Aimmune Therapeutics (AIMT) 10-Q 4 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	AIMT
Entity Registrant Name	AIMMUNE THERAPEUTICS, INC.
Entity Central Index Key	1,631,650
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		42,249,431

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 112,661	$ 2,269
Short-term investments	103,946
Prepaid expenses	1,180	106
Total current assets	217,787	2,375
Long-term investments	2,784
Property and equipment, net	1,829	87
Restricted cash	100	40
Other assets	314	29
Total assets	222,814	2,531
Current liabilities:
Accounts payable	1,014	478
Accrued liabilities	1,848	1,259
Other current liabilities	238	67
Total current liabilities	3,100	1,804
Other liabilities	826	56
Total liabilities	$ 3,926	$ 1,860
Commitments and contingencies (Note 5)
Stockholders’ equity:
Common stock, par value $0.0001 per share—50,046,000 and 32,925,000 shares authorized as of September 30, 2015 (unaudited) and December 31, 2014, respectively; 42,249,431 and 4,252,248 shares issued and outstanding as of September 30, 2015 (unaudited) and December 31, 2014, respectively (including 770,786 and 788,873 shares subject to repurchase, legally issued and outstanding as of September 30, 2015 (unaudited) and December 31, 2014, respectively)	$ 4
Additional paid-in capital	256,211	$ 1,260
Accumulated other comprehensive loss	(2)
Accumulated deficit	(37,325)	(17,517)
Total stockholders’ equity	218,888	671
Total liabilities and stockholders’ equity	$ 222,814	2,531
Series A Convertible Preferred Stock
Stockholders’ equity:
Convertible preferred stock		$ 16,928
Series B Convertible Preferred Stock
Stockholders’ equity:
Convertible preferred stock

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,046,000	32,925,000
Common stock, shares issued	42,249,431	4,252,248
Common stock, shares outstanding	42,249,431	4,252,248
Series A Convertible Preferred Stock
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	13,263,967
Preferred stock, shares issued	0	13,263,967
Preferred stock, shares outstanding	0	13,263,967
Preferred stock, liquidation preference	$ 0	$ 16,989
Series B Convertible Preferred Stock
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Preferred stock, liquidation preference	$ 0	$ 0
Common Stock Subject to Repurchase
Common stock, shares issued	770,786	788,873
Common stock, shares outstanding	770,786	788,873

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Operating expenses
Research and development	$ 3,850	$ 2,469	$ 9,050	$ 5,470
General and administrative	5,174	660	10,792	2,028
Total operating expenses	9,024	3,129	19,842	7,498
Loss from operations	(9,024)	(3,129)	(19,842)	(7,498)
Other income (expense), net
Interest income	33		34	12
Net loss	(8,991)	(3,129)	(19,808)	(7,486)
Other comprehensive loss, net of tax:
Unrealized losses on investments	(2)		(2)
Comprehensive loss	$ (8,993)	$ (3,129)	$ (19,810)	$ (7,486)
Net loss per common share, basic and diluted	$ (0.36)	$ (1.07)	$ (1.73)	$ (2.56)
Weighted average shares used in computing net loss per share, basic and diluted	25,149,428	2,926,665	11,446,922	2,926,665

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net loss	$ (19,808,000)	$ (7,486,000)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	60,000	15,000
Stock-based compensation	2,751,000	48,000
Investment premium amortization, net	57,000
Changes in operating assets and liabilities:
Prepaid expenses	(1,072,000)	(121,000)
Other assets	(285,000)	(3,000)
Accounts payable	536,000	586,000
Accrued liabilities	590,000	423,000
Other	73,000
Net cash used in operating activities	(17,098,000)	(6,538,000)
Cash flows from investing activities:
Purchase of property and equipment	(1,091,000)	(51,000)
Purchase of investments	(106,790,000)
Restricted cash	(60,000)	(40,000)
Net cash used in investing activities	(107,941,000)	(91,000)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	168,117,000
Net proceeds from issuance of Series B convertible preferred stock, net of issuance costs	79,779,000
Repurchase of Series A convertible preferred stock	(12,874,000)
Net cash proceeds from exercise of stock options, including early exercise	440,000
Repurchases of common stock subject to early exercise	(31,000)
Net cash provided by financing activities	235,431,000
Net increase (decrease) in cash and cash equivalents	110,392,000	(6,629,000)
Cash and cash equivalents at the beginning of the period	2,269,000	11,951,000
Cash and cash equivalents at the end of the period	112,661,000	$ 5,322,000
Supplemental schedule of non-cash investing and financing activities:
Capital expenditures and interest funded through long term lease obligation	711,000
Initial Public Offering
Supplemental schedule of non-cash investing and financing activities:
Conversion of convertible preferred stock to common stock at closing of initial public offering	$ 83,833,000

Formation and Business of the C

Formation and Business of the Company	9 Months Ended
	Sep. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Formation and Business of the Company	1. Formation and Business of the Company Aimmune Therapeutics, Inc. (“Aimmune Therapeutics” or the “Company”), formerly known as Allergen Research Corporation, is a clinical-stage biopharmaceutical company advancing a new therapeutic approach, including the development of proprietary candidates, for the treatment of peanut and other food allergies. The Company is headquartered in Brisbane, California and was incorporated in the state of Delaware on June 24, 2011. Since inception, the Company has incurred net losses and negative cash flows from operations. During the nine months ended September 30, 2015, the Company incurred a net loss of $19.8 million and used $17.1 million of cash in operations. As of September 30, 2015, the Company had an accumulated deficit of $37.3 million and the Company does not expect to experience positive cash flows in the near future. The Company has financed operations to date primarily through private placements of equity securities and its initial public offering (“IPO”) of common stock in August 2015. The Company’s ability to continue to meet its obligations and to achieve its business objectives is dependent upon a number of factors, which include raising additional capital, obtaining U.S. Food and Drug Administration (“FDA”) and European Medicines Agency (“EMA”) approval and commercializing in the United States and Europe, generating sufficient revenue and its ability to continue to control expenses, if necessary, to meet its obligations as they become due for the foreseeable future. Failure to obtain FDA and EMA approval, commercialize its lead product candidate, manage discretionary expenditures or raise additional financing, as required, may adversely impact the Company’s ability to achieve its intended business objectives. Initial Public Offering On August 5, 2015, the Company’s registration statement on Form S-1 (File No. 333-205501) relating to its IPO of common stock became effective. The IPO closed on August 11, 2015 at which time the Company issued 11,499,999 shares of its common stock at a price of $16.00 per share, which included 1,499,999 shares sold pursuant to the exercise of the underwriters’ option to purchase additional shares. The Company received proceeds of approximately $168 million, net of underwriting discounts and commissions, and offering expenses. In addition, upon the Company’s IPO, all outstanding shares of convertible preferred stock converted by their terms into approximately 25.1 million shares of common stock. As of September 30, 2015, the Company had 42,249,431 shares of common stock outstanding. See Note 6, “Stockholders’ Equity.” Stock Split On July 30, 2015, the Company effected a 1-for-1.317 stock split of the Company’s common stock and convertible preferred stock. The par value of the authorized stock was not adjusted as a result of the stock split. In addition, the Company increased the number of authorized shares of common stock to 55,051,264 and the number of authorized shares of preferred stock to 25,051,264. All issued and outstanding common stock, convertible preferred stock, stock options and per share amounts contained in the accompanying condensed consolidated financial statements and notes to the condensed consolidated financial statements have been retroactively adjusted to give effect to the stock split for all periods presented. In conjunction with the Company’s IPO, the Company filed its amended and restated certificate of incorporation that authorized 290,000,000 shares of common stock, $0.0001 par value per share, and 10,000,000 shares of preferred stock, $0.0001 par value per share.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Preparation The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2014 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These condensed consolidated financial statements have been prepared on the same basis as our annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair presentation of our financial information. The results of operations for the three and nine months ended September 30, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015 or for any other interim period or for any other future year. The company operates in one reportable segment. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2014 included in our Registration Statement on Form S-1 filed with the SEC. Basis of Consolidation The accompanying condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiary. All significant intercompany transactions have been eliminated. Use of Estimates The preparation of the accompanying condensed consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of costs and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results could differ from these estimates under different assumptions or conditions. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist primarily of money market funds and certain available-for-sale investments with maturities of three months or less. Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents and certain investments in money market funds, agency securities, corporate securities, and commercial paper. Bank deposits are primarily held by a single financial institution and these deposits may exceed insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash and cash equivalents and issuers of investments that are recorded on the condensed consolidated balance sheets. The Company mitigates its risk by investing in high-grade instruments and limiting the concentration in any one issuer, which limits the Company’s exposure. Investments The Company’s available-for-sale investments consist primarily of . Investments with original maturities of greater than 90 days but less than one (1) year are classified as short-term available-for-sale securities on the condensed consolidated balance sheets. Investments with original maturities greater than one (1) year are classified as long-term available-for-sale securities on the condensed consolidated balance sheets. The Company’s investments in available-for-sale securities are reported at fair value. Unrealized gains and losses related to changes in the fair value of securities are recognized in accumulated other comprehensive loss, net of tax, on our condensed consolidated balance sheets. Changes in the fair value of available-for-sale securities impact the statements of operations only when such securities are sold or an other-than-temporary impairment is recognized. Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis. The Company regularly reviews its investment portfolio to determine if any security is other-than-temporarily impaired, which would require us to record an impairment charge in the period any such determination is made. In making this judgment, the Company evaluates, among other things, the duration and extent to which the fair value of a security is less than its cost, the financial condition of the issuer and any changes thereto, and its intent to sell, or whether it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis. The Company’s assessment on whether a security is other-than-temporarily impaired could change in the future due to new developments or changes in assumptions related to any particular security. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the respective assets. Maintenance and repairs are charged to operations as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss, if any, is reflected in operations. The useful lives of property and equipment are as follows: Furniture and office equipment 4 years Computer equipment 3 years Buildings 25 years Fixtures 10 years Impairment of Long-Lived Assets The Company evaluates its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. Recoverability of these assets is measured by comparison of the carrying amount of each asset to the future undiscounted cash flows expected to result from the use of the asset and its eventual disposition. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired assets. The Company has not recorded impairment of any long-lived assets in the periods presented. Leases The Company entered into lease agreements for its previous corporate headquarters in San Mateo, California through July 2017. In March 2015, the Company entered into a lease for its current corporate headquarters in Brisbane, California. In May 2015, the Company ceased use of its San Mateo facility and moved into its current facility. In August 2015, the Company entered into an amendment to the Brisbane, California facility lease. Pursuant to the amendment, the Company will lease an additional 11,655 square feet of office space, and the term of the existing office space has been extended so that it is coterminous with the new space. These leases are classified as operating leases. Rent expense is recognized on a straight-line basis over the terms of the leases and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. Incentives granted under the Company’s facilities leases are deferred and recognized as adjustments to rental expense on a straight-line basis over the term of the lease. In June 2015, the Company signed a lease for a manufacturing facility in Clearwater, Florida. The Company was considered the deemed owner for accounting purposes. See Note 5, “Commitments and Contingencies.” Research and Development The Company expenses research and development costs as incurred. The Company records accrued liabilities for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of pre-clinical studies and clinical trials and contract manufacturing activities. These costs are a significant component of the Company’s research and development expenses. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers under the service agreements. The Company makes significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled and the rate of patient enrollments may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. Stock-based Compensation Stock-based awards issued to employees, including stock options, are measured at fair value on the grant date using the Black-Scholes option-pricing model and recognized as expense on a straight-line basis over the employee’s requisite service period (generally the vesting period). Because noncash stock compensation expense is based on awards ultimately expected to vest, it is reduced by an estimate for future forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from estimates. There were 3,980,328 and 1,635,679 stock options granted during the nine months ended September 30, 2015 and 2014, respectively. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of reported assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company has adopted Financial Accounted Standards Board Accounting Standards Codification 740, Income Taxes, regarding how uncertain tax positions should be recognized, measured, presented, and disclosed in the financial statements. As of September 30, 2015 and Comprehensive Income or Loss Comprehensive income or loss is defined as the change in equity during a period from transactions and other events, excluding changes resulting from investments from owners and distributions to owners. Other comprehensive loss includes net loss and unrealized losses on available-for-sale investments. Offering Costs Offering costs represent underwriting, legal, accounting and other direct costs related to the Company’s IPO. These costs were deferred until completion of the IPO, at which time they were reclassified to additional paid-in capital as a reduction of the proceeds. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or FASB, issued Auditing Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers (Topic 606) In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The carrying amounts of certain of the Company’s financial instruments, including cash equivalents and accounts payable approximated their fair values due to their short maturities. Assets and liabilities recorded at fair value on a recurring basis in the balance sheets, as well as assets and liabilities measured at fair value on a non-recurring basis or disclosed at fair value, are categorized based upon the level of judgment associated with inputs used to measure their fair values. The accounting guidance for fair value provide a framework for measuring fair value, and requires certain 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 —Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 —Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 —Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. The Company’s valuation techniques used to measure the fair value of money market funds and certain marketable equity securities were derived from quoted prices in active markets for identical assets or liabilities. The valuation techniques used to measure the fair value of the Company’s debt instruments and all other financial instruments, all of which have counterparties with high credit ratings, were valued based on quoted market prices or model driven valuations using significant inputs derived from or corroborated by observable market data. In accordance with fair value accounting requirements, companies may choose to measure eligible financial instruments and certain other items at fair value. The Company has not elected the fair value option for any eligible financial instruments. The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): September 30, 2015 (unaudited) Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 61,417 $ — $ — $ 61,417 Agency securities — 12,999 — 12,999 Corporate securities — 8,250 — 8,250 Commercial paper — 29,995 — 29,995 Total cash and cash equivalents $ 61,417 $ 51,244 $ — $ 112,661 Available-for-sale investments: Agency securities $ — $ 37,905 $ — $ 37,905 Corporate securities — 41,851 — 41,851 Commercial paper — 26,974 — 26,974 Total available-for-sale investments $ — $ 106,730 $ — $ 106,730 December 31, 2014 Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 2,269 $ — $ — $ 2,269 Agency securities — — — — Corporate securities — — — — Commercial paper — — — — Total cash and cash equivalents $ 2,269 $ — $ — $ 2,269 Available-for-sale investments: Agency securities $ — $ — $ — $ — Corporate securities — — — — Commercial paper — — — — Total available-for-sale investments $ — $ — $ — $ — Available-for-sale investments are carried at fair value and are included in the tables above. The aggregate market value, cost basis, and gross unrealized gains and losses of available-for-sale investments by security type, classified in cash equivalents, short-term investments, and long-term investments, as of September 30, 2015 are as follows (in thousands): Amortized Cost Gross unrealized gains Gross unrealized losses Total fair value Agency securities $ 50,889 $ 15 $ — $ 50,904 Corporate securities 50,118 9 (26 ) 50,101 Commercial paper 56,969 — — 56,969 Total available-for-sale investments $ 157,976 $ 24 $ (26 ) $ 157,974 There were no available-for-sale investments as of December 31, 2014. There were no gross realized gains or losses on sales of available-for-sale securities for the nine months ended September 30, 2015. The net adjustment to unrealized holding gains (losses) on available-for-sale securities included in other comprehensive loss totaled approximately $2,000 for the nine months ended September 30, 2015. Contractual maturities of debt investment securities as of September 30, 2015 are as follows (in thousands): Total Fair Value Maturing within one year $ 103,946 Maturing in one to five years 2,784 Total available-for-sale investments $ 106,730 There were no investment securities as of December 31, 2014. Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties. At each reporting date, the Company performs separate evaluations of impaired debt securities to determine if the unrealized losses are other-than-temporary. For debt securities, management determines whether it intends to sell or if it is more likely than not that it will be required to sell impaired securities. This determination considers current and forecasted liquidity requirements, regulatory and capital requirements and securities portfolio management. For all impaired debt securities for which there was no intent or expected requirement to sell, the evaluation considers all available evidence to assess whether it is likely the amortized cost value will be recovered. The Company conducts a regular assessment of its debt securities with unrealized losses to determine whether securities have other-than-temporary impairment considering, among other factors, the nature of the securities, credit rating or financial condition of the issuer, the extent and duration of the unrealized loss, expected cash flows of underlying collateral, market conditions and whether the Company intends to sell or it is more likely than not the Company will be required to sell the debt securities. Based on the Company’s analysis, the Company did not identify any other-than-temporary losses for the nine months ended September 30, 2015. The Company does not consider unrealized losses on its other debt securities to be credit-related. These unrealized losses relate to changes in interest rates and market spreads subsequent to purchase. A substantial portion of securities that have unrealized losses are US corporate securities that are highly-rated. The Company has not made a decision to sell securities with unrealized losses and believes it is more likely than not it would not be required to sell such securities before recovery of its amortized cost.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance Sheet Components Property and Equipment, Net Property and equipment, net consists of the following (in thousands): September 30, December (unaudited) Furniture and equipment $ 219 $ 58 Computer equipment 254 67 Construction in progress 1,454 — Property and equipment, gross 1,927 125 Less: accumulated depreciation (98 ) (38 ) Property and equipment, net $ 1,829 $ 87 Depreciation expense for the three months ended September 30, 2015 and 2014 was $30,000 and $9,000, respectively, and for the nine months ended September 30, 2015 and 2014, was $60,000 and $15,000, respectively. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): September 30, 2015 December (unaudited) Compensation and benefits $ 896 $ 645 Research and development 281 542 Professional and consulting 657 71 Other 14 1 Total $ 1,848 $ 1,259

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	5. Commitments and Contingencies Facility Leases In May 2015, the Company ceased use of its previous corporate headquarters and accrued a liability for approximately $121,000 as of June 30, 2015, net of estimated sublease payments. In September 2015, the Company revised its estimate for actual sublease payments which resulted in a complete reduction of the liability previously accrued. The reduction of the liability is reflected within rent expense for the period ended September 30, 2015. In March 2015, the Company signed a new facility lease for its corporate headquarters in Brisbane, California. The new lease, which has been classified as an operating lease, commenced on May 1, 2015 with an initial term of 51 months. In August 2015, the Company entered into an amendment to the lease. The amendment required a total security deposit of approximately $304,000. of the commencement of the amendment, future aggregate minimum lease payments for the combined space are as follows (in thousands): Year Ended December 31, 2015 $ 190 2016 1,010 2017 1,602 2018 1,650 and after 5,265 Total $ 9,717 The Company is responsible for operating expenses over base operating expenses as defined in the headquarters lease agreement. In June 2015, the Company signed a facility lease for a manufacturing facility in Clearwater, Florida. The initial term is Year Ended December 31, 2015 $ 38 2016 151 2017 156 2018 160 and after 1,198 Total $ 1,703 The Company is responsible for operating expenses including real estate taxes as defined in the manufacturing facility lease agreement. Rent expense under operating leases for the three months ended September 30, 2015 and 2014 was $87,000 and $41,000, respectively, and for the nine months ended September 30, 2015 and 2014 was $342,000 and $90,000, respectively. Purchase Commitments The Company purchases peanut flour, the source material for AR101, from the Golden Peanut Company pursuant to a long term exclusive commercial supply agreement. Pursuant to the agreement, the Company’s purchase obligation commences with the first delivery of peanut flour for commercial use, which it currently anticipates will not occur prior to 2018. Assuming the Company starts its purchase obligation of peanut flour for commercial use in 2018, which is not assured, the aggregate purchase commitment under this agreement is $1.2 million over a term of five years. Indemnifications The Company indemnifies each of its officers and directors for certain events or occurrences, subject to certain limits, while the officer or director is or was serving at the Company’s request in such capacity, as permitted under Delaware law and in accordance with its certificate of incorporation and bylaws. The term of the indemnification period lasts as long as an officer or a director may be subject to any proceeding arising out of acts or omissions of such officer or director in such capacity. The maximum amount of potential future indemnification is unlimited; however, the Company currently holds director and officer liability insurance. This insurance allows the transfer of risk associated with the Company’s exposure and may enable it to recover a portion of any future amounts paid. The Company believes that the fair value of these indemnification obligations is minimal. Accordingly, it has not recognized any liabilities relating to these obligations for any period. Legal During the normal course of business, the Company may be a party to legal claims that may not be covered by insurance. Management does not believe that any such claims would have a material impact on the Company’s consolidated financial statements.

Stock-based Awards

Stock-based Awards	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Awards	6. Stock-based Awards In January 2013, the Company adopted its Stock Plan (the “2013 Plan”) and in July 2015, the Company adopted a new Stock Plan (the “2015 Plan”). 4,681,544 shares of the Company’s common stock are initially reserved under the 2015 Plan for the issuance of stock options and restricted stock to employees, directors, and consultants under terms and provisions established by the Board of Directors and approved by the Company’s stockholders. Upon consummation of the Company’s IPO, the 2013 Plan was terminated and no further shares are reserved for issuance under the 2013 Plan. As of September 30, 2015 and and 639,625 and th th th The 2013 Plan allowed employees to exercise a stock option in exchange for cash before the requisite service is provided (e.g., before the award is vested under its original terms); however, such arrangements permit the Company to subsequently repurchase such shares at the exercise price if the vesting conditions are not satisfied. Such an exercise is not substantive for accounting purposes. Therefore, the payment received by the Company for the exercise price is recognized as an early exercise liability on the balance sheets and will be transferred to common stock and additional paid-in capital as such shares vest. As of September 30, 2015 and Activity under the Plan is set forth below: Options Outstanding Shares Available for Grant Number Options and Unvested Shares Weighted- Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Balance, December 31, 2014 639,625 2,566,559 $ 0.14 9.19 Additional shares authorized 7,908,194 Shares retired upon adoption of 2015 Plan (230,978 ) Options granted (3,980,328 ) 3,980,328 $ 5.47 Options exercised and shares vested (1,464,016 ) $ 0.16 Options repurchased 211,793 (211,793 ) $ 0.14 Options cancelled — — Balances – September 30, 2015 4,548,306 4,871,078 $ 4.49 9.59 $ 101,441 Options vested and expected to vest as of September 30, 2015 (unaudited) 4,489,667 $ 4.73 9.17 $ 92,439 Options exercisable as of September 30, 2015 (unaudited) 3,967,049 $ 4.82 9.59 $ 81,316 The aggregate intrinsic values of options outstanding, exercisable, and vested and expected to vest were calculated as the difference between the exercise price of the options and the market price for shares of the Company’s common stock as of September 30, 2015. The 2013 Plan provided for early exercise, therefore, all the Company’s outstanding stock options issued under that plan are exercisable. Stock Options Granted Stock options granted during the three months ended September 30, 2015 and 2014 had a weighted-average grant-date fair value of $11.05and $0.09, respectively. Stock options granted during the nine months ended September 30, 2015 and 2014 had a weighted-average grant-date fair value of $5.77 and $0.09, respectively. The fair value is being expensed over the vesting period of the options, which is either four years or two years on a straight-line basis as the services are being provided. No tax benefits were realized from options during the periods. The Company issued one grant totaling 213,354 options to a non-employee during the three and nine-months ended September 30, 2015. The fair value of the non-employee options was measured using the Black-Scholes option-pricing model reflecting the same assumptions as applied to employee options, other than the expected life, which is assumed to be the remaining contractual life of the option. As of September 30, 2015 and and $120,000, The fair value of employee stock options was estimated using the Black-Scholes pricing model, with the following weighted-average assumptions (unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected volatility 71.22 % 79.62 % 74.47 % 79.62 % Risk free interest rate 1.79 % 1.51 % 1.72 % 1.51 % Dividend yield — — — — Expected term (in years) 5.95 4.65 5.98 4.65 Determining Fair Value of Stock Options The fair value of each grant of stock options was determined by the Company using the methods and assumptions discussed below. The determination of each of these inputs is subjective and generally requires significant judgment. Expected volatility —The expected stock price volatility assumption was determined by examining the historical volatilities of a group of industry peers, as the Company did not have any trading history for the Company’s common stock. The Company will continue to analyze the historical stock price volatility and expected term assumptions as more historical data for the Company’s common stock becomes available. Expected term —The expected term of stock options represents the weighted average period the stock options are expected to be outstanding. The Company’s option grants are considered “plain vanilla.” Therefore, the Company has opted to use the simplified method for estimating the expected term as provided by the Securities and Exchange Commission. The simplified method calculates the expected term as the average time- to-vesting and the contractual life of the options. Expected dividend —The expected dividend assumption was based on the Company’s history and expectation that it will not declare dividend payout for the near future. Risk-free interest rate —The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected terms. Fair value of common stock —Prior to the Company’s IPO, the fair value of the shares of common stock underlying the stock options was the responsibility of and determined by the Company’s board of directors. Because there was no public market for the Company’s common stock, the board of directors determined fair value of common stock at the time of grant of the option by considering a number of objective and subjective factors including independent third-party valuations of the Company’s common stock, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the lack of liquidity of capital stock and general and industry specific economic outlook, amongst other factors. Following the IPO, the market traded price of the shares of common stock underlying the stock options is the fair value of the Company’s stock as reported on the NASDAQ Global Select Market on the grant date. Stock-based compensation expense, net of estimated forfeitures, is reflected in the statements of operations (in thousands, unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Research and development $ 300 $ 5 $ 396 $ 14 General and administrative 1,462 12 2,355 34 Total stock-based compensation expense $ 1,762 $ 17 $ 2,751 $ 48 During the three and nine months ended September 30, 2015, the Company recorded $0 and approximately $562,000 of stock compensation expense related to the acceleration of certain former executives’ stock options.

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Loss per Share	7. Net Loss per Share The following table sets forth the computation of the Company’s basic and diluted net loss per share during the three and nine months ended September 30, 2015 and 2014(in thousands, except share and per share data, unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Numerator: Net loss $ (8,991 ) $ (3,129 ) $ (19,808 ) $ (7,486 ) Denominator: Shares used in computing net loss per share, basic and diluted 25,149,428 2,926,665 11,446,922 2,926,665 Net loss per share basic and diluted $ (0.36 ) $ (1.07 ) $ (1.73 ) $ (2.56 ) The following common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because their inclusion would have been antidilutive (unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Convertible preferred stock 11,436,443 13,263,967 22,289,679 13,263,967 Stock options 1,198,209 3,501,939 4,871,078 3,501,939

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Events	8. Subsequent Events Executive Retirement On October 6, 2015, the Company’s Chief Operating Officer informed the Company of his decision to retire from his position effective October 31, 2015. In connection with his separation from the Company, the Company entered into a transition and separation agreement whereby he has agreed to provide transition consulting services to the Company through October 31, 2016, on an as needed basis. In addition, he will receive nine months of his base salary, company subsidized COBRA coverage until the earlier of the end of July 31, 2016 or the date on which he becomes eligible for coverage by another employer, and accelerated vesting of his outstanding equity awards that would have vested had he continued to provide service to the Company for the six (6)-month period following his termination date. His outstanding equity awards will continue to vest in accordance to their terms after giving effect to the accelerated vesting while he provides consulting services to the Company. The Company did not record any termination charges during the nine months ended September 30, 2015 related to the retirement

Summary of Significant Accoun14

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Basis of Preparation	Basis of Preparation The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted, and accordingly the balance sheet as of December 31, 2014 has been derived from audited consolidated financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. These condensed consolidated financial statements have been prepared on the same basis as our annual financial statements and, in the opinion of management, reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair presentation of our financial information. The results of operations for the three and nine months ended September 30, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015 or for any other interim period or for any other future year. The company operates in one reportable segment. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2014 included in our Registration Statement on Form S-1 filed with the SEC.
Basis of Consolidation	Basis of Consolidation The accompanying condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiary. All significant intercompany transactions have been eliminated.
Use of Estimates	Use of Estimates The preparation of the accompanying condensed consolidated financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the reported amounts of costs and expenses during the reporting period. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results could differ from these estimates under different assumptions or conditions.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist primarily of money market funds and certain available-for-sale investments with maturities of three months or less.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents and certain investments in money market funds, agency securities, corporate securities, and commercial paper. Bank deposits are primarily held by a single financial institution and these deposits may exceed insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash and cash equivalents and issuers of investments that are recorded on the condensed consolidated balance sheets. The Company mitigates its risk by investing in high-grade instruments and limiting the concentration in any one issuer, which limits the Company’s exposure.
Investments	Investments The Company’s available-for-sale investments consist primarily of . Investments with original maturities of greater than 90 days but less than one (1) year are classified as short-term available-for-sale securities on the condensed consolidated balance sheets. Investments with original maturities greater than one (1) year are classified as long-term available-for-sale securities on the condensed consolidated balance sheets. The Company’s investments in available-for-sale securities are reported at fair value. Unrealized gains and losses related to changes in the fair value of securities are recognized in accumulated other comprehensive loss, net of tax, on our condensed consolidated balance sheets. Changes in the fair value of available-for-sale securities impact the statements of operations only when such securities are sold or an other-than-temporary impairment is recognized. Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis. The Company regularly reviews its investment portfolio to determine if any security is other-than-temporarily impaired, which would require us to record an impairment charge in the period any such determination is made. In making this judgment, the Company evaluates, among other things, the duration and extent to which the fair value of a security is less than its cost, the financial condition of the issuer and any changes thereto, and its intent to sell, or whether it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis. The Company’s assessment on whether a security is other-than-temporarily impaired could change in the future due to new developments or changes in assumptions related to any particular security.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the respective assets. Maintenance and repairs are charged to operations as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss, if any, is reflected in operations. The useful lives of property and equipment are as follows: Furniture and office equipment 4 years Computer equipment 3 years Buildings 25 years Fixtures 10 years
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. Recoverability of these assets is measured by comparison of the carrying amount of each asset to the future undiscounted cash flows expected to result from the use of the asset and its eventual disposition. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired assets. The Company has not recorded impairment of any long-lived assets in the periods presented.
Leases	Leases The Company entered into lease agreements for its previous corporate headquarters in San Mateo, California through July 2017. In March 2015, the Company entered into a lease for its current corporate headquarters in Brisbane, California. In May 2015, the Company ceased use of its San Mateo facility and moved into its current facility. In August 2015, the Company entered into an amendment to the Brisbane, California facility lease. Pursuant to the amendment, the Company will lease an additional 11,655 square feet of office space, and the term of the existing office space has been extended so that it is coterminous with the new space. These leases are classified as operating leases. Rent expense is recognized on a straight-line basis over the terms of the leases and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. Incentives granted under the Company’s facilities leases are deferred and recognized as adjustments to rental expense on a straight-line basis over the term of the lease. In June 2015, the Company signed a lease for a manufacturing facility in Clearwater, Florida. The Company was considered the deemed owner for accounting purposes. See Note 5, “Commitments and Contingencies.”
Research and Development	Research and Development The Company expenses research and development costs as incurred. The Company records accrued liabilities for estimated costs of research and development activities conducted by third-party service providers, which include the conduct of pre-clinical studies and clinical trials and contract manufacturing activities. These costs are a significant component of the Company’s research and development expenses. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with its third-party service providers under the service agreements. The Company makes significant judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred. However, the status and timing of actual services performed, number of patients enrolled and the rate of patient enrollments may vary from the Company’s estimates, resulting in adjustments to expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations.
Stock-based Compensation	Stock-based Compensation Stock-based awards issued to employees, including stock options, are measured at fair value on the grant date using the Black-Scholes option-pricing model and recognized as expense on a straight-line basis over the employee’s requisite service period (generally the vesting period). Because noncash stock compensation expense is based on awards ultimately expected to vest, it is reduced by an estimate for future forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from estimates. There were 3,980,328 and 1,635,679 stock options granted during the nine months ended September 30, 2015 and 2014, respectively.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of reported assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company has adopted Financial Accounted Standards Board Accounting Standards Codification 740, Income Taxes, regarding how uncertain tax positions should be recognized, measured, presented, and disclosed in the financial statements. As of September 30, 2015 and
Comprehensive Income or Loss	Comprehensive Income or Loss Comprehensive income or loss is defined as the change in equity during a period from transactions and other events, excluding changes resulting from investments from owners and distributions to owners. Other comprehensive loss includes net loss and unrealized losses on available-for-sale investments.
Offering Costs	Offering Costs Offering costs represent underwriting, legal, accounting and other direct costs related to the Company’s IPO. These costs were deferred until completion of the IPO, at which time they were reclassified to additional paid-in capital as a reduction of the proceeds.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or FASB, issued Auditing Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers (Topic 606) In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.

Summary of Significant Accoun15

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Schedule of Useful Lives of Property and Equipment	The useful lives of property and equipment are as follows: Furniture and office equipment 4 years Computer equipment 3 years Buildings 25 years Fixtures 10 years

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured at Fair Value on a Recurring Basis	The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): September 30, 2015 (unaudited) Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 61,417 $ — $ — $ 61,417 Agency securities — 12,999 — 12,999 Corporate securities — 8,250 — 8,250 Commercial paper — 29,995 — 29,995 Total cash and cash equivalents $ 61,417 $ 51,244 $ — $ 112,661 Available-for-sale investments: Agency securities $ — $ 37,905 $ — $ 37,905 Corporate securities — 41,851 — 41,851 Commercial paper — 26,974 — 26,974 Total available-for-sale investments $ — $ 106,730 $ — $ 106,730 December 31, 2014 Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 2,269 $ — $ — $ 2,269 Agency securities — — — — Corporate securities — — — — Commercial paper — — — — Total cash and cash equivalents $ 2,269 $ — $ — $ 2,269 Available-for-sale investments: Agency securities $ — $ — $ — $ — Corporate securities — — — — Commercial paper — — — — Total available-for-sale investments $ — $ — $ — $ —
Summary of Aggregate Market Value, Cost Basis, and Gross Unrealized Gains and Losses of Short Term Available for Sale Investments by Security Type	The aggregate market value, cost basis, and gross unrealized gains and losses of available-for-sale investments by security type , classified in cash equivalents, short-term investments, and long-term investments, as of September 30, 2015 are as follows (in thousands) Amortized Cost Gross unrealized gains Gross unrealized losses Total fair value Agency securities $ 50,889 $ 15 $ — $ 50,904 Corporate securities 50,118 9 (26 ) 50,101 Commercial paper 56,969 — — 56,969 Total available-for-sale investments $ 157,976 $ 24 $ (26 ) $ 157,974
Summary of Contractual Maturities of Debt Investment Securities	Contractual maturities of debt investment securities as of September 30, 2015 are as follows (in thousands): Total Fair Value Maturing within one year $ 103,946 Maturing in one to five years 2,784 Total available-for-sale investments $ 106,730

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Summary of Property And Equipment, Net	Property and equipment, net consists of the following (in thousands): September 30, December (unaudited) Furniture and equipment $ 219 $ 58 Computer equipment 254 67 Construction in progress 1,454 — Property and equipment, gross 1,927 125 Less: accumulated depreciation (98 ) (38 ) Property and equipment, net $ 1,829 $ 87
Summary of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): September 30, 2015 December (unaudited) Compensation and benefits $ 896 $ 645 Research and development 281 542 Professional and consulting 657 71 Other 14 1 Total $ 1,848 $ 1,259

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Headquarters
Schedule of Future Aggregate Minimum Lease Payments	As of the commencement of the amendment, future aggregate minimum lease payments for the combined space are as follows (in thousands): Year Ended December 31, 2015 $ 190 2016 1,010 2017 1,602 2018 1,650 and after 5,265 Total $ 9,717
Manufacturing Facility
Schedule of Future Aggregate Minimum Lease Payments	The new lease calls for future aggregate minimum lease payments as of the commencement of the lease as follows (in thousands): Year Ended December 31, 2015 $ 38 2016 151 2017 156 2018 160 and after 1,198 Total $ 1,703

Stock-based Awards (Tables)

Stock-based Awards (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	Activity under the Plan is set forth below: Options Outstanding Shares Available for Grant Number Options and Unvested Shares Weighted- Average Exercise Price Weighted Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Balance, December 31, 2014 639,625 2,566,559 $ 0.14 9.19 Additional shares authorized 7,908,194 Shares retired upon adoption of 2015 Plan (230,978 ) Options granted (3,980,328 ) 3,980,328 $ 5.47 Options exercised and shares vested (1,464,016 ) $ 0.16 Options repurchased 211,793 (211,793 ) $ 0.14 Options cancelled — — Balances – September 30, 2015 4,548,306 4,871,078 $ 4.49 9.59 $ 101,441 Options vested and expected to vest as of September 30, 2015 (unaudited) 4,489,667 $ 4.73 9.17 $ 92,439 Options exercisable as of September 30, 2015 (unaudited) 3,967,049 $ 4.82 9.59 $ 81,316
Schedule of Fair Value of Employee Stock Options Estimated with Weighted-Average Assumptions	The fair value of employee stock options was estimated using the Black-Scholes pricing model, with the following weighted-average assumptions (unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Expected volatility 71.22 % 79.62 % 74.47 % 79.62 % Risk free interest rate 1.79 % 1.51 % 1.72 % 1.51 % Dividend yield — — — — Expected term (in years) 5.95 4.65 5.98 4.65
Summary of Stock-based Compensation Expense Net of Estimated Forfeitures	Stock-based compensation expense, net of estimated forfeitures, is reflected in the statements of operations (in thousands, unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Research and development $ 300 $ 5 $ 396 $ 14 General and administrative 1,462 12 2,355 34 Total stock-based compensation expense $ 1,762 $ 17 $ 2,751 $ 48

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net loss Per Share	The following table sets forth the computation of the Company’s basic and diluted net loss per share during the three and nine months ended September 30, 2015 and 2014(in thousands, except share and per share data, unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Numerator: Net loss $ (8,991 ) $ (3,129 ) $ (19,808 ) $ (7,486 ) Denominator: Shares used in computing net loss per share, basic and diluted 25,149,428 2,926,665 11,446,922 2,926,665 Net loss per share basic and diluted $ (0.36 ) $ (1.07 ) $ (1.73 ) $ (2.56 )
Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss per Share	The following common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because their inclusion would have been antidilutive (unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Convertible preferred stock 11,436,443 13,263,967 22,289,679 13,263,967 Stock options 1,198,209 3,501,939 4,871,078 3,501,939

Formation and Business of the21

Formation and Business of the Company - Additional Information (Details) $ / shares in Units, $ in Thousands	Aug. 11, 2015USD ($)$ / sharesshares	Jul. 30, 2015shares	Sep. 30, 2015USD ($)$ / sharesshares	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)$ / sharesshares	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)$ / sharesshares
Organization And Description Of Business [Line Items]
Net loss | $			$ 8,991	$ 3,129	$ 19,808	$ 7,486
Net cash used in operating activities | $					17,098	$ 6,538
Accumulated deficit | $			$ 37,325		$ 37,325		$ 17,517
Proceeds from initial public offering, net of underwriting discount and commissions | $	$ 168,000
Common stock, shares outstanding			42,249,431		42,249,431		4,252,248
Description of stock split					On July 30, 2015, the Company effected a 1-for-1.317 stock split of the Company’s common stock and convertible preferred stock.
Stock split conversion ratio		0.7593
Common stock, shares authorized		55,051,264	50,046,000		50,046,000		32,925,000
Preferred stock, shares authorized		25,051,264
Common stock, par value | $ / shares			$ 0.0001		$ 0.0001		$ 0.0001
IPO
Organization And Description Of Business [Line Items]
Common stock, shares issued	11,499,999
Common stock issued price per share | $ / shares	$ 16
Shares issued pursuant to exercise of underwriters' option	1,499,999
Outstanding shares of convertible preferred stock converted into common stock	25,100,000
Common stock, shares outstanding			42,249,431		42,249,431
Common stock, shares authorized	290,000,000
Preferred stock, shares authorized	10,000,000
Common stock, par value | $ / shares	$ 0.0001
Preferred stock, par value | $ / shares	$ 0.0001

Summary of Significant Accoun22

Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)Segmentshares	Sep. 30, 2014USD ($)shares	Aug. 31, 2015ft²	Dec. 31, 2014USD ($)
Accounting Policies [Abstract]
Number of reportable segments | Segment			1
Impairment of any long lived assets	$ 0	$ 0	$ 0	$ 0
Additional lease area for office space | ft²					11,655
Stock options granted | shares			3,980,328	1,635,679
Unrecognized tax benefits	$ 0		$ 0			$ 0

Summary of Significant Accoun23

Summary of Significant Accounting Policies - Schedule of Useful Lives of Property and Equipment (Details)	9 Months Ended
	Sep. 30, 2015
Furniture And Office Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	4 years
Computer Equipment
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	3 years
Buildings
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	25 years
Fixtures
Property Plant And Equipment [Line Items]
Useful lives of property and equipment	10 years

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Available-for-sale investments
Total available-for-sale investments		$ 0
Fair Value Measurements Recurring
Cash and cash equivalents
Total cash and cash equivalents	$ 112,661,000
Available-for-sale investments
Total available-for-sale investments	106,730,000
Fair Value Measurements Recurring | Commercial Paper
Cash and cash equivalents
Total cash and cash equivalents	29,995,000
Available-for-sale investments
Total available-for-sale investments	26,974,000
Fair Value Measurements Recurring | Corporate Debt Securities
Cash and cash equivalents
Total cash and cash equivalents	8,250,000
Available-for-sale investments
Total available-for-sale investments	41,851,000
Fair Value Measurements Recurring | Agency Securities
Cash and cash equivalents
Total cash and cash equivalents	12,999,000
Available-for-sale investments
Total available-for-sale investments	37,905,000
Fair Value Measurements Recurring | Cash and money market funds
Cash and cash equivalents
Total cash and cash equivalents	61,417,000
Fair Value Measurements Recurring | Level 1
Cash and cash equivalents
Total cash and cash equivalents	61,417,000
Fair Value Measurements Recurring | Level 1 | Cash and money market funds
Cash and cash equivalents
Total cash and cash equivalents	61,417,000
Fair Value Measurements Recurring | Level 2
Cash and cash equivalents
Total cash and cash equivalents	51,244,000
Available-for-sale investments
Total available-for-sale investments	106,730,000
Fair Value Measurements Recurring | Level 2 | Commercial Paper
Cash and cash equivalents
Total cash and cash equivalents	29,995,000
Available-for-sale investments
Total available-for-sale investments	26,974,000
Fair Value Measurements Recurring | Level 2 | Corporate Debt Securities
Cash and cash equivalents
Total cash and cash equivalents	8,250,000
Available-for-sale investments
Total available-for-sale investments	41,851,000
Fair Value Measurements Recurring | Level 2 | Agency Securities
Cash and cash equivalents
Total cash and cash equivalents	12,999,000
Available-for-sale investments
Total available-for-sale investments	$ 37,905,000
Fair Value Measurements Nonrecurring
Cash and cash equivalents
Total cash and cash equivalents		2,269,000
Fair Value Measurements Nonrecurring | Cash and money market funds
Cash and cash equivalents
Total cash and cash equivalents		2,269,000
Fair Value Measurements Nonrecurring | Level 1
Cash and cash equivalents
Total cash and cash equivalents		2,269,000
Fair Value Measurements Nonrecurring | Level 1 | Cash and money market funds
Cash and cash equivalents
Total cash and cash equivalents		$ 2,269,000

Fair Value Measurements - Sum25

Fair Value Measurements - Summary of Aggregate Market Value, Cost Basis, and Gross Unrealized Gains and Losses of Short Term Available for Sale Investments by Security Type (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale investments		$ 0
Cash Equivalents, Short-term and Long-term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	$ 157,976,000
Gross unrealized gains	24,000
Gross unrealized losses	(26,000)
Total available-for-sale investments	157,974,000
Cash Equivalents, Short-term and Long-term Investments | Commercial Paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	56,969,000
Total available-for-sale investments	56,969,000
Cash Equivalents, Short-term and Long-term Investments | Corporate Debt Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	50,118,000
Gross unrealized gains	9,000
Gross unrealized losses	(26,000)
Total available-for-sale investments	50,101,000
Cash Equivalents, Short-term and Long-term Investments | Agency Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Amortized Cost	50,889,000
Gross unrealized gains	15,000
Total available-for-sale investments	$ 50,904,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Total available-for-sale investments		$ 0
Available-for-sale securities, gross realized gain (loss)	$ 0
Available-for-sale securities in other comprehensive loss	$ 2,000

Fair Value Measurements - Sum27

Fair Value Measurements - Summary of Contractual Maturities of Debt Investment Securities (Details) $ in Thousands	Sep. 30, 2015USD ($)
Fair Value Disclosures [Abstract]
Maturing within one year	$ 103,946
Maturing in one to five years	2,784
Total available-for-sale investments	$ 106,730

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,927	$ 125
Less: accumulated depreciation	(98)	(38)
Property and equipment, net	1,829	87
Furniture and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	219	58
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	254	$ 67
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,454

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Balance Sheet Related Disclosures [Abstract]
Depreciation	$ 30,000	$ 9,000	$ 60,000	$ 15,000

Balance Sheet Components - Su30

Balance Sheet Components - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Accrued Liabilities Current [Abstract]
Compensation and benefits	$ 896	$ 645
Research and development	281	542
Professional and consulting	657	71
Other	14	1
Total	$ 1,848	$ 1,259

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Aug. 31, 2015USD ($)ft²	May. 01, 2015	Jun. 30, 2015USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)
Commitments And Contingencies [Line Items]
Additional lease area for office space | ft²	11,655
Long-term purchase commitment amount						$ 1,200,000
Long-term purchase commitment period						5 years
Facility Leases
Commitments And Contingencies [Line Items]
Accrued liabilities, net of estimated sublease payments			$ 121,000
Term of lease for corporate headquarters		51 months	120 months
Amendment to the lease term	72 months
Additional lease area for office space | ft²	11,655
Security deposit	$ 304,000		$ 35,000
Design costs related to building						$ 188,000
Construction in progress for costs incurred by the lessor			$ 687,500
Rent expense under operating leases				$ 87,000	$ 41,000	$ 342,000	$ 90,000

Commitments and Contingencies32

Commitments and Contingencies - Future Aggregate Minimum Lease Payments (Details) $ in Thousands	Sep. 30, 2015USD ($)
Headquarters
Operating Leased Assets [Line Items]
2,015	$ 190
2,016	1,010
2,017	1,602
2,018	1,650
and after	5,265
Total	9,717
Manufacturing Facility
Operating Leased Assets [Line Items]
2,015	38
2,016	151
2,017	156
2,018	160
and after	1,198
Total	$ 1,703

Stock-based Awards - Additional

Stock-based Awards - Additional Information (Details)	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2015shares	Sep. 30, 2015USD ($)Grant$ / sharesshares	Sep. 30, 2014$ / shares	Sep. 30, 2015USD ($)Grant$ / sharesshares	Sep. 30, 2014$ / sharesshares	Dec. 31, 2014USD ($)shares	Jan. 31, 2013shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grant		4,548,306		4,548,306		639,625
Unvested shares outstanding		4,871,078		4,871,078		2,566,559
Number of shares available for grant				3,980,328	1,635,679
Former Executive
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accelerated stock compensation expense | $		$ 0		$ 562,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option granted, weighted average grant-date fair value | $ / shares		$ 11.05	$ 0.09	$ 5.77	$ 0.09
Tax benefit realized from option | $				$ 0
Unrecognized stock-based compensation expense | $		$ 17,503,000		$ 17,503,000		$ 120,000
Expected recognized over weighted-average remaining vesting period				3 years 5 months 19 days		2 years 5 months 5 days
Stock Options | Non-Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant		213,354		213,354
Number of grants issued | Grant		1		1
Maximum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period				4 years
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period				2 years
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares reserved for issuance	4,681,544
Number of shares available for future grant		4,548,306		4,548,306		639,625
Minimum percentage of voting rights of all classes of stock	10.00%
Percentage of statutory stock options	110.00%
Options expiration period	10 years
2015 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options expiration period	10 years
2015 Plan | First Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period	4 years
Option vesting rights, percentage	25.00%
2015 Plan | Thereafter
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option vesting rights, percentage	2.08%
2015 Plan | Over Two Years
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period	2 years
Option vesting rights, percentage	4.17%
2015 Plan | Over Four Years
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period	4 years
Option vesting rights, percentage	2.08%
2013 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares reserved for issuance							0
Unvested shares issued		770,786		770,786		788,873
Unvested shares outstanding		770,786		770,786		788,873
Exercise liability | $		$ 271,000		$ 271,000
Exercise liability current | $		156,000		156,000
Exercise liability non current | $		$ 115,000		$ 115,000

Stock-based Awards - Summary of

Stock-based Awards - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Shares Available for Grant
Shares Available for Grant, Beginning Balance	639,625
Shares Available for Grant, Additional shares authorized	7,908,194
Shares Available for Grant, Shares retired upon adoption of 2015 Plan	(230,978)
Shares Available for Grant, Options granted	(3,980,328)	(1,635,679)
Shares Available for Grant, Options repurchased	211,793
Shares Available for Grant, Ending Balance	4,548,306		639,625
Number of Options and Unvested Shares
Number of Options and Unvested Shares, Beginning Balance	2,566,559
Number of Options and Unvested Shares, Options granted	3,980,328	1,635,679
Number of Options and Unvested Shares, Options exercised and shares vested	(1,464,016)
Number of Options and Unvested Shares, Options repurchased	(211,793)
Number of Options and Unvested Shares, Ending Balance	4,871,078		2,566,559
Number of Options and Unvested Shares, Options vested and expected to vest as of September 30, 2015 (unaudited)	4,489,667
Number of Options and Unvested Shares, Options exercisable as of September 30, 2015 (unaudited)	3,967,049
Weighted-Average Exercise Price
Weighted-Average Exercise Price, Beginning Balance	$ 0.14
Weighted-Average Exercise Price, Options granted	5.47
Weighted-Average Exercise Price, Options exercised and shares vested	0.16
Weighted-Average Exercise Price, Options repurchased	0.14
Weighted-Average Exercise Price, Ending Balance	4.49		$ 0.14
Weighted-Average Exercise Price, Options vested and expected to vest as of September 30, 2015 (unaudited)	4.73
Weighted-Average Exercise Price, Options exercisable as of September 30, 2015 (unaudited)	$ 4.82
Weighted Average Remaining Contractual Life (in years)
Weighted Average Remaining Contractual Life (in years), Balance	9 years 7 months 2 days		9 years 2 months 9 days
Weighted Average Remaining Contractual Life, Options vested and expected to vest as of September 30, 2015 (unaudited)	9 years 2 months 1 day
Weighted Average Remaining Contractual Life, Options exercisable as of September 30, 2015 (unaudited)	9 years 7 months 2 days
Aggregate Intrinsic Value, Ending Balances	$ 101,441
Aggregate Intrinsic Value, Options vested and expected to vest as of September 30, 2015 (unaudited)	92,439
Aggregate Intrinsic Value, Options exercisable as of September 30, 2015 (unaudited)	$ 81,316

Stock-based Awards - Schedule o

Stock-based Awards - Schedule of Fair Value of Employee Stock Options Estimated with Weighted-Average Assumptions (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]
Expected volatility	71.22%	79.62%	74.47%	79.62%
Risk free interest rate	1.79%	1.51%	1.72%	1.51%
Expected term (in years)	5 years 11 months 12 days	4 years 7 months 24 days	5 years 11 months 23 days	4 years 7 months 24 days

Stock-based Awards - Summary 36

Stock-based Awards - Summary of Stock-based Compensation Expense Net of Estimated Forfeitures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,762	$ 17	$ 2,751	$ 48
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	300	5	396	14
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,462	$ 12	$ 2,355	$ 34

Net Loss per Share - Computatio

Net Loss per Share - Computation of Basic and Diluted Net loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net loss	$ (8,991)	$ (3,129)	$ (19,808)	$ (7,486)
Denominator:
Shares used in computing net loss per share, basic and diluted	25,149,428	2,926,665	11,446,922	2,926,665
Net loss per common share, basic and diluted	$ (0.36)	$ (1.07)	$ (1.73)	$ (2.56)

Net Loss per Share -Schedule of

Net Loss per Share -Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	11,436,443	13,263,967	22,289,679	13,263,967
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted net loss per share	1,198,209	3,501,939	4,871,078	3,501,939