Heron Therapeutics (HRTX) 10-K 2 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 03, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	HRTX
Entity Registrant Name	HERON THERAPEUTICS, INC. /DE/
Entity Central Index Key	0000818033
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		90,374,284
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-33221
Entity Tax Identification Number	94-2875566
Entity Address, Address Line One	4242 CAMPUS POINT COURT
Entity Address, Address Line Two	SUITE 200
Entity Address, City or Town	SAN DIEGO
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	251-4400
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Document Annual Report	true
Entity Public Float			$ 1.4
Document Transition Report	false
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement related to its 2020 Annual Meeting of Stockholders’ to be held on or about June 17, 2020 are incorporated by reference into Part III of this Annual Report on Form 10-K. Such Definitive Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates. Except as expressly incorporated by reference, the registrant’s Definitive Proxy Statement shall not be deemed to be part of this report.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 71,898	$ 31,836
Short-term investments	319,074	300,535
Accounts receivable, net	39,879	64,652
Inventory	24,968	39,032
Prepaid expenses and other current assets	23,245	11,193
Total current assets	479,064	447,248
Property and equipment, net	19,618	14,677
Right-of-use lease assets	13,754
Other assets	346	254
Total assets	512,782	462,179
Current liabilities:
Accounts payable	2,758	16,863
Accrued clinical and manufacturing liabilities	34,614	24,470
Accrued payroll and employee liabilities	15,248	13,397
Other accrued liabilities	36,535	32,715
Current lease liabilities	1,926
Convertible notes payable to related parties, net of discount	5,624	4,574
Total current liabilities	96,705	92,019
Non-current lease liabilities	12,242
Total liabilities	108,947	92,019
Commitments and contingencies (see Note 6)
Stockholders’ equity:
Preferred stock, $0.01 par value: 2,500 shares authorized; no shares issued or outstanding at December 31, 2019 and 2018
Common stock, $0.01 par value: 150,000 shares authorized; 90,304 and 78,174 shares issued and outstanding at December 31, 2019 and 2018, respectively	903	782
Additional paid-in capital	1,568,317	1,330,186
Accumulated other comprehensive income (loss)	85	(87)
Accumulated deficit	(1,165,470)	(960,721)
Total stockholders’ equity	403,835	370,160
Total liabilities and stockholders’ equity	$ 512,782	$ 462,179

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	2,500	2,500
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	150,000	150,000
Common stock, shares issued (in shares)	90,304	78,174
Common stock, shares outstanding (in shares)	90,304	78,174

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Net product sales	$ 145,968	$ 77,474	$ 30,767
Operating expenses:
Cost of product sales	61,619	27,512	4,588
Research and development	167,382	140,032	138,582
General and administrative	37,897	29,263	25,554
Sales and marketing	89,764	64,604	56,601
Total operating expenses	356,662	261,411	225,325
Loss from operations	(210,694)	(183,937)	(194,558)
Other income (expense), net:
Interest income	7,259	5,965	1,049
Interest expense	(1,472)	(2,672)	(3,937)
Other income (expense)	158	1,804	(38)
Total other income (expense), net	5,945	5,097	(2,926)
Net loss	(204,749)	(178,840)	(197,484)
Other comprehensive loss:
Unrealized gains (losses) on short-term investments	172	(77)	7
Comprehensive loss	$ (204,577)	$ (178,917)	$ (197,477)
Basic and diluted net loss per share	$ (2.50)	$ (2.44)	$ (3.65)
Shares used in computing basic and diluted net loss per share	81,779	73,193	54,040

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Balance at Dec. 31, 2016	$ (21,251)	$ 394	$ 564,343	$ (17)	$ (585,971)
Balance (in shares) at Dec. 31, 2016		39,355,000
Issuance of common stock in public offerings, net	306,279	$ 238	306,041
Issuance of common stock in public offerings, net (in shares)		23,822,000
Conversion benefit included in Convertible Notes issued	369		369
Issuance of common stock under Employee Stock Purchase Plan	989	$ 1	988
Issuance of common stock under Employee Stock Purchase Plan (in shares)		77,000
Issuance of common stock on exercise of stock options	$ 11,463	$ 13	11,450
Issuance of common stock on exercise of stock options (in shares)	1,350,605	1,351,000
Issuance of common stock on exercise of warrants (in shares)		4,000
Issuance of warrants	$ 226		226
Stock-based compensation expense	30,538		30,538
Net loss	(197,484)				(197,484)
Net unrealized gain (loss) on short-term investments	7			7
Comprehensive loss	(197,477)
Balance at Dec. 31, 2017	131,136	$ 646	913,955	(10)	(783,455)
Balance (in shares) at Dec. 31, 2017		64,609,000
Cumulative effect of adoption of new accounting standard at Dec. 31, 2017	1,574				1,574
Issuance of common stock in public offerings, net	363,128	$ 120	363,008
Issuance of common stock in public offerings, net (in shares)		11,963,000
Conversion benefit included in Convertible Notes issued	392		392
Issuance of common stock under Employee Stock Purchase Plan	1,179	$ 1	1,178
Issuance of common stock under Employee Stock Purchase Plan (in shares)		72,000
Issuance of common stock on exercise of stock options	$ 18,301	$ 15	18,286
Issuance of common stock on exercise of stock options (in shares)	1,529,509	1,530,000
Stock-based compensation expense	$ 33,367		33,367
Net loss	(178,840)				(178,840)
Net unrealized gain (loss) on short-term investments	(77)			(77)
Comprehensive loss	(178,917)
Balance at Dec. 31, 2018	370,160	$ 782	1,330,186	(87)	(960,721)
Balance (in shares) at Dec. 31, 2018		78,174,000
Issuance of common stock in public offerings, net	162,151	$ 99	162,052
Issuance of common stock in public offerings, net (in shares)		9,857,000
Conversion benefit included in Convertible Notes issued	416		416
Issuance of common stock under Employee Stock Purchase Plan	2,109	$ 1	2,108
Issuance of common stock under Employee Stock Purchase Plan (in shares)		126,000
Issuance of common stock on exercise of stock options	$ 22,164	$ 20	22,144
Issuance of common stock on exercise of stock options (in shares)	1,983,221	1,983,000
Issuance of common stock on exercise of warrants	$ 1	$ 1
Issuance of common stock on exercise of warrants (in shares)		132,000
Issuance of common stock on conversion of convertible notes (in shares)		32,000
Stock-based compensation expense	51,411		51,411
Net loss	(204,749)				(204,749)
Net unrealized gain (loss) on short-term investments	172			172
Comprehensive loss	(204,577)
Balance at Dec. 31, 2019	$ 403,835	$ 903	$ 1,568,317	$ 85	$ (1,165,470)
Balance (in shares) at Dec. 31, 2019		90,304,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net loss	$ (204,749,000)	$ (178,840,000)	$ (197,484,000)
Adjustments to reconcile net loss to net cash used for operating activities:
Stock-based compensation expense	51,411,000	33,367,000	30,538,000
Depreciation and amortization	2,044,000	1,513,000	1,531,000
Amortization of debt discount	1,050,000	890,000	773,000
Accretion of discount on short-term investments	(3,730,000)	(3,412,000)	(278,000)
Realized gain on available-for-sale investments	(8,000)	0	0
Impairment of property and equipment	107,000	72,000
Loss on disposal of property and equipment	62,000	29,000	39,000
Change in operating assets and liabilities:
Accounts receivable	24,773,000	(22,778,000)	(39,914,000)
Prepaid expenses and other assets	(12,052,000)	(7,482,000)	3,000
Inventory	14,064,000	(29,122,000)	(4,768,000)
Accounts payable	(14,105,000)	(1,906,000)	11,955,000
Accrued clinical and manufacturing liabilities	10,144,000	(3,614,000)	13,713,000
Accrued payroll and employee liabilities	1,851,000	4,537,000	446,000
Deferred revenue			1,664,000
Other accrued liabilities	4,558,000	14,941,000	11,482,000
Net cash used for operating activities	(124,580,000)	(191,805,000)	(170,300,000)
Investing activities:
Purchases of short-term investments	(477,035,000)	(497,104,000)	(121,570,000)
Maturities and sales of short-term investments	462,406,000	227,700,000	131,783,000
Purchases of property and equipment	(7,154,000)	(9,171,000)	(2,553,000)
Proceeds from the sale of property and equipment		25,000	78,000
Net cash (used for) provided by investing activities	(21,783,000)	(278,550,000)	7,738,000
Financing activities:
Net proceeds from sale of common stock and/or pre-funded warrants	162,151,000	363,128,000	306,279,000
Proceeds from purchases under the Employee Stock Purchase Plan	2,109,000	1,179,000	989,000
Proceeds from stock option exercises	22,164,000	18,301,000	11,463,000
Proceeds from warrant exercises	1,000
Repayment of promissory note payable to related party		(25,000,000)	(25,000,000)
Net cash provided by financing activities	186,425,000	357,608,000	293,731,000
Net increase (decrease) in cash and cash equivalents	40,062,000	(112,747,000)	131,169,000
Cash and cash equivalents at beginning of year	31,836,000	144,583,000	13,414,000
Cash and cash equivalents at end of year	$ 71,898,000	31,836,000	144,583,000
Supplemental disclosure of cash flow information:
Interest paid		1,183,000	$ 2,789,000
Cumulative effect of adoption of new accounting standard		$ 1,574,000

Organization and Business

Organization and Business	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Business	1. Organization and Business Heron Therapeutics, Inc. (“Company,” “Heron” or “we”) is a commercial-stage biotechnology company focused on improving the lives of patients by developing best-in-class treatments to address some of the most important unmet patient needs. We are developing novel, patient-focused solutions that apply our innovative science and technologies to already-approved pharmacological agents for patients suffering from pain or cancer. In August 2016, our first commercial product, SUSTOL (granisetron) extended-release injection (“SUSTOL”), was approved by the U.S. Food and Drug Administration (“FDA”). SUSTOL is indicated in combination with other antiemetics in adults for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic chemotherapy (MEC) or anthracycline and cyclophosphamide (AC) combination chemotherapy regimens. SUSTOL is an extended-release, injectable 5-hydroxytryptamine type 3 receptor antagonist that utilizes our proprietary Biochronomer drug delivery technology to maintain therapeutic levels of granisetron for ≥5 days. We commenced commercial sales of SUSTOL in the U.S. in October 2016. In November 2017, our second commercial product, CINVANTI (aprepitant) injectable emulsion (“CINVANTI”) In October 2019, the FDA approved our supplemental New Drug Application (“sNDA”) for CINVANTI to expand the indication and recommended dosage to include the 130 mg single-dose regimen for patients receiving (“MEC”). 1 1 approved our sNDA for CINVANTI, for IV use, which expanded the administration of CINVANTI beyond the initially approved administration method (a 30-minute IV infusion) to include a 2-minute IV injection. HTX-011, an investigational agent, is a dual-acting, fixed-dose combination of the local anesthetic bupivacaine with a low dose of the nonsteroidal anti-inflammatory drug meloxicam. It is the first and only extended-release local anesthetic to demonstrate in Phase 3 studies significantly reduced pain and opioid use through 72 hours compared to bupivacaine solution, the current standard-of-care local anesthetic for postoperative pain control. HTX-011 was granted Fast Track designation from the FDA in the fourth quarter of 2017 and Breakthrough Therapy designation in the second quarter of 2018. Heron submitted a New Drug Application (“NDA”) to the FDA for HTX-011 in October of 2018 and received Priority Review designation in December of 2018. A Complete Response Letter was received from the FDA regarding the NDA for HTX-011 on April 30, 2019 relating to chemistry, manufacturing and controls and non-clinical information. No issues related to clinical efficacy or safety were noted. Heron resubmitted an NDA to the FDA for HTX-011 in September 2019. The Prescription Drug User Fee Act goal date is June 26, 2020. A Marketing Authorisation Application for HTX-011 was validated by the European Medicines Agency in March 2019 for review under the Centralised Procedure. Heron’s New Drug Submission for HTX-011 for the management of postoperative pain was granted Priority Review status by Health Canada in October 2019 and accepted by Health Canada in November 2019. HTX-034, our next-generation product candidate for postoperative pain management, is in development for postoperative pain via local application. Based on the positive results of preclinical studies in which HTX-034 demonstrated significant pain reduction for 7 days, we have initiated formal development of this next-generation postoperative pain management product candidate. As of December 31, 2019, we had $391.0 million in cash, cash equivalents and short-term investments. We have incurred significant operating losses and negative cash flows from operations. Management believes that the Company’s existing cash, cash equivalents and short-term investments will be sufficient to meet the Company’s anticipated cash requirements for at least one year from the date this Annual Report on Form 10-K is filed with the U.S. Securities and Exchange Commission (“SEC”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation The accompanying consolidated financial statements include the accounts of Heron Therapeutics, Inc. and its wholly-owned subsidiary, Heron Therapeutics B.V., which was organized in the Netherlands in March 2015. Heron Therapeutics B.V. has no operations and no material assets or liabilities, and there have been no significant transactions related to Heron Therapeutics B.V. since its inception. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and disclosures made in the accompanying notes to the financial statements. Our significant accounting policies that involve significant judgment and estimates include revenue recognition, investments, inventory and the related reserves, accrued clinical liabilities, income taxes and stock-based compensation. Actual results could differ materially from those estimates. Cash, Cash Equivalents and Short-term Investments Cash and cash equivalents consist of cash and highly liquid investments with contractual maturities of three months or less from the original purchase date. Short-term investments consist of securities with contractual maturities of greater than three months from the original purchase date. Securities with contractual maturities greater than one year are classified as short-term investments on the consolidated balance sheets, as we have the ability, if necessary, to liquidate these securities to meet our liquidity needs in the next 12 months. We have classified our short-term investments as available-for-sale securities in the accompanying consolidated financial statements. Available-for-sale securities are stated at fair market value, with net changes in unrealized gains and losses reported in other comprehensive loss and realized gains and losses included in other income (expense), net. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in interest income. Our bank and investment accounts have been placed under control agreements in accordance with our Senior Secured Convertible Notes (“Convertible Notes”) (see Note 8). Fair Value of Financial Instruments A company may elect to use fair value to measure accounts and loans receivable, available-for-sale and held-to-maturity securities, equity method investments, accounts payable, guarantees and issued debt. Other eligible items include firm commitments for financial instruments that otherwise would not be recognized at inception and non-cash warranty obligations where a warrantor is permitted to pay a third party to provide the warranty goods or services. If the use of fair value is elected, any upfront costs and fees related to the item such as debt issuance costs must be recognized in earnings and cannot be deferred. The fair value election is irrevocable and generally made on an instrument-by-instrument basis, even if a company has similar instruments that it elects not to measure based on fair value. Unrealized gains and losses on existing items for which fair value has been elected are reported as a cumulative adjustment to beginning retained earnings and any changes in fair value are recognized in earnings. We have elected to not apply the fair value option to our financial assets and liabilities. Financial instruments, including cash and cash equivalents, receivables, inventory, prepaid expenses, other current assets, accounts payable and accrued expenses, are carried at cost, which is considered to be representative of their respective fair values because of the short-term maturity of these instruments. Short-term available-for-sale investments are carried at fair value (see Note 3 ) . Our Convertible Notes outstanding at December 31, 201 9 do not have a readily available ascertainable market value, however, the carrying value is considered to approximate its fair value. Concentration of Credit Risk Cash, cash equivalents and short-term investments are financial instruments that potentially subject us to concentrations of credit risk. We deposit our cash in financial institutions. At times, such deposits may be in excess of insured limits. We may also invest our excess cash in money market funds, U.S. government and agencies, corporate debt securities and commercial paper. We have established guidelines relative to our diversification of our cash investments and their maturities in an effort to maintain safety and liquidity. These guidelines are periodically reviewed and modified to take advantage of trends in yields and interest rates. Our products are distributed in the U.S. through a limited number of specialty distributors and full line wholesalers (collectively, “Customers”) that resell our products to healthcare providers and hospitals, the end users. The following table includes the percentage of net product sales and accounts receivable balances for our three major Customers, each of which comprised 10% or more of our net product sales: Net Product Sales Accounts Receivable Year Ended December 31, 2019 As of December 31, 2019 Customer A 40.9 % 48.9 % Customer B 39.5 % 38.6 % Customer C 17.4 % 11.7 % Total 97.8 % 99.2 % Accounts Receivable, Net Accounts receivable are recorded at the invoice amount, net of an allowance for doubtful accounts. The allowance for doubtful accounts reflects accounts receivable balances that are believed to be uncollectible. In estimating the allowance for doubtful accounts, we consider: (1) our historical experience with collections and write-offs; (2) the credit quality of our Customers and any recent or anticipated changes thereto; and (3) the outstanding balances and past due amounts from our Customers. We offered extended payment terms to our Customers in connection with our product launches of SUSTOL and CINVANTI in October 2016 and January 2018, respectively, in anticipation of the timing in reimbursement by government and commercial payers. Effective January 2018, we shortened payment terms to certain of our SUSTOL Customers. Effective January 2019, we shortened payment terms to our CINVANTI Customers. As of December 31, 2019, extended payment terms given to our Customers were evaluated in accordance with GAAP and did not impact the collectability of accounts receivables. As of December 31, 2019, we determined that an allowance for doubtful accounts was not required. For the year ended December 31, 2019, we did not write-off any accounts receivable balances. Inventory Inventory is stated at the lower of cost or estimated net realizable value on a first-in, first-out, or FIFO, basis. We periodically analyze our inventory levels and write down inventory that has become obsolete, inventory that has a cost basis in excess of its estimated realizable value and inventory quantities that are in excess of expected sales requirements as cost of product sales. The determination of whether inventory costs will be realizable requires estimates by management. If actual market conditions are less favorable than projected by management, additional write-downs of inventory may be required, which would be recorded as cost of product sales. Property and Equipment Property and equipment is stated at cost less accumulated depreciation and amortization. Depreciation is calculated on a straight-line basis over the estimated useful lives of the assets (generally 5 years). Leasehold improvements are stated at cost and amortized on a straight-line basis over the shorter of the estimated useful life of the asset or the lease term. Impairment of Long-Lived Assets If indicators of impairment exist, we assess the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through undiscounted future operating cash flows. If impairment is indicated, we measure the amount of such impairment by comparing the carrying value of the asset to the fair value of the asset and record the impairment as a reduction in the carrying value of the related asset with a corresponding charge to operating expenses. Estimating the undiscounted future operating cash flows associated with long-lived assets requires judgment and assumptions that could differ materially from actual results. Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements Codification Improvements to Topic 842, Leases Leases We determine if an agreement is a lease or contains lease components at inception. Operating leases are recorded as lease liabilities with corresponding ROU lease assets on the consolidated balance sheets. ROU lease assets represent our right to use the underlying assets over the lease term, and lease liabilities represent the present value of our obligation to make lease payments arising from the lease. Lease liabilities are recognized at the lease commencement based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. We use the implicit rate when readily determinable. The ROU lease assets equal the lease liabilities, less unamortized lease incentives, unamortized initial direct costs and the cumulative difference between rent expense and amounts paid under the lease. The lease term includes any option to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. We have lease agreements with both lease and non-lease components, which are generally accounted for separately. Revenue Recognition In May 2014, FASB issued ASU No. 2014-09, Revenue from Contracts with Customers Accrued Clinical Liabilities We accrue clinical costs based on work performed, which relies on estimates of the progress of the trials and the related expenses incurred. Clinical trial related contracts vary significantly in duration, and may be for a fixed amount, based on the achievement of certain contingent events or deliverables, a variable amount based on actual costs incurred, capped at a certain limit or contain a combination of these elements. Revisions are recorded to research and development expense in the period in which the facts that give rise to the revision become known. Historically, revisions have not resulted in material changes to research and development expense; however, a modification in the protocol of a clinical trial or cancellation of a clinical trial could result in a material charge to our results of operations. Research and Development Expense All costs of research and development are expensed in the period incurred. Research and development expense primarily consists of personnel and related costs, stock-based compensation expense, fees paid to outside service providers and consultants, facilities costs and materials used in clinical and preclinical trials and research and development. Patent Costs We incur outside legal fees in connection with filing and maintaining our various patent applications. All patent costs are expensed as incurred and are included in general and administrative expense in the consolidated statements of operations and comprehensive loss. Stock-Based Compensation Expense We estimate the fair value of stock-based payment awards using the Black-Scholes option pricing model. This fair value is then amortized using the straight-line single-option method of attributing the value of stock-based compensation to expense over the requisite service periods of the awards. The Black-Scholes option pricing model requires the input of complex and subjective assumptions, including each option’s expected life and price volatility of the underlying stock. As stock-based compensation expense is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Forfeitures are estimated based on historical data . Warrants We have issued warrants to purchase shares of our common stock in conjunction with certain equity financings or in exchange for services. The terms of the warrants were evaluated to determine the appropriate classification as equity or a liability. Income Taxes We recognize the impact of a tax position in our consolidated financial statements if the position is more likely than not to be sustained on examination and on the technical merits of the position. The total amount of unrecognized tax benefits, if recognized, would affect other tax accounts, primarily deferred taxes in future periods, and would not affect our effective tax rate, since we maintain a full valuation allowance against our deferred tax assets (see Note 10). We recognize interest and penalties related to income tax matters in income tax expense. Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Net changes in unrealized gains and losses on available-for-sale securities are included in other comprehensive loss and represent the difference between our net loss and comprehensive net loss for all periods presented. Net Loss per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration of common stock equivalents. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, stock options, warrants and shares of common stock underlying Convertible Notes are considered to be common stock equivalents and are included in the calculation of diluted net loss per share only when their effect is dilutive. Because we have incurred a net loss for all periods presented in the consolidated statements of operations and comprehensive loss, the following common stock equivalents were not included in the computation of net loss per share because their effect would be anti-dilutive (in thousands): December 31, 2019 2018 2017 Stock options outstanding 16,665 15,265 13,463 Warrants outstanding 508 640 620 Shares of common stock underlying Convertible Notes outstanding 8,960 8,473 7,983 Recent Accounting Pronouncements Adopted in 2020 In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”) , which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables and available-for-sale debt securities. In May 2019, the FASB issued ASU No. 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief (“ASU 2019-05”), which amends ASU 2016-13 by providing entities with an option to irrevocably elect the fair value option to be applied on an instrument-by-instrument basis for eligible financial instruments that are within the scope of Topic 326. The fair value option election does not apply to held-to-maturity debt securities. On January 1, 2020, we adopted the provisions of ASU 2016-13 and we have substantially completed our assessment based on the composition of our portfolio of financial instruments and current and forecasted economic conditions as of January 1, 2020. We are continuing to finalize our calculations for credit losses and to establish processes and internal controls that may be required to comply with ASU 2016-13. We do not expect the adoption of ASU 2016-13 to have a significant impact on our results of operations, financial condition or internal controls. Not Yet Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740)

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The FASB ASC Topic 820, Fair Value Measurements & Disclosures , establishes a 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 for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. We measure cash, cash equivalents and short-term investments at fair value on a recurring basis. The fair values of these such assets were as follows (in thousands): Fair Value Measurements at Reporting Date Using Balance at December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and money market funds $ 56,931 $ 56,931 $ — $ — U.S. treasury bills and government agency obligations 140,626 140,626 — — U.S. corporate debt securities 80,170 — 80,170 — Foreign corporate debt securities 23,203 — 23,203 — U.S. commercial paper 32,801 — 32,801 — Foreign commercial paper 57,241 — 57,241 — Total $ 390,972 $ 197,557 $ 193,415 $ — Fair Value Measurements at Reporting Date Using Balance at December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and money market funds $ 22,751 $ 22,751 $ — $ — U.S. treasury bills and government agency obligations 59,741 $ 59,741 $ — $ — U.S. corporate debt securities 59,087 — 59,087 — Foreign corporate debt securities 5,046 — 5,046 — U.S. commercial paper 61,885 — 61,885 — Foreign commercial paper 123,861 — 123,861 — Total $ 332,371 $ 82,492 $ 249,879 $ — We have not transferred any investment securities between the three levels of the fair value hierarchy. As of December 31, 2019, cash equivalents included $15.0 million of available-for-sale securities with contractual maturities of three months or less. As of December 31, 2019, short-term investments included $279.7 million of available-for-sale securities with contractual maturities of three months to one year and $39.4 million of available-for-sale securities with contractual maturities greater than one year. As of December 31, 2018, cash equivalents included $9.1 million of available-for-sale securities with contractual maturities of three months or less, and short-term investments included $300.5 million of available-for-sale securities with contractual maturities of three months to one year. The money market funds as of December 31, 2019 and 2018 are included in cash and cash equivalents on the consolidated balance sheets.

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Details	4. Balance Sheet Details Short-Term Investments The following is a summary of our short-term investments (in thousands): December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. treasury bills and government agency obligations $ 140,567 $ 59 $ — $ 140,626 U.S. corporate debt 80,159 11 — 80,170 Foreign corporate debt 23,188 15 — 23,203 U.S. commercial paper 32,801 — — 32,801 Foreign commercial paper 42,274 — — 42,274 Total $ 318,989 $ 85 $ — $ 319,074 December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. treasury bills and government agency obligations $ 59,747 $ — $ (6 ) $ 59,741 U.S. corporate debt securities 59,164 — (77 ) 59,087 Foreign corporate debt securities 5,041 5 — 5,046 U.S. commercial paper 52,800 — — 52,800 Foreign commercial paper 123,870 — (9 ) 123,861 Total $ 300,622 $ 5 $ (92 ) $ 300,535 The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity. We regularly monitor and evaluate the realizable value of our marketable securities. We did not recognize any impairment losses for the years ended December 31, 2019 and 2018. Unrealized gains and losses associated with our investments are reported in accumulated other comprehensive loss. For the years ended December 31, 2019 and 2017, we recorded $172,000 and $7,000, respectively, in net unrealized gains associated with our short-term investments. For the year ended December 31, 2018, we recorded $77,000 in net unrealized losses associated with our short-term investments. Realized gains and losses associated with our investments, if any, are reported in the statements of operations and comprehensive loss. We recognized $8,000 in realized gains during the year ended December 31, 2019. We did not recognize any realized gains or losses during the years ended December 31, 2018 and 2017. Inventory Inventory consists of the following (in thousands): December 31, 2019 2018 Raw materials $ 6,635 $ 10,112 Work in process 12,571 20,604 Finished goods 5,762 8,316 Total inventory $ 24,968 $ 39,032 As of December 31, 2019, total inventory included $23.5 million related to CINVANTI and $1.5 million related to SUSTOL. As of December 31, 2018, total inventory included $32.3 million related to CINVANTI and $6.7 million related to SUSTOL. In addition, cost of product sales for the years ended December 31, 2019 and 2018 included charges of $3.3 million and $1.8 million, respectively, resulting from the write-off of short-dated SUSTOL inventory. Property and Equipment Property and equipment, net consists of the following (in thousands): December 31, 2019 2018 Scientific equipment $ 24,603 $ 18,077 Leasehold improvements 206 1,783 Computer equipment and software 1,314 1,190 Furniture, fixtures and office equipment 1,520 1,722 Property and equipment, gross 27,643 22,772 Less: accumulated depreciation and amortization (8,025 ) (8,095 ) Property and equipment, net $ 19,618 $ 14,677 Depreciation and amortization expense for the years ended December 31, 2019, 2018 and 2017 was $2.0 million, $1.5 million and $1.5 million, respectively. As of December 31, 2019 and 2018, $13.5 million and $10.3 million of property and equipment, respectively, was in process and not depreciated during the respective years. Accrued Payroll and Employee Liabilities and Other Accrued Liabilities Accrued payroll and employee liabilities consist of the following (in thousands): December 31, 2019 2018 Accrued employee salaries and benefits $ 3,047 $ 2,330 Accrued bonuses 9,545 9,139 Accrued vacation 2,656 1,928 Total accrued payroll and employee liabilities $ 15,248 $ 13,397 Other accrued liabilities consist of the following (in thousands): December 31, 2019 2018 Accrued product sales allowances $ 27,939 $ 25,503 Accrued consulting and professional fees 7,742 5,768 Deferred rent — 780 Accrued accounts payable 310 224 Other accrued liabilities 544 440 Total other accrued liabilities $ 36,535 $ 32,715

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2019
Revenue From Contract With Customer [Abstract]
Revenue Recognition	5 . Revenue Recognition Product Sales CINVANTI is distributed in the U.S. through a limited number of Customers that resell CINVANTI to healthcare providers and hospitals, the end users of CINVANTI. SUSTOL is distributed in the U.S. through a limited number of Customers that resell SUSTOL to healthcare providers, the end users of SUSTOL. Adoption of Topic 606 On January 1, 2018, we adopted Topic 606 using the modified retrospective approach applied to those contracts that were not completed as of January 1, 2018. Results from reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historical accounting under the FASB ASC Topic 605, Revenue Recognition Revenue is recognized in an amount that reflects the consideration we expect to receive in exchange for our products. To determine revenue recognition for contracts with customers within the scope of Topic 606, we performed the following 5 steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations of the contract(s); (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract(s); and (v) recognize revenue when (or as) we satisfy the performance obligations. The following table shows the reconciliation of assets and liabilities disclosed in our Annual Report on Form 10-K for the year ended December 31, 2017, as adjusted, due to the modified retrospective adoption of Topic 606 on January 1, 2018 (in thousands): As Reported Under Topic 605 Effect of Change As Adjusted Under Topic 606 Inventory $ 10,108 $ (198 ) $ 9,910 Other accrued liabilities 17,175 991 18,166 Deferred revenue 2,763 (2,763 ) — Accumulated deficit (783,455 ) 1,574 (781,881 ) The following table shows the consolidated financial statement line items as if revenue from contracts with customers had been accounted for under Topic 605 (in thousands, except per share data): As Reported As Calculated Under Effect of Under Topic 606 Change Topic 605 Consolidated Balance Sheet as of December 31, 2018: Inventory $ 39,032 $ 2,181 $ 41,213 Other accrued liabilities 32,715 (7,195 ) 25,520 Deferred revenue — 14,010 14,010 Accumulated deficit (960,721 ) (4,634 ) (965,355 ) Consolidated Statement of Operations for the Year Ended December 31, 2018: Net product sales $ 77,474 $ (5,043 ) $ 72,431 Cost of product sales 27,512 (1,983 ) 25,529 Loss from operations (183,937 ) (3,060 ) (186,997 ) Net loss (178,840 ) (3,060 ) (181,900 ) Basic and diluted net loss per share (2.44 ) (0.05 ) (2.49 ) Consolidated Statement of Cash Flows for the Year Ended December 31, 2018: Net loss $ (178,840 ) $ (3,060 ) $ (181,900 ) Adjustments to reconcile net loss to net cash used in operating activities: Inventory (29,122 ) (1,983 ) (31,105 ) Other accrued liabilities 14,941 (6,204 ) 8,737 Deferred revenue — 11,247 11,247 Product Sales Allowances We recognize product sales allowances as a reduction of product sales in the same period the related revenue is recognized. Product sales allowances are based on amounts owed or to be claimed on the related sales. These estimates take into consideration the terms of our agreements with Customers, historical product returns, rebates or discounts taken, the shelf life of the product and specific known market events, such as competitive pricing and new product introductions. If actual future results vary from our estimates, we may need to adjust these estimates, which could have an effect on product sales and earnings in the period of adjustment. Our product sales allowances include: • Product Returns—We allow our Customers to return product for credit for up to 12 months after its product expiration date. As such, there may be a significant period of time between the time the product is shipped and the time the credit is issued on returned product. • Distributor Fees—We offer contractually determined discounts to our Customers. These discounts are paid no later than two months after the quarter in which product was shipped. • Group Purchasing Organization (“GPO”) Discounts and Rebates—We offer cash discounts to GPO members. These discounts are taken when the GPO members purchase CINVANTI or SUSTOL from our Customers, who then charge back to us the discount amount. Additionally, we offer volume and contract-tier rebates to GPO members. Rebates are based on actual purchase levels during the quarterly rebate purchase period. • GPO Administrative Fees—We pay administrative fees to GPOs for services and access to data. These fees are based on contracted terms and are paid after the quarter in which the product was purchased by the GPOs’ members. • Medicaid Rebates—We participate in Medicaid rebate programs, which provide assistance to certain low-income patients based on each individual state’s guidelines regarding eligibility and services. Under the Medicaid rebate programs, we pay a rebate to each participating state, generally within three months after the quarter in which CINVANTI or SUSTOL was sold. We believe our estimated allowance for product returns requires a high degree of judgment and is subject to change based on our experience and certain quantitative and qualitative factors. We believe our estimated allowances for distributor fees, GPO discounts, rebates and administrative fees and Medicaid rebates do not require a high degree of judgment because the amounts are settled within a relatively short period of time. Our product sales allowances and related accruals are evaluated each reporting period and adjusted when trends or significant events indicate that a change in estimate is appropriate. Changes in product sales allowance estimates could materially affect our results of operations and financial position. Net product sales for the year ended December 31, 2019 were $146.0 million, compared to $77.5 million for the same period in 2018. For the year ended December 31, 2019, net products sales of CINVANTI were $132.2 million, compared to $56.2 million for the same period in 2018. For the year ended December 31, 2019, net product sales of SUSTOL were $13.8 million, compared to $21.3 million for the same period in 2018. The following table provides a summary of activity with respect to our product returns, distributor fees and discounts, rebates and administrative fees, which are included in other accrued liabilities on the consolidated balance sheets (in thousands): Discounts, Rebates and Product Distributor Administrative Returns Fees Fees Total Balance at December 31, 2018 $ 947 $ 2,813 $ 21,743 $ 25,503 Provision 2,960 18,934 140,305 162,199 Payments/credits (1,556 ) (17,748 ) (140,459 ) (159,763 ) Balance at December 31, 2019 $ 2,351 $ 3,999 $ 21,589 $ 27,939

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6 . Commitments and Contingencies Leases As of December 31, 2019, we had an operating lease for 52,148 square feet of laboratory and office space in San Diego, California, with a lease term that expires on December 31, 2025 . In January 2020, we expanded our space in San Diego, with the addition of 21,180 square feet of office space. The lease of the additional space began on January 1, 2020 and expires on December 31, 2025. We have one 5-year option to renew this lease on expiration. We leased 26,067 square feet of laboratory, office and warehouse space in Redwood City, California. The lease for the Redwood City space expired on May 31, 2019. On March 15, 2018, we entered into a sublease agreement for the Redwood City property. The sublease agreement expired on May 31, 2019. We also leased 1,898 square feet of office space in Jersey City, New Jersey. The lease for the Jersey City office space expired on December 31, 2019. We believe our facilities are adequate and suitable for our current needs and that we will be able to obtain new or additional leased space in the future when necessary. On January 1, 2019, on the adoption of Topic 842, we recognized initial ROU lease assets of $13.7 million and initial lease liabilities of $14.5 million. Our weighted-average remaining lease term for our operating leases was 6 years. Annual future minimum lease payments as of December 31, 2019 are as follows (in thousands): Year ended December 31: 2020 $ 2,724 2021 2,804 2022 2,885 2023 2,969 2024 3,030 Thereafter 3,097 Total future minimum lease payments 17,509 Less: discount (3,341 ) Total lease liabilities $ 14,168 On January 1, 2020, we recognized an initial ROU lease asset of $5.1 million, an unamortized lease incentive of $0.6 million and a lease liability of $5.7 million related to the additional space leased in San Diego, California. We have agreed to pay a basic annual rent for the additional office space that increases incrementally over the term of the lease from $0.9 million for the first 12 months of the lease (inclusive of certain rent abatements) to $1.3 million for the last 12 months of the lease, and such other amounts as set forth in the lease. Rent expense under all operating leases totaled $3.1 million, $3.2 million and $3.1 million for the years ended December 31, 2019, 2018 and 2017, respectively. Clinical Development Agreements We enter into agreements with clinical sites and clinical research organizations for the conduct of our clinical trials. We make payments to these sites and organizations based in part on the number of eligible patients enrolled and the length of their participation in the clinical trials. Under certain of these agreements, we may be subject to penalties in the event that we prematurely terminate these agreements. At this time, due to the variability associated with clinical site and contract research organization agreements, we are unable to estimate with certainty the future costs we will incur. We intend to use our current financial resources to fund our obligations under these commitments.

Realignment of Goals and Object

Realignment of Goals and Objectives and New Development Focus	12 Months Ended
	Dec. 31, 2019
Note To Financial Statement Details Textual
Realignment of Goals and Objectives and New Development Focus	7 . Realignment of Goals and Objectives and New Development Focus Following the approval of SUSTOL and consistent with our transition into a commercial-stage biotechnology company, we realigned our goals and objectives and refocused our development efforts to the area of postoperative pain management. On September 30, 2016, the Board of Directors accepted the resignations of three executive officers, and these executive officers and other employees directly affected by the realignment and refocusing were provided with one-time severance payments on termination, continued benefits for a specified period of time and outplacement assistance. The total expense for these activities was $9.4 million, $5.5 million of which is primarily for severance and $3.9 million of which is for non-cash, stock-based compensation expense. The total expense was recognized between September 30, 2016 and December 31, 2017. As of December 31, 2018, we had paid all of the cash severance charges. In March 2018, we shut down operations at our Redwood City facility and entered into a sublease agreement for the remainder of the lease term. The fair value of the cease-use liability was calculated using the remaining lease payments, offset by future sublease payments, deferred rent amortization and prepaid rent amounts. In the first quarter of 2018, we recorded expense of $0.5 million to general and administrative expense as a loss on the lease. We have accounted for these expenses in accordance with the FASB ASC Topic 420, Exit or Disposal Cost Obligations

Secured Notes to Related Party

Secured Notes to Related Party	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Secured Notes to Related Party	8 . Secured Notes to Related Party Convertible Notes In April 2011, we entered into a securities purchase agreement for a private placement of up to $4.5 million in Convertible Notes with certain investors, including Tang Capital Partners, LP (“TCP”). TCP is controlled by Tang Capital Management, LLC (“TCM”). The manager of TCM is Kevin Tang, who served as a director at the time and currently serves as the Chairman of our Board of Directors. At the time of issuance, the terms of the Convertible Notes were determined by our independent directors to be no less favorable than terms that would be obtained in an arm’s length financing transaction. We received a total of $4.3 million, net of issuance costs, from the issuance of these Convertible Notes. The Convertible Notes are secured by substantially all of our assets, including placing our bank and investment accounts under a control agreement. The Convertible Notes bear interest at 6% per annum, payable quarterly in cash or in additional principal amount of Convertible Notes, at the election of the purchasers. The Convertible Notes mature on May 2, 2021; however, the holders of the Convertible Notes may require prepayment of the Convertible Notes at any time, at each holder’s option. The Convertible Notes are convertible into shares of our common stock at a rate of 1,250 shares for every $1,000 of outstanding principal due under the Convertible Notes. There is no right to convert the Convertible Notes to the extent that, after giving effect to such conversion, the holder would beneficially own in excess of 9.99% of our outstanding common stock. Each holder of the Convertible Notes can increase or decrease this beneficial ownership conversion limit by written notice to us, which will not be effective until 61 days after delivery of the notice. As of December 31, 2019, we were in compliance with all covenants under the Convertible Notes. On the occurrence of an event of default under the Convertible Notes, the holders of the Convertible Notes have the right to require us to redeem all or a portion of their Convertible Notes. In 2011, we filed a registration statement with the SEC to register for resale 3.5 million shares underlying the Convertible Notes. The registration statement was declared effective on July 29, 2011. The Convertible Note holders have agreed to waive their right to require us to maintain the effectiveness of the registration statement and to register the additional shares underlying the Convertible Notes until they provide notice otherwise. The Convertible Notes contain an embedded conversion feature that was in-the-money on the issuance dates. Based on an effective fixed conversion rate of 1,250 shares for every $1,000 of principal and accrued interest due under the Convertible Notes, the total conversion benefit at issuance exceeded the loan proceeds. Therefore, a debt discount was recorded in an amount equal to the face value of the Convertible Notes on the issuance dates, and we began amortizing the resultant debt discount over the respective 10-year term of the Convertible Notes. During the year ended December 31, 2019, accrued interest of $0.4 million was paid-in-kind and rolled into the Convertible Note principal balance, which resulted in an additional debt discount of $0.4 million. For the years ended December 31, 2019, 2018 and 2017, interest expense relating to the stated rate was $0.4 million for each of the three periods. Interest expense relating to the amortization of the debt discount was $1.1 million, $0.9 million and $0.8 million, respectively. As of December 31, 2019, the carrying value of the Convertible Notes was $5.6 million, which is comprised of the $7.2 million principal amount of the Convertible Notes outstanding, less a debt discount of $1.6 million. As of December 31, 2019, the Convertible Notes were convertible into 9.0 million shares of our common stock. Promissory Note In August 2016, we entered into the Subordinated Secured Promissory Note (“Promissory Note”) with TCP whereby TCP agreed to lend us up to $100.0 million. The Promissory Note had a two-year For the years ended December 31, 2018 and 2017, interest expense was $1.2 million and $2.8 million, respectively. In August 2018, we paid the remaining obligation under the Promissory Note, which included $25.0 million of outstanding principal and $0.2 million of accrued interest. As of December 31, 2018, there were no remaining obligations under the Promissory Note.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders’ Equity	9 . Stockholders’ Equity 2017 Common Stock Offerings In January 2017, we sold 14.1 million shares of our common stock at a public offering price of $12.20 per share. We received total net proceeds of $163.7 million (net of $8.8 million in issuance costs) from the sale of the common stock. In December 2017, we sold 9.7 million shares of our common stock at a public offering price of $15.50 per share. We received total net proceeds of $142.6 million (net of $7.4 million in issuance costs) from the sale of the common stock. 2018 Common Stock Offerings In April 2018, we sold 6.9 million shares of our common stock at a public offering price of $26.00 per share. We received total net cash proceeds of $168.7 million (net of $10.7 million in issuance costs) from the sale of the common stock. In June 2018, we sold 5.1 million shares of our common stock at a public offering price of $39.50 per share. We received total net cash proceeds of $194.4 million (net of $5.6 million in issuance costs) from the sale of the common stock. 2019 Common Stock Offerings In October 2019, we sold 9.9 million shares of our common stock at a public offering price of $17.50 per share. We received total net cash proceeds of $162.2 million (net of $10.3 million in issuance costs) from the sale of the common stock. Public Offering Warrants In June 2014, as a component of our public offering, we sold 600,000 pre-funded warrants to purchase shares of our common stock. The pre-funded warrants have an exercise price of $0.01 per share and expire on June 30, 2021. During the year ended December 31, 2017, warrant holders exercised 4,426 warrants under the cashless exercise provision in each such holder’s warrant, which resulted in the net issuance of 4,423 shares of common stock and no net cash proceeds to us. During the year ended December 31, 2019, warrant holders exercised 132,130 warrants, which resulted in the issuance of 132,130 shares for net cash proceeds of $1,321. As of December 31, 2019, 463,444 warrants from the June 2014 public offering remain outstanding. Common Stock Reserved for Future Issuance Shares of our common stock reserved for future issuance as of December 31, 2019 were as follows (in thousands): Number of Shares Stock options outstanding 16,665 Stock options available for grant 4,971 Employee Stock Purchase Plan 370 Warrants outstanding 508 Shares of common stock underlying Convertible Notes outstanding (see Note 8) 8,960 Total shares reserved for future issuance 31,474 Employee Stock Purchase Plan In 1997, our stockholders approved our Employee Stock Purchase Plan (“ESPP”) at which time a maximum of 10,000 shares of common stock were available for issuance. In December 2007, May 2009, June 2011, May 2014, May 2015, June 2016, June 2017 and June 2019, our stockholders authorized increases in the number of shares reserved for issuance under the ESPP by 5,000, 10,000, 25,000, 25,000, 100,000, 100,000, 200,000 and 300,000 shares, respectively, for a total of 775,000 shares reserved at December 31, 2019. Under the terms of the ESPP, employees can elect to have up to a maximum of 10% of their base earnings withheld to purchase shares of our common stock. The purchase price of the stock is 85% of the lower of the closing prices for our common stock on either: (i) the first trading day in the enrollment period, as defined in the ESPP, in which the purchase is made, or (ii) the purchase date. The length of the enrollment period is 6 months. Enrollment dates are the first business day of May and November. Under the ESPP, we issued 125,727, 71,499, and 77,283 shares in 2019, 2018 and 2017, respectively. The weighted-average exercise price per share of the purchase rights exercised during 2019, 2018 and 2017 was $16.77, $16.48 and $12.80, respectively. As of December 31, 2019, 404,909 shares of common stock have been issued under the ESPP and 370,091 shares of common stock are available for future issuance. Stock Option Plans We currently have one stock option plan from which we can grant options and restricted stock awards to employees, officers, directors and consultants. In December 2007, the stockholders approved our 2007 Equity Incentive Plan (“2007 Plan”) at which time a maximum of 150,000 shares of common stock were available for grant. In May 2010, June 2011, May 2014, May 2015, June 2016, June 2017 and June 2019, our stockholders approved amendments to our 2007 Plan to increase the maximum number of shares of common stock available for grant by 100,000, 4,500,000, 1,750,000, 4,300,000, 3,000,000, 5,000,000 and 7,000,000 shares of common stock, respectively, resulting in an aggregate of 25,800,000 shares of common stock authorized for issuance as of December 31, 2019. At December 31, 2019, there were 4,971,026 shares available for future grant under the 2007 Plan. Any shares that are issuable on exercise of options granted that expire, are cancelled or that we receive pursuant to a net exercise of options are available for future grant and issuance. In 2014, 2013 and 2012, we granted options to certain employees outside of our stockholder approved stock option plans. All options to purchase our common stock were granted with an exercise price that equals fair market value of the underlying common stock on the grant dates and expire no later than 10 years from the date of grant. The options are exercisable in accordance with vesting schedules that generally provide for them to be fully vested and exercisable 4 years after the date of grant, provided, however, that we have also issued stock options awards that are subject to performance vesting requirements. All stock option grants issued outside of our stockholder approved plans have been registered on Form S-8 with the SEC. The following table summarizes the stock option activity: Outstanding Options Weighted- Average Number of Exercise Shares Price Balance at December 31, 2016 11,845,376 $ 14.44 Granted 4,300,621 $ 16.17 Exercised (1,350,605 ) $ 8.49 Cancelled (1,332,428 ) $ 20.06 Balance at December 31, 2017 13,462,964 $ 15.03 Granted 4,052,011 $ 26.83 Exercised (1,529,509 ) $ 11.97 Cancelled (720,859 ) $ 17.98 Balance at December 31, 2018 15,264,607 $ 18.33 Granted 4,933,480 $ 24.21 Exercised (1,983,221 ) $ 11.18 Cancelled (1,550,226 ) $ 23.26 Balance at December 31, 2019 16,664,640 $ 20.47 For the year ended December 31, 2019, options cancelled (included in the above table) consisted of 1,021,453 options forfeited with a weighted-average exercise price of $20.91 and 528,773 options expired with a weighted-average exercise price of $27.81. As of December 31, 2019, options exercisable have a weighted-average remaining contractual term of 6.3 years. The total intrinsic value of stock option exercises, which is the difference between the exercise price and closing price of our common stock on the date of exercise, during the years ended December 31, 2019 and 2018 was $25.0 million and $31.4 million, respectively. As of December 31, 2019 and 2018, the total intrinsic value of options outstanding and exercisable was $56.3 million and $75.7 million, respectively. Years Ended December 31, 2019 2018 2017 Weighted- Weighted- Weighted- Average Average Average Exercise Exercise Exercise Options Price Options Price Options Price Exercisable at end of year 7,436,379 $ 17.02 6,523,093 $ 14.83 5,446,586 $ 13.25 Options vested or expected to vest 15,962,432 $ 20.31 14,449,017 $ 18.11 12,854,571 $ 14.98 Exercise prices and weighted-average remaining contractual lives for the options outstanding as of December 31, 2019 were: Weighted- Weighted- Average Average Weighted- Exercise Remaining Average Price of Options Range of Contractual Exercise Options Options Outstanding Exercise Prices Life (in years) Price Exercisable Exercisable 3,027,881 $5.20–$13.00 4.97 $ 10.16 2,720,921 $ 9.84 3,834,655 $13.05–$17.00 7.42 16.23 2,326,188 16.17 1,623,707 $17.05–$24.55 8.01 20.10 704,338 20.48 2,336,151 $24.97 8.93 24.97 644,066 24.97 3,877,880 $25.02 9.95 25.02 — — 1,940,366 $25.06–$38.75 7.58 30.48 1,032,365 30.38 24,000 $39.00 8.56 39.00 8,501 39.00 16,664,640 7.58 20.47 7,436,379 17.02 On December 31, 2019, we had reserved 16,664,640 shares of common stock for future issuance on exercise of outstanding options granted under the 2007 Plan, as well as the non-plan grants. Valuation and Expense Information The following table summarizes stock-based compensation expense related to stock-based payment awards granted pursuant to all of our equity compensation arrangements (in thousands): December 31, 2019 2018 2017 Research and development $ 19,202 $ 13,689 $ 11,312 General and administrative 13,564 9,630 9,469 Sales and marketing 18,645 10,048 9,757 Total stock-based compensation expense $ 51,411 $ 33,367 $ 30,538 As of December 31, 2019, there was $128.7 million of total unrecognized compensation cost related to non-vested, stock-based payment awards granted under all of our equity compensation plans and all non-plan option grants. Total unrecognized compensation cost will be adjusted for future changes in estimated forfeitures. We expect to recognize this compensation cost over a weighted-average period of 3.0 years. We estimated the fair value of each option grant and ESPP purchase right on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions: Options: December 31, 2019 2018 2017 Risk-free interest rate 1.8 % 2.8 % 2.1 % Dividend yield — % — % — % Volatility 66.5 % 70.4 % 74.0 % Expected life (years) 6 6 6 ESPP: December 31, 2019 2018 2017 Risk-free interest rate 1.9 % 2.4 % 1.2 % Dividend yield — % — % — % Volatility 52.1 % 59.7 % 50.0 % Expected life (months) 6 6 6 The weighted-average fair value of options granted was $14.70, $17.24 and $10.61 for the years ended December 31, 2019, 2018 and 2017, respectively. The weighted-average fair value of shares purchased through the ESPP was $5.94, $9.95 and $4.51 for the years ended December 31, 2019, 2018 and 2017, respectively. The risk-free interest rate assumption is based on observed interest rates on U.S. Treasury debt securities with maturities close to the expected term of our employee and director stock options and ESPP purchases. The dividend yield assumption is based on our history and expectation of dividend payouts. We have never paid dividends on our common stock, and we do not anticipate paying dividends in the foreseeable future. We used our historical stock price to estimate volatility. The expected life of employee and director stock options represents the average of the contractual term of the options and the weighted-average vesting period, as permitted under the simplified method. We have elected to use the simplified method, as we do not have enough historical exercise experience to provide a reasonable basis on which to estimate the expected term. The expected life for the ESPP purchase rights is 6 months, which represents the length of each purchase period.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	10 . Income Taxes For the years ended December 31, 2019, 2018 and 2017, we did not record a provision for income taxes due to a full valuation allowance against our deferred tax assets. The difference between the provision for income taxes and income taxes computed using the effective U.S. federal statutory rate is as follows (in thousands): December 31, 2019 2018 2017 Tax at statutory federal rate $ (42,997 ) $ (37,557 ) $ (67,145 ) State tax, net of federal benefit (9,823 ) (6,527 ) (6,203 ) Research and development credits (4,855 ) (4,775 ) (5,962 ) Stock-based compensation expense 2,906 (2,059 ) 3,151 Non-deductible compensation 4,720 901 — Change in valuation allowance 49,479 50,834 3,241 Impact of the 2017 Tax Act — — 74,361 Other 570 (817 ) (1,443 ) Provision for income taxes $ — $ — $ — Deferred income tax assets and liabilities arising from differences between accounting for financial statement purposes and tax purposes, less valuation allowance at year-end are as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Net operating loss carryforward $ 210,301 $ 172,113 Research and development credits 42,490 35,670 Stock-based compensation 15,628 11,905 Lease liabilities 3,487 — Other 3,818 3,171 Total gross deferred tax assets 275,724 222,859 Deferred tax liabilities: Right-of-use lease assets (3,385 ) — Total gross deferred tax liabilities (3,385 ) — Valuation allowance (272,339 ) (222,859 ) Net deferred tax assets $ — $ — We have established a valuation allowance to offset net deferred tax assets as of December 31, 2019 and 2018 due to the uncertainty of realizing future tax benefits from such assets. As of December 31, 2019, we had federal, California and other state net operating loss (“NOL”) carryforwards of $865.2 million, $125.9 million and $1.1 billion, respectively. The federal NOL carryforwards consist of $549.7 million generated before January 1, 2018, which will begin to expire in 2021, and $315.5 million that can be carried forward indefinitely, but are subject to the 80% taxable income limitation. The state NOL carryforwards will begin to expire in 2028. As of December 31, 2019, we had federal and state research and development credit carryforwards of $33.7 million and $15.8 million, respectively. The federal research and development credit carryforwards will begin to expire in 2022. The state research and development credit carryforwards can be carried forward indefinitely. Internal Revenue Code (“IRC”) Section 382 and 383 places a limitation on the amount of taxable income that can be offset by NOL and credit carryforwards after a change in control (generally greater than 50% change in ownership within a three-year period) of a loss corporation. California has similar rules. Generally, after a change in control, a loss corporation cannot deduct NOL and credit carryforwards in excess of the IRC Section 382 and 383 limitation. We have performed an IRC Section 382 and 383 analysis and determined there were ownership changes in 2007, 2011 and 2013. We are currently in the process of completing the IRC Section 382 and 383 analysis for 201 9 . The limitation in the federal and state NOL and research and development credit carryforwards reduce the deferred tax assets, which are further offset by a full valuation allowance. The limitation can result in the expiration of the NOLs and research and development credit carryforwards available as of December 31, 201 9 . We file U.S. and state income tax returns with varying statutes of limitations. The tax years from 2001 to 2019 remain open to examination due to the carryover of unused NOL carryforwards and tax credits. The Tax Cuts and Jobs Act of 2017 (“2017 Tax Act”) was enacted in December 2017. The 2017 Tax Act, among other things, reduced the U.S. federal corporate tax rate from 35% to 21%, effective January 1, 2018, required companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and created new taxes on certain foreign earnings. We revalued our deferred tax assets as of December 31, 2017 based on a U.S. federal tax rate of 21%, which resulted in a reduction to our deferred tax assets of $74.3 million fully offset by a reduction to the valuation allowance. We were not required to pay a one-time transition tax on earnings of our foreign subsidiary as the foreign subsidiary has an accumulated deficit. In addition, the Global Intangible Low-taxed Income provision, as defined in the 2017 Tax Act, is not applicable given the Company’s controlled foreign corporations incurred losses for the years ended December 31, 2018 and 2019. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), which provided guidance for the tax effects of the 2017 Tax Act. SAB 118 provided a measurement period that should not extend beyond one year from the 2017 Tax Act’s enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, we must have reflected the income tax effects of those aspects of the 2017 Tax Act for which the accounting under ASC 740 was complete. To the extent that our accounting for certain income tax effects of the 2017 Tax Act was incomplete, but we were able to determine a reasonable estimate, we were required to record a provisional estimate in our financial statements. If were not able to determine a provisional estimate to be included in our financial statements, we should have continued to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. We completed our analysis of the 2017 Tax Act’s income tax effects. In accordance with SAB 118, the 2017 Tax Act-related income tax effects that we initially reported as provisional estimates were refined as additional analysis was performed. Our analysis was completed in the fourth quarter of 2018 and there was no material impact to our consolidated balance sheets or statements of operations and comprehensive loss. A reconciliation of our unrecognized tax benefits is as follows (in thousands): Year Ended December 31, 2019 2018 2017 Balance at beginning of year $ 2,385 $ 120 $ 120 Additions for tax positions of prior years 147 — — Additions based on tax positions related to current year 2,252 2,265 — Balance at end of year $ 4,784 $ 2,385 $ 120 Due to our valuation allowance, the $4.8 million of unrecognized tax benefits would not affect the effective tax rate, if recognized. It is the Company’s practice to recognize interest and penalties related to income tax matters in income tax expense. As of December 31, 2019, we had no accrued interest and penalties related to uncertain tax positions. We do not expect any material changes to the estimated amount of liability associated with our uncertain tax positions within the next 12 months.

Other Income (Expense), Net

Other Income (Expense), Net	12 Months Ended
	Dec. 31, 2019
Other Income And Expenses [Abstract]
Other Income (Expense), Net	1 1 . Other Income (Expense), Net In 2018, we recorded $1.9 million in income to other income (expense), net resulting from the disgorgement of short-swing profits arising from the sales of our common stock by a beneficial owner pursuant to Section 16(b) of the Securities and Exchange Act of 1934.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	1 2 . Employee Benefit Plan We have a defined contribution 401(k) plan (“Plan”) covering substantially all of our employees. In the past three calendar years, we made matching cash contributions equal to 50% of each participant’s contribution during the Plan year up to a maximum amount equal to the lesser of 3% of each participant’s annual compensation or $8,400, $8,250 and $8,100 for the years ended December 31, 2019, 2018 and 2017, respectively. Such amounts were recorded as expense in the corresponding years. We may also contribute additional discretionary amounts to the Plan as we determine. For the years ended December 31, 2019, 2018 and 2017, we contributed $1.0 million, $0.7 million and $0.6 million, respectively, to the Plan. No discretionary contributions have been made to the Plan since its inception.

Summary of Quarterly Consolidat

Summary of Quarterly Consolidated Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Consolidated Financial Data (Unaudited)	1 3 . Summary of Quarterly Consolidated Financial Data (Unaudited) The following is a summary of the unaudited quarterly results of operations for the years ended December 31, 2019 and 2018: 2019 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share amounts) Revenues: Net product sales $ 31,602 $ 36,659 $ 42,624 $ 35,083 Cost of product sales (14,962 ) (13,588 ) (17,195 ) (15,874 ) Gross Profit 16,640 23,071 25,429 19,209 Operating expenses: Research and development 42,972 41,425 34,708 48,277 General and administrative 9,648 9,778 8,597 9,874 Sales and marketing 28,720 23,647 16,977 20,420 Loss from operations (64,700 ) (51,779 ) (34,853 ) (59,362 ) Other income, net 1,688 1,557 1,258 1,442 Net loss $ (63,012 ) $ (50,222 ) $ (33,595 ) $ (57,920 ) Basic and diluted net loss per share $ (0.80 ) $ (0.63 ) $ (0.42 ) $ (0.65 ) 2018 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share amounts) Revenues: Net product sales $ 11,567 $ 17,277 $ 19,786 $ 28,844 Cost of product sales (3,133 ) (5,231 ) (7,576 ) (11,572 ) Gross Profit 8,434 12,046 12,210 17,272 Operating expenses: Research and development 39,561 30,159 30,421 39,891 General and administrative 7,028 6,209 7,288 8,738 Sales and marketing 13,835 14,531 16,281 19,957 Loss from operations (51,990 ) (38,853 ) (41,780 ) (51,314 ) Other expense, net (275 ) 183 3,434 1,755 Net loss $ (52,265 ) $ (38,670 ) $ (38,346 ) $ (49,559 ) Basic and diluted net loss per share $ (0.81 ) $ (0.54 ) $ (0.49 ) $ (0.63 )

Summary of Significant Account

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of Heron Therapeutics, Inc. and its wholly-owned subsidiary, Heron Therapeutics B.V., which was organized in the Netherlands in March 2015. Heron Therapeutics B.V. has no operations and no material assets or liabilities, and there have been no significant transactions related to Heron Therapeutics B.V. since its inception.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in the financial statements and disclosures made in the accompanying notes to the financial statements. Our significant accounting policies that involve significant judgment and estimates include revenue recognition, investments, inventory and the related reserves, accrued clinical liabilities, income taxes and stock-based compensation. Actual results could differ materially from those estimates.
Cash, Cash Equivalents and Short-term Investments	Cash, Cash Equivalents and Short-term Investments Cash and cash equivalents consist of cash and highly liquid investments with contractual maturities of three months or less from the original purchase date. Short-term investments consist of securities with contractual maturities of greater than three months from the original purchase date. Securities with contractual maturities greater than one year are classified as short-term investments on the consolidated balance sheets, as we have the ability, if necessary, to liquidate these securities to meet our liquidity needs in the next 12 months. We have classified our short-term investments as available-for-sale securities in the accompanying consolidated financial statements. Available-for-sale securities are stated at fair market value, with net changes in unrealized gains and losses reported in other comprehensive loss and realized gains and losses included in other income (expense), net. The cost of securities sold is based on the specific identification method. Interest and dividends on securities classified as available-for-sale are included in interest income. Our bank and investment accounts have been placed under control agreements in accordance with our Senior Secured Convertible Notes (“Convertible Notes”) (see Note 8).
Fair Value of Financial Instruments	Fair Value of Financial Instruments A company may elect to use fair value to measure accounts and loans receivable, available-for-sale and held-to-maturity securities, equity method investments, accounts payable, guarantees and issued debt. Other eligible items include firm commitments for financial instruments that otherwise would not be recognized at inception and non-cash warranty obligations where a warrantor is permitted to pay a third party to provide the warranty goods or services. If the use of fair value is elected, any upfront costs and fees related to the item such as debt issuance costs must be recognized in earnings and cannot be deferred. The fair value election is irrevocable and generally made on an instrument-by-instrument basis, even if a company has similar instruments that it elects not to measure based on fair value. Unrealized gains and losses on existing items for which fair value has been elected are reported as a cumulative adjustment to beginning retained earnings and any changes in fair value are recognized in earnings. We have elected to not apply the fair value option to our financial assets and liabilities. Financial instruments, including cash and cash equivalents, receivables, inventory, prepaid expenses, other current assets, accounts payable and accrued expenses, are carried at cost, which is considered to be representative of their respective fair values because of the short-term maturity of these instruments. Short-term available-for-sale investments are carried at fair value (see Note 3 ) . Our Convertible Notes outstanding at December 31, 201 9 do not have a readily available ascertainable market value, however, the carrying value is considered to approximate its fair value.
Concentration of Credit Risk	Concentration of Credit Risk Cash, cash equivalents and short-term investments are financial instruments that potentially subject us to concentrations of credit risk. We deposit our cash in financial institutions. At times, such deposits may be in excess of insured limits. We may also invest our excess cash in money market funds, U.S. government and agencies, corporate debt securities and commercial paper. We have established guidelines relative to our diversification of our cash investments and their maturities in an effort to maintain safety and liquidity. These guidelines are periodically reviewed and modified to take advantage of trends in yields and interest rates. Our products are distributed in the U.S. through a limited number of specialty distributors and full line wholesalers (collectively, “Customers”) that resell our products to healthcare providers and hospitals, the end users. The following table includes the percentage of net product sales and accounts receivable balances for our three major Customers, each of which comprised 10% or more of our net product sales: Net Product Sales Accounts Receivable Year Ended December 31, 2019 As of December 31, 2019 Customer A 40.9 % 48.9 % Customer B 39.5 % 38.6 % Customer C 17.4 % 11.7 % Total 97.8 % 99.2 %
Accounts Receivable, Net	Accounts Receivable, Net Accounts receivable are recorded at the invoice amount, net of an allowance for doubtful accounts. The allowance for doubtful accounts reflects accounts receivable balances that are believed to be uncollectible. In estimating the allowance for doubtful accounts, we consider: (1) our historical experience with collections and write-offs; (2) the credit quality of our Customers and any recent or anticipated changes thereto; and (3) the outstanding balances and past due amounts from our Customers. We offered extended payment terms to our Customers in connection with our product launches of SUSTOL and CINVANTI in October 2016 and January 2018, respectively, in anticipation of the timing in reimbursement by government and commercial payers. Effective January 2018, we shortened payment terms to certain of our SUSTOL Customers. Effective January 2019, we shortened payment terms to our CINVANTI Customers. As of December 31, 2019, extended payment terms given to our Customers were evaluated in accordance with GAAP and did not impact the collectability of accounts receivables. As of December 31, 2019, we determined that an allowance for doubtful accounts was not required. For the year ended December 31, 2019, we did not write-off any accounts receivable balances.
Inventory	Inventory Inventory is stated at the lower of cost or estimated net realizable value on a first-in, first-out, or FIFO, basis. We periodically analyze our inventory levels and write down inventory that has become obsolete, inventory that has a cost basis in excess of its estimated realizable value and inventory quantities that are in excess of expected sales requirements as cost of product sales. The determination of whether inventory costs will be realizable requires estimates by management. If actual market conditions are less favorable than projected by management, additional write-downs of inventory may be required, which would be recorded as cost of product sales.
Property and Equipment	Property and Equipment Property and equipment is stated at cost less accumulated depreciation and amortization. Depreciation is calculated on a straight-line basis over the estimated useful lives of the assets (generally 5 years). Leasehold improvements are stated at cost and amortized on a straight-line basis over the shorter of the estimated useful life of the asset or the lease term.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets If indicators of impairment exist, we assess the recoverability of the affected long-lived assets by determining whether the carrying value of such assets can be recovered through undiscounted future operating cash flows. If impairment is indicated, we measure the amount of such impairment by comparing the carrying value of the asset to the fair value of the asset and record the impairment as a reduction in the carrying value of the related asset with a corresponding charge to operating expenses. Estimating the undiscounted future operating cash flows associated with long-lived assets requires judgment and assumptions that could differ materially from actual results.
Leases	Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements Codification Improvements to Topic 842, Leases Leases We determine if an agreement is a lease or contains lease components at inception. Operating leases are recorded as lease liabilities with corresponding ROU lease assets on the consolidated balance sheets. ROU lease assets represent our right to use the underlying assets over the lease term, and lease liabilities represent the present value of our obligation to make lease payments arising from the lease. Lease liabilities are recognized at the lease commencement based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. We use the implicit rate when readily determinable. The ROU lease assets equal the lease liabilities, less unamortized lease incentives, unamortized initial direct costs and the cumulative difference between rent expense and amounts paid under the lease. The lease term includes any option to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. We have lease agreements with both lease and non-lease components, which are generally accounted for separately.
Revenue Recognition	Revenue Recognition In May 2014, FASB issued ASU No. 2014-09, Revenue from Contracts with Customers
Accrued Clinical Liabilities	Accrued Clinical Liabilities We accrue clinical costs based on work performed, which relies on estimates of the progress of the trials and the related expenses incurred. Clinical trial related contracts vary significantly in duration, and may be for a fixed amount, based on the achievement of certain contingent events or deliverables, a variable amount based on actual costs incurred, capped at a certain limit or contain a combination of these elements. Revisions are recorded to research and development expense in the period in which the facts that give rise to the revision become known. Historically, revisions have not resulted in material changes to research and development expense; however, a modification in the protocol of a clinical trial or cancellation of a clinical trial could result in a material charge to our results of operations.
Research and Development Expense	Research and Development Expense All costs of research and development are expensed in the period incurred. Research and development expense primarily consists of personnel and related costs, stock-based compensation expense, fees paid to outside service providers and consultants, facilities costs and materials used in clinical and preclinical trials and research and development.
Patent Costs	Patent Costs We incur outside legal fees in connection with filing and maintaining our various patent applications. All patent costs are expensed as incurred and are included in general and administrative expense in the consolidated statements of operations and comprehensive loss.
Stock-Based Compensation Expense	Stock-Based Compensation Expense We estimate the fair value of stock-based payment awards using the Black-Scholes option pricing model. This fair value is then amortized using the straight-line single-option method of attributing the value of stock-based compensation to expense over the requisite service periods of the awards. The Black-Scholes option pricing model requires the input of complex and subjective assumptions, including each option’s expected life and price volatility of the underlying stock. As stock-based compensation expense is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Forfeitures are estimated based on historical data .
Warrants	Warrants We have issued warrants to purchase shares of our common stock in conjunction with certain equity financings or in exchange for services. The terms of the warrants were evaluated to determine the appropriate classification as equity or a liability.
Income Taxes	Income Taxes We recognize the impact of a tax position in our consolidated financial statements if the position is more likely than not to be sustained on examination and on the technical merits of the position. The total amount of unrecognized tax benefits, if recognized, would affect other tax accounts, primarily deferred taxes in future periods, and would not affect our effective tax rate, since we maintain a full valuation allowance against our deferred tax assets (see Note 10). We recognize interest and penalties related to income tax matters in income tax expense.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Net changes in unrealized gains and losses on available-for-sale securities are included in other comprehensive loss and represent the difference between our net loss and comprehensive net loss for all periods presented.
Net Loss per Share	Net Loss per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration of common stock equivalents. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, stock options, warrants and shares of common stock underlying Convertible Notes are considered to be common stock equivalents and are included in the calculation of diluted net loss per share only when their effect is dilutive. Because we have incurred a net loss for all periods presented in the consolidated statements of operations and comprehensive loss, the following common stock equivalents were not included in the computation of net loss per share because their effect would be anti-dilutive (in thousands): December 31, 2019 2018 2017 Stock options outstanding 16,665 15,265 13,463 Warrants outstanding 508 640 620 Shares of common stock underlying Convertible Notes outstanding 8,960 8,473 7,983
Recent Accounting Pronouncements	Recent Accounting Pronouncements Adopted in 2020 In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”) , which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables and available-for-sale debt securities. In May 2019, the FASB issued ASU No. 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief (“ASU 2019-05”), which amends ASU 2016-13 by providing entities with an option to irrevocably elect the fair value option to be applied on an instrument-by-instrument basis for eligible financial instruments that are within the scope of Topic 326. The fair value option election does not apply to held-to-maturity debt securities. On January 1, 2020, we adopted the provisions of ASU 2016-13 and we have substantially completed our assessment based on the composition of our portfolio of financial instruments and current and forecasted economic conditions as of January 1, 2020. We are continuing to finalize our calculations for credit losses and to establish processes and internal controls that may be required to comply with ASU 2016-13. We do not expect the adoption of ASU 2016-13 to have a significant impact on our results of operations, financial condition or internal controls. Not Yet Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740)

Summary of Significant Accou_2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Percentage of Net Product Sales and Accounts Receivable Balance	The following table includes the percentage of net product sales and accounts receivable balances for our three major Customers, each of which comprised 10% or more of our net product sales: Net Product Sales Accounts Receivable Year Ended December 31, 2019 As of December 31, 2019 Customer A 40.9 % 48.9 % Customer B 39.5 % 38.6 % Customer C 17.4 % 11.7 % Total 97.8 % 99.2 %
Common Stock Equivalents Excluded From Computation of Net Loss Per Share	Because we have incurred a net loss for all periods presented in the consolidated statements of operations and comprehensive loss, the following common stock equivalents were not included in the computation of net loss per share because their effect would be anti-dilutive (in thousands): December 31, 2019 2018 2017 Stock options outstanding 16,665 15,265 13,463 Warrants outstanding 508 640 620 Shares of common stock underlying Convertible Notes outstanding 8,960 8,473 7,983

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	We measure cash, cash equivalents and short-term investments at fair value on a recurring basis. The fair values of these such assets were as follows (in thousands): Fair Value Measurements at Reporting Date Using Balance at December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and money market funds $ 56,931 $ 56,931 $ — $ — U.S. treasury bills and government agency obligations 140,626 140,626 — — U.S. corporate debt securities 80,170 — 80,170 — Foreign corporate debt securities 23,203 — 23,203 — U.S. commercial paper 32,801 — 32,801 — Foreign commercial paper 57,241 — 57,241 — Total $ 390,972 $ 197,557 $ 193,415 $ — Fair Value Measurements at Reporting Date Using Balance at December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and money market funds $ 22,751 $ 22,751 $ — $ — U.S. treasury bills and government agency obligations 59,741 $ 59,741 $ — $ — U.S. corporate debt securities 59,087 — 59,087 — Foreign corporate debt securities 5,046 — 5,046 — U.S. commercial paper 61,885 — 61,885 — Foreign commercial paper 123,861 — 123,861 — Total $ 332,371 $ 82,492 $ 249,879 $ —

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Short-Term Investments	The following is a summary of our short-term investments (in thousands): December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. treasury bills and government agency obligations $ 140,567 $ 59 $ — $ 140,626 U.S. corporate debt 80,159 11 — 80,170 Foreign corporate debt 23,188 15 — 23,203 U.S. commercial paper 32,801 — — 32,801 Foreign commercial paper 42,274 — — 42,274 Total $ 318,989 $ 85 $ — $ 319,074 December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. treasury bills and government agency obligations $ 59,747 $ — $ (6 ) $ 59,741 U.S. corporate debt securities 59,164 — (77 ) 59,087 Foreign corporate debt securities 5,041 5 — 5,046 U.S. commercial paper 52,800 — — 52,800 Foreign commercial paper 123,870 — (9 ) 123,861 Total $ 300,622 $ 5 $ (92 ) $ 300,535
Schedule of Inventory	Inventory consists of the following (in thousands): December 31, 2019 2018 Raw materials $ 6,635 $ 10,112 Work in process 12,571 20,604 Finished goods 5,762 8,316 Total inventory $ 24,968 $ 39,032
Schedule of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands): December 31, 2019 2018 Scientific equipment $ 24,603 $ 18,077 Leasehold improvements 206 1,783 Computer equipment and software 1,314 1,190 Furniture, fixtures and office equipment 1,520 1,722 Property and equipment, gross 27,643 22,772 Less: accumulated depreciation and amortization (8,025 ) (8,095 ) Property and equipment, net $ 19,618 $ 14,677
Schedule of Accrued Liabilities	Accrued payroll and employee liabilities consist of the following (in thousands): December 31, 2019 2018 Accrued employee salaries and benefits $ 3,047 $ 2,330 Accrued bonuses 9,545 9,139 Accrued vacation 2,656 1,928 Total accrued payroll and employee liabilities $ 15,248 $ 13,397 Other accrued liabilities consist of the following (in thousands): December 31, 2019 2018 Accrued product sales allowances $ 27,939 $ 25,503 Accrued consulting and professional fees 7,742 5,768 Deferred rent — 780 Accrued accounts payable 310 224 Other accrued liabilities 544 440 Total other accrued liabilities $ 36,535 $ 32,715

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue From Contract With Customer [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table shows the reconciliation of assets and liabilities disclosed in our Annual Report on Form 10-K for the year ended December 31, 2017, as adjusted, due to the modified retrospective adoption of Topic 606 on January 1, 2018 (in thousands): As Reported Under Topic 605 Effect of Change As Adjusted Under Topic 606 Inventory $ 10,108 $ (198 ) $ 9,910 Other accrued liabilities 17,175 991 18,166 Deferred revenue 2,763 (2,763 ) — Accumulated deficit (783,455 ) 1,574 (781,881 ) The following table shows the consolidated financial statement line items as if revenue from contracts with customers had been accounted for under Topic 605 (in thousands, except per share data): As Reported As Calculated Under Effect of Under Topic 606 Change Topic 605 Consolidated Balance Sheet as of December 31, 2018: Inventory $ 39,032 $ 2,181 $ 41,213 Other accrued liabilities 32,715 (7,195 ) 25,520 Deferred revenue — 14,010 14,010 Accumulated deficit (960,721 ) (4,634 ) (965,355 ) Consolidated Statement of Operations for the Year Ended December 31, 2018: Net product sales $ 77,474 $ (5,043 ) $ 72,431 Cost of product sales 27,512 (1,983 ) 25,529 Loss from operations (183,937 ) (3,060 ) (186,997 ) Net loss (178,840 ) (3,060 ) (181,900 ) Basic and diluted net loss per share (2.44 ) (0.05 ) (2.49 ) Consolidated Statement of Cash Flows for the Year Ended December 31, 2018: Net loss $ (178,840 ) $ (3,060 ) $ (181,900 ) Adjustments to reconcile net loss to net cash used in operating activities: Inventory (29,122 ) (1,983 ) (31,105 ) Other accrued liabilities 14,941 (6,204 ) 8,737 Deferred revenue — 11,247 11,247
Summary of Activity to Product Returns, Distributor Fees and Discounts, Rebates and Administrative Fees	The following table provides a summary of activity with respect to our product returns, distributor fees and discounts, rebates and administrative fees, which are included in other accrued liabilities on the consolidated balance sheets (in thousands): Discounts, Rebates and Product Distributor Administrative Returns Fees Fees Total Balance at December 31, 2018 $ 947 $ 2,813 $ 21,743 $ 25,503 Provision 2,960 18,934 140,305 162,199 Payments/credits (1,556 ) (17,748 ) (140,459 ) (159,763 ) Balance at December 31, 2019 $ 2,351 $ 3,999 $ 21,589 $ 27,939

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Summary of Future Minimum Lease Payments	Annual future minimum lease payments as of December 31, 2019 are as follows (in thousands): Year ended December 31: 2020 $ 2,724 2021 2,804 2022 2,885 2023 2,969 2024 3,030 Thereafter 3,097 Total future minimum lease payments 17,509 Less: discount (3,341 ) Total lease liabilities $ 14,168

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Summary of Common Stock Reserved for Future Issuance	Shares of our common stock reserved for future issuance as of December 31, 2019 were as follows (in thousands): Number of Shares Stock options outstanding 16,665 Stock options available for grant 4,971 Employee Stock Purchase Plan 370 Warrants outstanding 508 Shares of common stock underlying Convertible Notes outstanding (see Note 8) 8,960 Total shares reserved for future issuance 31,474
Summary of Stock Option Activity	The following table summarizes the stock option activity: Outstanding Options Weighted- Average Number of Exercise Shares Price Balance at December 31, 2016 11,845,376 $ 14.44 Granted 4,300,621 $ 16.17 Exercised (1,350,605 ) $ 8.49 Cancelled (1,332,428 ) $ 20.06 Balance at December 31, 2017 13,462,964 $ 15.03 Granted 4,052,011 $ 26.83 Exercised (1,529,509 ) $ 11.97 Cancelled (720,859 ) $ 17.98 Balance at December 31, 2018 15,264,607 $ 18.33 Granted 4,933,480 $ 24.21 Exercised (1,983,221 ) $ 11.18 Cancelled (1,550,226 ) $ 23.26 Balance at December 31, 2019 16,664,640 $ 20.47
Schedule of Options Exercisable, Vested or Expected to Vest	Years Ended December 31, 2019 2018 2017 Weighted- Weighted- Weighted- Average Average Average Exercise Exercise Exercise Options Price Options Price Options Price Exercisable at end of year 7,436,379 $ 17.02 6,523,093 $ 14.83 5,446,586 $ 13.25 Options vested or expected to vest 15,962,432 $ 20.31 14,449,017 $ 18.11 12,854,571 $ 14.98
Schedule of Exercise Prices And Weighted-average Remaining Contractual Lives For Options Outstanding	Exercise prices and weighted-average remaining contractual lives for the options outstanding as of December 31, 2019 were: Weighted- Weighted- Average Average Weighted- Exercise Remaining Average Price of Options Range of Contractual Exercise Options Options Outstanding Exercise Prices Life (in years) Price Exercisable Exercisable 3,027,881 $5.20–$13.00 4.97 $ 10.16 2,720,921 $ 9.84 3,834,655 $13.05–$17.00 7.42 16.23 2,326,188 16.17 1,623,707 $17.05–$24.55 8.01 20.10 704,338 20.48 2,336,151 $24.97 8.93 24.97 644,066 24.97 3,877,880 $25.02 9.95 25.02 — — 1,940,366 $25.06–$38.75 7.58 30.48 1,032,365 30.38 24,000 $39.00 8.56 39.00 8,501 39.00 16,664,640 7.58 20.47 7,436,379 17.02
Summary of Stock-Based Compensation Expense related to Stock-Based Payment Awards Granted	The following table summarizes stock-based compensation expense related to stock-based payment awards granted pursuant to all of our equity compensation arrangements (in thousands): December 31, 2019 2018 2017 Research and development $ 19,202 $ 13,689 $ 11,312 General and administrative 13,564 9,630 9,469 Sales and marketing 18,645 10,048 9,757 Total stock-based compensation expense $ 51,411 $ 33,367 $ 30,538
Summary of Fair Value of Option Grant and ESPP Purchase Right on Grant Date Using Black-Scholes Option Pricing Model	We estimated the fair value of each option grant and ESPP purchase right on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions: Options: December 31, 2019 2018 2017 Risk-free interest rate 1.8 % 2.8 % 2.1 % Dividend yield — % — % — % Volatility 66.5 % 70.4 % 74.0 % Expected life (years) 6 6 6 ESPP: December 31, 2019 2018 2017 Risk-free interest rate 1.9 % 2.4 % 1.2 % Dividend yield — % — % — % Volatility 52.1 % 59.7 % 50.0 % Expected life (months) 6 6 6

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The difference between the provision for income taxes and income taxes computed using the effective U.S. federal statutory rate is as follows (in thousands): December 31, 2019 2018 2017 Tax at statutory federal rate $ (42,997 ) $ (37,557 ) $ (67,145 ) State tax, net of federal benefit (9,823 ) (6,527 ) (6,203 ) Research and development credits (4,855 ) (4,775 ) (5,962 ) Stock-based compensation expense 2,906 (2,059 ) 3,151 Non-deductible compensation 4,720 901 — Change in valuation allowance 49,479 50,834 3,241 Impact of the 2017 Tax Act — — 74,361 Other 570 (817 ) (1,443 ) Provision for income taxes $ — $ — $ —
Schedule of Deferred Tax Assets and Liabilities	Deferred income tax assets and liabilities arising from differences between accounting for financial statement purposes and tax purposes, less valuation allowance at year-end are as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Net operating loss carryforward $ 210,301 $ 172,113 Research and development credits 42,490 35,670 Stock-based compensation 15,628 11,905 Lease liabilities 3,487 — Other 3,818 3,171 Total gross deferred tax assets 275,724 222,859 Deferred tax liabilities: Right-of-use lease assets (3,385 ) — Total gross deferred tax liabilities (3,385 ) — Valuation allowance (272,339 ) (222,859 ) Net deferred tax assets $ — $ —
Summary of Unrecognized Tax Benefits	A reconciliation of our unrecognized tax benefits is as follows (in thousands): Year Ended December 31, 2019 2018 2017 Balance at beginning of year $ 2,385 $ 120 $ 120 Additions for tax positions of prior years 147 — — Additions based on tax positions related to current year 2,252 2,265 — Balance at end of year $ 4,784 $ 2,385 $ 120

Summary of Quarterly Consolid_2

Summary of Quarterly Consolidated Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Summary of Unaudited Quarterly Results of Operations	The following is a summary of the unaudited quarterly results of operations for the years ended December 31, 2019 and 2018: 2019 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share amounts) Revenues: Net product sales $ 31,602 $ 36,659 $ 42,624 $ 35,083 Cost of product sales (14,962 ) (13,588 ) (17,195 ) (15,874 ) Gross Profit 16,640 23,071 25,429 19,209 Operating expenses: Research and development 42,972 41,425 34,708 48,277 General and administrative 9,648 9,778 8,597 9,874 Sales and marketing 28,720 23,647 16,977 20,420 Loss from operations (64,700 ) (51,779 ) (34,853 ) (59,362 ) Other income, net 1,688 1,557 1,258 1,442 Net loss $ (63,012 ) $ (50,222 ) $ (33,595 ) $ (57,920 ) Basic and diluted net loss per share $ (0.80 ) $ (0.63 ) $ (0.42 ) $ (0.65 ) 2018 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share amounts) Revenues: Net product sales $ 11,567 $ 17,277 $ 19,786 $ 28,844 Cost of product sales (3,133 ) (5,231 ) (7,576 ) (11,572 ) Gross Profit 8,434 12,046 12,210 17,272 Operating expenses: Research and development 39,561 30,159 30,421 39,891 General and administrative 7,028 6,209 7,288 8,738 Sales and marketing 13,835 14,531 16,281 19,957 Loss from operations (51,990 ) (38,853 ) (41,780 ) (51,314 ) Other expense, net (275 ) 183 3,434 1,755 Net loss $ (52,265 ) $ (38,670 ) $ (38,346 ) $ (49,559 ) Basic and diluted net loss per share $ (0.81 ) $ (0.54 ) $ (0.49 ) $ (0.63 )

Organization and Business - Add

Organization and Business - Additional Information (Details) $ in Millions	Dec. 31, 2019USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Cash, cash equivalents and short-term investments	$ 391

Summary of Significant Accoun_2

Summary of Significant Accounting Policies - Percentage of Net Product Sales and Accounts Receivable Balance (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2019
Revenue Benchmark
Product Information [Line Items]
Concentration risk percentage	97.80%
Revenue Benchmark | Largest Customer
Product Information [Line Items]
Concentration risk percentage	40.90%
Revenue Benchmark | Second Largest Customer
Product Information [Line Items]
Concentration risk percentage	39.50%
Revenue Benchmark | Third Largest Customer
Product Information [Line Items]
Concentration risk percentage	17.40%
Accounts Receivable
Product Information [Line Items]
Concentration risk percentage	99.20%
Accounts Receivable | Largest Customer
Product Information [Line Items]
Concentration risk percentage	48.90%
Accounts Receivable | Second Largest Customer
Product Information [Line Items]
Concentration risk percentage	38.60%
Accounts Receivable | Third Largest Customer
Product Information [Line Items]
Concentration risk percentage	11.70%

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands

Jan. 01, 2018

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Mar. 31, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Product Information [Line Items]

Cumulative adjustment to accumulated deficit

$ 1,574

Product sales allowances

$ 27,939

$ 25,503

$ 27,939

$ 25,503

Cost of product sales

$ 15,874

$ 17,195

$ 13,588

$ 14,962

$ 11,572

$ 7,576

$ 5,231

$ 3,133

$ 61,619

$ 27,512

4,588

Accounting Standards Update 2014-09

Product Information [Line Items]

Gross product sales

$ 2,900

Cost of product sales

200

Accounting Standards Update 2014-09 | Product Sales Allowance

Product Information [Line Items]

Product sales allowances

1,100

Accumulated Earnings

Product Information [Line Items]

Cumulative adjustment to accumulated deficit

$ 1,574

Accumulated Earnings | Accounting Standards Update 2014-09

Product Information [Line Items]

Cumulative adjustment to accumulated deficit

$ (1,600)

Leasehold Improvements

Product Information [Line Items]

Estimated useful lives

5 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Common Stock Equivalents Excluded From Computation of Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement, Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares excluded (in shares)	16,665	15,265	13,463
Warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares excluded (in shares)	508	640	620
Convertible Debt Securities
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Shares excluded (in shares)	8,960	8,473	7,983

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 319,074	$ 300,535
U.S. Treasury Bills and Government Agency Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	140,626	59,741
U.S. Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	80,170	59,087
Foreign Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	23,203	5,046
U.S. Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	32,801	52,800
Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	390,972	332,371
Fair Value, Recurring | Foreign Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	57,241	123,861
Fair Value, Recurring | U.S. Treasury Bills and Government Agency Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	140,626	59,741
Fair Value, Recurring | U.S. Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	80,170	59,087
Fair Value, Recurring | Foreign Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	23,203	5,046
Fair Value, Recurring | U.S. Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	32,801	61,885
Fair Value, Recurring | Cash and Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and money market funds	56,931	22,751
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	197,557	82,492
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury Bills and Government Agency Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	140,626	59,741
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and money market funds	56,931	22,751
Fair Value, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	193,415	249,879
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Foreign Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	57,241	123,861
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	80,170	59,087
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Foreign Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	23,203	5,046
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 32,801	$ 61,885

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Financial instruments transferred among fair value hierarchy levels	$ 0
Cash equivalents included of available-for-sale securities	15,000,000	$ 9,100,000
Available for sale securities with contractual maturities of three months to one year.	279,700,000	$ 300,500,000
Available for sale securities with contractual maturities greater than one year	$ 39,400,000

Balance Sheet Details - Summary

Balance Sheet Details - Summary of Short -Term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, amortized cost	$ 318,989	$ 300,622
Available-for-sale securities, gross unrealized gains	85	5
Available-for-sale securities, gross unrealized losses		(92)
Available-for-sale securities	319,074	300,535
U.S. Treasury Bills and Government Agency Obligations
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, amortized cost	140,567	59,747
Available-for-sale securities, gross unrealized gains	59
Available-for-sale securities, gross unrealized losses		(6)
Available-for-sale securities	140,626	59,741
U.S. Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, amortized cost	80,159	59,164
Available-for-sale securities, gross unrealized gains	11
Available-for-sale securities, gross unrealized losses		(77)
Available-for-sale securities	80,170	59,087
Foreign Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, amortized cost	23,188	5,041
Available-for-sale securities, gross unrealized gains	15	5
Available-for-sale securities	23,203	5,046
U.S. Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, amortized cost	32,801	52,800
Available-for-sale securities	32,801	52,800
Foreign Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale securities, amortized cost	42,274	123,870
Available-for-sale securities, gross unrealized losses		(9)
Available-for-sale securities	$ 42,274	$ 123,861

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt securities, impairment losses	$ 0	$ 0
Debt securities, available-for-sale, unrealized gain (loss)	172,000	(77,000)	$ 7,000
Debt securities, available-for-sale, realized gain (loss)	8,000	0	0
Inventory	24,968,000	39,032,000	10,108,000
Depreciation and amortization	2,044,000	1,513,000	$ 1,531,000
Construction in Progress, Gross	13,500,000	10,300,000
SUSTOL
Inventory	1,500,000	6,700,000
Cost of product sales, charges	3,300,000	1,800,000
CINVANTI
Inventory	$ 23,500,000	$ 32,300,000

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 6,635	$ 10,112
Work in process	12,571	20,604
Finished goods	5,762	8,316
Total inventory	$ 24,968	$ 39,032	$ 10,108

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 27,643	$ 22,772
Less: accumulated depreciation and amortization	(8,025)	(8,095)
Property and equipment, net	19,618	14,677
Scientific Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	24,603	18,077
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	206	1,783
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,314	1,190
Furniture, Fixtures and Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,520	$ 1,722

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accrued payroll and employee liabilities
Accrued employee salaries and benefits	$ 3,047	$ 2,330
Accrued bonuses	9,545	9,139
Accrued vacation	2,656	1,928
Total accrued payroll and employee liabilities	15,248	13,397
Other accrued liabilities
Accrued product sales allowances	27,939	25,503
Accrued consulting and professional fees	7,742	5,768
Deferred rent		780
Accrued accounts payable	310	224
Other accrued liabilities	544	440
Total other accrued liabilities	$ 36,535	$ 32,715	$ 17,175

Revenue Recognition - Adoption

Revenue Recognition - Adoption of Topic 606 (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Inventory		$ 24,968				$ 39,032				$ 24,968	$ 39,032	$ 10,108
Other accrued liabilities		36,535				32,715				36,535	32,715	17,175
Deferred revenue												2,763
Accumulated deficit		(1,165,470)				(960,721)				(1,165,470)	(960,721)	(783,455)
Net product sales		35,083	$ 42,624	$ 36,659	$ 31,602	28,844	$ 19,786	$ 17,277	$ 11,567	145,968	77,474	30,767
Cost of product sales		15,874	17,195	13,588	14,962	11,572	7,576	5,231	3,133	61,619	27,512	4,588
Loss from operations		(59,362)	(34,853)	(51,779)	(64,700)	(51,314)	(41,780)	(38,853)	(51,990)	(210,694)	(183,937)	(194,558)
Net loss		$ (57,920)	$ (33,595)	$ (50,222)	$ (63,012)	$ (49,559)	$ (38,346)	$ (38,670)	$ (52,265)	$ (204,749)	$ (178,840)	$ (197,484)
Basic and diluted net loss per share		$ (0.65)	$ (0.42)	$ (0.63)	$ (0.80)	$ (0.63)	$ (0.49)	$ (0.54)	$ (0.81)	$ (2.50)	$ (2.44)	$ (3.65)
Adjustments to reconcile net loss to net cash used for operating activities:
Inventory										$ 14,064	$ (29,122)	$ (4,768)
Other accrued liabilities										$ 4,558	14,941	11,482
Deferred revenue												$ 1,664
Accounting Standards Update 2014-09
Disaggregation Of Revenue [Line Items]
Inventory	$ 9,910
Other accrued liabilities	18,166
Accumulated deficit	(781,881)
Cost of product sales	200
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Disaggregation Of Revenue [Line Items]
Inventory	(198)					$ 2,181					2,181
Other accrued liabilities	991					(7,195)					(7,195)
Deferred revenue	(2,763)					14,010					14,010
Accumulated deficit	$ 1,574					(4,634)					(4,634)
Net product sales											(5,043)
Cost of product sales											(1,983)
Loss from operations											(3,060)
Net loss											$ (3,060)
Basic and diluted net loss per share											$ 0.05
Adjustments to reconcile net loss to net cash used for operating activities:
Inventory											$ (1,983)
Other accrued liabilities											(6,204)
Deferred revenue											11,247
Accounting Standards Update 2014-09 | Calculated under Revenue Guidance in Effect before Topic 606
Disaggregation Of Revenue [Line Items]
Inventory						41,213					41,213
Other accrued liabilities						25,520					25,520
Deferred revenue						14,010					14,010
Accumulated deficit						$ (965,355)					(965,355)
Net product sales											72,431
Cost of product sales											25,529
Loss from operations											(186,997)
Net loss											$ (181,900)
Basic and diluted net loss per share											$ (2.49)
Adjustments to reconcile net loss to net cash used for operating activities:
Inventory											$ (31,105)
Other accrued liabilities											8,737
Deferred revenue											$ 11,247

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Net product sales	$ 35,083	$ 42,624	$ 36,659	$ 31,602	$ 28,844	$ 19,786	$ 17,277	$ 11,567	$ 145,968	$ 77,474	$ 30,767
CINVANTI
Disaggregation Of Revenue [Line Items]
Net product sales									132,200	56,200
SUSTOL
Disaggregation Of Revenue [Line Items]
Net product sales									$ 13,800	$ 21,300

Revenue Recognition - Summary o

Revenue Recognition - Summary of Product Sales Allowance (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Disaggregation Of Revenue [Line Items]
Balance	$ 25,503
Provision	162,199
Payments/credits	(159,763)
Balance	27,939
Product Returns
Disaggregation Of Revenue [Line Items]
Balance	947
Provision	2,960
Payments/credits	(1,556)
Balance	2,351
Distributor Fees
Disaggregation Of Revenue [Line Items]
Balance	2,813
Provision	18,934
Payments/credits	(17,748)
Balance	3,999
Discounts, Rebates and Administrative Fees
Disaggregation Of Revenue [Line Items]
Balance	21,743
Provision	140,305
Payments/credits	(140,459)
Balance	$ 21,589

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	Mar. 15, 2018	Jan. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)ft²	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jan. 01, 2019USD ($)
Lessee Lease Description [Line Items]
Operating lease, initial ROU lease assets			$ 13,754			$ 13,700
Operating lease, initial lease liabilities			14,168			$ 14,500
Operating lease, weighted-average remaining lease term						6 years
Operating lease, expense			3,100	$ 3,200	$ 3,100
Operating lease, payments			$ 3,400
San Diego, California
Lessee Lease Description [Line Items]
Area of real estate property | ft²			52,148
Lease expiration date			Dec. 31, 2025
Lessee, operating lease, renewal term			5 years
Rent expense for additional office space for first twelve months			$ 900
Rent expense for additional office space for last twelve month			$ 1,300
San Diego, California | Subsequent Event
Lessee Lease Description [Line Items]
Area of real estate property | ft²		21,180
Lease expiration date		Dec. 31, 2025
Operating lease, initial ROU lease assets		$ 5,100
Operating lease, initial lease liabilities		5,700
Unamortized lease incentive		$ 600
Redwood City, California
Lessee Lease Description [Line Items]
Area of real estate property | ft²			26,067
Lease expiration date			May 31, 2019
Sublease expiration date	May 31, 2019
Jersey City, New Jersey
Lessee Lease Description [Line Items]
Area of real estate property | ft²			1,898
Lease expiration date			Dec. 31, 2019
Accounting Standards Update 2016-02
Lessee Lease Description [Line Items]
Operating lease, expense			$ 3,000

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Commitments And Contingencies Disclosure [Abstract]
2020	$ 2,724
2021	2,804
2022	2,885
2023	2,969
2024	3,030
Thereafter	3,097
Total future minimum lease payments	17,509
Less: discount	(3,341)
Total lease liabilities	$ 14,168	$ 14,500

Realignment of Goals and Obje_2

Realignment of Goals and Objectives and New Development Focus - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2018
Restructuring and related cost, expected cost, total		$ 9.4
Restructuring Plan | General and Administrative Expense
Restructuring charges, total	$ 0.5
Restructuring Plan | Employee Severance
Restructuring and related cost, expected cost, total		5.5
Restructuring Plan | Accelerated Non-Cash Stock Option Expense
Restructuring and related cost, expected cost, total		$ 3.9

Secured Notes to Related Party

Secured Notes to Related Party - Additional Information (Details)	Aug. 05, 2016USD ($)	Aug. 02, 2016USD ($)shares	Jul. 29, 2011shares	Aug. 31, 2018USD ($)	Aug. 31, 2016USD ($)	Apr. 30, 2011USD ($)Dayshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Proceeds from convertible debt						$ 4,300,000
Amortization of debt discount							$ 1,050,000	$ 890,000	$ 773,000
Debt instrument, convertible, number shares of equity instruments | shares							9,000,000
Convertible Notes
Debt Instrument [Line Items]
Convertible debt issuable in connection with private placement						$ 4,500,000
Debt instrument, interest rate						6.00%
Debt instrument, maturity date						May 2, 2021
Debt instrument conversion ratio multiple of principal						$ 1,000
Beneficial ownership after conversion						9.99%
Notice period associated with beneficial ownership percentage limitation convertible notes | Day						61
Common shares registered for resale in connection with convertible notes | shares			3,500,000
Debt instrument, term						10 years
Paid-in-kind interest							$ 400,000
Debt instrument, additional debt discount							400,000
Interest expense, debt, excluding amortization							400,000	400,000	400,000
Amortization of debt discount							1,100,000	900,000	800,000
Carrying value of debt							5,600,000
Debt instrument, face amount							7,200,000
Debt instrument, unamortized discount, total							$ 1,600,000
Convertible Notes | Common Stock
Debt Instrument [Line Items]
Debt instrument, number of shares issued for convertible notes | shares						1,250
Term Loan | Tang Capital
Debt Instrument [Line Items]
Debt instrument, interest rate					8.00%
Debt instrument, term					2 years
Carrying value of debt								0
Debt agreement, maximum borrowing capacity					$ 100,000,000
Proceeds from issuance of long-term debt, total	$ 50,000,000
Proceeds from issuance of long-term debt, subject to achievement of corporate milestone		$ 50,000,000
Debt instrument, fee amount		$ 0
Debt instrument, number of warrants | shares		0
Debt instrument, convertible, beneficial conversion feature		$ 0
Interest expense								$ 1,200,000	$ 2,800,000
Debt outstanding principal paid				$ 25,000,000
Debt accrued interest paid				$ 200,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	1 Months Ended															12 Months Ended
	Oct. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Apr. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Jan. 31, 2017	Jun. 30, 2016	May 31, 2015	Jun. 30, 2014	May 31, 2014	Jun. 30, 2011	May 31, 2010	May 31, 2009	Dec. 31, 2007	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 1997
Class Of Stock [Line Items]
Proceeds from issuance of common stock	$ 162,200,000		$ 194,400,000	$ 168,700,000	$ 142,600,000		$ 163,700,000									$ 162,151,000	$ 363,128,000	$ 306,279,000
Class of warrant or right, number of securities called by warrants or rights																508,000
Share-based compensation arrangements by share-based payment award, options, exercises in period, weighted average exercise price																$ 11.18	$ 11.97	$ 8.49
Common stock, shares, issued, total																90,304,000	78,174,000
Common stock, capital shares reserved for future issuance																31,474,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant																4,971,000
Share-based compensation arrangement by share-based payment award, expiration period																10 years
Share-based compensation arrangement by share-based payment award, award vesting period																4 years
Share-based compensation arrangement by share-based payment award, options, forfeitures in period																1,021,453
Share-based compensation arrangements by share-based payment award, options, forfeitures in period, weighted average exercise price																$ 20.91
Share-based compensation arrangement by share-based payment award, options, expirations in period																528,773
Share-based compensation arrangements by share-based payment award, options, expirations in period, weighted average exercise price																$ 27.81
Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term																6 years 3 months 18 days
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value																$ 25,000	$ 31,400
Share-based compensation arrangement by share-based payment award, options, outstanding, intrinsic value																$ 56,300	$ 75,700
Common stock future issuance on exercise of outstanding options granted																16,664,640
Total unrecognized compensation cost related to non-vested, stock-based payment awards																$ 128,700
Total unrecognized compensation cost, expect to recognize over weighted average period																3 years
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized																			10,000
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		300,000				200,000		100,000	100,000		25,000	25,000		10,000	5,000	775,000
Share-based compensation arrangement by share-based payment award maximum employee earnings with held to purchase common stock percent																10.00%
Share-based compensation arrangement by share-based payment award discount on stock price																85.00%
Share-based compensation arrangement by share-based payment award, shares issued in period																125,727	71,499	77,283
Share-based compensation arrangements by share-based payment award, options, exercises in period, weighted average exercise price																$ 16.77	$ 16.48	$ 12.80
Common stock, shares, issued, total																404,909
Common stock, capital shares reserved for future issuance																370,091
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value																$ 14.70	17.24	10.61
Share-based compensation arrangement by share-based payment award, per share weighted-average fair value price of shares purchased					$ 4.51											$ 5.94	$ 9.95	$ 4.51
Expected life																6 months
Equity Incentive Plan 2007
Class Of Stock [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized															150,000
Share-based compensation arrangement by share-based payment award, number of additional shares authorized		7,000,000				5,000,000		3,000,000	4,300,000		1,750,000	4,500,000	100,000			25,800,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant																4,971,026
Pre-funded Warrants
Class Of Stock [Line Items]
Class of warrant or right, number of securities called by warrants or rights										600,000
Class of warrant or right, exercise price of warrants or rights										$ 0.01
Class of warrant or right, expiration date										Jun. 30, 2021
Class of warrant or right, exercised during period																132,130		4,426
Proceeds from issuance of warrants																$ 1,321,000		$ 0
Class of warrant or right, outstanding																463,444
Common Stock
Class Of Stock [Line Items]
Number of shares issued	9,900,000		5,100,000	6,900,000	9,700,000		14,100,000									9,857,000	11,963,000	23,822,000
Share price	$ 17.50		$ 39.50	$ 26	$ 15.50		$ 12.20											$ 15.50
Payments of stock issuance costs	$ 10,300,000		$ 5,600,000	$ 10,700,000	$ 7,400,000		$ 8,800,000
Issuance of common stock on exercise of warrants (in shares)																132,000		4,000
Common Stock | Pre-funded Warrants
Class Of Stock [Line Items]
Issuance of common stock on exercise of warrants (in shares)																132,130		4,423

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockholders Equity Note [Abstract]
Stock options outstanding	16,664,640	15,264,607	13,462,964	11,845,376
Stock options available for grant	4,971,000
Employee Stock Purchase Plan	370,000
Warrants outstanding	508,000
Shares of common stock underlying Convertible Notes outstanding (see Note 8)	8,960,000
Total shares reserved for future issuance	31,474,000

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Number of shares outstanding	15,264,607	13,462,964	11,845,376
Number of shares granted	4,933,480	4,052,011	4,300,621
Number of shares exercised	(1,983,221)	(1,529,509)	(1,350,605)
Number of shares cancelled	(1,550,226)	(720,859)	(1,332,428)
Number of shares outstanding	16,664,640	15,264,607	13,462,964
Number of shares outstanding, weighted average exercise price	$ 18.33	$ 15.03	$ 14.44
Number of shares granted, weighted average exercise price	24.21	26.83	16.17
Number of shares exercised, weighted average exercise price	11.18	11.97	8.49
Number of shares cancelled, weighted average exercise price	23.26	17.98	20.06
Number of shares outstanding, weighted average exercise price	$ 20.47	$ 18.33	$ 15.03

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Options Exercisable, Vested or Expected to Vest (Details) - $ / shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Options exercisable at end of year	7,436,379	6,523,093	5,446,586
Options vested or expected to vest	15,962,432	14,449,017	12,854,571
Options exercisable at end of year, weighted average exercise price	$ 17.02	$ 14.83	$ 13.25
Options vested or expected to vest, weighted average exercise price	$ 20.31	$ 18.11	$ 14.98

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Exercise Prices And Weighted-average Remaining Contractual Lives For Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Options Outstanding (in shares) | shares	16,664,640
Weighted- Average Remaining Contractual Life (Year)	7 years 6 months 29 days
Weighted- Average Exercise Price (in dollars per share)	$ 20.47
Options Exercisable (in shares) | shares	7,436,379
Weighted- Average Exercise Price of Options Exercisable	$ 17.02
Exercise Price Range 1
Options Outstanding (in shares) | shares	3,027,881
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 5.20
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 13
Weighted- Average Remaining Contractual Life (Year)	4 years 11 months 19 days
Weighted- Average Exercise Price (in dollars per share)	$ 10.16
Options Exercisable (in shares) | shares	2,720,921
Weighted- Average Exercise Price of Options Exercisable	$ 9.84
Exercise Price Range 2
Options Outstanding (in shares) | shares	3,834,655
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 13.05
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 17
Weighted- Average Remaining Contractual Life (Year)	7 years 5 months 1 day
Weighted- Average Exercise Price (in dollars per share)	$ 16.23
Options Exercisable (in shares) | shares	2,326,188
Weighted- Average Exercise Price of Options Exercisable	$ 16.17
Exercise Price Range 3
Options Outstanding (in shares) | shares	1,623,707
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 17.05
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 24.55
Weighted- Average Remaining Contractual Life (Year)	8 years 3 days
Weighted- Average Exercise Price (in dollars per share)	$ 20.10
Options Exercisable (in shares) | shares	704,338
Weighted- Average Exercise Price of Options Exercisable	$ 20.48
Exercise Price Range 4
Options Outstanding (in shares) | shares	2,336,151
Exercise Prices	$ 24.97
Weighted- Average Remaining Contractual Life (Year)	8 years 11 months 4 days
Weighted- Average Exercise Price (in dollars per share)	$ 24.97
Options Exercisable (in shares) | shares	644,066
Weighted- Average Exercise Price of Options Exercisable	$ 24.97
Exercise Price Range 5
Options Outstanding (in shares) | shares	3,877,880
Exercise Prices	$ 25.02
Weighted- Average Remaining Contractual Life (Year)	9 years 11 months 12 days
Weighted- Average Exercise Price (in dollars per share)	$ 25.02
Exercise Price Range 6
Options Outstanding (in shares) | shares	1,940,366
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 25.06
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 38.75
Weighted- Average Remaining Contractual Life (Year)	7 years 6 months 29 days
Weighted- Average Exercise Price (in dollars per share)	$ 30.48
Options Exercisable (in shares) | shares	1,032,365
Weighted- Average Exercise Price of Options Exercisable	$ 30.38
Exercise Price Range 7
Options Outstanding (in shares) | shares	24,000
Exercise Prices	$ 39
Weighted- Average Remaining Contractual Life (Year)	8 years 6 months 21 days
Weighted- Average Exercise Price (in dollars per share)	$ 39
Options Exercisable (in shares) | shares	8,501
Weighted- Average Exercise Price of Options Exercisable	$ 39

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Stock-Based Compensation Expense related to Stock-Based Payment Awards Granted (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 51,411	$ 33,367	$ 30,538
Research and Development Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	19,202	13,689	11,312
General and Administrative Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	13,564	9,630	9,469
Selling and Marketing Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 18,645	$ 10,048	$ 9,757

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of Fair Value of Option Grant and ESPP Purchase Right on Grant Date Using Black-Scholes Option Pricing Model (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement, Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	1.80%	2.80%	2.10%
Dividend yield	0.00%	0.00%	0.00%
Volatility	66.50%	70.40%	74.00%
Expected life	6 years	6 years	6 years
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	1.90%	2.40%	1.20%
Dividend yield	0.00%	0.00%	0.00%
Volatility	52.10%	59.70%	50.00%
Expected life	6 months	6 months	6 months

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax at statutory federal rate	$ (42,997)	$ (37,557)	$ (67,145)
State tax, net of federal benefit	(9,823)	(6,527)	(6,203)
Research and development credits	(4,855)	(4,775)	(5,962)
Stock-based compensation expense	2,906	(2,059)	3,151
Non-deductible compensation	4,720	901
Change in valuation allowance	49,479	50,834	3,241
Impact of the 2017 Tax Act			74,361
Other	570	(817)	(1,443)
Provision for income taxes	$ 0	$ 0	$ 0

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforward	$ 210,301	$ 172,113
Research and development credits	42,490	35,670
Stock-based compensation	15,628	11,905
Lease liabilities	3,487
Other	3,818	3,171
Total gross deferred tax assets	275,724	222,859
Deferred tax liabilities:
Right-of-use lease assets	(3,385)
Total gross deferred tax liabilities	(3,385)
Valuation allowance	$ (272,339)	$ (222,859)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	Jan. 01, 2018	Dec. 31, 2019	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Research		$ 42,490,000		$ 35,670,000
Effective income tax rate reconciliation, at federal statutory income tax rate, percent	21.00%	21.00%	35.00%
Adjustment of deferred tax (asset) liability, revaluation based on new tax rate			$ 74,300,000
Unrecognized Tax Benefits, Ending Balance		$ 4,784,000	120,000	$ 2,385,000	$ 120,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total		0
Deferred Tax Assets Revaluated
Operating Loss Carryforwards [Line Items]
Valuation allowance, deferred tax asset, increase (decrease)			$ (74,300,000)
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total		865,200,000
Expiring Operating Loss Carryforwards		$ 549,700,000
Net operating loss carryforwards expiration year		2021
Indefinite Operating Loss Carryforwards		$ 315,500,000
Taxable income limitation percentage for operating loss carryforward		80.00%
Deferred Tax Assets, Tax Credit Carryforwards, Research		$ 33,700,000
Research and development credit carryforwards expiration year		2022
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards expiration year		2028
Deferred Tax Assets, Tax Credit Carryforwards, Research		$ 15,800,000
State and Local Jurisdiction | California Franchise Tax Board
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total		125,900,000
State and Local Jurisdiction | Other State Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards, Total		$ 1,100,000,000

Income Taxes - Summary of Unrec

Income Taxes - Summary of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 2,385	$ 120
Additions for tax positions of prior years	147
Additions based on tax positions related to current year	2,252	2,265
Balance at end of year	$ 4,784	$ 2,385

Other Income (Expense), Net - A

Other Income (Expense), Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other income (expense)	$ 158	$ 1,804	$ (38)
Disgorgement of Short-Swing Profits from the Sale of Common Stock
Other income (expense)		$ 1,900

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of match	50.00%	50.00%	50.00%
Defined contribution plan, maximum annual contributions by employer per employee, amount	$ 8,400	$ 8,250	$ 8,100
Defined contribution plan, cost	$ 1,000,000	$ 700,000	$ 600,000
Maximum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	3.00%	3.00%	3.00%

Summary of Quarterly Consolid_3

Summary of Quarterly Consolidated Financial Data (Unaudited) - Summary of Unaudited Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Net product sales	$ 35,083	$ 42,624	$ 36,659	$ 31,602	$ 28,844	$ 19,786	$ 17,277	$ 11,567	$ 145,968	$ 77,474	$ 30,767
Cost of product sales	(15,874)	(17,195)	(13,588)	(14,962)	(11,572)	(7,576)	(5,231)	(3,133)	(61,619)	(27,512)	(4,588)
Gross Profit	19,209	25,429	23,071	16,640	17,272	12,210	12,046	8,434
Operating expenses:
Research and development	48,277	34,708	41,425	42,972	39,891	30,421	30,159	39,561	167,382	140,032	138,582
General and administrative	9,874	8,597	9,778	9,648	8,738	7,288	6,209	7,028	37,897	29,263	25,554
Sales and marketing	20,420	16,977	23,647	28,720	19,957	16,281	14,531	13,835	89,764	64,604	56,601
Loss from operations	(59,362)	(34,853)	(51,779)	(64,700)	(51,314)	(41,780)	(38,853)	(51,990)	(210,694)	(183,937)	(194,558)
Other income (expense), net	1,442	1,258	1,557	1,688	1,755	3,434	183	(275)	5,945	5,097	(2,926)
Net loss	$ (57,920)	$ (33,595)	$ (50,222)	$ (63,012)	$ (49,559)	$ (38,346)	$ (38,670)	$ (52,265)	$ (204,749)	$ (178,840)	$ (197,484)
Basic and diluted net loss per share	$ (0.65)	$ (0.42)	$ (0.63)	$ (0.80)	$ (0.63)	$ (0.49)	$ (0.54)	$ (0.81)	$ (2.50)	$ (2.44)	$ (3.65)