Ardelyx (ARDX) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'ARDX	'
Entity Registrant Name	'Ardelyx, Inc.	'
Entity Central Index Key	'0001437402	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	18,540,094

Condensed_Balance_Sheets

Condensed Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$112,044	$34,435
Accounts receivable	2,660	6,436
Prepaid expenses and other current assets	1,669	965
Total current assets	116,373	41,836
Property and equipment, net	1,152	530
Other assets	'	358
Restricted cash	204	180
Total assets	117,729	42,904
Current liabilities:	'	'
Accounts payable	1,022	2,284
Accrued compensation and benefits	1,106	927
Other accrued liabilities	789	95
Deferred rent	'	5
Deferred revenue, current portion	16,480	13,828
Total current liabilities	19,397	17,139
Deferred revenue, non-current	34,959	26,470
Convertible preferred stock warrant liability	'	6,456
Liabilities related to early exercise of options	72	163
Total liabilities	54,428	50,228
Commitments and contingencies	'	'
Convertible preferred stock, $0.0001 par value per share — no shares and 108,829,748 shares authorized as of September 30, 2014 and December 31, 2013, respectively; no shares and 11,517,222 shares issued and outstanding as of September 30, 2014 and December 31, 2013, respectively	'	56,155
Stockholders’ equity (deficit):	'	'
Preferred stock, $0.0001 par value; 5,000,000 shares and no shares authorized as of September 30, 2014 and December 31, 2013, respectively; no shares issued and outstanding as of September 30, 2014 and December 31, 2013, respectively	'	'
Common stock, $0.0001 par value — 300,000,000 and 130,360,121 shares authorized as of September 30, 2014 and December 31, 2013, respectively; 18,399,761 and 1,225,481 shares issued and outstanding as of September 30, 2014 and December 31, 2013, respectively	2	'
Additional paid-in capital	131,195	5,174
Accumulated deficit	-67,896	-68,653
Total stockholders’ equity (deficit)	63,301	-63,479
Total liabilities, convertible preferred stock, and stockholders’ equity (deficit)	$117,729	$42,904

Condensed_Balance_Sheets_Paren

Condensed Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]	'	'
Convertible preferred stock, par value	$0.00	$0.00
Convertible preferred stock, shares authorized	0	108,829,748
Convertible preferred stock, shares issued	0	11,517,222
Convertible preferred stock, shares outstanding	0	11,517,222
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	300,000,000	130,360,121
Common stock, shares issued	18,399,761	1,225,481
Common stock, shares outstanding	18,399,761	1,225,481

Condensed_Statements_of_Operat

Condensed Statements of Operations and Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue:	'	'	'	'
Licensing revenue	$4,767	$1,989	$14,509	$5,967
Collaborative development revenue	2,831	4,604	10,775	14,473
Total revenue	7,598	6,593	25,284	20,440
Operating expenses:	'	'	'	'
Research and development	5,694	6,584	18,514	19,757
General and administrative	1,823	895	4,401	2,830
Total operating expenses	7,517	7,479	22,915	22,587
Income (loss) from operations	81	-886	2,369	-2,147
Other expense, net	-7	-13	-19	-42
Change in fair value of preferred stock warrant liability	'	'	-1,593	'
Income (loss) before provision for income taxes	74	-899	757	-2,189
Provision for income taxes	'	35	'	106
Net income (loss) and comprehensive income (loss)	74	-934	757	-2,295
Net income (loss) attributable to common stockholders:	'	'	'	'
Basic	74	-934	'	-2,295
Diluted	$74	($934)	'	($2,295)
Shares used to compute net income (loss) per share attributable to common stockholders:	'	'	'	'
Basic	18,374,277	1,156,446	7,476,642	1,100,885
Diluted	19,133,217	1,156,446	7,476,642	1,100,885
Net income (loss) per share attributable to common stockholders:	'	'	'	'
Basic	'	($0.81)	'	($2.08)
Diluted	'	($0.81)	'	($2.08)

Condensed_Statements_of_Cash_F

Condensed Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities	'	'
Net income (loss)	$757	($2,295)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:	'	'
Depreciation and amortization expense	202	512
Stock-based compensation	484	279
Change in fair value of preferred stock warrant liability	1,593	'
Changes in operating assets and liabilities:	'	'
Accounts receivable	3,776	-1,258
Prepaid and other current assets	-704	-359
Other assets	334	-529
Accounts payable	-1,262	1,016
Accrued compensation and benefits	179	-244
Other accrued liabilities	694	-662
Deferred revenue	11,141	-5,192
Deferred rent	-5	-364
Net cash provided by (used in) operating activities	17,189	-9,096
Investing activities	'	'
Purchases of property and equipment	-824	-278
Net cash used in investing activities	-824	-278
Financing activities	'	'
Proceeds from issuance of common stock	61,241	1
Proceeds from exercise of stock options	3	'
Repurchase of unvested common stock	'	-2
Net cash provided by (used in) financing activities	61,244	-1
Net increase (decrease) in cash and cash equivalents	77,609	-9,375
Cash and cash equivalents at beginning of period	34,435	32,903
Cash and cash equivalents at end of period	$112,044	$23,528

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Organization and Basis of Presentation	'
	1. Organization and Basis of Presentation
	Ardelyx, Inc. (the “Company”) is a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of innovative, minimally-systemic, small molecule therapeutics that work exclusively in the gastrointestinal tract to treat cardio-renal, gastrointestinal and metabolic diseases. The Company has developed a drug discovery and design platform enabling it, in a rapid and cost-efficient manner, to discover and design novel drug candidates. The Company was incorporated in Delaware on October 17, 2007, under the name Nteryx and changed its name to Ardelyx, Inc. in June 2008.
	The Company operates in only one business segment, which is the development of biopharmaceutical products.
	Basis of Presentation
	The accompanying unaudited condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and following the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments that are necessary for a fair statement of the Company’s financial information. The results of operations for the three and nine months ended September 30, 2014 are not necessarily indicative of the results to be expected for the year ending December 31, 2014 or for any other interim period or for any other future year. The balance sheet as of December 31, 2013 has been derived from audited financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements.
	The accompanying condensed financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2013 included in the Company’s Prospectus filed pursuant to Rule 424(b)(4) on June 19, 2014 with the SEC (the “Prospectus”).
	Reverse Stock Split
	On June 18, 2014, the Company’s Amended and Restated Certificate of Incorporation became effective resulting in a reverse split of the Company’s common stock and convertible preferred stock at a 1-for-9 ratio (the “Reverse Stock Split”). The par value and the authorized shares of the common stock and convertible preferred stock were not adjusted as a result of the Reverse Stock Split. All issued and outstanding common stock, convertible preferred stock, warrants for preferred stock, options for common stock and per share amounts contained in the financial statements have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented.
	Initial Public Offering
	On June 18, 2014, the Company’s registration statement on Form S-1 (File No. 333-196090) relating to the initial public offering (the “IPO”) of its common stock was declared effective by the SEC. The IPO closed on June 24, 2014 at which time the Company sold 4,928,900 shares of its common stock, which included the exercise in full by the underwriters of the IPO of their option to purchase 642,900 additional shares of the Company’s common stock. The Company received cash proceeds of $61.2 million from the IPO, net of underwriting discounts and commissions and expenses paid by the Company.
	On June 24, 2014, prior to the closing of the IPO, all outstanding shares of convertible preferred stock converted into 11,517,222 shares of common stock with the related carrying value of $56.2 million reclassified to common stock and additional paid-in capital. In addition, all convertible preferred stock warrants were net exercised and converted to common stock and the related convertible preferred stock warrant liability was reclassified to additional paid-in capital.
	On June 24, 2014, the Company’s Amended and Restated Certificate of Incorporation became effective and the number of shares of capital stock the Company is authorized to issue was increased to 305,000,000 shares, of which 300,000,000 shares may be common stock and 5,000,000 shares may be preferred stock. Both the common stock and preferred stock have a par value of $0.0001 per share. There are no shares of preferred stock outstanding at September 30, 2014.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	2. Summary of Significant Accounting Policies
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, income taxes, and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with an original maturity date of 90 days or less on the date of purchase to be cash equivalents. The Company invests its cash in bank deposits and money market accounts.
	Restricted Cash
	The Company is required to guarantee the credit limit on its corporate credit card with a certificate of deposit of $100,000. The collateral will be released upon the cancellation of the corporate credit card.
	The Company is required under its facility lease agreement to maintain a line of credit with a bank in the amount of $104,000 for the benefit of the lessor. The line of credit is secured by a cash deposit with the bank. The cash deposit will be released upon expiration of the line of credit.
	Comprehensive Income (Loss)
	Comprehensive income (loss) is composed of two components: net income (loss) and other comprehensive income (loss). Other comprehensive income (loss) refers to gains and losses that under GAAP are recorded as an element of stockholders’ equity (deficit), but are excluded from net income (loss). The Company did not record any transactions within other comprehensive income (loss) in the periods presented and, therefore, the net income (loss) and comprehensive income (loss) were the same for all periods presented.
	Revenue Recognition
	Revenue from research activities made under collaboration partnership agreements are recognized as the services are provided and when there is persuasive evidence that an arrangement exists, delivery has occurred, the price is fixed or determinable, and collectability is reasonably assured. Revenue generated from research and licensing agreements typically includes up-front signing or license fees, cost reimbursements, research services, minimum sublicense fees, milestone payments, and royalties on future licensees’ product sales.
	For revenue agreements with multiple-element arrangements, such as license and development agreements, the Company allocates revenue to each deliverable based on the relative selling price of each deliverable. When applying the relative selling price method, the Company determines the selling price for each deliverable using vendor-specific objective evidence or third-party evidence. If neither exists, the Company uses its best estimate of selling price for that deliverable. Revenue allocated is then recognized when the four basic revenue recognition criteria are met for each deliverable.
	The Company recognizes revenue from upfront payments ratably over the term of its estimated period of performance under the agreement which is recorded as licensing revenue. Reimbursements for development costs incurred under the Company’s license agreement with AstraZeneca are classified as collaborative development revenue. The Company recognizes cost reimbursement revenue under collaboration partnership agreements as the related research and development costs for services are rendered. Deferred revenue represents the portion of research or license payments received which has not been earned.
	Revenues from milestones, if they are nonrefundable and deemed substantive, are recognized upon successful accomplishment of the milestones. To the extent that non-substantive milestones are achieved and the Company has remaining performance obligations, milestones are deferred and recognized as revenue over the estimated remaining period of performance. The Company will recognize revenue associated with the non-substantive milestones upon achievement of the milestone if there are no undelivered elements and it has no remaining performance obligations. The Company will account for sales-based milestones as royalties that will be recognized as revenue upon achievement of the milestone.
	Net Income (Loss) per Share Attributable to Common Stockholders
	Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. Prior to the Company’s IPO of its common stock, the Company’s Series A and Series B convertible preferred stock was entitled to receive dividends of up to $0.8181 and $0.2781 per share, respectively, prior and in preference to any declaration or payment of any dividend on common stock and thereafter participate pro rata on an as converted basis with the common stock holders on any distributions to common stockholders. The convertible preferred shares were therefore considered to be participating securities as were the unvested early exercised shares. As a result, the Company calculated the net income (loss) per share attributable to common stockholders using the two-class method. The convertible preferred stock and warrants were included in the calculation for the period of time they were outstanding during the nine months ended September 30, 2014. They would not be reflected for the three months ended September 30, 2014 since they were converted in the second quarter. Accordingly, the net income (loss) attributable to common stockholders is derived from the net income (loss) for the period and, in periods in which the Company has net income attributable to common stockholders, an adjustment is made for the noncumulative dividends and allocations of earnings to participating securities based on their outstanding shareholder rights. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible preferred stock as the convertible preferred stock did not have a contractual obligation to share in the Company’s losses. The diluted net income per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. In periods when the Company has incurred a net loss, convertible preferred stock, options to purchase common stock and convertible preferred stock warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update (“ASU”) 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The ASU concludes an unrecognized tax benefit should be presented as a reduction of a deferred tax asset when settlement in this manner is available under the law. The Company adopted this amendment as of January 1, 2014, which did not have a significant impact on the balance sheet.
	In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which converges the FASB and the International Accounting Standards Board standards on revenue recognition. Areas of revenue recognition that will be affected include, but are not limited to, transfer of control, variable consideration, allocation of transfer pricing, licenses, time value of money, contract costs and disclosures. This guidance is effective for the fiscal years and interim reporting periods beginning after December 15, 2016, at which time the Company may adopt the new standard under the full retrospective method or the modified retrospective method. Early adoption is not permitted. The Company has not yet selected a transition method nor has the Company determined the impact of the new standard on its financial statements and related disclosures.
	In August 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. In doing so, companies will have reduced diversity in the timing and content of footnote disclosures than under today’s guidance. ASU 2014-15 is effective for the Company in the first quarter of 2016 with early adoption permitted. The Company does not believe the impact of adopting ASU 2014-15 on its financial statements will be material.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	3. Fair Value Measurements
	Financial assets and liabilities are recorded at fair value. The carrying amounts of certain of the Company’s financial instruments, including cash equivalents, accounts receivable and accounts payable, are valued at cost, which approximates fair value due to their short maturities. The accounting guidance for fair value provides a framework for measuring fair value, and requires certain new disclosures about how fair value is determined. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance also establishes a three-level valuation hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity.
	The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows:
	Level 1	–	Observable inputs such as quoted prices (unadjusted) for identical instruments in active markets.
	Level 2	–	Observable inputs such as quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, or model-derived valuations whose significant inputs are observable.
	Level 3	–	Unobservable inputs that reflect the reporting entity’s own assumptions.
	The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy:
		September 30, 2014
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets:
	Money market funds	$	109,155		$	109,155	$	—	$	—
	Certificates of deposit		204			—		204		—
	Total	$	109,359		$	109,155	$	204	$	—
		December 31, 2013
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets:
	Money market funds	$	32,472		$	32,472	$	—	$	—
	Certificates of deposit		180			—		180		—
	Total	$	32,652		$	32,472	$	180	$	—
	Liabilities:
	Convertible preferred stock warrant liability	$	6,456		$	—	$	—	$	6,456
	Total	$	6,456		$	—	$	—	$	6,456
	Where quoted prices are available in an active market, securities are classified as Level 1. The Company classifies money market funds as Level 1. When quoted market prices are not available for the specific security, then the Company estimates fair value by using benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. The Company classifies certificates of deposit as Level 2. In certain cases where there is limited activity or less transparency around inputs to valuation, securities are classified as Level 3. There were no transfers between Level 1 and Level 2 during the periods presented.
	Level 3 liabilities that are measured at fair value on a recurring basis consist of the preferred stock warrant liability, which was measured using the probability weighted expected return method that calculated the probability of the Company going public or being acquired, and the option-pricing method for remaining private in the near to mid-term. The fair value of the preferred stock warrant liability as of December 31, 2013 was estimated using such scenarios that were weighted based on the Company’s estimate of the probability of each scenario: 20% for IPO; 10% for merger and 70% for stay private as of December 31, 2013. At the end of each reporting period, the change in estimated fair value during the period is recorded in change in fair value of convertible preferred stock warrant liability in the statements of operations and comprehensive income (loss). Generally, increases or decreases in the fair value of the underlying convertible preferred stock would result in a directionally similar impact in the fair value measurement of the warrant liability. The preferred stock warrant liability was remeasured prior to the net exercise of the warrants using the IPO price. The preferred stock warrants were net exercised and converted to common stock upon the completion of the IPO and are no longer subject to remeasurement.
	The following table sets forth a summary of the changes in the estimated fair value of the Company’s preferred stock warrants which were measured at fair value on a recurring basis (in thousands):
		Convertible
		Preferred Stock
		Warrant Liability
	Balance at December 31, 2013	$	6,456
	Net increase in fair value of warrant liabilities upon revaluation		1,593
	Reclassification of warrant liability to additional paid-in capital		(8,049	)
	Balance at September 30, 2014	$	—

Collaboration_and_Licensing_Ag

Collaboration and Licensing Agreements	9 Months Ended
	Sep. 30, 2014
Collaboration And Licensing Agreements [Abstract]	'
Collaboration and Licensing Agreements	'
	4. Collaboration and Licensing agreements
	AstraZeneca AB (“AstraZeneca”)
	Under the terms of the AstraZeneca collaboration partnership agreement, the Company received an up-front license fee of $35.0 million in October 2012 and a $15.0 million payment in December 2013, which are both being recognized as revenue on a straight-line basis over the estimated period of performance. The estimated period of performance is currently estimated to be December 2017, which was changed during the quarter ended September 30, 2014 from December 2016 due to the extension of the estimated completion date of all Phase 2 clinical trials. The expected period of performance is reviewed quarterly and adjusted, as needed, to reflect our current assumptions regarding the timing of clinical studies. AstraZeneca reimburses the Company for its internal and external development-related costs. These reimbursements are recognized as collaborative development revenue when the development-related costs are incurred.
	In May 2014, the Company received from AstraZeneca a $25.0 million payment as a result of the dosing of the first patient in the Phase 2b clinical trial in hyperphosphatemia. As the $25.0 million did not meet the criteria to be considered the achievement of a substantive milestone for accounting purposes, the amount was recorded as deferred revenue when received and is being recognized as revenue on a straight-line basis over the remaining estimated period of performance under the AstraZeneca collaboration partnership agreement, which is currently estimated to be December 2017.
	As of September 30, 2014, the Company was eligible to receive future contingent payments up to a total of $795.0 million, which is comprised of future development milestones up to an additional $197.5 million and launch, commercialization, and sales milestones up to an additional $597.5 million. The contingent payments are triggered upon the activities expected to be undertaken by AstraZeneca. Revenue from milestones, if they are nonrefundable and deemed substantive, are recognized upon successful accomplishment of the milestone. The Company will recognize revenue associated with non-substantive milestones upon achievement of the milestones if there are no undelivered elements and it has no remaining performance obligation. To the extent that non-substantive milestones are achieved and the Company has remaining performance obligations, milestones are deferred and recognized as revenue over the estimated remaining period of performance.
	For the three months ended September 30, 2014 and 2013, the Company recognized revenue of $4.8 million and $2.0 million, respectively, related to amortization of the up-front and other license fees, and $2.8 million and $4.6 million, respectively, for collaborative development services. For the nine months ended September 30, 2014 and 2013, the Company recognized revenues from the AstraZeneca collaboration partnership of $13.3 million and $6.0 million, respectively, related to amortization of the up-front and other license fees, and $10.8 million and $14.5 million, respectively, for collaborative development services. As of September 30, 2014 and December 31, 2013, the Company had total deferred revenue of $51.4 million and $40.3 million related to the AstraZeneca license agreement.
	Sanofi SA (“Sanofi”)
	Under the terms of the License Option and License Agreement with Sanofi, the Company granted Sanofi an exclusive worldwide license to conduct research utilizing the Company’s small molecule NaP2b inhibitors. In addition, Sanofi has the option to obtain an exclusive license to develop, manufacture and commercialize potential products under the agreement. Under the License Option and License Agreement, Sanofi is responsible for all of the costs and expenses for research and preclinical activities and, should it exercise its option, for the development and commercialization efforts under the program. Under the License Option and License Agreement, the Company received a payment of $1.25 million in March 2014, which was fully recognized as licensing revenue in May 2014 after the Company completed its obligation to provide to Sanofi the background know-how, listed patents, and materials described in the License Option and License Agreement.
	The Company has the potential to earn future development, regulatory and commercial milestone payments of up to $196.8 million if Sanofi continues to advance the program into development and through commercialization. If a NaP2b inhibitor is commercialized by Sanofi as a result of this program, the Company will receive tiered royalties ranging from mid-single digits into the low double digits. As part of the arrangement with Sanofi, the Company retains an option to participate in co-promotional activities in the United States. Future potential milestone payments do not meet the criteria to be considered substantive milestones, and therefore will be treated as other contingent consideration and recognized as revenue as they are achieved as the Company has no performance obligations under the License Option and License Agreement. No milestones have been received since the inception of the agreement.

Equity_Incentive_Plans

Equity Incentive Plans	9 Months Ended
	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Equity Incentive Plans	'
	5. Equity Incentive Plans
	As of September 30, 2014, a total of 2,149,021 shares of common stock had been reserved for issuance under the 2008 Plan, and no shares are available for future grant.
	The 2014 Equity Incentive Award Plan (“2014 Plan”) became effective on June 18, 2014, immediately prior to the time the Company’s Registration Statement on Form S-1 became effective. Under the 2014 Plan, 1,419,328 shares of common stock were initially reserved for issuance pursuant to a variety of stock-based compensation awards, including stock options, stock appreciation rights, or SARs, restricted stock awards, restricted stock unit awards, deferred stock awards, deferred stock unit awards, dividend equivalent awards, stock payment awards and performance awards. In addition, 35,221 shares that had been available for future awards under the 2008 Plan as of June 18, 2014, were added to the initial reserve available under the 2014 Plan, bringing the total reserve upon the effective date of the 2014 Plan to 1,454,549. The number of shares initially reserved for issuance or transfer pursuant to awards under the 2014 Plan will be increased by (i) the number of shares represented by awards outstanding under 2008 Plan on June 18, 2014, that are either forfeited or lapse unexercised or that are repurchased for the original purchase price thereof, up to a maximum of 1,153,279 shares, and (ii) if approved by the Administrator of the 2014 Plan, an annual increase on the first day of each fiscal year beginning in 2015 and ending in 2024, equal to the lesser of (A) four percent (4.0%) of the shares of stock outstanding (on an as converted basis) on the last day of the immediately preceding fiscal year and (B) such smaller number of shares of stock as determined by our board of directors; provided, however, that no more than 10,683,053 shares of stock may be issued upon the exercise of incentive stock options. The Company also adopted the 2014 Employee Stock Purchase Plan (ESPP) and initially reserved 202,762 shares of common stock as of its effective date of June 18, 2014. If approved by the Administrator of the ESPP, on the first day of each calendar year, beginning in 2015 and ending in 2024, the number of shares in the reserve will increase by an amount equal to the lesser of (i) one percent (1.0%) of the shares of common stock outstanding on the last day of the immediately preceding fiscal year and (ii) such number of shares of common stock as determined by the board of directors; provided, however, no more than 2,230,374 shares of our common stock may be issued under the ESPP. Under the ESPP, participants are offered the option to purchase shares of the Company’s common stock at a discount during a series of successive offering periods normally commencing on March 1 and September 1 of each year. The initial offering period commenced on September 1, 2014 and will end on February 28, 2015. No shares have been sold under the ESPP since its adoption.
	The following table summarizes activity under the 2008 Plan and the 2014 Plan, including grants to nonemployees and restricted stock issued:
		Shares			Options			Weighted			Aggregate
		Available			Outstanding			Average			Intrinsic
		for Grant						Exercise Price			Value
								per Share			(in thousands)
	Balances at December 31, 2013		3,914			1,162,829		$	1.03
	Options authorized under the 2008 Plan		33,333			—
	Options authorized under the 2014 Plan		1,419,328			—
	Options granted		(63,888	)		63,888			13.95
	Options cancelled		4,084			(4,084	)		2.21
	Options exercised or lapsed		—			(156,914	)		0.61
	Balances at September 30, 2014		1,396,771			1,065,719		$	1.86		$	13,162
	Vested at September 30, 2014					653,666		$	1.08		$	8,583
	Expected to vest at September 30, 2014					1,065,719		$	1.86		$	13,162
	No options were granted during the three months ended September 30, 2014. The weighted-average grant-date estimated fair value of options granted during the nine months ended September 30, 2014 was $10.96 and during the three and nine months ended September 30, 2013 was $2.70 and $2.68 per share, respectively. The aggregate intrinsic value was calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock of $14.21 per share as of September 30, 2014.
	Liability for Early Exercise of Stock Options
	As of September 30, 2014 and December 31, 2013, there were 133,844 and 286,217 shares of common stock outstanding, respectively, subject to the Company’s right of repurchase at prices ranging from $0.27 to $1.08 per share. As of September 30, 2014 and December 31, 2013, the Company recorded $72,000 and $163,000, respectively, as liabilities associated with shares issued with repurchase rights.
	Modification of Stock Awards
	During the three months ended September 30, 2014, the Company entered into a Transition and Separation Agreement with its Chief Scientific Officer, Dominique Charmot, under which certain restricted shares that were subject to vesting and repurchase by the Company will become fully vested as of Dr. Charmot’s separation from the Company as an employee and director on December 23, 2014.  This will result in the acceleration of the vesting for 58,969 shares of restricted stock.   As a result of the acceleration, the Company has recorded a stock-based compensation charge of $203,000 during the three months ended September 30, 2014 and will record a charge of $633,000 during the quarter ending December 31, 2014 to reflect the revised service period for the restricted stock and related vesting of shares that would otherwise not have vested.
	Stock-based Compensation
	Total stock-based compensation recognized was as follows (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2014				2013				2014				2013
	Research and development	$	240			$	57			$	314			$	156
	General and administrative		82				32				170				123
	Total	$	322			$	89			$	484			$	279
	As of September 30, 2014 and December 31, 2013, there was $1.0 million and $549,000, respectively, of unrecognized stock-based compensation expense, net of estimated forfeitures, related to unvested share options with a weighted-average remaining recognition period of 1.4 and 1.8 years.
	The fair value of stock option awards to employees was estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Expected term (years)		—			6.06			5.79			6.07
	Volatility		—			99	%		101	%		98	%
	Risk-free interest rate		—			1.64	%		1.77	%		1.35	%
	Dividend yield		—			—	%		—	%		—	%

Net_Income_Loss_per_Share_Attr

Net Income (Loss) per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Net Income (Loss) per Share Attributable to Common Stockholders	'
	6. Net Income (Loss) per Share Attributable to Common Stockholders
	The following table sets forth the computation of the unaudited basic and diluted net income (loss) per share attributable to common stockholders (in thousands, except share and per share data):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Net income (loss)	$	74		$	(934	)	$	757		$	(2,295	)
	Noncumulative dividends on convertible preferred		—			—			(757	)		—
	stock
	Net income (loss) attributable to common stockholders, basic and diluted	$	74		$	(934	)	$	—		$	(2,295	)
	Basic shares:
	Weighted average common shares outstanding		18,374,277			1,156,446			7,476,642			1,100,885
	Diluted shares:
	Weighted average effect of dilutive stock options		758,940			—			—			—
			19,133,217			1,156,446			7,476,642			1,100,885
	Net income (loss) per share attributable to common stockholders:
	Basic	$	—		$	-0.81		$	—		$	(2.08	)
	Diluted	$	—		$	-0.81		$	—		$	(2.08	)
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net income (loss) per share attributable to common stockholders for the periods presented because including them would have been antidilutive:
		Three Months Ended			Nine Months Ended
		September 30,			September  30,
		2014		2013	2014			2013
	Convertible preferred stock	—		11,517,222		—			11,517,222
	Options to purchase common stock	63,888		1,211,855		1,065,719			1,211,855
	Warrants to purchase convertible preferred stock	—		574,953		—			574,953
	Total	63,888		13,304,030		1,065,719			13,304,030

Related_Party_Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	7. Related Party Transactions
	As part of the consulting arrangement with the spouse of an executive of the Company to provide research and development services related to clinical operations, the Company incurred expenses of $58,000 and $60,000 for services rendered during the three months ended September 30, 2014 and 2013, respectively and $190,000 and $186,000 for services rendered during the nine months ended September 30, 2014 and 2013, respectively. As of September 30, 2014 and December 31, 2013, the Company owed $19,000 and $18,000, respectively, to the individual, which is recorded in accounts payable.

Facility_Lease_Commitment

Facility Lease Commitment	9 Months Ended
	Sep. 30, 2014
Leases [Abstract]	'
Facility Lease Commitment	'
	8. Facility Lease Commitment
	In September 2014, the Company signed the second amendment to its facility lease agreement in Fremont, California to add space and to extend the lease term through September 2019. In addition, the amended lease agreement provides for a tenant improvement allowance of up to $600,000.  The extended lease has rent escalation clauses through the lease term. Rent increases, including the impact of a rent holiday and leasehold improvement allowance from the landlord, will be recognized as deferred rent and amortized on a straight-line basis over the term of the lease.
	Under the terms of the lease agreement, the Company provided the lessor with an irrevocable letter of credit in the amount of $104,000. The lessor shall be entitled to draw on the letter of credit in the event of any uncured default by the Company under the terms of the lease.
	The future minimum payments under the noncancelable operating lease at September 30, 2014, are as follows (in thousands):
	Year ending December 31,	Amounts
	2014 (remaining three months)	$	209
	2015		843
	2016		868
	2017		895
	2018		921
	2019		653
	Total	$	4,389

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to revenue recognition, clinical trial accruals, income taxes, and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results may differ from those estimates.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	The Company considers all highly liquid investments purchased with an original maturity date of 90 days or less on the date of purchase to be cash equivalents. The Company invests its cash in bank deposits and money market accounts.
Restricted Cash	'
	Restricted Cash
	The Company is required to guarantee the credit limit on its corporate credit card with a certificate of deposit of $100,000. The collateral will be released upon the cancellation of the corporate credit card.
	The Company is required under its facility lease agreement to maintain a line of credit with a bank in the amount of $104,000 for the benefit of the lessor. The line of credit is secured by a cash deposit with the bank. The cash deposit will be released upon expiration of the line of credit.
Comprehensive Income (Loss)	'
	Comprehensive Income (Loss)
	Comprehensive income (loss) is composed of two components: net income (loss) and other comprehensive income (loss). Other comprehensive income (loss) refers to gains and losses that under GAAP are recorded as an element of stockholders’ equity (deficit), but are excluded from net income (loss). The Company did not record any transactions within other comprehensive income (loss) in the periods presented and, therefore, the net income (loss) and comprehensive income (loss) were the same for all periods presented.
Revenue Recognition	'
	Revenue Recognition
	Revenue from research activities made under collaboration partnership agreements are recognized as the services are provided and when there is persuasive evidence that an arrangement exists, delivery has occurred, the price is fixed or determinable, and collectability is reasonably assured. Revenue generated from research and licensing agreements typically includes up-front signing or license fees, cost reimbursements, research services, minimum sublicense fees, milestone payments, and royalties on future licensees’ product sales.
	For revenue agreements with multiple-element arrangements, such as license and development agreements, the Company allocates revenue to each deliverable based on the relative selling price of each deliverable. When applying the relative selling price method, the Company determines the selling price for each deliverable using vendor-specific objective evidence or third-party evidence. If neither exists, the Company uses its best estimate of selling price for that deliverable. Revenue allocated is then recognized when the four basic revenue recognition criteria are met for each deliverable.
	The Company recognizes revenue from upfront payments ratably over the term of its estimated period of performance under the agreement which is recorded as licensing revenue. Reimbursements for development costs incurred under the Company’s license agreement with AstraZeneca are classified as collaborative development revenue. The Company recognizes cost reimbursement revenue under collaboration partnership agreements as the related research and development costs for services are rendered. Deferred revenue represents the portion of research or license payments received which has not been earned.
	Revenues from milestones, if they are nonrefundable and deemed substantive, are recognized upon successful accomplishment of the milestones. To the extent that non-substantive milestones are achieved and the Company has remaining performance obligations, milestones are deferred and recognized as revenue over the estimated remaining period of performance. The Company will recognize revenue associated with the non-substantive milestones upon achievement of the milestone if there are no undelivered elements and it has no remaining performance obligations. The Company will account for sales-based milestones as royalties that will be recognized as revenue upon achievement of the milestone.
Net Income (Loss) per Share Attributable to Common Stockholders	'
	Net Income (Loss) per Share Attributable to Common Stockholders
	Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. Prior to the Company’s IPO of its common stock, the Company’s Series A and Series B convertible preferred stock was entitled to receive dividends of up to $0.8181 and $0.2781 per share, respectively, prior and in preference to any declaration or payment of any dividend on common stock and thereafter participate pro rata on an as converted basis with the common stock holders on any distributions to common stockholders. The convertible preferred shares were therefore considered to be participating securities as were the unvested early exercised shares. As a result, the Company calculated the net income (loss) per share attributable to common stockholders using the two-class method. The convertible preferred stock and warrants were included in the calculation for the period of time they were outstanding during the nine months ended September 30, 2014. They would not be reflected for the three months ended September 30, 2014 since they were converted in the second quarter. Accordingly, the net income (loss) attributable to common stockholders is derived from the net income (loss) for the period and, in periods in which the Company has net income attributable to common stockholders, an adjustment is made for the noncumulative dividends and allocations of earnings to participating securities based on their outstanding shareholder rights. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible preferred stock as the convertible preferred stock did not have a contractual obligation to share in the Company’s losses. The diluted net income per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. In periods when the Company has incurred a net loss, convertible preferred stock, options to purchase common stock and convertible preferred stock warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update (“ASU”) 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The ASU concludes an unrecognized tax benefit should be presented as a reduction of a deferred tax asset when settlement in this manner is available under the law. The Company adopted this amendment as of January 1, 2014, which did not have a significant impact on the balance sheet.
	In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which converges the FASB and the International Accounting Standards Board standards on revenue recognition. Areas of revenue recognition that will be affected include, but are not limited to, transfer of control, variable consideration, allocation of transfer pricing, licenses, time value of money, contract costs and disclosures. This guidance is effective for the fiscal years and interim reporting periods beginning after December 15, 2016, at which time the Company may adopt the new standard under the full retrospective method or the modified retrospective method. Early adoption is not permitted. The Company has not yet selected a transition method nor has the Company determined the impact of the new standard on its financial statements and related disclosures.
	In August 2014, the Financial Accounting Standards Board issued Accounting Standards Update No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. In doing so, companies will have reduced diversity in the timing and content of footnote disclosures than under today’s guidance. ASU 2014-15 is effective for the Company in the first quarter of 2016 with early adoption permitted. The Company does not believe the impact of adopting ASU 2014-15 on its financial statements will be material.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Summary of Fair Value Measurements of Company's Financial Assets and Liabilities	'
	The following table sets forth the fair value of the Company’s financial assets and liabilities measured on a recurring basis by level within the fair value hierarchy:
		September 30, 2014
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets:
	Money market funds	$	109,155		$	109,155	$	—	$	—
	Certificates of deposit		204			—		204		—
	Total	$	109,359		$	109,155	$	204	$	—
		December 31, 2013
		Total			Level 1		Level 2		Level 3
		(In thousands)
	Assets:
	Money market funds	$	32,472		$	32,472	$	—	$	—
	Certificates of deposit		180			—		180		—
	Total	$	32,652		$	32,472	$	180	$	—
	Liabilities:
	Convertible preferred stock warrant liability	$	6,456		$	—	$	—	$	6,456
	Total	$	6,456		$	—	$	—	$	6,456
Summary of Changes in Estimated Fair Value of Preferred Stock Warrant Liability	'
	The following table sets forth a summary of the changes in the estimated fair value of the Company’s preferred stock warrants which were measured at fair value on a recurring basis (in thousands):
		Convertible
		Preferred Stock
		Warrant Liability
	Balance at December 31, 2013	$	6,456
	Net increase in fair value of warrant liabilities upon revaluation		1,593
	Reclassification of warrant liability to additional paid-in capital		(8,049	)
	Balance at September 30, 2014	$	—

Equity_Incentive_Plans_Tables

Equity Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Activity Under 2008 Plan and 2014 Plan, Including Grants to Nonemployees and Restricted Stock Issued	'
	The following table summarizes activity under the 2008 Plan and the 2014 Plan, including grants to nonemployees and restricted stock issued:
		Shares			Options			Weighted			Aggregate
		Available			Outstanding			Average			Intrinsic
		for Grant						Exercise Price			Value
								per Share			(in thousands)
	Balances at December 31, 2013		3,914			1,162,829		$	1.03
	Options authorized under the 2008 Plan		33,333			—
	Options authorized under the 2014 Plan		1,419,328			—
	Options granted		(63,888	)		63,888			13.95
	Options cancelled		4,084			(4,084	)		2.21
	Options exercised or lapsed		—			(156,914	)		0.61
	Balances at September 30, 2014		1,396,771			1,065,719		$	1.86		$	13,162
	Vested at September 30, 2014					653,666		$	1.08		$	8,583
	Expected to vest at September 30, 2014					1,065,719		$	1.86		$	13,162
Summary of Stock-Based Compensation Recognized	'
	Total stock-based compensation recognized was as follows (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2014				2013				2014				2013
	Research and development	$	240			$	57			$	314			$	156
	General and administrative		82				32				170				123
	Total	$	322			$	89			$	484			$	279
Summary of Weighted Average Assumptions to Estimate Fair value of Stock Option Awards	'
	The fair value of stock option awards to employees was estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions:
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Expected term (years)		—			6.06			5.79			6.07
	Volatility		—			99	%		101	%		98	%
	Risk-free interest rate		—			1.64	%		1.77	%		1.35	%
	Dividend yield		—			—	%		—	%		—	%

Net_Income_Loss_per_Share_Attr1

Net Income (Loss) per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Computation of Unaudited Basic and Diluted Net Loss per Common Share	'
	The following table sets forth the computation of the unaudited basic and diluted net income (loss) per share attributable to common stockholders (in thousands, except share and per share data):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2014			2013			2014			2013
	Net income (loss)	$	74		$	(934	)	$	757		$	(2,295	)
	Noncumulative dividends on convertible preferred		—			—			(757	)		—
	stock
	Net income (loss) attributable to common stockholders, basic and diluted	$	74		$	(934	)	$	—		$	(2,295	)
	Basic shares:
	Weighted average common shares outstanding		18,374,277			1,156,446			7,476,642			1,100,885
	Diluted shares:
	Weighted average effect of dilutive stock options		758,940			—			—			—
			19,133,217			1,156,446			7,476,642			1,100,885
	Net income (loss) per share attributable to common stockholders:
	Basic	$	—		$	-0.81		$	—		$	(2.08	)
	Diluted	$	—		$	-0.81		$	—		$	(2.08	)
Antidilutive Common Stock Equivalents Excluded from Computation of Diluted Net Income (Loss)	'
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net income (loss) per share attributable to common stockholders for the periods presented because including them would have been antidilutive:
		Three Months Ended			Nine Months Ended
		September 30,			September  30,
		2014		2013	2014			2013
	Convertible preferred stock	—		11,517,222		—			11,517,222
	Options to purchase common stock	63,888		1,211,855		1,065,719			1,211,855
	Warrants to purchase convertible preferred stock	—		574,953		—			574,953
	Total	63,888		13,304,030		1,065,719			13,304,030

Facility_Lease_Commitment_Tabl

Facility Lease Commitment (Tables)	9 Months Ended
	Sep. 30, 2014
Leases [Abstract]	'
Schedule of Future Minimum Payments Under the Noncancelable Operating Lease	'
	The future minimum payments under the noncancelable operating lease at September 30, 2014, are as follows (in thousands):
	Year ending December 31,	Amounts
	2014 (remaining three months)	$	209
	2015		843
	2016		868
	2017		895
	2018		921
	2019		653
	Total	$	4,389

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation - Additional Information (Details) (USD $)	0 Months Ended	9 Months Ended			0 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 18, 2014	Sep. 30, 2014	Jun. 24, 2014	Dec. 31, 2013	Jun. 24, 2014	Jun. 24, 2014
		Segment			Common Stock	IPO
Organization And Basis Of Presentation [Line Items]	'	'	'	'	'	'
Date of incorporation	'	17-Oct-07	'	'	'	'
Place of incorporation	'	'Delaware	'	'	'	'
Number of operating segments	'	1	'	'	'	'
Reverse stock split, description	'	'On June 18, 2014, the Company’s Amended and Restated Certificate of Incorporation became effective resulting in a reverse split of the Company’s common stock and convertible preferred stock at a 1-for-9 ratio (the “Reverse Stock Split”). The par value and the authorized shares of the common stock and convertible preferred stock were not adjusted as a result of the Reverse Stock Split. All issued and outstanding common stock, convertible preferred stock, warrants for preferred stock, options for common stock and per share amounts contained in the financial statements have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented.	'	'	'	'
Reverse stock split ratio	0.11	'	'	'	'	'
Stock issued during period, shares, new issues	'	'	'	'	'	4,928,900
Additional common stock issued on exercise of option by Underwriters	'	'	'	'	'	642,900
Net proceeds from the IPO	$61.20	'	'	'	'	'
Convertible preferred stock converted to common stock, shares	'	'	'	'	11,517,222	'
Convertible preferred stock converted to common stock, value	'	'	'	'	$56.20	'
Shares authorized	'	'	305,000,000	'	'	'
Common stock, shares authorized	'	300,000,000	300,000,000	130,360,121	'	'
Preferred stock, shares authorized	'	5,000,000	5,000,000	0	'	'
Common stock, par value	'	$0.00	'	$0.00	'	'
Preferred stock, par value	'	$0.00	'	$0.00	'	'
Preferred stock, shares outstanding	'	0	'	0	'	'

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
In Thousands, except Per Share data, unless otherwise specified			Prior to Initial Public Offering	Prior to Initial Public Offering	Line of Credit	Certificate of Deposit
			Series A Convertible Preferred Stock	Series B Convertible Preferred Stock
Organization And Basis Of Presentation [Line Items]	'	'	'	'	'	'
Restricted cash	$204	$180	'	'	$104	$100
Preferred stock dividend per share	'	'	$0.82	$0.28	'	'

Fair_Value_Measurements_Summar

Fair Value Measurements - Summary of Fair Value Measurements of Company's Financial Assets and Liabilities (Details) (Fair Value, Recurring, USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets:	'	'
Assets at fair value	$109,359	$32,652
Liabilities:	'	'
Liabilities at fair value	'	6,456
Convertible preferred stock warrant liability	'	'
Liabilities:	'	'
Liabilities at fair value	'	6,456
Level 1	'	'
Assets:	'	'
Assets at fair value	109,155	32,472
Liabilities:	'	'
Liabilities at fair value	'	0
Level 1 | Convertible preferred stock warrant liability	'	'
Liabilities:	'	'
Liabilities at fair value	'	0
Level 2	'	'
Assets:	'	'
Assets at fair value	204	180
Liabilities:	'	'
Liabilities at fair value	'	0
Level 2 | Convertible preferred stock warrant liability	'	'
Liabilities:	'	'
Liabilities at fair value	'	0
Level 3	'	'
Liabilities:	'	'
Liabilities at fair value	'	6,456
Level 3 | Convertible preferred stock warrant liability	'	'
Liabilities:	'	'
Liabilities at fair value	'	6,456
Money Market Fund	'	'
Assets:	'	'
Assets at fair value	109,155	32,472
Money Market Fund | Level 1	'	'
Assets:	'	'
Assets at fair value	109,155	32,472
Certificate of Deposit	'	'
Assets:	'	'
Assets at fair value	204	180
Certificate of Deposit | Level 2	'	'
Assets:	'	'
Assets at fair value	$204	$180

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Details)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair value of preferred stock warrant liability, probability of IPO scenario, percentage	20.00%
Fair value of preferred stock warrant liability, probability of merger scenario, percentage	10.00%
Fair value of preferred stock warrant liability, probability of stay private scenario, percentage	70.00%

Fair_Value_Measurements_Summar1

Fair Value Measurements - Summary of Changes in Estimated Fair Value of Preferred Stock Warrant Liability (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]	'
Net increase in fair value of warrant liabilities upon revaluation	$1,593
Fair Value, Recurring | Convertible preferred stock warrant liability	'
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]	'
Beginning balance	6,456
Net increase in fair value of warrant liabilities upon revaluation	1,593
Reclassification of warrant liability to additional paid-in capital	-8,049
Ending balance	$0

Collaboration_and_Licensing_Ag1

Collaboration and Licensing Agreements - Additional Information (Details) (USD $)

1 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

In Millions, unless otherwise specified

31-May-14

Oct. 31, 2012

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

31-May-14

Sep. 30, 2014

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

AstraZeneca

Sanofi

Sanofi

Future Development Milestones

Launch, Commercialization, and Sales Milestones

Amortization of Up-Front and Other License Fees

Amortization of Up-Front and Other License Fees

Amortization of Up-Front and Other License Fees

Amortization of Up-Front and Other License Fees

Collaborative Development Services

Collaborative Development Services

Collaborative Development Services

Collaborative Development Services

Revenue Recognition Multiple Deliverable Arrangements [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred Revenue, Additions

$25

$35

$15

'

'

'

'

'

'

'

'

'

'

'

'

'

Future potential payments to be received

'

'

'

795

197.5

597.5

'

'

'

'

'

'

'

'

'

196.8

Revenue recognized

'

'

'

'

'

'

4.8

2

13.3

6

2.8

4.6

10.8

14.5

1.25

'

Deferred revenue

'

'

$40.30

$51.40

'

'

'

'

'

'

'

'

'

'

'

'

Equity_Incentive_Plans_Additio

Equity Incentive Plans - Additional Information (Details) (USD $)

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

In Thousands, except Share data, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Dec. 31, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Jun. 18, 2014

Jun. 18, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Scenario, Forecast

Maximum

Minimum

2008 Stock Incentive Plan

2008 Stock Incentive Plan

2008 Stock Incentive Plan

2014 Equity Incentive Award Plan

2014 Employee Stock Purchase Plan

Restricted Stock

Maximum

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common shares authorized under stock incentive plan

'

'

'

'

'

'

'

'

'

2,149,021

'

'

'

'

'

Shares available for future grant

1,396,771

1,396,771

'

1,396,771

'

3,914

'

'

'

0

35,221

'

'

'

'

Common stock reserved

'

'

'

'

'

'

'

'

'

'

'

1,153,279

1,419,328

202,762

'

Shares remained available for issuance

'

'

'

'

'

'

'

'

'

'

'

'

1,454,549

'

'

Possible increase in shares reserved for issuance as percentage of outstanding stock

'

'

'

'

'

'

'

'

'

'

'

'

4.00%

1.00%

'

Increase in shares reserved for issuance, maximum shares to be issued up on exercise of stock options

'

'

'

'

'

'

'

'

'

'

'

'

10,683,053

2,230,374

'

Employee stock purchase plan initial offering commenced period

'

'

'

1-Sep-14

'

'

'

'

'

'

'

'

'

'

'

Employee stock purchase plan initial offering ending period

'

'

'

28-Feb-15

'

'

'

'

'

'

'

'

'

'

'

Number of shares issued under employee stock purchase plan

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average grant-date estimated fair value of options granted

'

'

$2.70

$10.96

$2.68

'

'

'

'

'

'

'

'

'

'

Estimated fair value of common stock

$14.21

$14.21

'

$14.21

'

'

'

'

'

'

'

'

'

'

'

Options Outstanding, Options granted

'

0

'

63,888

'

'

'

'

'

'

'

'

'

'

'

Common stock outstanding subject to repurchase

133,844

133,844

'

133,844

'

286,217

'

'

'

'

'

'

'

'

'

Liabilities related to early exercise of options

$72

$72

'

$72

'

$163

'

'

'

'

'

'

'

'

'

Repurchase price of common stock

'

'

'

'

'

'

'

$1.08

$0.27

'

'

'

'

'

'

Share-based award accelerated vesting number of shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

58,969

Stock-based compensation charge

'

203

'

'

'

'

633

'

'

'

'

'

'

'

'

Unrecognized stock based compensation expense

$1,000

$1,000

'

$1,000

'

$549

'

'

'

'

'

'

'

'

'

Unrecognized stock based compensation expense, weighted-average remaining recognition period

'

'

'

'1 year 4 months 24 days

'

'1 year 9 months 18 days

'

'

'

'

'

'

'

'

'

Equity_Incentive_Plans_Summary

Equity Incentive Plans - Summary of Activity Under 2008 Plan and 2014 Plan, Including Grants to Nonemployees and Restricted Stock Issued (Details) (USD $)	3 Months Ended	9 Months Ended			9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Jun. 18, 2014	Sep. 30, 2014
			2008 Stock Incentive Plan	2008 Stock Incentive Plan	2014 Equity Incentive Award Plan
Shares Available for Grant	'	'	'	'	'
Shares Available for Grant, Beginning balance	'	3,914	'	35,221	'
Shares Available for Grant, Options authorized	'	'	33,333	'	1,419,328
Shares Available for Grant, Options granted	0	-63,888	'	'	'
Shares Available for Grant, Options cancelled	'	4,084	'	'	'
Shares Available for Grant, Options exercised or lapsed	'	0	'	'	'
Shares Available for Grant, Ending balance	1,396,771	1,396,771	0	35,221	'
Options Outstanding	'	'	'	'	'
Options Outstanding, Beginning balance	'	1,162,829	'	'	'
Options Outstanding, Options authorized	'	'	0	'	0
Options Outstanding, Options granted	0	63,888	'	'	'
Options Outstanding, Options cancelled	'	-4,084	'	'	'
Options Outstanding, Options exercised or lapsed	'	-156,914	'	'	'
Options Outstanding, Ending balance	1,065,719	1,065,719	'	'	'
Options Outstanding, Vested	653,666	653,666	'	'	'
Options Outstanding, Expected to vest	1,065,719	1,065,719	'	'	'
Weighted Average Exercise Price per Share	'	'	'	'	'
Weighted Average Exercise Price per Share, Beginning balance	'	$1.03	'	'	'
Weighted Average Exercise Price per Share, Options granted	'	$13.95	'	'	'
Weighted Average Exercise Price per Share, Options cancelled	'	$2.21	'	'	'
Weighted Average Exercise Price per Share, Options exercised or lapsed	'	$0.61	'	'	'
Weighted Average Exercise Price per Share, Ending balance	$1.86	$1.86	'	'	'
Weighted Average Exercise Price per Share, Vested	$1.08	$1.08	'	'	'
Weighted Average Exercise Price per Share, Expected to vest	$1.86	$1.86	'	'	'
Aggregate Intrinsic Value	'	'	'	'	'
Aggregate Intrinsic Value, Ending balance	$13,162	$13,162	'	'	'
Aggregate Intrinsic Value, Vested	8,583	8,583	'	'	'
Aggregate Intrinsic Value, Expected to vest	$13,162	$13,162	'	'	'

Equity_Incentive_Plans_Summary1

Equity Incentive Plans - Summary of Stock-Based Compensation Recognized (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	$322	$89	$484	$279
Research and Development	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	240	57	314	156
General and Administrative	'	'	'	'
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation	$82	$32	$170	$123

Equity_Incentive_Plans_Summary2

Equity Incentive Plans - Summary of Weighted Average Assumptions to Estimate Fair value of Stock Option Awards (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]	'	'	'	'
Expected term (years)	'	'6 years 22 days	'5 years 9 months 15 days	'6 years 26 days
Volatility	'	99.00%	101.00%	98.00%
Risk-free interest rate	'	1.64%	1.77%	1.35%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Net_Income_Loss_per_Share_Attr2

Net Income (Loss) per Share Attributable to Common Stockholders - Computation of Unaudited Basic and Diluted Net Loss per Common Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net income (loss)	$74	($934)	$757	($2,295)
Noncumulative dividends on convertible preferred stock	'	'	-757	'
Net income (loss) attributable to common stockholders, basic and diluted	$74	($934)	'	($2,295)
Basic shares:	'	'	'	'
Weighted average common shares outstanding	18,374,277	1,156,446	7,476,642	1,100,885
Shares used to compute net income (loss) per share attributable to common stockholders:	'	'	'	'
Weighted average effect of dilutive stock options	758,940	'	'	'
Weighted Average Number of Shares Outstanding, Diluted	19,133,217	1,156,446	7,476,642	1,100,885
Net income (loss) per share attributable to common stockholders:	'	'	'	'
Basic	'	($0.81)	'	($2.08)
Diluted	'	($0.81)	'	($2.08)

Net_Income_Loss_per_Share_Attr3

Net Income (Loss) per Share Attributable to Common Stockholders - Antidilutive Common Stock Equivalents Excluded from Computation of Diluted Net Income (Loss) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share, shares	63,888	13,304,030	1,065,719	13,304,030
Convertible Preferred Stock	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share, shares	'	11,517,222	'	11,517,222
Options to Purchase Common Stock	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share, shares	63,888	1,211,855	1,065,719	1,211,855
Warrants to Purchase Convertible Preferred Stock	'	'	'	'
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive securities excluded from computation of earnings per share, shares	'	574,953	'	574,953

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Related Party Transactions [Abstract]	'	'	'	'	'
Research and development service expenses	$58	$60	$190	$186	'
Accounts payable	$19	'	$19	'	$18

Facility_Lease_Commitment_Addi

Facility Lease Commitment - Additional Information (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014
Leases [Abstract]	'
Lease expiration date	30-Sep-19
Lease improvement allowance maximum amount	$600
Amount provided lessor with irrevocable letter of credit	$104

Facility_Lease_Commitment_Sche

Facility Lease Commitment - Schedule of Future Minimum Payments Under the Noncancelable Operating Lease (Details) (USD $)	Sep. 30, 2014
In Thousands, unless otherwise specified
Leases [Abstract]	'
2014 (remaining three months)	$209
2015	843
2016	868
2017	895
2018	921
2019	653
Total	$4,389