Corcept Therapeutics (CORT) 10-K 28 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 23, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	CORT
Entity Registrant Name	CORCEPT THERAPEUTICS INC
Entity Central Index Key	1,088,856
Current Fiscal Year End Date	--12-31
Entity Well Known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1,147,542,935
Entity Common Stock, Shares Outstanding		114,830,345

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 31,062	$ 51,536
Short-term marketable securities	57,682	0
Trade receivables, net of allowances	15,300	9,860
Other receivable (Note 11)	12,896	0
Inventory	4,576	2,329
Prepaid expenses and other current assets	2,669	1,964
Total current assets	124,185	65,689
Strategic inventory	3,800	2,835
Property and equipment, net of accumulated depreciation	518	205
Long-term marketable securities	15,281	0
Other assets	50	24
Deferred tax assets, net	76,703	0
Total assets	220,537	68,753
Current liabilities:
Accounts payable	8,579	2,290
Accrued clinical expenses	2,247	1,467
Other accrued liabilities	18,743	8,953
Debt obligation - current portion	0	14,664
Total current liabilities	29,569	27,374
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, par value $0.001 per share, 10,000 shares authorized and no shares outstanding at December 31, 2017 and December 31, 2016
Common stock, par value $0.001 per share, 280,000 shares authorized and 114,717 and 112,710 shares issued and outstanding at December 31, 2017 and December 31, 2016, respectively	115	113
Additional paid-in capital	384,074	363,534
Accumulated other comprehensive loss	(75)	0
Accumulated deficit	(193,146)	(322,268)
Total stockholders’ equity	190,968	41,379
Total liabilities and stockholders’ equity	$ 220,537	$ 68,753

BALANCE SHEETS (Parenthetical)

BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	280,000,000	280,000,000
Common stock, shares issued	114,717,000	112,710,000
Common stock, shares outstanding	114,717,000	112,710,000

STATEMENTS OF COMPREHENSIVE INC

STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Product revenue, net	$ 159,201,000	$ 81,321,000	$ 50,286,000
Operating expenses:
Cost of sales	3,554,000	2,058,000	1,361,000
Research and development	40,376,000	23,844,000	15,419,000
Selling, general and administrative	62,416,000	45,240,000	36,949,000
Total operating expenses	106,346,000	71,142,000	53,729,000
Income (loss) from operations	52,855,000	10,179,000	(3,443,000)
Interest and other expense	(49,000)	(2,039,000)	(2,965,000)
Income before income taxes	52,806,000	8,140,000	(6,408,000)
Income tax benefit	76,316,000	0	0
Net income (loss)	129,122,000	8,140,000	(6,408,000)
Other comprehensive income (loss):
Net unrealized loss on available-for-sale investments	(75,000)	0	0
Total comprehensive income (loss)	$ 129,047,000	$ 8,140,000	$ (6,408,000)
Basic net income (loss) per common share	$ 1.14	$ 0.07	$ (0.06)
Diluted net income (loss) per common share	$ 1.04	$ 0.07	$ (0.06)
Weighted average shares outstanding used in computing net income (loss) per share
Basic	113,527	110,566	106,883
Diluted	124,515	116,139	106,883

STATEMENTS OF STOCKHOLDERS EQUI

STATEMENTS OF STOCKHOLDERS EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Total	Employees and Directors	Non-employee	Common Stock	Additional Paid-in Capital	Additional Paid-in CapitalEmployees and Directors	Additional Paid-in CapitalNon-employee	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance at Dec. 31, 2014	$ (3,388)			$ 101	$ 320,511				$ (324,000)
Beginning Balance (in shares) at Dec. 31, 2014				101,395
Issuance of common stock upon exercise of options	$ 5,193			$ 3	5,190
Issuance of common stock upon exercise of options (in shares)	2,041			2,041
Issuance of common stock upon exercise of warrants, net	$ 17,088			$ 6	17,082
Issuance of common stock upon exercise of warrants, net (in shares)				6,206
Stock-based compensation		$ 5,926	$ 87			$ 5,926	$ 87
Net income (loss)	(6,408)								(6,408)
Ending Balance at Dec. 31, 2015	18,498			$ 110	348,796				(330,408)
Ending Balance (in shares) at Dec. 31, 2015				109,642
Issuance of common stock upon exercise of options	$ 7,683			$ 3	7,680
Issuance of common stock upon exercise of options (in shares)	3,068			3,068
Stock-based compensation		7,002	56			7,002	56
Net income (loss)	$ 8,140								8,140
Ending Balance at Dec. 31, 2016	41,379			$ 113	363,534				(322,268)
Ending Balance (in shares) at Dec. 31, 2016				112,710
Issuance of common stock upon exercise of options	$ 7,181			$ 2	7,179
Issuance of common stock upon exercise of options (in shares)	2,007			2,007
Stock-based compensation		$ 13,330	$ 31			$ 13,330	$ 31
Net unrealized loss on marketable securities	$ (75)							$ (75)
Net income (loss)	129,122								129,122
Ending Balance at Dec. 31, 2017	$ 190,968			$ 115	$ 384,074			$ (75)	$ (193,146)
Ending Balance (in shares) at Dec. 31, 2017				114,717

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ 129,122	$ 8,140	$ (6,408)
Adjustments to reconcile net income (loss) to net cash provided by operations:
Stock-based compensation	13,361	7,058	6,013
Accretion of interest expense	456	1,929	2,848
Amortization of debt financing costs	14	21	22
Deferred taxes	(76,703)	0	0
Excess tax benefits from stock option activity	293	0	0
Depreciation and amortization of property and equipment	106	87	155
Changes in operating assets and liabilities:
Trade receivables	(5,440)	(3,639)	(2,887)
Other receivable (Note 11)	(12,896)	0	0
Inventory	(2,262)	(682)	815
Prepaid expenses and other current assets	(705)	(1,322)	799
Other assets	(26)	0	(7)
Accounts payable	6,289	965	(561)
Accrued clinical expenses	780	296	835
Other accrued liabilities	8,546	5,696	1,381
Deferred revenue	0	(158)	125
Net cash provided by operating activities	60,935	18,391	3,130
Cash flows from investing activities:
Purchases of property and equipment	(419)	(194)	(17)
Purchases of marketable securities	(73,037)	0	0
Cash used in investing activities	(73,456)	(194)	(17)
Cash flows from financing activities:
Proceeds from exercise of warrants, net of issuance costs	0	0	17,088
Proceeds from exercise of stock options, net of issuance costs	7,181	7,683	5,193
Payments related to debt obligation	(15,134)	(14,779)	(9,207)
Net cash (used in) provided by financing activities	(7,953)	(7,096)	13,074
Net (decrease) increase in cash and cash equivalents	(20,474)	11,101	16,187
Cash and cash equivalents, at beginning of period	51,536	40,435	24,248
Cash and cash equivalents, at end of period	31,062	51,536	40,435
Supplemental disclosure:
Income taxes paid	$ 377	$ 40	$ 57

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	1. Basis of Presentation and Summary of Significant Accounting Policies Description of Business and Basis of Presentation Corcept Therapeutics Incorporated was incorporated in the State of Delaware in May 1998, and our headquarters are located in Menlo Park, California. We are a pharmaceutical company engaged in the discovery, development and commercialization of medications that treat severe metabolic, oncologic, and psychiatric disorders by modulating the effect of the stress hormone cortisol. In 2012, the United States Food and Drug Administration (“FDA”) approved Korlym ® . Basis of Presentation The financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). Principles of Consolidation Our financial statements include the financial position and results of Corcept Therapeutics UK Limited, our wholly owned subsidiary. Corcept Therapeutics UK Limited was incorporated in the United Kingdom in March 2017, and to date, there have been no material financial transactions or balances related to this entity. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ materially from those estimates . We reevaluate our estimates and assumptions each quarter, including those related to revenue recognition, sales returns, recognition and measurement of income tax assets and liabilities, inventory, allowances for doubtful accounts and accrued liabilities, including our bonus accrual, clinical trial accruals and stock-based compensation . Fair Value Measurements We value financial instruments using the assumptions we believe third-party market participants would adopt when valuing such instruments. Our methodology uses a “fair value hierarchy” that gives the highest priority to quoted prices in active markets for identical instruments (called “Level 1 inputs”). If no Level 1 inputs are available, we consider (i) quoted prices in non-active markets for identical instruments; (ii) active markets for similar instruments; (iii) inputs other than quoted prices for the instrument; and (iv) inputs that are not directly observable, but that are corroborated by observable data (“Level 2 inputs”). In the absence of Level 2 inputs, we rely on unobservable inputs, such as our own data about the assumptions market participants would use in pricing the instrument (“Level 3 inputs”). Cash and Cash Equivalents and Marketable Securities We consider all highly liquid investments purchased with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents are carried at fair value as measured using Level 1 inputs, which approximates cost. As of December 31, 2016, all of our funds were held in checking and money market fund accounts maintained at major U.S. financial institutions . Effective January 2017, we invested a portion of our funds in marketable securities, primarily U.S. Treasury securities, commercial paper and corporate notes. We classify our marketable securities as available-for-sale securities and report them at fair value as “cash equivalents” or “marketable securities” on our balance sheet, with related unrealized gains and losses included in stockholders' equity. Realized gains and losses and permanent declines in value are included in “interest and other income” on our statement of comprehensive income (loss). Credit and Concentration Risks Our cash, cash equivalents and marketable securities are held in one financial institution. We are exposed to credit and concentration risks in the event of default by the financial institution holding our funds and investments or by the entity or entities that issued the securities held by the funds to the extent of the amount recorded on our balance sheet. We mitigate these risks by investing in liquid U.S. Treasury securities, highly-rated commercial paper and corporate notes, and money market funds that invest primarily in short-term U.S. Treasury notes and bills. We have never experienced a loss or lack of access to our operating or investment accounts. Among other services, Optime Care, Inc. (“Optime”), a specialty pharmacy, dispenses Korlym to patients for us, with title to the medicine passing from us to the patient upon the patient’s receipt of the drug. Accordingly, our receivables risk is spread among various third-party payors – pharmacy benefit managers, insurance companies, private charities, government programs – and individual patients. We extend credit to third-party payors based on their creditworthiness. We monitor our exposure and record an allowance against uncollectible trade receivables as necessary. To date, we have not incurred any credit losses. Through August 9, 2017 our exclusive specialty pharmacy was Dohmen Life Science Services (“Dohmen”). On August 10, 2017, Optime Care, Inc. (“Optime”) became our exclusive specialty pharmacy. We have a concentration of risk in regard to the manufacture and distribution of our product. As of December 31, 2017, we had one tablet manufacturer for Korlym – Alcami Corporation (formerly known as AAI Pharma Services Corp.). In addition, we have a single-source manufacturer of mifepristone, the active pharmaceutical ingredient (API), in Korlym – Produits Chimiques Auxiliaires et de Synthèse SA (PCAS). If either of these companies is unable to manufacture API or Korlym tablets in the quantities and time frame required, we may not be able to manufacture our product in a timely manner. In order to mitigate these risks related to the manufacture of our product, we purchased and hold in inventory additional quantities of mifepristone API and Korlym tablets. Optime is our sole specialty pharmacy. Its unwillingness or inability to dispense Korlym to patients in a timely manner would harm our business. Inventory We value inventory at the lower of cost or net realizable value. We determine the cost of inventory using the specific identification method, which approximates a first-in, first-out basis. We write down inventory that has become obsolete or has a cost basis in excess of its expected net realizable value. Any expired inventory is disposed of and the related costs are recognized as cost of sales in the statement of comprehensive income (loss) in that period. Inventory amounts that are not expected to be consumed within 12 months following the balance sheet date are classified as strategic inventory, a noncurrent asset. We expense the manufacturing costs for product candidates incurred prior to regulatory approval as research and development expense as we incur them. We begin capitalizing costs related to the manufacture of a product candidate when we obtain regulatory approval to begin marketing that product . Debt Obligation In August 2012, we entered into a Purchase and Sale Agreement (“Financing Agreement”) with Biopharma Secured Debt Fund II Sub, S.à r.l (“Biopharma”), a private limited liability company organized under the laws of Luxembourg. Under the terms of the Financing Agreement, we received $30.0 million from Biopharma, which we recorded as a long-term obligation. In return, we were obligated to make payments to Biopharma totaling $45.0 million. These payments equaled a percentage of (i) our net product sales, including sales from any product containing mifepristone or any of our proprietary selective cortisol modulators (“Covered Products”) and (ii) cash or cash equivalents received from any licensing transaction or co-promotion arrangement involving Covered Products (together, “Korlym Receipts”). Once we had paid Biopharma a total of $45.0 million, no more payments were due and the obligation was extinguished . We recognized a portion of each quarterly payment under the Financing Agreement as interest expense, which we determined by calculating the interest rate to Biopharma implied by the stream of quarterly payments we expected to make. In each period, the amount shown on our balance sheet as the current portion was our estimate of the amount we expected to pay Biopharma in the following 12 months. We recorded the rest of the outstanding portion of the obligation, if any, as a long-term liability . We made our final payment to Biopharma, completely satisfying our obligations under the Financing Agreement, in July 2017. See Note 5, Debt Obligation Net Product Revenue We primarily sell Korlym directly to patients through a specialty pharmacy. We recognize revenue upon the delivery of Korlym if (i) there is persuasive evidence that an arrangement exists with the customer, (ii) collectability is reasonably assured and (iii) the sales price is fixed or determinable. In order to conclude that the price is fixed or determinable, we must be able to (i) calculate gross product revenue from a sale and (ii) reasonably estimate the associated net revenue. Confirmation of coverage by the patient’s private or government insurance plan or by a third-party charity is a prerequisite for selling Korlym to a patient. We provide Korlym at no cost to patients without insurance who do not qualify for charitable support . Through August 9, 2017 our exclusive specialty pharmacy was Dohmen. On August 10, 2017, Optime became our exclusive specialty pharmacy. We also sell Korlym to a specialty distributor (“SD”), which we recognize at the time the SD receives the Korlym. SD sales were less than one percent of our net revenue in the year ended December 31, 2017. We donate cash to charities that help patients with financial need pay for the treatment of Cushing’s syndrome. We do not include payments we receive from these organizations in revenue . We calculate gross product revenues based on the price we charge our customers. We estimate net product revenues by deducting from gross product revenues (a) estimated government rebates and chargebacks, (b) estimated costs of our patient co-pay assistance program, (c) discounts for prompt payment and (d) reserves for expected product returns. We record estimates for these deductions at the time we recognize the gross revenue and update them as new information becomes available . Rebates and Chargebacks: Korlym is eligible for purchase by or qualifies for partial or full reimbursement from Medicaid and other government programs. We estimate any government rebate amounts by applying the discount rates applicable to each government-funded program against our sales to patients covered by such programs . Our allowance activity included in Trade Receivables includes our allowance for doubtful accounts, prompt pay cash discounts and chargebacks is summarized as follows: Balance at Beginning of Period Charges Deductions Balance at End of Period (in thousands) Year ended December 31, 2016: Accounts receivable allowances $ 18 $ 2,081 $ (1,749 ) $ 350 Year ended December 31, 2017: Accounts receivable allowances $ 350 $ 2,755 $ (2,178 ) $ 927 There were no material changes in reserve estimates relating to prior periods. Allowances for Patient Assistance Program: It is our policy that no patient be denied Korlym due to inability to pay. We provide financial assistance to eligible patients whose insurance policies require them to pay high deductibles and co-payments and deduct the amount of such assistance from these sales from gross revenue. We determine the amount of such assistance by applying our program guidelines to all eligible sales in the period . Sales Returns : We deduct from each period’s gross revenue the amount of Korlym we estimate will be returned. When estimating returns, we analyze quantitative and qualitative information including, but not limited to, historical return rates, the amount of product in the distribution channel, the expiration date of the product, current and projected product demand, the introduction of competing products that may erode demand, and broad economic and industry-wide indicators. If we cannot reasonably estimate product returns with respect to a particular sale, we defer recognition of revenue from that sale until we can make a reasonable estimate. Research and Development Research and development expenses consist of direct expenses, such as the cost of discovery research, pre-clinical studies, and clinical trials relating to our portfolio of proprietary, selective cortisol modulators, manufacturing development, preparations for submissions to the FDA or other regulatory agencies and related overhead expenses. We expense nonrefundable payments and the cost of technologies and materials used in research and development as they are incurred . We base our cost accruals for research, preclinical activities, and clinical trials on estimates of work completed under service agreements, milestones achieved, patient enrollment and past experience with similar contracts. Our estimates of work completed and associated cost accruals include our assessments of information from third-party contract research organizations and the overall status of clinical trial and other development and administrative activities . Segment Reporting We determine our operating segments based on the way we organize our business, make decisions and assess performance. We have only one operating segment, which is the discovery, development and commercialization of pharmaceutical products. Stock-Based Compensation We account for stock-based compensation related to option grants under the fair value method, based on the value of the award at the grant date, using the Black-Scholes option valuation model. We recognize this expense over the requisite vesting period, net of estimated forfeitures . If actual forfeitures differ from our estimates, we adjust stock-based compensation expense accordingly. We recognize the expense of options granted to non-employees based on the fair value-based measurement of the option grants at the time of vesting . Income Taxes We account for income taxes in accordance with ASC 740, Income Taxes In deciding whether a valuation allowance is necessary, GAAP requires us to give significant weight to objective evidence. It is difficult to conclude that sufficient taxable income will be generated when there is significant evidence – such as Corcept’s substantial cumulative losses – that future taxable income is not assured. Because forecasts of taxable income are inherently uncertain and not objectively verifiable, our cumulative losses must weigh heavily in our analysis. We are also required to evaluate and quantify other sources of taxable income, such as the possible reversal of future deferred tax liabilities, should any arise, and the implementation of tax planning strategies. Evaluating and quantifying these amounts is difficult and involves significant judgment, based on all of the available evidence and assumptions about our future activities. Until the fourth quarter of 2017, we maintained a valuation allowance on the entire value of our deferred taxes and did not report these amounts in our balance sheet. We also account for uncertain tax positions in accordance with ASC 740, which requires us to adjust our financial statements to reflect only those tax positions that are more-likely-than-not to be sustained upon review by federal or state examiners. We may recognize a tax benefit only if it is more likely than not the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. Our policy is to report interest and penalties related to unrecognized tax benefits as income tax expenses. Recently Adopted Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-15 (Subtopic 205-40), “Presentation of Financial Statements—Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”. We adopted this standard on January 1, 2017. Because we generated cash in 2016 and 2017 and expect to generate cash in 2018, adoption had no impact on our financial statements . In July 2015, FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory, which requires certain inventory to be measured at the lower of cost or net realizable value. We adopted this standard on January 1, 2017 and it did not have a material impact on our financial statements. In November 2015, FASB issued ASU No. 2015-17 "Balance Sheet Classification of Deferred Taxes," which requires that deferred tax liabilities and assets be classified as noncurrent. Before adoption, companies were required to separate deferred liabilities and assets into current and noncurrent amounts in their balance sheets. We adopted this standard prospectively on January 1, 2017. Prior period balance sheets were not impacted, as we had a full valuation allowance against our deferred taxes, resulting in no deferred taxes being recorded in our financial statements. As of December 31, 2017, we have released a portion of our valuation allowance of our deferred tax assets. Accordingly, we presented the associated net deferred tax assets as noncurrent on our balance sheet. In March 2016, FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) “Improvements to Employee Share-Based Payment Accounting,” which simplifies accounting for transactions involving shares awarded to employees. It requires companies to record excess tax benefits and deficiencies as income tax expenses or benefits instead of including them in additional paid-in capital. At the start of the year in which they implement the guidance, companies must adjust retained earnings by an amount equal to any previously unrecognized excess tax expenses or benefits. We adopted this guidance prospectively on January 1, 2017, at which time we recognized a $0.7 million deferred tax asset, which was offset by a corresponding increase to our deferred tax valuation allowance, resulting in no change to our balance sheet. Prior periods have not been adjusted. We elected to report on a prospective basis cash flows related to excess tax benefits as an operating activity and to continue to recognize stock compensation expense net of estimated forfeitures. Adoption of this standard did not have a material impact on our financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers,” which changes the way companies recognize revenue. We plan to adopt this update using the modified retrospective approach, with the cumulative effect of adoption being recorded to our retained earnings on January 1, 2018. We have completed our evaluation of the contracts governing our sales process and have reviewed our related disclosures, policies and controls, which we will change as required when we adopt the standard. Because our arrangements with customers contain variable consideration, we have focused our analysis on how the new standard will affect our estimate of transaction prices, which will not change materially. The adoption will not have a material impact on our financial statements. In February 2016, FASB issued ASU No. 2016-02, “Leases”, which requires the recognition of lease transactions with terms longer than 12 months on the balance sheet as “lease liabilities” and “right-of-use assets.” We plan to adopt this new standard prospectively on January 1, 2019. Although we are in the process of evaluating the impact of this standard, we expect that adoption will increase our “lease liabilities” and “right-of-use assets” equally. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments .” The standard changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. This standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. We plan to adopt this standard in the first quarter of 2020 and are currently evaluating the impact of this new standard on our consolidated financial statements. In August 2016, FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which is intended to reduce the existing diversity in practice in how certain cash receipts and cash payments are classified in the statement of cash flows. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows, Restricted Cash (Topic 230) (ASU 2016-18), which requires the inclusion of restricted cash with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-15 and ASU 2016-18 are both effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, provided that all of the amendments are adopted in the same period. In May 2017 FASB issued ASU No. 2017-09, Stock Compensation (Topic 718): “Scope of Modification Accounting,” which changes the accounting for modifications to the terms and conditions of share-based payment awards. We plan to adopt this standard on January 1, 2018 and do not expect it to have a material impact on our financial statements.

Significant Agreements

Significant Agreements	12 Months Ended
	Dec. 31, 2017
Significant Agreements Disclosure [Abstract]
Significant Agreements	2. Significant Agreements Commercial Agreements In May 2013, we entered into a services agreement with Dohmen to provide exclusive specialty pharmacy and patient services programs for Korlym beginning July 1, 2013, which was terminated on August 9, 2017. On August 4, 2017, we entered into a distribution services agreement with Optime to provide exclusive specialty pharmacy and patient services programs for Korlym beginning August 10, 2017. Under the terms of this agreement, Optime acts as the exclusive specialty pharmacy distributor of Korlym in the United States, subject to certain exceptions. Among other services, Optime provides services related to pharmacy operations; patient intake, access and reimbursement; patient support; claims management and accounts receivable; and data and reporting. We provide Korlym to Optime, which it dispenses to patients. Optime does not take title to the product. Title passes directly from us to the patient at the time the patient receives the medicine. The initial term of the agreement is a period of five years, unless earlier terminated pursuant to its terms. The agreement contains customary termination provisions, representations, warranties and covenants. Subject to certain limitations, we have agreed to indemnify Optime for certain third-party claims related to the product, and we have each agreed to indemnify the other for certain breaches of representations, warranties, covenants and other specified matters. Manufacturing Agreements Related to Korlym Active Pharmaceutical Ingredient In March 2014, we entered into a new long-term manufacturing and supply agreement with PCAS for the manufacture of mifepristone, the active pharmaceutical ingredient (API) in Korlym. We have agreed to purchase a minimum percentage of our mifepristone requirements from PCAS; the amount of the commitment will depend on our future needs. The initial term of the agreement is five years, with an automatic extension of one year unless either party gives 12 months’ prior written notice that it does not want an extension. We have the right to terminate the agreement if PCAS is unable to manufacture the product for a consecutive nine-month period. Tablet Manufacture In April 2014, we entered into a new manufacturing agreement with Alcami Corporation for the manufacture and package of Korlym tablets. The initial term of this agreement is a period of three years, with consecutive automatic extensions of two years unless either party gives written notice – in the case of Alcami Corporation, 18 months prior to the end of the applicable term, and in our case 12 months prior to the end of the applicable term – that it does not want such an extension. We have the right to terminate the agreement if Alcami Corporation is unable to manufacture the product for a consecutive four-month period or if the product is withdrawn from the market. There are no minimum purchase obligations under this agreement. Research and Development Agreements In 1999, we entered into an agreement with The Board of Trustees of Leland Stanford Junior University (Stanford) in which Stanford granted us an exclusive license to patents covering the use of glucocorticoid receptor antagonists for the treatment of psychotic depression, early dementia, and cocaine-induced psychosis, as specified in the license agreement. This license agreement expires upon the expiration of the related patents or upon notification by us to Stanford. In exchange for the license, we paid Stanford an initial non-refundable fee, immediately issued 30,000 shares of our common stock to Stanford and are obligated to pay Stanford $50,000 per year as a nonrefundable royalty payment. In addition, we are obligated to pay additional milestone payments in the future, which are not material and a portion of which are creditable against future royalties and will pay a royalty based on net revenue generated by any product arising from the patent until its expiration. We have also exclusively licensed from the University of Chicago five issued U.S. patents for the use of cortisol modulators in the treatment of triple-negative breast cancer and a second patent family with applications in the United States and Europe having claims directed to the use of cortisol modulators to treat castration-resistant prostate cancer. In exchange for these licenses, we paid initial non-refundable fees to the University of Chicago and are committed to additional annual and milestone payments in the future, which are not material and which are creditable against future royalties. We will also pay royalties based on net revenue generated by any product arising from these patents until their expiration.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	3. Fair Value of Financial Instruments As of December 31, 2017 and 2016, we had invested our financial assets in marketable securities and a money market fund that can be converted to cash at par on demand. We measured these funds, which totaled $87.9 million and $31.6 million as of December 31, 2017 and 2016, respectively, at fair value, which approximates cost and classified them as Level 1 and Level 2 assets in the fair value hierarchy. Our available-for-sale securities included: Fair Value Estimated Fair Value Hierarchy December 31, December 31, Level 2017 2016 (in thousands) Corporate bonds Level 2 $ 26,116 $ — Commercial paper Level 2 32,637 — U.S. treasury securities Level 1 14,210 — Money market funds Level 1 14,979 31,605 Total Marketable securities $ 87,942 $ 31,605 Classified as: Cash equivalents $ 14,979 $ 31,605 Short-term marketable securities 57,682 — Long-term marketable securities 15,281 — Total marketable securities $ 87,942 $ 31,605 The estimated fair value of marketable securities is based on quoted market prices for these or similar investments obtained from a commercial pricing service. The fair value of marketable securities classified within Level 2 is based upon inputs that may include benchmark yields, reported trades, broker/dealer quotes and issuer spreads. Our accumulated other comprehensive loss on our balance sheets consisted of net unrealized losses on available-for-sale investments of $75,000 and zero at December 31, 2017 and 2016, respectively. We did not recognize any realized gains or losses on sales of investments for any period presented. As of December 31 2017, all our marketable securities had original maturities of less than two years. The weighted-average maturity of our holdings was seven months. None of our marketable securities changed from one fair value hierarchy to another during the year ended December 31, 2017.

Composition of Certain Balance

Composition of Certain Balance Sheet Items	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Composition of Certain Balance Sheet Items	4. Composition of Certain Balance Sheet Items Inventory The composition of inventory was as follows: December 31, 2017 2016 (in thousands) Raw materials $ 4,287 $ 1,848 Work in progress 64 1,414 Finished goods 4,025 1,902 Total inventory 8,376 5,164 Less strategic inventory classified as non-current (3,800 ) (2,835 ) Total inventory classified as current $ 4,576 $ 2,329 In order to be prepared for potential demand for Korlym and because we rely on single-source manufacturers of both the active pharmaceutical ingredient (“API”) for Korlym and Korlym tablets, we have purchased significant inventory of these materials. We classify inventory we do not expect to use within 12 months of the balance sheet date as “Strategic Inventory,” a long-term asset . Property and Equipment Property and equipment consisted of the following: December 31, 2017 2016 (in thousands) Furniture and equipment $ 188 $ 300 Software 705 351 Leasehold improvements 14 6 907 657 Less: accumulated depreciation (389 ) (452 ) $ 518 $ 205 Other Accrued Liabilities Other accrued liabilities consisted of the following: December 31, 2017 2016 (in thousands) Government rebates $ 7,961 $ 3,426 Accrued compensation 8,574 4,702 Accrued manufacturing costs 955 — Commercialization costs 208 308 Legal fees 276 164 Professional fees 207 34 Other 562 319 Total other accrued liabilities $ 18,743 $ 8,953

Debt Obligation

Debt Obligation	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt Obligation	5. Debt Obligation As discussed in Note 1, Basis of Presentation and Summary of Significant Accounting Policies, Debt Obligation . have fully paid Biopharma $45.0 million. We recorded interest expense of $0.5 million . The following table provides a summary of the payment obligations under the Financing Agreement as of December 31, 2017 and 2016. December 31, 2017 2016 (in thousands) Total repayment obligation $ 45,000 $ 45,000 Less interest in future periods — (456 ) Less unamortized financing costs — (14 ) Less payments made (45,000 ) (29,866 ) Less current portion — (14,664 ) Debt obligation, net of current portion $ — $ — We capitalized $0.1 million of issuance costs related to the Financing Agreement, which we amortized over the term of the obligation, based on the assumptions discussed above . At December 31, 2017 and 2016,

Lease Obligation

Lease Obligation	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Lease Obligations	6. Lease Obligations In February 2016, we extended the lease for our office space through 2019 and added more space. Effective May 1, 2016, we terminated our lease early and replaced it with a new one effective through March 31, 2019. On June 1, 2017, we amended that lease to add more space . Rent expense for the years ended December 31, 2017, 2016 and 2015 was $1.1 million, $0.9 million and $0.7 million, respectively. As of December 31, 2017, future minimum lease payments under non-cancelable operating leases were as follows: Lease Payments 2018 $ 1,256 2019 314 Thereafter — Total $ 1,570

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	7. Related Party Transactions See discussion below in Note 8, Preferred Stock and Stockholders’ Equity Common Stock

Preferred Stock and Stockholder

Preferred Stock and Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Preferred Stock and Stockholders' Equity	8. Preferred Stock and Stockholders’ Equity Preferred Stock Our Board of Directors is authorized, subject to any limitations prescribed by law, without stockholder approval, to issue up to an aggregate of 10,000,000 shares of preferred stock at $0.001 par value in one or more series and to fix the rights, preferences, privileges and restrictions granted to or imposed upon the preferred stock, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences. The rights of the holders of common stock will be subject to the rights of holders of any preferred stock that may be issued in the future. As of December 31, 2017 and 2016, we had no outstanding shares of preferred stock. Common Stock Significant stock transactions We issued approximately 6.2 million shares of our common stock in March 2015, upon the exercise of warrants that had been issued in two private placement transactions, one in 2008 and the other in 2012, to qualified investors, including members of our board of directors and their affiliates. The transactions generated aggregate net proceeds of approximately $17.1 million, after the deduction of issuance costs. Approximately 3.1 million shares of the securities, which generated aggregate gross proceeds of $5.9 million, were issued in these transactions to venture capital funds, trusts and other entities affiliated with members of our Board of Directors. We have never declared or paid any dividends. Shares of common stock reserved for future issuance as of December 31, 2017 are as follows: Common stock: (in thousands) Exercise of outstanding options 20,454 Shares available for grant under stock option plans 7,630 28,084 On February 7, 2018, our Board of Directors authorized an additional increase of 4.6 million shares in the number of shares available under the 2012 Equity Incentive Plan (the 2012 Plan), which was equivalent to 4% of the shares of our common stock outstanding at December 31, 2017. Stock Option Plans We have two active stock option plans at December 31, 2016 – the 2004 Equity Incentive Plan (the 2004 Plan) and the 2012 Plan. In 2004, our board of directors and stockholders approved the 2004 Plan, which became effective upon the completion of our initial public offering (IPO). Under the 2004 Plan, options, stock purchase and stock appreciation rights and restricted stock awards can be issued to our employees, officers, directors and consultants. The 2004 Plan provided that the exercise price for incentive stock options will be no less than 100% of the fair value of the Company’s common stock, as of the date of grant. Options granted under the 2004 Plan vest over periods ranging from one to five years. The vesting period of the options is generally equivalent to the requisite service period. In 2012, our board of directors and stockholders approved the 2012 Plan. As of the effective date of the 2012 Plan, 5.3 million shares that remained available for issuance of new grants under the 2004 Plan were transferred to the 2012 Plan. After that date, no additional options were or will be issued under the 2004 Plan. Vested options under the 2004 Plan that are not exercised within the remaining contractual life and any options under the 2004 Plan that do not vest because of terminations after the effective date of the 2012 Plan will be added to the pool of shares available for future grants under the 2012 Plan. Under the 2012 Plan, we can issue options, stock purchase and stock appreciation rights and restricted stock awards to our employees, officers, directors and consultants. The 2012 Plan provides that the exercise price for incentive stock options will be no less than 100 percent of the fair value of our common stock as of the date of grant. Options granted under the 2012 Plan are expected to vest over periods ranging from one to four years. We expect the vesting period of the options that we grant under the 2012 Plan to be generally equivalent to the requisite service period. Upon exercise of options, new shares are issued. On February 10, 2017, our Board of Directors authorized an increase of 4.5 million shares in the number of shares available under the 2012 Plan, which was equivalent to 4% of the shares of our common stock outstanding as of December 31, 2016, pursuant to the terms of the 2012 Plan. Option activity during 2015, 2016 and 2017 The following table summarizes all stock plan activity: Outstanding Options Shares Available For Future Grant Options Shares Subject to Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (in (in (in years) (in Balance at December 31, 2014 7,546 14,704 $ 2.62 Increase in shares authorized for grant 4,056 — Shares granted (4,902 ) 4,902 $ 3.88 Shares exercised — (2,041 ) $ 2.55 Shares cancelled and forfeited 1,370 (1,370 ) $ 3.07 Balance at December 31, 2015 8,070 16,195 $ 2.98 Increase in shares authorized for grant 4,386 Shares granted (5,906 ) 5,906 $ 4.92 Shares exercised — (3,068 ) $ 2.50 Shares cancelled and forfeited 1,370 (1,370 ) $ 3.98 Balance at December 31, 2016 7,920 17,663 $ 3.63 Increase in shares authorized for grant 4,508 Shares granted (5,282 ) 5,282 $ 9.90 Shares exercised — (2,007 ) $ 3.60 Shares cancelled and forfeited 484 (484 ) $ 5.04 Balance at December 31, 2017 7,630 20,454 $ 5.22 6.79 $ 263,129 Options exercisable at December 31, 2017 12,046 $ 3.61 5.46 $ 174,019 Options fully vested and expected to vest at December 31, 2017 19,737 $ 5.08 6.71 $ 256,476 The total intrinsic value of options exercised during the years ended December 31, 2017, 2016 and 2015 was $22.4 million, $14.8 million and $5.5 million, respectively, based on the difference between the closing price of our common stock on the date of exercise of the options and the exercise price. The total grant date fair value of options to employees and directors that vested during the years ended December 31, 2017, 2016 and 2015 was $12.3 million, $7.0 million and $5.4 million, respectively. The following is a summary of options outstanding and options exercisable at December 31, 2017. Options Outstanding Options Exercisable Exercise Prices of Options Number of Shares Weighted- Average Remaining Contractual Life Weighted- Average Exercise Price Aggregate Intrinsic Value Number of Shares Weighted- Average Exercise Price Aggregate Intrinsic Value (in thousands) (in years) (in thousands) (in thousands) (in thousands) $ 0.96 - $ 4.00 10,548 5.7 $ 2.82 $ 160,714 8,399 $ 2.62 $ 129,668 $ 4.01 - $ 9.00 8,220 7.7 $ 6.57 94,476 3,503 $ 5.64 43,521 $ 9.01 - $ 17.00 1,296 9.4 $ 11.94 7,939 140 $ 12.13 830 $ 17.01 - $ 19.73 390 9.8 $ 19.23 — 4 $ 19.73 — 20,454 6.8 $ 5.22 $ 263,129 12,046 $ 3.61 $ 174,019 The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value that option holders would have received had all option holders exercised their options on December 31, 2017. The aggregate intrinsic value is the difference between our closing stock price on December 31, 2017 and the exercise price, multiplied by the number of in-the-money options. Stock-Based Compensation related to Employee and Director Options Assumptions used in determining fair value-based measurements for options to employees and directors The following table summarizes the weighted-average assumptions and resultant fair value-based measurements for options granted to employees and directors. Year Ended December 31, 2017 2016 2015 Weighted-average assumptions for stock options granted: Risk-free interest rate 1.99% 1.31% 1.77% Expected term 6.1 years 5.8 years 7.2 years Expected volatility of stock price 68.1% 69.0% 77.0% Dividend rate 0% 0% 0% Weighted-average grant date fair value-based measurement $6.14 $2.98 $2.72 The expected term of options reflected in the table above has been based on a formula that considers the expected service period and expected post-vesting termination behavior differentiated by whether the grantee is an employee, an officer or a director. The expected volatility of our stock used in determining the fair value-based measurement of option grants to employees, officers and directors is based on a weighted-average combination of the volatility of our own stock price. For stock options granted to employees with expected terms of less than the period of time that we have been a public company, the volatility is based on historical data of the price for our common stock for periods of time equivalent to the expected term of these grants. We calculated employee stock-based compensation expense based on awards ultimately expected to vest and reduced it for estimated forfeitures. ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates Summary of compensation expense related to options to employees and directors We recognized compensation expense of $13.4 million, $7.1 million and $6.0 million related to options to employees and directors during the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, we had $33.7 million of unrecognized compensation expense for employee and director options outstanding as of that date, which had a remaining weighted-average vesting period of 2.87 years. Stock Options to Non-Employees We expense stock-based compensation related to service-based option grants to non-employees on a straight-line basis over the vesting period of the options, which approximates the period over which the related services are rendered, based on the fair value-based measurement of the options using the Black-Scholes option pricing model. The assumptions used in these calculations are similar to those used for the determination of fair value-based measurement for options granted to employees and directors, with the exception that, for non-employee options, the remaining contractual term is utilized as the expected term of the option and the fair value-based measurement related to unvested non-employee options is re-measured quarterly, based on the then current stock price as reflected on the NASDAQ Capital Market. We recorded charges to expense for non-employee stock options of $31,000, $56,000 and $87,000 for the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, there were no awards outstanding to non-employees. Summary of Stock-based Compensation Expense The following table presents a summary of non-cash stock-based compensation by financial statement classification. Year ended December 31, 2017 2016 2015 (in thousands) Research and development $ 3,743 $ 1,312 $ 839 Selling, general and administrative 9,618 5,746 5,174 Total stock-based compensation $ 13,361 $ 7,058 $ 6,013

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	9. Net Income (Loss) Per Share Basic and diluted net income (loss) per share is computed by dividing the net income (loss) by the weighted-average number of common shares outstanding during the period. We used the treasury stock method to determine the number of dilutive shares of common stock resulting from the potential exercise of stock options. The following table shows the computation of net income (loss) per share for each period, including the number of weighted-average shares outstanding. Year ended December 31, 2017 2016 2015 (in thousands) Numerator: Net income (loss) $ 129,122 $ 8,140 $ (6,408 ) Denominator: Weighted-average shares used to compute basic net income (loss) per share 113,527 110,566 106,883 Dilutive effect of employee stock options 10,988 5,573 — Weighted-average shares used to compute diluted net income (loss) per share 124,515 116,139 106,883 Net income (loss) per share attributable to common stockholders Basic $ 1.14 $ 0.07 $ (0.06 ) Diluted $ 1.04 $ 0.07 $ (0.06 ) On a weighted-average basis, 1.1 million and 4.4 million stock options outstanding during the years ended December 31, 2017 and 2016, respectively, were excluded from the computation of diluted net income per share because including them would have reduced dilution. We have excluded the impact of all common stock equivalents relating to shares underlying outstanding options and warrants from the calculation of diluted net loss per common share for the year ended December 31, 2015 because all such securities are antidilutive . The following table presents information on securities outstanding as of the end of each period that could potentially dilute the per share data in the future. December 31, 2017 2016 2015 (in thousands) Stock options outstanding 20,454 17,663 16,195

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The income tax (benefit) for the year ended December 31, 2017 consisted of the following: Year ended December 31, 2017 (in thousands) U.S. federal taxes: Current $ — Deferred (71,839 ) Total U.S. federal taxes (71,839 ) State taxes: Current 388 Deferred (4,865 ) Total state taxes (4,477 ) Total $ (76,316 ) There was no income tax benefit or expense for the years ended December 31, 2015 and 2016. The income tax benefit for the year ended December 31, 2017 resulted primarily from the partial release of our valuation allowance, described more fully below. On December 22, 2017 President Donald Trump signed into U.S. law the Tax Cuts and Jobs Act of 2017 (“Tax Act”). The Tax Act introduced a broad range of tax reform measures that significantly change the federal income tax regime. Among other things, the Tax Act reduces the corporate income tax rate from 35% to 21% effective for tax years including or commencing on January 1, 2018, repeals corporate alternative minimum tax, limits various business deductions, modifies the maximum deduction of net operating loss with no carryback but indefinite carryforward provision, expands the deduction limit applicable to compensation paid to top executives of publicly traded companies, and includes various international tax related provisions. In accordance with ASC 740, the companies are required to recognize the effect of tax law changes in the period of enactment even though the effective date for most provisions of Tax Act is for tax years beginning after December 31, 2017, or in the case of certain other provisions of the law, January 1, 2018. Accounting Standards Codification (ASC) 740, Income Taxes, requires companies to recognize the effect of the tax law changes in the period of enactment. However, the SEC staff issued Staff Accounting Bulletin 118 which will allow companies to record provisional amounts during a measurement period that is similar to the measurement period used when accounting for business combinations. We have adjusted our deferred taxes based on the reduction of the U.S. federal corporate tax rate from 35% to 21% and assessed the realizability of our deferred tax assets based on our current understanding of the provisions of the new law. We consider our accounting for the impacts of the new tax law to be provisional and will continue to assess the impact of the recently enacted tax law (and expected further guidance from federal and state tax authorities as well as further guidance for the associated income tax accounting) on our business and consolidated financial statements over the next 12 months. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets are as follows: December 31, 2017 2016 Deferred tax assets: (in thousands) Federal and state net operating losses $ 41,902 $ 68,605 Capitalized research and patent costs 13,278 23,575 Research credits 22,606 19,058 Biopharma Financing Agreement — 5,556 Stock-based compensation costs 5,596 6,508 Other 5,795 6,067 Total deferred tax assets 89,177 129,369 Valuation allowance (12,474 ) (129,369 ) Net deferred tax assets $ 76,703 $ — Realization of deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Until the quarter ended December 31, 2017, we have maintained a full valuation allowance against our deferred tax assets due to the Company’s cumulative loss position and uncertainties regarding sustainable future profitability since inception . We regularly assess the ability to realize deferred tax assets based on the weight of all available evidence, including such factors as the history of recent earnings and expected future taxable income on a jurisdiction by jurisdiction basis. During the fourth quarter, after considering these factors, we determined that the positive evidence overcame any negative evidence, primarily due to cumulative income in recent years, and the expectation of sustained profitability in future periods and concluded that it was more likely than not that the U.S. federal deferred tax assets and other-than-California state deferred tax assets were realizable. As a result, we released the valuation allowance against all of the U.S. federal deferred tax assets and other-than-California state deferred tax assets during the fourth quarter of fiscal year 2017. We maintain a full valuation allowance in relation to California deferred tax assets as of December 31, 2017 because of the uncertainty regarding the realizability of these deferred tax assets. The valuation allowance decreased by $116.9 million, $4.3 million and $2.4 million for the years ended December 31, 2017, 2016 and 2015, respectively. The decrease in the valuation allowance during 2017 was the result of our release of the entire valuation allowance previously established on our federal and non-California state deferred tax assets. At December 31, 2017, we had net operating loss carryforwards available to offset any future taxable income that we may generate for federal income tax purposes of $159.5 million, which expire in the years 2025 through 2036, California net operating loss carryforwards of $95.4 million, which expire in the years 2018 through 2035, and net operating loss carryforwards from other states of $23.6 million, which expire in the years 2023 through 2036. At December 31, 2017, we also had federal and California research and development tax credits of $19.2 million and $4.2 million, respectively. The federal research credits will expire in the years 2023 through 2037 and the California research credits have no expiration date. Utilization of our net operating losses and tax credit carryforwards may be subject to substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code and similar state provisions. Such limitations could result in the expiration of the net operating losses and tax credit carryforwards before utilization. Due to the adoption of ASU 2016-09 in 2017, all excess tax benefits and deficiencies are recognized as income tax expense in our consolidated statement of comprehensive income (loss). This will result in increased volatility in our effective tax rate. The following table presents a reconciliation from the statutory federal income tax rate to the effective rate. Year ended December 31, 2017 2016 2015 (in thousands) U.S. federal taxes (benefit) at statutory rate $ 17,954 $ 2,840 $ (2,178 ) Changes in valuation allowance (119,765 ) (3,679 ) 2,495 Federal tax rate change impact to change in valuation allowance 33,233 — — Unutilized research credits (1,199 ) (69 ) (445 ) State income taxes (2,955 ) — — Non-deductible Compensation 33 2,435 — Stock-based compensation (3,826 ) (1,660 ) 6 Other 209 133 122 Total $ (76,316 ) $ — $ — We maintain liabilities for uncertain tax positions. The measurement of these liabilities involves considerable judgment and estimation and are continuously monitored by management based on the best information available, including changes in tax regulations, the outcome of relevant court cases, and other pertinent information. No amounts have been recognized as interest or penalties on income tax related matters. The aggregate annual changes in the balance of gross unrecognized tax benefits are as follows (in thousands): Year ended December 31, 2017 2016 Beginning Balance $ 3,527 $ 4,342 Increase in tax positions for prior years 150 222 Decreases in tax positions for prior years — (1,189 ) Increase in tax positions for current year 462 152 Ending Balance $ 4,139 $ 3,527 As of December 31, 2017 and 2016, the total amount of unrecognized tax benefits was approximately $4.1 million and $3.5 million, respectively. Of this balance, approximately $3.4 million would impact the effective tax rate since the valuation allowance related to these benefits was released in 2017. A valuation allowance is maintained on the remaining tax benefits related to California deferred tax assets and would not impact the effective tax rate. We had no or immaterial amounts of accrued interest and no accrued penalties related to unrecognized tax benefits as of December 31, 2017, December 31, 2016 and December 31, 2015. We do not expect our unrecognized tax benefits to change materially over the next 12 months While we believe we have adequately provided for all tax positions, amounts asserted by tax authorities could be greater or less than the recorded position. Accordingly, our provisions on federal and state tax-related matters to be recorded in the future may change as revised estimates are made or the underlying matters are settled or otherwise resolved. All tax years from inception remain open to examination by the Internal Revenue Service, the California Franchise Tax Board and other state taxing authorities until such time as the net operating losses and research credits are either fully utilized or expire.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and contingencies	11. Commitments and contingencies We have entered into a number of agreements to purchase API for the manufacturing of relacorilant, CORT118335 and CORT125281. See the discussion in Note 2, Significant Agreements In the ordinary course of business, we may be subject to legal claims and regulatory actions that could have a material adverse effect on our business or financial position. We assess our potential liability in such situations by analyzing potential outcomes, assuming various litigation, regulatory and settlement strategies. If we determine a loss is probable and its amount can be reasonably estimated, we accrue an amount equal to the estimated loss. On August 4, 2017, we terminated our pharmaceutical services agreement with Dohmen, dated as of May 21, 2013, as amended July 22, 2013 and again on October 6, 2014 (the “Dohmen Agreement”) for material breach, pursuant to Section 5.2.2 of the Dohmen Agreement. On August 7, 2017, Dohmen filed a complaint in the Court of Chancery of the State of Delaware against us alleging unlawful termination and breach of contract and requesting declaratory relief and damages (the “Dohmen Lawsuit”). On August 29, 2017, we filed a complaint against Dohmen in the Superior Court of the State of Delaware and a motion to dismiss the Dohmen complaint against us. On November 10, 2017, we answered Dohmen’s complaint in the Court of Chancery of the State of Delaware and asserted counterclaims against Dohmen. Dohmen refused to transfer to us the cash it collects from $12.9 million in Korlym ® . As of December 31, 2017, the total amount of these receivables has been included in “Other receivable” on our balance sheet. On January 11, 2018, we entered into a settlement agreement with Dohmen and mutual release of any and all claims that may have existed between the parties as of that date. Pursuant to the settlement agreement, Dohmen agreed to deliver to us all of the cash Dohmen had collected from the sale of Korlym on our behalf. The total amount delivered by Dohmen to us under the settlement agreement was the $12.9 million of ® . No losses and no provision for a loss contingency have been recorded to date.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	12. Quarterly Financial Data (Unaudited) The following table is in thousands, except per share amounts: Quarter Ended March 31 June 30 September 30 December 31 2017 Product sales, net $ 27,599 $ 35,559 $ 42,763 $ 53,280 Gross profit on product sales 26,953 34,784 41,787 52,123 Net income 4,388 12,647 13,757 98,330 Basic net income per share 0.04 0.11 0.12 0.86 Diluted net income per share 0.04 0.10 0.11 0.77 2016 Product sales, net $ 16,061 $ 19,724 $ 21,725 $ 23,811 Gross profit on product sales 15,658 19,298 21,057 23,250 Net income (loss) (19 ) 977 2,585 4,597 Basic and diluted net income (loss) per share (0.00 ) 0.01 0.02 0.04

Basis of Presentation and Sum19

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”).
Principles of Consolidation	Principles of Consolidation Our financial statements include the financial position and results of Corcept Therapeutics UK Limited, our wholly owned subsidiary. Corcept Therapeutics UK Limited was incorporated in the United Kingdom in March 2017, and to date, there have been no material financial transactions or balances related to this entity.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ materially from those estimates . We reevaluate our estimates and assumptions each quarter, including those related to revenue recognition, sales returns, recognition and measurement of income tax assets and liabilities, inventory, allowances for doubtful accounts and accrued liabilities, including our bonus accrual, clinical trial accruals and stock-based compensation .
Fair Value Measurements	Fair Value Measurements We value financial instruments using the assumptions we believe third-party market participants would adopt when valuing such instruments. Our methodology uses a “fair value hierarchy” that gives the highest priority to quoted prices in active markets for identical instruments (called “Level 1 inputs”). If no Level 1 inputs are available, we consider (i) quoted prices in non-active markets for identical instruments; (ii) active markets for similar instruments; (iii) inputs other than quoted prices for the instrument; and (iv) inputs that are not directly observable, but that are corroborated by observable data (“Level 2 inputs”). In the absence of Level 2 inputs, we rely on unobservable inputs, such as our own data about the assumptions market participants would use in pricing the instrument (“Level 3 inputs”).
Cash and Cash Equivalents and Marketable Securities	Cash and Cash Equivalents and Marketable Securities We consider all highly liquid investments purchased with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents are carried at fair value as measured using Level 1 inputs, which approximates cost. As of December 31, 2016, all of our funds were held in checking and money market fund accounts maintained at major U.S. financial institutions . Effective January 2017, we invested a portion of our funds in marketable securities, primarily U.S. Treasury securities, commercial paper and corporate notes. We classify our marketable securities as available-for-sale securities and report them at fair value as “cash equivalents” or “marketable securities” on our balance sheet, with related unrealized gains and losses included in stockholders' equity. Realized gains and losses and permanent declines in value are included in “interest and other income” on our statement of comprehensive income (loss).
Credit and Concentration Risks	Credit and Concentration Risks Our cash, cash equivalents and marketable securities are held in one financial institution. We are exposed to credit and concentration risks in the event of default by the financial institution holding our funds and investments or by the entity or entities that issued the securities held by the funds to the extent of the amount recorded on our balance sheet. We mitigate these risks by investing in liquid U.S. Treasury securities, highly-rated commercial paper and corporate notes, and money market funds that invest primarily in short-term U.S. Treasury notes and bills. We have never experienced a loss or lack of access to our operating or investment accounts. Among other services, Optime Care, Inc. (“Optime”), a specialty pharmacy, dispenses Korlym to patients for us, with title to the medicine passing from us to the patient upon the patient’s receipt of the drug. Accordingly, our receivables risk is spread among various third-party payors – pharmacy benefit managers, insurance companies, private charities, government programs – and individual patients. We extend credit to third-party payors based on their creditworthiness. We monitor our exposure and record an allowance against uncollectible trade receivables as necessary. To date, we have not incurred any credit losses. Through August 9, 2017 our exclusive specialty pharmacy was Dohmen Life Science Services (“Dohmen”). On August 10, 2017, Optime Care, Inc. (“Optime”) became our exclusive specialty pharmacy. We have a concentration of risk in regard to the manufacture and distribution of our product. As of December 31, 2017, we had one tablet manufacturer for Korlym – Alcami Corporation (formerly known as AAI Pharma Services Corp.). In addition, we have a single-source manufacturer of mifepristone, the active pharmaceutical ingredient (API), in Korlym – Produits Chimiques Auxiliaires et de Synthèse SA (PCAS). If either of these companies is unable to manufacture API or Korlym tablets in the quantities and time frame required, we may not be able to manufacture our product in a timely manner. In order to mitigate these risks related to the manufacture of our product, we purchased and hold in inventory additional quantities of mifepristone API and Korlym tablets. Optime is our sole specialty pharmacy. Its unwillingness or inability to dispense Korlym to patients in a timely manner would harm our business.
Inventory	Inventory We value inventory at the lower of cost or net realizable value. We determine the cost of inventory using the specific identification method, which approximates a first-in, first-out basis. We write down inventory that has become obsolete or has a cost basis in excess of its expected net realizable value. Any expired inventory is disposed of and the related costs are recognized as cost of sales in the statement of comprehensive income (loss) in that period. Inventory amounts that are not expected to be consumed within 12 months following the balance sheet date are classified as strategic inventory, a noncurrent asset. We expense the manufacturing costs for product candidates incurred prior to regulatory approval as research and development expense as we incur them. We begin capitalizing costs related to the manufacture of a product candidate when we obtain regulatory approval to begin marketing that product .
Debt Obligation	Debt Obligation In August 2012, we entered into a Purchase and Sale Agreement (“Financing Agreement”) with Biopharma Secured Debt Fund II Sub, S.à r.l (“Biopharma”), a private limited liability company organized under the laws of Luxembourg. Under the terms of the Financing Agreement, we received $30.0 million from Biopharma, which we recorded as a long-term obligation. In return, we were obligated to make payments to Biopharma totaling $45.0 million. These payments equaled a percentage of (i) our net product sales, including sales from any product containing mifepristone or any of our proprietary selective cortisol modulators (“Covered Products”) and (ii) cash or cash equivalents received from any licensing transaction or co-promotion arrangement involving Covered Products (together, “Korlym Receipts”). Once we had paid Biopharma a total of $45.0 million, no more payments were due and the obligation was extinguished . We recognized a portion of each quarterly payment under the Financing Agreement as interest expense, which we determined by calculating the interest rate to Biopharma implied by the stream of quarterly payments we expected to make. In each period, the amount shown on our balance sheet as the current portion was our estimate of the amount we expected to pay Biopharma in the following 12 months. We recorded the rest of the outstanding portion of the obligation, if any, as a long-term liability . We made our final payment to Biopharma, completely satisfying our obligations under the Financing Agreement, in July 2017. See Note 5, Debt Obligation
Net Product Revenue	Net Product Revenue We primarily sell Korlym directly to patients through a specialty pharmacy. We recognize revenue upon the delivery of Korlym if (i) there is persuasive evidence that an arrangement exists with the customer, (ii) collectability is reasonably assured and (iii) the sales price is fixed or determinable. In order to conclude that the price is fixed or determinable, we must be able to (i) calculate gross product revenue from a sale and (ii) reasonably estimate the associated net revenue. Confirmation of coverage by the patient’s private or government insurance plan or by a third-party charity is a prerequisite for selling Korlym to a patient. We provide Korlym at no cost to patients without insurance who do not qualify for charitable support . Through August 9, 2017 our exclusive specialty pharmacy was Dohmen. On August 10, 2017, Optime became our exclusive specialty pharmacy. We also sell Korlym to a specialty distributor (“SD”), which we recognize at the time the SD receives the Korlym. SD sales were less than one percent of our net revenue in the year ended December 31, 2017. We donate cash to charities that help patients with financial need pay for the treatment of Cushing’s syndrome. We do not include payments we receive from these organizations in revenue . We calculate gross product revenues based on the price we charge our customers. We estimate net product revenues by deducting from gross product revenues (a) estimated government rebates and chargebacks, (b) estimated costs of our patient co-pay assistance program, (c) discounts for prompt payment and (d) reserves for expected product returns. We record estimates for these deductions at the time we recognize the gross revenue and update them as new information becomes available . Rebates and Chargebacks: Korlym is eligible for purchase by or qualifies for partial or full reimbursement from Medicaid and other government programs. We estimate any government rebate amounts by applying the discount rates applicable to each government-funded program against our sales to patients covered by such programs . Our allowance activity included in Trade Receivables includes our allowance for doubtful accounts, prompt pay cash discounts and chargebacks is summarized as follows: Balance at Beginning of Period Charges Deductions Balance at End of Period (in thousands) Year ended December 31, 2016: Accounts receivable allowances $ 18 $ 2,081 $ (1,749 ) $ 350 Year ended December 31, 2017: Accounts receivable allowances $ 350 $ 2,755 $ (2,178 ) $ 927 There were no material changes in reserve estimates relating to prior periods. Allowances for Patient Assistance Program: It is our policy that no patient be denied Korlym due to inability to pay. We provide financial assistance to eligible patients whose insurance policies require them to pay high deductibles and co-payments and deduct the amount of such assistance from these sales from gross revenue. We determine the amount of such assistance by applying our program guidelines to all eligible sales in the period . Sales Returns : We deduct from each period’s gross revenue the amount of Korlym we estimate will be returned. When estimating returns, we analyze quantitative and qualitative information including, but not limited to, historical return rates, the amount of product in the distribution channel, the expiration date of the product, current and projected product demand, the introduction of competing products that may erode demand, and broad economic and industry-wide indicators. If we cannot reasonably estimate product returns with respect to a particular sale, we defer recognition of revenue from that sale until we can make a reasonable estimate.
Research and Development	Research and Development Research and development expenses consist of direct expenses, such as the cost of discovery research, pre-clinical studies, and clinical trials relating to our portfolio of proprietary, selective cortisol modulators, manufacturing development, preparations for submissions to the FDA or other regulatory agencies and related overhead expenses. We expense nonrefundable payments and the cost of technologies and materials used in research and development as they are incurred . We base our cost accruals for research, preclinical activities, and clinical trials on estimates of work completed under service agreements, milestones achieved, patient enrollment and past experience with similar contracts. Our estimates of work completed and associated cost accruals include our assessments of information from third-party contract research organizations and the overall status of clinical trial and other development and administrative activities .
Segment Reporting	Segment Reporting We determine our operating segments based on the way we organize our business, make decisions and assess performance. We have only one operating segment, which is the discovery, development and commercialization of pharmaceutical products.
Stock-Based Compensation	Stock-Based Compensation We account for stock-based compensation related to option grants under the fair value method, based on the value of the award at the grant date, using the Black-Scholes option valuation model. We recognize this expense over the requisite vesting period, net of estimated forfeitures . If actual forfeitures differ from our estimates, we adjust stock-based compensation expense accordingly. We recognize the expense of options granted to non-employees based on the fair value-based measurement of the option grants at the time of vesting .
Income Taxes	Income Taxes We account for income taxes in accordance with ASC 740, Income Taxes In deciding whether a valuation allowance is necessary, GAAP requires us to give significant weight to objective evidence. It is difficult to conclude that sufficient taxable income will be generated when there is significant evidence – such as Corcept’s substantial cumulative losses – that future taxable income is not assured. Because forecasts of taxable income are inherently uncertain and not objectively verifiable, our cumulative losses must weigh heavily in our analysis. We are also required to evaluate and quantify other sources of taxable income, such as the possible reversal of future deferred tax liabilities, should any arise, and the implementation of tax planning strategies. Evaluating and quantifying these amounts is difficult and involves significant judgment, based on all of the available evidence and assumptions about our future activities. Until the fourth quarter of 2017, we maintained a valuation allowance on the entire value of our deferred taxes and did not report these amounts in our balance sheet. We also account for uncertain tax positions in accordance with ASC 740, which requires us to adjust our financial statements to reflect only those tax positions that are more-likely-than-not to be sustained upon review by federal or state examiners. We may recognize a tax benefit only if it is more likely than not the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. Our policy is to report interest and penalties related to unrecognized tax benefits as income tax expenses.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In August 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-15 (Subtopic 205-40), “Presentation of Financial Statements—Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern”. We adopted this standard on January 1, 2017. Because we generated cash in 2016 and 2017 and expect to generate cash in 2018, adoption had no impact on our financial statements . In July 2015, FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory, which requires certain inventory to be measured at the lower of cost or net realizable value. We adopted this standard on January 1, 2017 and it did not have a material impact on our financial statements. In November 2015, FASB issued ASU No. 2015-17 "Balance Sheet Classification of Deferred Taxes," which requires that deferred tax liabilities and assets be classified as noncurrent. Before adoption, companies were required to separate deferred liabilities and assets into current and noncurrent amounts in their balance sheets. We adopted this standard prospectively on January 1, 2017. Prior period balance sheets were not impacted, as we had a full valuation allowance against our deferred taxes, resulting in no deferred taxes being recorded in our financial statements. As of December 31, 2017, we have released a portion of our valuation allowance of our deferred tax assets. Accordingly, we presented the associated net deferred tax assets as noncurrent on our balance sheet. In March 2016, FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) “Improvements to Employee Share-Based Payment Accounting,” which simplifies accounting for transactions involving shares awarded to employees. It requires companies to record excess tax benefits and deficiencies as income tax expenses or benefits instead of including them in additional paid-in capital. At the start of the year in which they implement the guidance, companies must adjust retained earnings by an amount equal to any previously unrecognized excess tax expenses or benefits. We adopted this guidance prospectively on January 1, 2017, at which time we recognized a $0.7 million deferred tax asset, which was offset by a corresponding increase to our deferred tax valuation allowance, resulting in no change to our balance sheet. Prior periods have not been adjusted. We elected to report on a prospective basis cash flows related to excess tax benefits as an operating activity and to continue to recognize stock compensation expense net of estimated forfeitures. Adoption of this standard did not have a material impact on our financial statements.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In May 2014, FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers,” which changes the way companies recognize revenue. We plan to adopt this update using the modified retrospective approach, with the cumulative effect of adoption being recorded to our retained earnings on January 1, 2018. We have completed our evaluation of the contracts governing our sales process and have reviewed our related disclosures, policies and controls, which we will change as required when we adopt the standard. Because our arrangements with customers contain variable consideration, we have focused our analysis on how the new standard will affect our estimate of transaction prices, which will not change materially. The adoption will not have a material impact on our financial statements. In February 2016, FASB issued ASU No. 2016-02, “Leases”, which requires the recognition of lease transactions with terms longer than 12 months on the balance sheet as “lease liabilities” and “right-of-use assets.” We plan to adopt this new standard prospectively on January 1, 2019. Although we are in the process of evaluating the impact of this standard, we expect that adoption will increase our “lease liabilities” and “right-of-use assets” equally. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments .” The standard changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. This standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. We plan to adopt this standard in the first quarter of 2020 and are currently evaluating the impact of this new standard on our consolidated financial statements. In August 2016, FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which is intended to reduce the existing diversity in practice in how certain cash receipts and cash payments are classified in the statement of cash flows. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows, Restricted Cash (Topic 230) (ASU 2016-18), which requires the inclusion of restricted cash with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-15 and ASU 2016-18 are both effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, provided that all of the amendments are adopted in the same period. In May 2017 FASB issued ASU No. 2017-09, Stock Compensation (Topic 718): “Scope of Modification Accounting,” which changes the accounting for modifications to the terms and conditions of share-based payment awards. We plan to adopt this standard on January 1, 2018 and do not expect it to have a material impact on our financial statements.

Basis of Presentation and Sum20

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Allowance Activity Included in Trade Receivables Includes Allowance for Doubtful Accounts, Prompt Pay Cash Discounts and Chargebacks	Our allowance activity included in Trade Receivables includes our allowance for doubtful accounts, prompt pay cash discounts and chargebacks is summarized as follows: Balance at Beginning of Period Charges Deductions Balance at End of Period (in thousands) Year ended December 31, 2016: Accounts receivable allowances $ 18 $ 2,081 $ (1,749 ) $ 350 Year ended December 31, 2017: Accounts receivable allowances $ 350 $ 2,755 $ (2,178 ) $ 927

Fair Value of Financial Instr21

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Available For Sale Securities And Fair Value Measurements [Abstract]
Schedule of Available-for-Sale Securities	Our available-for-sale securities included: Fair Value Estimated Fair Value Hierarchy December 31, December 31, Level 2017 2016 (in thousands) Corporate bonds Level 2 $ 26,116 $ — Commercial paper Level 2 32,637 — U.S. treasury securities Level 1 14,210 — Money market funds Level 1 14,979 31,605 Total Marketable securities $ 87,942 $ 31,605 Classified as: Cash equivalents $ 14,979 $ 31,605 Short-term marketable securities 57,682 — Long-term marketable securities 15,281 — Total marketable securities $ 87,942 $ 31,605

Composition of Certain Balanc22

Composition of Certain Balance Sheet Items (Tables)	12 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Composition of Inventory	December 31, 2017 2016 (in thousands) Raw materials $ 4,287 $ 1,848 Work in progress 64 1,414 Finished goods 4,025 1,902 Total inventory 8,376 5,164 Less strategic inventory classified as non-current (3,800 ) (2,835 ) Total inventory classified as current $ 4,576 $ 2,329
Property and Equipment	December 31, 2017 2016 (in thousands) Furniture and equipment $ 188 $ 300 Software 705 351 Leasehold improvements 14 6 907 657 Less: accumulated depreciation (389 ) (452 ) $ 518 $ 205
Other Accrued Liabilities	December 31, 2017 2016 (in thousands) Government rebates $ 7,961 $ 3,426 Accrued compensation 8,574 4,702 Accrued manufacturing costs 955 — Commercialization costs 208 308 Legal fees 276 164 Professional fees 207 34 Other 562 319 Total other accrued liabilities $ 18,743 $ 8,953

Debt Obligation (Tables)

Debt Obligation (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Payment Obligations under Financing Agreement	The following table provides a summary of the payment obligations under the Financing Agreement as of December 31, 2017 and 2016. December 31, 2017 2016 (in thousands) Total repayment obligation $ 45,000 $ 45,000 Less interest in future periods — (456 ) Less unamortized financing costs — (14 ) Less payments made (45,000 ) (29,866 ) Less current portion — (14,664 ) Debt obligation, net of current portion $ — $ —

Lease Obligations (Tables)

Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases	As of December 31, 2017, future minimum lease payments under non-cancelable operating leases were as follows: Lease Payments 2018 $ 1,256 2019 314 Thereafter — Total $ 1,570

Preferred Stock and Stockhold25

Preferred Stock and Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Shares of Common Stock Reserved for Future Issuance	Shares of common stock reserved for future issuance as of December 31, 2017 are as follows: Common stock: (in thousands) Exercise of outstanding options 20,454 Shares available for grant under stock option plans 7,630 28,084
Summary of Stock Plan Activity	The following table summarizes all stock plan activity: Outstanding Options Shares Available For Future Grant Options Shares Subject to Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (in (in (in years) (in Balance at December 31, 2014 7,546 14,704 $ 2.62 Increase in shares authorized for grant 4,056 — Shares granted (4,902 ) 4,902 $ 3.88 Shares exercised — (2,041 ) $ 2.55 Shares cancelled and forfeited 1,370 (1,370 ) $ 3.07 Balance at December 31, 2015 8,070 16,195 $ 2.98 Increase in shares authorized for grant 4,386 Shares granted (5,906 ) 5,906 $ 4.92 Shares exercised — (3,068 ) $ 2.50 Shares cancelled and forfeited 1,370 (1,370 ) $ 3.98 Balance at December 31, 2016 7,920 17,663 $ 3.63 Increase in shares authorized for grant 4,508 Shares granted (5,282 ) 5,282 $ 9.90 Shares exercised — (2,007 ) $ 3.60 Shares cancelled and forfeited 484 (484 ) $ 5.04 Balance at December 31, 2017 7,630 20,454 $ 5.22 6.79 $ 263,129 Options exercisable at December 31, 2017 12,046 $ 3.61 5.46 $ 174,019 Options fully vested and expected to vest at December 31, 2017 19,737 $ 5.08 6.71 $ 256,476
Summary of Options Outstanding and Exercisable	The following is a summary of options outstanding and options exercisable at December 31, 2017. Options Outstanding Options Exercisable Exercise Prices of Options Number of Shares Weighted- Average Remaining Contractual Life Weighted- Average Exercise Price Aggregate Intrinsic Value Number of Shares Weighted- Average Exercise Price Aggregate Intrinsic Value (in thousands) (in years) (in thousands) (in thousands) (in thousands) $ 0.96 - $ 4.00 10,548 5.7 $ 2.82 $ 160,714 8,399 $ 2.62 $ 129,668 $ 4.01 - $ 9.00 8,220 7.7 $ 6.57 94,476 3,503 $ 5.64 43,521 $ 9.01 - $ 17.00 1,296 9.4 $ 11.94 7,939 140 $ 12.13 830 $ 17.01 - $ 19.73 390 9.8 $ 19.23 — 4 $ 19.73 — 20,454 6.8 $ 5.22 $ 263,129 12,046 $ 3.61 $ 174,019
Summary of Weighted-Average Assumptions and Resultant Fair Value-Based Measurements for Options Granted to Employees and Directors	The following table summarizes the weighted-average assumptions and resultant fair value-based measurements for options granted to employees and directors. Year Ended December 31, 2017 2016 2015 Weighted-average assumptions for stock options granted: Risk-free interest rate 1.99% 1.31% 1.77% Expected term 6.1 years 5.8 years 7.2 years Expected volatility of stock price 68.1% 69.0% 77.0% Dividend rate 0% 0% 0% Weighted-average grant date fair value-based measurement $6.14 $2.98 $2.72
Summary of Stock-Based Compensation	The following table presents a summary of non-cash stock-based compensation by financial statement classification. Year ended December 31, 2017 2016 2015 (in thousands) Research and development $ 3,743 $ 1,312 $ 839 Selling, general and administrative 9,618 5,746 5,174 Total stock-based compensation $ 13,361 $ 7,058 $ 6,013

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Computation of Net Income (Loss) Per Share	The following table shows the computation of net income (loss) per share for each period, including the number of weighted-average shares outstanding. Year ended December 31, 2017 2016 2015 (in thousands) Numerator: Net income (loss) $ 129,122 $ 8,140 $ (6,408 ) Denominator: Weighted-average shares used to compute basic net income (loss) per share 113,527 110,566 106,883 Dilutive effect of employee stock options 10,988 5,573 — Weighted-average shares used to compute diluted net income (loss) per share 124,515 116,139 106,883 Net income (loss) per share attributable to common stockholders Basic $ 1.14 $ 0.07 $ (0.06 ) Diluted $ 1.04 $ 0.07 $ (0.06 )
Securities Outstanding that could Potentially Dilute Per Share Data	The following table presents information on securities outstanding as of the end of each period that could potentially dilute the per share data in the future. December 31, 2017 2016 2015 (in thousands) Stock options outstanding 20,454 17,663 16,195

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Components of Income Tax (Benefit)	The income tax (benefit) for the year ended December 31, 2017 consisted of the following: Year ended December 31, 2017 (in thousands) U.S. federal taxes: Current $ — Deferred (71,839 ) Total U.S. federal taxes (71,839 ) State taxes: Current 388 Deferred (4,865 ) Total state taxes (4,477 ) Total $ (76,316 )
Significant Components of Deferred Tax Assets	Significant components of our deferred tax assets are as follows: December 31, 2017 2016 Deferred tax assets: (in thousands) Federal and state net operating losses $ 41,902 $ 68,605 Capitalized research and patent costs 13,278 23,575 Research credits 22,606 19,058 Biopharma Financing Agreement — 5,556 Stock-based compensation costs 5,596 6,508 Other 5,795 6,067 Total deferred tax assets 89,177 129,369 Valuation allowance (12,474 ) (129,369 ) Net deferred tax assets $ 76,703 $ —
Reconciliation of Statutory Federal Income Tax Rate to Effective Rate	The following table presents a reconciliation from the statutory federal income tax rate to the effective rate. Year ended December 31, 2017 2016 2015 (in thousands) U.S. federal taxes (benefit) at statutory rate $ 17,954 $ 2,840 $ (2,178 ) Changes in valuation allowance (119,765 ) (3,679 ) 2,495 Federal tax rate change impact to change in valuation allowance 33,233 — — Unutilized research credits (1,199 ) (69 ) (445 ) State income taxes (2,955 ) — — Non-deductible Compensation 33 2,435 — Stock-based compensation (3,826 ) (1,660 ) 6 Other 209 133 122 Total $ (76,316 ) $ — $ —
Changes in Balance of Gross Unrecognized Tax Benefits	The aggregate annual changes in the balance of gross unrecognized tax benefits are as follows (in thousands): Year ended December 31, 2017 2016 Beginning Balance $ 3,527 $ 4,342 Increase in tax positions for prior years 150 222 Decreases in tax positions for prior years — (1,189 ) Increase in tax positions for current year 462 152 Ending Balance $ 4,139 $ 3,527

Quarterly Financial Data (Una28

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	The following table is in thousands, except per share amounts: Quarter Ended March 31 June 30 September 30 December 31 2017 Product sales, net $ 27,599 $ 35,559 $ 42,763 $ 53,280 Gross profit on product sales 26,953 34,784 41,787 52,123 Net income 4,388 12,647 13,757 98,330 Basic net income per share 0.04 0.11 0.12 0.86 Diluted net income per share 0.04 0.10 0.11 0.77 2016 Product sales, net $ 16,061 $ 19,724 $ 21,725 $ 23,811 Gross profit on product sales 15,658 19,298 21,057 23,250 Net income (loss) (19 ) 977 2,585 4,597 Basic and diluted net income (loss) per share (0.00 ) 0.01 0.02 0.04

Basis of Presentation and Sum29

Basis of Presentation and Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2012USD ($)	Dec. 31, 2017USD ($)Segmentitem	Jan. 01, 2017USD ($)	Dec. 31, 2016USD ($)
Accounting Policies [Line Items]
Date of incorporation		May 1, 1998
Entity incorporated, State		Delaware
Number of manufacturers | item		1
Cumulative payments to be made under financing agreement		$ 45,000		$ 45,000
Number of operating segments | Segment		1
Accounting Standards Update 2016-09
Accounting Policies [Line Items]
Deferred tax asset			$ 700
Maximum | Sales Revenue, Net | Customer Concentration Risk
Accounting Policies [Line Items]
Percentage of sales to one specialty distributor		1.00%
Financing Agreement with Biopharma
Accounting Policies [Line Items]
Proceeds from issuance of long-term obligation	$ 30,000
Cumulative payments to be made under financing agreement	$ 45,000	$ 45,000

Basis of Presentation and Sum30

Basis of Presentation and Summary of Significant Accounting Policies (Summary of Allowance Activity Included in Trade Receivables Includes Allowance for Doubtful Accounts, Prompt Pay Cash Discounts and Chargebacks) (Details) - Sales Allowances, Discounts and Chargebacks - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]
Balance at Beginning of Period	$ 350	$ 18
Charges	2,755	2,081
Deductions	(2,178)	(1,749)
Balance at End of Period	$ 927	$ 350

Significant Agreements (Narrati

Significant Agreements (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)item	Dec. 31, 1999USD ($)shares
Debt And Credit Agreements [Line Items]
Number of Patents | item	5
Stanford license agreement
Debt And Credit Agreements [Line Items]
Issuance of common stock in conjunction with a license agreement | shares		30,000
Stanford license agreement | Annual Payment
Debt And Credit Agreements [Line Items]
Royalty payments to be made		$ 50,000
Optime Care, Inc.
Debt And Credit Agreements [Line Items]
Initial agreement period	5 years
Agreement with PCAS
Debt And Credit Agreements [Line Items]
Initial agreement period	5 years
Automatic extension period	1 year
Agreement termination, written notice period	12 months
Right to terminate agreement if unable to manufacture product, period	9 months
Agreement with Alcami Corporation
Debt And Credit Agreements [Line Items]
Initial agreement period	3 years
Automatic extension period	2 years
Agreement termination, written notice period	12 months
Right to terminate agreement if unable to manufacture product, period	4 months
Termination notice period for manufacturer	18 months
Purchase obligations	$ 0

Fair Value of Financial Instr32

Fair Value of Financial Instruments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Net unrealized losses on available-for-sale investments	$ (75,000)	$ 0	$ 0
Maximum maturity period	2 years
Weighted average maturity period	7 months
Fair value, assets, Level 1 to Level 2 transfers, amount	$ 0
Fair value, assets, Level 2 to Level 1 transfers, amount	0
Estimated Fair Value
Schedule Of Available For Sale Securities [Line Items]
Marketable securities and money market fund	$ 87,942,000	$ 31,605,000

Fair Value of Financial Instr33

Fair Value of Financial Instruments (Schedule of Available-for-Sale Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Short-term marketable securities	$ 57,682	$ 0
Long-term marketable securities	15,281	0
Estimated Fair Value
Schedule Of Available For Sale Securities [Line Items]
Marketable securities	87,942	31,605
Cash equivalents	14,979	31,605
Short-term marketable securities	57,682	0
Long-term marketable securities	15,281	0
Corporate Bonds | Estimated Fair Value | Level 2
Schedule Of Available For Sale Securities [Line Items]
Marketable securities	26,116	0
Commercial Paper | Estimated Fair Value | Level 2
Schedule Of Available For Sale Securities [Line Items]
Marketable securities	32,637	0
U.S. Treasury Securities | Estimated Fair Value | Level 1
Schedule Of Available For Sale Securities [Line Items]
Marketable securities	14,210	0
Money Market Funds | Estimated Fair Value | Level 1
Schedule Of Available For Sale Securities [Line Items]
Marketable securities	$ 14,979	$ 31,605

Composition of Certain Balanc34

Composition of Certain Balance Sheet Items (Composition of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 4,287	$ 1,848
Work in progress	64	1,414
Finished goods	4,025	1,902
Total inventory	8,376	5,164
Less strategic inventory classified as non-current	(3,800)	(2,835)
Total inventory classified as current	$ 4,576	$ 2,329

Composition of Certain Balanc35

Composition of Certain Balance Sheet Items (Property and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities [Line Items]
Property and equipment	$ 907	$ 657
Less: accumulated depreciation	(389)	(452)
Property and equipment net	518	205
Furniture and Equipment
Other Liabilities [Line Items]
Property and equipment	188	300
Software
Other Liabilities [Line Items]
Property and equipment	705	351
Leasehold Improvements
Other Liabilities [Line Items]
Property and equipment	$ 14	$ 6

Composition of Certain Balanc36

Composition of Certain Balance Sheet Items (Other Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Government rebates	$ 7,961	$ 3,426
Accrued compensation	8,574	4,702
Accrued manufacturing costs	955	0
Commercialization costs	208	308
Legal fees	276	164
Professional fees	207	34
Other	562	319
Total other accrued liabilities	$ 18,743	$ 8,953

Debt Obligation (Narrative) (De

Debt Obligation (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended			60 Months Ended
	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jul. 31, 2017	Aug. 31, 2012
Contractual Obligation [Line Items]
Cumulative payments to be made under financing agreement		$ 45,000	$ 45,000
Aggregate payments to long-term obligations		15,134	14,779	$ 9,207
Accretion of interest expense		456	1,929	$ 2,848	$ 15,000
Issuance costs capitalized		100
Unamortized issuance cost		0	$ 14
Financing Agreement with Biopharma
Contractual Obligation [Line Items]
Cumulative payments to be made under financing agreement		$ 45,000				$ 45,000
Aggregate payments to long-term obligations	$ 45,000

Debt Obligation (Summary of Pay

Debt Obligation (Summary of Payment Obligations under Financing Agreement) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Total repayment obligation	$ 45,000	$ 45,000
Less interest in future periods	0	(456)
Less unamortized financing costs	0	(14)
Less payments made	(45,000)	(29,866)
Less current portion	0	(14,664)
Debt obligation, net of current portion	$ 0	$ 0

Lease Obligations (Narratives)

Lease Obligations (Narratives) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Lease expiration date	Mar. 31, 2019
Rent expenses	$ 1.1	$ 0.9	$ 0.7

Lease Obligations (Schedule of

Lease Obligations (Schedule of Future Minimum Lease Payments under Non-Cancelable Operating Leases) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,018	$ 1,256
2,019	314
Thereafter	0
Total	$ 1,570

Preferred Stock and Stockhold41

Preferred Stock and Stockholders' Equity (Narrative) (Details)	Feb. 07, 2018shares	Feb. 10, 2017shares	Mar. 31, 2015USD ($)shares	Dec. 31, 2017USD ($)item$ / sharesshares	Dec. 31, 2016USD ($)item$ / sharesshares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014shares	Dec. 31, 2012shares
Shareholders Equity [Line Items]
Preferred stock, shares authorized				10,000,000	10,000,000
Preferred stock, par value | $ / shares				$ 0.001	$ 0.001
Preferred stock, shares outstanding				0	0
Proceeds from exercise of warrants, net of issuance costs | $				$ 0	$ 0	$ 17,088,000
Increase in shares authorized for grant				4,508,000	4,386,000	4,056,000
Number of stock option plans | item					2
Shares available for future grants				7,630,000	7,920,000	8,070,000	7,546,000
Total intrinsic value of options exercised | $				$ 22,400,000	$ 14,800,000	$ 5,500,000
Fair value of options vested | $				12,300,000	7,000,000	5,400,000
Non-cash stock-based compensation expense | $				13,361,000	7,058,000	6,013,000
Non-employee
Shareholders Equity [Line Items]
Non-cash stock-based compensation expense | $				$ 31,000	56,000	87,000
Number of awards outstanding | item				0
Employee and Director Stock Option
Shareholders Equity [Line Items]
Non-cash stock-based compensation expense | $				$ 13,400,000	$ 7,100,000	$ 6,000,000
Unrecognized compensation expense | $				$ 33,700,000
Unrecognized compensation expense, weighted-average vesting period				2 years 10 months 13 days
2012 Equity Incentive Award Plan
Shareholders Equity [Line Items]
Increase in shares authorized for grant		4,500,000
Increase in shares available for issuance based on percentage of common stock outstanding				4.00%	4.00%
Shares available for future grants								5,300,000
2012 Equity Incentive Award Plan | Minimum
Shareholders Equity [Line Items]
Exercise price as percentage of fair value of common stock				100.00%
Stock options, vesting period				1 year
2012 Equity Incentive Award Plan | Maximum
Shareholders Equity [Line Items]
Stock options, vesting period				4 years
2012 Equity Incentive Award Plan | Subsequent Event
Shareholders Equity [Line Items]
Increase in shares authorized for grant	4,600,000
2004 Equity Incentive Plan
Shareholders Equity [Line Items]
Shares available for future grants								0
2004 Equity Incentive Plan | Minimum
Shareholders Equity [Line Items]
Exercise price as percentage of fair value of common stock				100.00%
Stock options, vesting period				1 year
2004 Equity Incentive Plan | Maximum
Shareholders Equity [Line Items]
Stock options, vesting period				5 years
Private Placement
Shareholders Equity [Line Items]
Shares issued upon exercise of warrants			6,200,000
Number of private placement transactions | item				2
Proceeds from exercise of warrants, net of issuance costs | $			$ 17,100,000
Venture Capital Funds, Trusts and Other Entities | Private Placement
Shareholders Equity [Line Items]
Shares issued upon exercise of warrants			3,100,000
Proceeds from exercise of warrants, net of issuance costs | $			$ 5,900,000

Preferred Stock and Stockhold42

Preferred Stock and Stockholders' Equity (Shares of Common Stock Reserved for Future Issuance) (Details) shares in Thousands	Dec. 31, 2017shares
Shareholders Equity [Line Items]
Shares of common stock reserved for future issuance	28,084
Stock Options Outstanding
Shareholders Equity [Line Items]
Shares of common stock reserved for future issuance	20,454
Shares Available For Grant Under Stock Option Plans
Shareholders Equity [Line Items]
Shares of common stock reserved for future issuance	7,630

Preferred Stock and Stockhold43

Preferred Stock and Stockholders' Equity (Summary of Stock Plan Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shares Available For Future Grant
Beginning balance	7,920	8,070	7,546
Increase in shares authorized for grant	4,508	4,386	4,056
Shares granted	(5,282)	(5,906)	(4,902)
Shares cancelled and forfeited	484	1,370	1,370
Ending balance	7,630	7,920	8,070
Shares Subject to Options Outstanding
Beginning balance	17,663	16,195	14,704
Shares granted	5,282	5,906	4,902
Shares exercised	(2,007)	(3,068)	(2,041)
Shares cancelled and forfeited	(484)	(1,370)	(1,370)
Ending balance	20,454	17,663	16,195
Options exercisable	12,046
Options fully vested and expected to vest	19,737
Outstanding Options, Weighted- Average Exercise Price
Beginning balance	$ 3.63	$ 2.98	$ 2.62
Shares granted	9.90	4.92	3.88
Shares exercised	3.60	2.50	2.55
Shares cancelled and forfeited	5.04	3.98	3.07
Ending balance	5.22	$ 3.63	$ 2.98
Options exercisable	3.61
Options fully vested and expected to vest	$ 5.08
Outstanding Options, Weighted Average Remaining Contractual Life
Weighted average remaining contractual life	6 years 9 months 14 days
Weighted average remaining contractual life, Options exercisable	5 years 5 months 15 days
Weighted average remaining contractual life, Options fully vested and expected to vest	6 years 8 months 15 days
Outstanding Options, Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 263,129
Options exercisable	174,019
Options fully vested and expected to vest	$ 256,476

Preferred Stock and Stockhold44

Preferred Stock and Stockholders' Equity (Summary of Options Outstanding and Exercisable) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares	20,454	17,663	16,195	14,704
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	6 years 9 months 14 days
Options Outstanding, Weighted Average Exercise Price	$ 5.22	$ 3.63	$ 2.98	$ 2.62
Options Outstanding, Aggregate Intrinsic Value	$ 263,129
Options Exercisable, Number of Shares	12,046
Options Exercisable, Weighted Average Exercise Price	$ 3.61
Options Exercisable, Aggregate Intrinsic Value	$ 174,019
$0.96 - $ 4.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Of Options, minimum	$ 0.96
Exercise Price Of Options, Maximum	$ 4
Options Outstanding, Number of Shares	10,548
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	5 years 8 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 2.82
Options Outstanding, Aggregate Intrinsic Value	$ 160,714
Options Exercisable, Number of Shares	8,399
Options Exercisable, Weighted Average Exercise Price	$ 2.62
Options Exercisable, Aggregate Intrinsic Value	$ 129,668
$4.01 - $ 9.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Of Options, minimum	$ 4.01
Exercise Price Of Options, Maximum	$ 9
Options Outstanding, Number of Shares	8,220
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 6.57
Options Outstanding, Aggregate Intrinsic Value	$ 94,476
Options Exercisable, Number of Shares	3,503
Options Exercisable, Weighted Average Exercise Price	$ 5.64
Options Exercisable, Aggregate Intrinsic Value	$ 43,521
$9.01 - $ 17.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Of Options, minimum	$ 9.01
Exercise Price Of Options, Maximum	$ 17
Options Outstanding, Number of Shares	1,296
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 4 months 24 days
Options Outstanding, Weighted Average Exercise Price	$ 11.94
Options Outstanding, Aggregate Intrinsic Value	$ 7,939
Options Exercisable, Number of Shares	140
Options Exercisable, Weighted Average Exercise Price	$ 12.13
Options Exercisable, Aggregate Intrinsic Value	$ 830
$17.01 - $ 19.73
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Of Options, minimum	$ 17.01
Exercise Price Of Options, Maximum	$ 19.73
Options Outstanding, Number of Shares	390
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 9 months 18 days
Options Outstanding, Weighted Average Exercise Price	$ 19.23
Options Exercisable, Number of Shares	4
Options Exercisable, Weighted Average Exercise Price	$ 19.73

Preferred Stock and Stockhold45

Preferred Stock and Stockholders' Equity (Summary of Weighted-Average Assumptions and Resultant Fair Value-Based Measurements for Options Granted to Employees and Directors) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted-average assumptions for stock options granted:
Risk-free interest rate	1.99%	1.31%	1.77%
Expected term	6 years 1 month 6 days	5 years 9 months 18 days	7 years 2 months 12 days
Expected volatility of stock price	68.10%	69.00%	77.00%
Dividend rate	0.00%	0.00%	0.00%
Weighted-average grant date fair value-based measurement	$ 6.14	$ 2.98	$ 2.72

Preferred Stock and Stockhold46

Preferred Stock and Stockholders' Equity (Summary of Stock-Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 13,361	$ 7,058	$ 6,013
Research And Development Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	3,743	1,312	839
Selling, General And Administrative Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 9,618	$ 5,746	$ 5,174

Schedule of Computation of Net

Schedule of Computation of Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net income (loss)	$ 98,330	$ 13,757	$ 12,647	$ 4,388	$ 4,597	$ 2,585	$ 977	$ (19)	$ 129,122	$ 8,140	$ (6,408)
Denominator:
Weighted-average shares used to compute basic net income (loss) per share									113,527	110,566	106,883
Dilutive effect of employee stock options									10,988	5,573	0
Weighted-average shares used to compute diluted net income (loss) per share									124,515	116,139	106,883
Net income (loss) per share attributable to common stockholders
Basic	$ 0.86	$ 0.12	$ 0.11	$ 0.04					$ 1.14	$ 0.07	$ (0.06)
Diluted	$ 0.77	$ 0.11	$ 0.10	$ 0.04					$ 1.04	$ 0.07	$ (0.06)

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average options excluded from the computation of diluted net income per share	1.1	4.4

Net Income (Loss) Per Share (Se

Net Income (Loss) Per Share (Securities Outstanding that could Potentially Dilute Per Share Data) (Details) - shares shares in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Securities outstanding that could potentially dilute per share data	20,454	17,663	16,195

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax (Benefit)) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. federal taxes:
Current	$ 0
Deferred	(71,839,000)
Total U.S. federal taxes	(71,839,000)
State taxes:
Current	388,000
Deferred	(4,865,000)
Total state taxes	(4,477,000)
Total	$ (76,316,000)	$ 0	$ 0

Income Taxes - (Narrative) (Det

Income Taxes - (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Income tax benefit or expense		$ (76,316,000)	$ 0	$ 0
Corporate income tax rate		35.00%
Decrease in valuation allowance		$ 116,900,000	4,300,000	2,400,000
Recognized interest or penalties		0
Unrecognized Tax Benefits		4,139,000	3,527,000	4,342,000
Unrecognized tax benefits would impact effective tax rate due to release of valuation allowance related to benefits in 2017		3,400,000
Accrued interest related to unrecognized tax benefits		0	0	0
Accrued penalties related to unrecognized tax benefits		0	$ 0	$ 0
Federal
Income Taxes [Line Items]
Net operating loss carryforwards		159,500,000
Research and development tax credits		$ 19,200,000
Minimum | Federal
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year		2,025
Research and development tax credit, expiration year		2,023
Maximum | Federal
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year		2,036
Research and development tax credit, expiration year		2,037
California State
Income Taxes [Line Items]
Net operating loss carryforwards		$ 95,400,000
Research and development tax credits		$ 4,200,000
California State | Minimum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year		2,018
California State | Maximum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year		2,035
Other States
Income Taxes [Line Items]
Net operating loss carryforwards		$ 23,600,000
Other States | Minimum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year		2,023
Other States | Maximum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year		2,036
Scenario, Forecast
Income Taxes [Line Items]
Corporate income tax rate	21.00%

Income Taxes (Significant Compo

Income Taxes (Significant Components of Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Federal and state net operating losses	$ 41,902	$ 68,605
Capitalized research and patent costs	13,278	23,575
Research credits	22,606	19,058
Biopharma Financing Agreement	0	5,556
Stock-based compensation costs	5,596	6,508
Other	5,795	6,067
Total deferred tax assets	89,177	129,369
Valuation allowance	(12,474)	(129,369)
Net deferred tax assets	$ 76,703	$ 0

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Statutory Federal Income Tax Rate to Effective Rate) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. federal taxes (benefit) at statutory rate	$ 17,954,000	$ 2,840,000	$ (2,178,000)
Changes in valuation allowance	(119,765,000)	(3,679,000)	2,495,000
Federal tax rate change impact to change in valuation allowance	33,233,000	0	0
Unutilized research credits	(1,199,000)	(69,000)	(445,000)
State income taxes	(2,955,000)	0	0
Non-deductible Compensation	33,000	2,435,000	0
Stock-based compensation	(3,826,000)	(1,660,000)	6,000
Other	209,000	133,000	122,000
Total	$ (76,316,000)	$ 0	$ 0

Income Taxes (Changes in Balanc

Income Taxes (Changes in Balance of Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Beginning Balance	$ 3,527	$ 4,342
Increase in tax positions for prior years	150	222
Decreases in tax positions for prior years	0	(1,189)
Increase in tax positions for current year	462	152
Ending Balance	$ 4,139	$ 3,527

Commitments and contingencies (

Commitments and contingencies (Narratives) (Details) - USD ($)	Jan. 11, 2018	Dec. 31, 2017
Commitment And Contingencies [Line Items]
Losses for contingent liability		$ 0
Provision for a loss contingency		0
Dohmen Life Science Services | Subsequent Event
Commitment And Contingencies [Line Items]
Settlement agreement date	January 11, 2018
Amount received under settlement agreement	$ 12,900,000
Dohmen Life Science Services | Other Receivable
Commitment And Contingencies [Line Items]
Net receivables outstanding		$ 12,900,000

Quarterly Financial Data (Una56

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Product sales, net	$ 53,280	$ 42,763	$ 35,559	$ 27,599	$ 23,811	$ 21,725	$ 19,724	$ 16,061	$ 159,201	$ 81,321	$ 50,286
Gross profit on product sales	52,123	41,787	34,784	26,953	23,250	21,057	19,298	15,658
Net income (loss)	$ 98,330	$ 13,757	$ 12,647	$ 4,388	$ 4,597	$ 2,585	$ 977	$ (19)	$ 129,122	$ 8,140	$ (6,408)
Basic net income per share	$ 0.86	$ 0.12	$ 0.11	$ 0.04					$ 1.14	$ 0.07	$ (0.06)
Diluted net income per share	$ 0.77	$ 0.11	$ 0.10	$ 0.04					$ 1.04	$ 0.07	$ (0.06)
Basic and diluted net income (loss) per share					$ 0.04	$ 0.02	$ 0.01	$ 0