividing net loss from continuing operations by the weighted average number of shares outstanding for the period. Diluted net loss from continuing operations per share is calculated by dividing net loss from continuing operations by the weighted average number of shares of common stock and potential dilutive common stock equivalents outstanding during the period if the effect is dilutive.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis at March 31, 2018 and December 31, 2017 were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total March 31, 2018 Assets Cash equivalents (1) $ 256,615 $ — $ — $ 256,615 Liabilities Common stock warrant liabilities (2) $ — $ — $ 495 $ 495 Contingent consideration liabilities (3) $ — $ — $ 76,900 $ 76,900 December 31, 2017 Assets Cash equivalents (1) $ 289,782 $ — $ — $ 289,782 Liabilities Common stock warrant liabilities (2) $ — $ — $ 512 $ 512 Contingent consideration liabilities (3) $ — $ — $ 76,900 $ 76,900 (1) Cash equivalents are comprised of money market fund shares and are included as a component of cash and cash equivalents on the condensed consolidated balance sheets. (2) Represents the fair value of common stock warrants outstanding that may require cash settlement under certain circumstances. The Company estimated the fair value of the warrant liabilities using the Black-Scholes valuation model. As of December 31, 2017 and March 31, 2018 , common stock warrant liabilities relate to warrants issued in July 2011 in connection with a debt financing arrangement. The warrants entitle the holder to purchase up to 28,125 shares of common stock at an exercise price of $72.00 per share. The warrants will expire in July 2021. (3) In connection with a prior acquisition, the Company may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approval or sales-based milestone events. The Company estimated the fair value of the contingent consideration liabilities on the acquisition date using a probability-weighted income approach, which reflects the probability and timing of future payments. This fair value measurement is based on significant Level 3 inputs such as the anticipated timelines and probability of achieving development, regulatory approval or sales-based milestone events and projected revenues. The resulting probability-weighted cash flows are discounted at risk-adjusted rates. Subsequent to the acquisition date, at each reporting period prior to settlement, the Company revalues these liabilities by performing a review of the assumptions listed above and record increases or decreases in the fair value of these contingent consideration liabilities. In the absence of any significant changes in key assumptions, the quarterly determination of fair values of these contingent consideration liabilities would primarily reflect the passage of time. Significant judgment is used in determining Level 3 inputs and fair value measurements as of the acquisition date and for each subsequent reporting period. Updates to assumptions could have a significant impact on the Company’s results of operations in any given period and actual results may differ from estimates. For example, significant increases in the probability of achieving a milestone or projected revenues would result in a significantly higher fair value measurement while significant decreases in the estimated probability of achieving a milestone or projected revenues would result in a significantly lower fair value measurement. Significant increases in the discount rate or in the anticipated timelines would result in a significantly lower fair value measurement while significant decreases in the discount rate or anticipated timelines would result in a significantly higher fair value measurement. The potential contingent consideration payments required upon achievement of development, regulatory approval and sales-based milestones related to the Company’s acquisition of ZX008 range from zero if none of the milestones are achieved to a maximum of $95.0 million (undiscounted). There were no transfers between levels during the periods presented.
Assets Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis at March 31, 2018 and December 31, 2017 were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total March 31, 2018 Assets Cash equivalents (1) $ 256,615 $ — $ — $ 256,615 Liabilities Common stock warrant liabilities (2) $ — $ — $ 495 $ 495 Contingent consideration liabilities (3) $ — $ — $ 76,900 $ 76,900 December 31, 2017 Assets Cash equivalents (1) $ 289,782 $ — $ — $ 289,782 Liabilities Common stock warrant liabilities (2) $ — $ — $ 512 $ 512 Contingent consideration liabilities (3) $ — $ — $ 76,900 $ 76,900 (1) Cash equivalents are comprised of money market fund shares and are included as a component of cash and cash equivalents on the condensed consolidated balance sheets. (2) Represents the fair value of common stock warrants outstanding that may require cash settlement under certain circumstances. The Company estimated the fair value of the warrant liabilities using the Black-Scholes valuation model. As of December 31, 2017 and March 31, 2018 , common stock warrant liabilities relate to warrants issued in July 2011 in connection with a debt financing arrangement. The warrants entitle the holder to purchase up to 28,125 shares of common stock at an exercise price of $72.00 per share. The warrants will expire in July 2021. (3) In connection with a prior acquisition, the Company may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approval or sales-based milestone events. The Company estimated the fair value of the contingent consideration liabilities on the acquisition date using a probability-weighted income approach, which reflects the probability and timing of future payments. This fair value measurement is based on significant Level 3 inputs such as the anticipated timelines and probability of achieving development, regulatory approval or sales-based milestone events and projected revenues. The resulting probability-weighted cash flows are discounted at risk-adjusted rates. Subsequent to the acquisition date, at each reporting period prior to settlement, the Company revalues these liabilities by performing a review of the assumptions listed above and record increases or decreases in the fair value of these contingent consideration liabilities. In the absence of any significant changes in key assumptions, the quarterly determination of fair values of these contingent consideration liabilities would primarily reflect the passage of time. Significant judgment is used in determining Level 3 inputs and fair value measurements as of the acquisition date and for each subsequent reporting period. Updates to assumptions could have a significant impact on the Company’s results of operations in any given period and actual results may differ from estimates. For example, significant increases in the probability of achieving a milestone or projected revenues would result in a significantly higher fair value measurement while significant decreases in the estimated probability of achieving a milestone or projected revenues would result in a significantly lower fair value measurement. Significant increases in the discount rate or in the anticipated timelines would result in a significantly lower fair value measurement while significant decreases in the discount rate or anticipated timelines would result in a significantly higher fair value measurement. The potential contingent consideration payments required upon achievement of development, regulatory approval and sales-based milestones related to the Company’s acquisition of ZX008 range from zero if none of the milestones are achieved to a maximum of $95.0 million (undiscounted). There were no transfers between levels during the periods presented.
Reconciliation of Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3)	The following table provides a reconciliation of liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2018 and 2017 (in thousands): Change in Fair Value March 31, December 31, 2016 Change in Fair Value March 31, 2017 Contingent consideration liabilities $ 76,900 $ — $ 76,900 $ 52,800 $ 600 $ 53,400 Common stock warrant liabilities 512 (17 ) 495 809 (587 ) 222

Commitments and Contingencies C

Commitments and Contingencies Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Payments Under Non-cancelable Operating Leases	Future minimum lease payments under our non-cancellable operating leases at March 31, 2018 , net of sublease income, were as follows (in thousands): Gross Lease Payments Sublease Income Net Lease Payments 2018 (remaining 9 months) $ 1,424 $ (379 ) $ 1,045 2019 1,955 (576 ) 1,379 2020 1,234 (148 ) 1,086 2021 1,004 — 1,004 2022 946 — 946 Total $ 6,563 $ (1,103 ) $ 5,460

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock-based Compensation Activity	The following is a summary of stock option activity for the three months ended March 31, 2018 (in thousands, except per share data): Shares (in thousands) Weighted- Average Exercise Price per Share Outstanding at December 31, 2017 3,392 $ 14.41 Granted 490 42.37 Exercised (102 ) 19.09 Canceled (7 ) 19.00 Outstanding at March 31, 2018 3,773 $ 17.90 The following is a summary of restricted stock unit activity for the three months ended March 31, 2018 (in thousands, except per share data): Shares (in thousands) Weighted- Average Fair Value per Share at Grant Date Outstanding as of December 31, 2017 259 $ 10.43 Granted 131 42.65 Vested (97 ) 10.38 Canceled — — Outstanding as of March 31, 2018 293 $ 24.84
Assumptions used in the Black-Scholes Option-Pricing Model	The estimated grant date fair value of the stock options was estimated using the Black-Scholes option pricing model, based on the following assumptions: Three Months Ended March 31, 2018 2017 Risk free interest rate 2.3% to 2.7% 2.1% to 2.3% Expected term 6.0 to 6.1 years 6.0 to 6.1 years Expected volatility 84.2% to 85.2% 76.4% to 76.6% Expected dividend yield —% —%
Stock-Based Compensation Expense	The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations (in thousands): Three Months Ended March 31, 2018 2017 Cost of contract manufacturing $ — $ 77 Research and development 681 517 Selling, general and administrative 1,231 1,079 Total $ 1,912 $ 1,673

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	A reconciliation of the numerators and denominators used in computing net loss from continuing operations per share is as follows (in thousands, except per share amounts): Three Months Ended March 31, 2018 2017 Numerator: Net loss from continuing operations $ (30,180 ) $ (21,126 ) Denominator: Shares used in per share calculation 34,841 24,813 Net loss from continuing operations per share, basic and diluted $ (0.87 ) $ (0.85 )
Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss per Share	The following table presents the potential shares of common stock outstanding that were excluded from the computation of diluted net loss from continuing operations per share for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Ended March 31, 2018 2017 Shares subject to outstanding common stock options 3,478 3,490 Shares subject to outstanding restricted stock units 266 137 Shares subject to outstanding warrants to purchase common stock 38 1,975 Total 3,782 5,602

Organization, Basis of Presen18

Organization, Basis of Presentation and Going Concern - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 602,220	$ 572,040

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Shares of common stock exercisable through warrants	28,125
Warrants exercise price per share (usd per share)	$ 72
Money market fund shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on a recurring basis	$ 256,615,000	$ 289,782,000
Money market fund shares | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on a recurring basis	256,615,000	289,782,000
Money market fund shares | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on a recurring basis	0	0
Money market fund shares | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on a recurring basis	0	0
Common Stock Warrant Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	495,000	512,000
Common Stock Warrant Liabilities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	0	0
Common Stock Warrant Liabilities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	0	0
Common Stock Warrant Liabilities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	495,000	512,000
Contingent Consideration Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	76,900,000	76,900,000
Contingent Consideration Liabilities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	0	0
Contingent Consideration Liabilities | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	0	0
Contingent Consideration Liabilities | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	76,900,000	$ 76,900,000
ZX008
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Potential contingent consideration payment, minimum	0
Potential contingent consideration payment, maximum	$ 95,000,000

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Contingent Consideration Liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 76,900	$ 52,800
Changes in fair value	0	600
Ending Balance	76,900	53,400
Common Stock Warrant Liabilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	512	809
Changes in fair value	(17)	(587)
Ending Balance	$ 495	$ 222

Commitments and Contingencies21

Commitments and Contingencies (Details)	Dec. 31, 2017lease
Commitments and Contingencies Disclosure [Abstract]
Number of Noncancelable Leases	2

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments (Details) $ in Thousands	Mar. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2018 (remaining 9 months) gross lease payment due	$ 1,424
2019 gross lease payment due	1,955
2020 gross lease payment due	1,234
2021 gross lease payment due	1,004
2022 gross lease payment due	946
Total gross lease payment due	6,563
2018 (remaining 9 months) sublease income	(379)
2019 sublease income	(576)
2020 sublease income	(148)
2021 sublease income	0
2022 sublease income	0
Total sublease income	(1,103)
2018 (remaining 9 months) net lease payments	1,045
2019 net lease payments	1,379
2020 net lease payments	1,086
2021 net lease payments	1,004
2022 net lease payments	946
Total net lease payments	$ 5,460

Stock-Based Compensation - Opti

Stock-Based Compensation - Options Activity (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Shares (in thousands)
December 31, 2017 (in shares) | shares	3,392
Granted (in shares) | shares	490
Exercised (in shares) | shares	(102)
Canceled (in shares) | shares	(7)
March 31, 2018 (in shares) | shares	3,773
Weighted- Average Exercise Price per Share
Outstanding weighted average exercise price, beginning balance (in usd per share) | $ / shares	$ 14.41
Granted weighted average exercise price (in usd per share | $ / shares	42.37
Exercised weighted average exercise price (in usd per share | $ / shares	19.09
Canceled weighted average exercise price (in usd per share | $ / shares	19
Outstanding weighted average exercise price, ending balance (in usd per share | $ / shares	$ 17.90

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Unit Activity (Details) - Restricted stock units shares in Thousands	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31, 2017 (in shares) | shares	259
Granted (in shares) | shares	131
Vested (in shares) | shares	(97)
Canceled (in shares) | shares	0
Outstanding at March 31, 2018 (in shares) | shares	293
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested at December 31, 2017 - Weighted average fair value per share at grant date (in usd per share) | $ / shares	$ 10.43
Granted - Weighted average fair value per share at grant date (in usd per share) | $ / shares	42.65
Vested - Weighted average fair value per share at grant date (in usd per share) | $ / shares	10.38
Canceled - Weighted average fair value per share at grant date (in usd per share) | $ / shares	0
Nonvested at March 31, 2018 - Weighted average fair value per share at grant date (in usd per share) | $ / shares	$ 24.84

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions used in Black-Scholes Option-Pricing Model (Detail) - Stock Options	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate, minimum	2.30%	2.10%
Risk free interest rate, maximum	2.70%	2.30%
Expected volatility, minimum	84.20%	76.40%
Expected volatility, maximum	85.20%	76.60%
Expected dividend yield	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years	6 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 1 month	6 years 1 month

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,912	$ 1,673
Cost of contract manufacturing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	0	77
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	681	517
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,231	$ 1,079

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - shares	Mar. 31, 2018	Feb. 28, 2018	Dec. 31, 2017
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding RSUs at March 31, 2018 (in shares)	293,000		259,000
Non-employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options granted upon initial election to board (shares)	20,000	30,000
Additional number of options available for grant annually (shares)	15,000	20,000
Employees and Executives | Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding RSUs at March 31, 2018 (in shares)	162,000

Net Loss Per Share - Reconcilia

Net Loss Per Share - Reconciliation of Numerator and Denominators in Computing Net Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net loss from continuing operations	$ (30,180)	$ (21,126)
Shares used in per share calculation (in shares)	34,841	24,813
Net loss from continuing operations per share, basic and diluted (in dollars per share)	$ (0.87)	$ (0.85)

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share amount	3,782	5,602
Shares subject to outstanding common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share amount	3,478	3,490
Shares subject to outstanding restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share amount	266	137
Shares subject to outstanding warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share amount	38	1,975

Other (Details)

Other (Details) $ in Millions	Mar. 31, 2018USD ($)
Income Tax Disclosure [Abstract]
Claim for refundable cash credit	$ 3.1