Zosano Pharma (ZSANQ) 10-Q 10 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 05, 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	ZSAN
Entity Registrant Name	Zosano Pharma Corp
Entity Central Index Key	1,587,221
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		11,966,958

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 4,875	$ 1,214
Accounts receivable	0	111
Interest receivable	84	0
Short-term investments in marketable securities	34,098	0
Prepaid expenses and other current assets	459	311
Total current assets	39,516	1,636
Restricted cash	35	35
Long-term investments in marketable securities	4,923	0
Property and equipment, net	8,036	9,681
Other long-term assets	513	1,991
Total assets	53,023	13,343
Current liabilities:
Accounts payable	2,036	1,447
Accrued compensation	1,257	1,676
Deferred revenue	0	170
Related parties convertible notes (including accrued interest)	0	7,362
Secured promissory note, current portion (net of issuance cost and including accrued interest)	1,958	1,408
Freestanding warrant liability	0	300
Other accrued liabilities	573	992
Total current liabilities	5,824	13,355
Deferred rent	40	98
Secured promissory note, net of debt discount and issuance costs (including accrued interest)	13,264	2,530
Related party note payable (including accrued interest)	$ 0	$ 10,761
Commitments and contingencies
Stockholders' equity (deficit):
Common stock, $0.0001 par value; 100,000 shares and 30,000 shares authorized as of September 30, 2015 and December 31, 2014, respectively; 11,967 shares and 5,165 shares issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	$ 1	$ 1
Additional paid-in capital	193,154	125,062
Accumulated deficit	(159,245)	(138,464)
Accumulated other comprehensive loss	(15)	0
Stockholders' equity (deficit)	33,895	(13,401)
Total liabilities and stockholders' equity (deficit)	$ 53,023	$ 13,343

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	30,000,000
Common stock, shares issued	11,967,000	5,165,000
Common stock, shares outstanding	11,967,000	5,165,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue:
License fees revenue	$ 0	$ 176	$ 170	$ 1,819
Collaborative development support services	0	198	143	662
Total revenue	0	374	313	2,481
Operating expenses:
Cost of license fees revenue	0	0	0	100
Research and development	6,627	2,587	14,701	8,230
General and administrative	1,719	894	4,797	3,208
Total operating expenses	8,346	3,481	19,498	11,538
Loss from operations	(8,346)	(3,107)	(19,185)	(9,057)
Other income (expense):
Interest expense, net	(314)	(579)	(1,247)	(1,261)
Other income (expense)	41	3	49	(143)
Warrant revaluation income	0	0	48	0
Gain on debt forgiveness	0	0	0	497
Loss on debt extinguishment	0	0	(446)	0
Net loss	(8,619)	(3,683)	(20,781)	(9,964)
Other comprehensive loss:
Unrealized holding gain (loss) on marketable securities, net of tax effect	23	0	(15)	0
Comprehensive loss	$ (8,596)	$ (3,683)	$ (20,796)	$ (9,964)
Net loss per common share - basic and diluted	$ (0.72)	$ (0.72)	$ (1.85)	$ (1.95)
Weighted-average shares used in computing net loss per common share - basic and diluted	11,961	5,138	11,230	5,121

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net loss	$ (20,781)	$ (9,964)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation	1,835	2,278
Stock-based compensation	369	122
Gain on debt forgiveness	0	(497)
Loss on debt extinguishment	446	0
Cost of debt subordination	0	141
Revaluation of warrants to fair value	(48)	0
Amortization of debt (premium) issuance costs	(9)	34
Accretion of interest	193	1,106
Deferred rent	(58)	(197)
Change in operating assets and liabilities:
Accounts and interest receivable	27	(173)
Accounts receivable from joint venture partner	0	3,426
Prepaid expenses and other assets	915	(1,191)
Accounts payable	589	(2,003)
Accrued compensation and other accrued liabilities	(838)	(1,262)
Deferred revenue	(170)	(819)
Net cash flow used in operating activities	(17,530)	(9,001)
Cash flow from investing activities:
Purchase of property and equipment	(191)	(1,079)
Decrease in restricted cash	0	30
Purchases of marketable securities	(42,606)	0
Proceeds from maturities of investment in marketable securities	3,480	0
(Increase) decrease in other investment	(25)	18
Net cash flow used in investing activities	(39,342)	(1,031)
Cash flow from financing activities:
Proceeds from initial public offering of securities, net of underwriting discounts and commissions	47,140	0
Payment of deferred offering costs	(1,359)	0
Proceeds from a private placement concurrent with the initial public offering, net of private placement fee	14,475	0
Proceeds from exercise of stock options and issuance of common stock	37	2
Proceeds from borrowing under related parties bridge notes	0	2,500
Proceeds from debt financing, net of issuance costs	11,705	3,920
Payment of loan principal and accrued interest	(11,465)	0
Net cash flow provided by financing activities	60,533	6,422
Net increase (decrease) in cash and cash equivalents	3,661	(3,610)
Cash and cash equivalents at beginning of period	1,214	5,913
Cash and cash equivalents at end of period	4,875	2,303
Supplemental cash flow information:
Interest paid	3,290	0
Non-cash investing and financing activities:
Conversion of debt to common stock	7,407	0
Issuance of common stock in connection with debt financing	0	141
Issuance of warrant in connection with debt financing	212	115
Accrued deferred offering cost	0	1,068
Reclassification of warrant liability to equity	$ 252	$ 0

Organization

Organization	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization The Company Zosano Pharma Corporation and subsidiaries (the Company) is a clinical stage specialty pharmaceutical company that has developed a proprietary transdermal microneedle patch system to deliver drug formulations through the skin for the treatment of a variety of indications. The Company’s microneedle patch system offers rapid onset, consistent drug delivery, improved ease of use and room-temperature stability, benefits which the Company believes often are unavailable using oral formulations or injections. The Company’s microneedle patch system has the potential to deliver numerous medications for a wide variety of indications, in commercially attractive markets. The Company has two wholly owned subsidiaries: ZP Opco, Inc. (Opco), through which the Company conducts its primary research and development activities, and ZP Group LLC, originally a joint venture with Asahi Kasei Pharma USA, which ceased operations in connection with the termination of the joint venture in December 2013. The Company operates in one business segment to develop human pharmaceutical products. Management uses one measurement of profitability and does not segregate its business for internal reporting. Initial Public Offering and Concurrent Private Placement On January 30, 2015, the Company completed its initial public offering, in which it sold 4,500,000 shares of its common stock at a price of $11.00 per share, resulting in net proceeds of approximately $44.2 million, after deducting underwriting discounts and commissions and other offering expenses. The common stock began trading on The NASDAQ Capital Market on January 27, 2015 under the ticker symbol “ZSAN.” Upon the closing of the Company’s initial public offering, the principal and all unpaid and accrued interest on the related parties convertible notes outstanding as of January 30, 2015, totaling $7.4 million, automatically converted into an aggregate of 792,182 shares of common stock at a price equal to 85% of the initial public offering price, resulting in the liability for such notes being reclassified to permanent equity. On February 27, 2015, the Company sold an additional 110,000 shares of its common stock at the initial public offering price of $11.00 per share, pursuant to the underwriters’ partial exercise of their over-allotment option, resulting in additional net proceeds of approximately $1.1 million after deducting underwriting discounts and commissions. Concurrently with the closing of its initial public offering on January 30, 2015, the Company issued and sold 1,363,636 shares of its common stock to Eli Lilly and Company (Lilly) in a private placement pursuant to a common stock purchase agreement dated November 21, 2014 between the Company and Lilly, and received net proceeds of $14.5 million, after payment of a private placement fee.

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 Presentation and Use of Estimates The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) and as required by Regulation S-X, Rule 10-01 for interim financial reporting. 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 as of the date of the condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates. Unaudited Interim Financial Information The accompanying interim condensed consolidated financial statements are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair presentation of the financial positions and results of operations for the periods presented. The financial data and other information disclosed in these notes to the interim condensed consolidated financial statements are also unaudited. Since they are interim statements, the accompanying financial statements do not include all of the information and notes required by U.S. GAAP for complete financial statements. The results for the 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 future year. These financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 as filed with the Securities and Exchange Commission. Consolidation The consolidated financial statements include the accounts of Zosano Pharma Corporation, ZP Opco, Inc., and ZP Group LLC post-termination of the joint venture. Intercompany balances and transactions have been eliminated in consolidation. Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies during the nine months ended September 30, 2015, as compared to the significant accounting policies described in Note 2 of the “Notes to Consolidated Financial Statements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, except for the following updates: Investments in Marketable Securities The Company classifies its investments in marketable securities as available-for-sale. Investments with maturities between three and twelve (12) months are considered short-term investments. Investments with maturities greater than 12 months are considered long-term investments. The Company’s investments classified as available-for-sale are recorded at fair value based upon quoted market prices at period end. Unrealized gains and losses that are deemed temporary in nature are recorded in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity (deficit). A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Premiums and discounts are amortized (accreted) over the life of the corresponding security as an adjustment to its yield. Dividend and interest income are recognized when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of investments sold. Deferred Offering Costs Deferred offering costs, consisting of legal, accounting, printing and filing fees totaling approximately $1.8 million related to the initial public offering were capitalized and offset against proceeds from the initial public offering upon the closing of the offering in January 2015. As of December 31, 2014, approximately $1.5 million of expenses related to the initial public offering had been deferred as other long-term assets in the Company’s consolidated balance sheet. Research and Development Expenses Research and development costs are charged to expense as incurred and consist of costs related to (i) servicing the Company’s collaborative development efforts with other pharmaceutical companies, (ii) furthering the Company’s research and development efforts, and (iii) designing and manufacturing the Company’s transdermal microneedle patch and applicator for the Company’s clinical and nonclinical studies. For the three months ended September 30, 2015, the Company incurred no research and development costs in support of the Company’s collaborative development services, approximately $3.0 million in connection with the Company’s research and development efforts, and approximately $3.6 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. For the three months ended September 30, 2014, the Company incurred research and development costs of approximately $0.1 million in support of the Company’s collaborative development services to Novo Nordisk A/S (Novo Nordisk), approximately $1.0 million in connection with the Company’s research and development efforts and approximately $1.5 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. For the nine months ended September 30, 2015, the Company incurred research and development costs of approximately $0.1 million in support of the Company’s collaborative development services, approximately $6.3 million in connection with the Company’s research and development efforts, and approximately $8.3 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. For the nine months ended September 30, 2014, the Company incurred research and development costs of approximately $0.4 million in support of the Company’s collaborative development services to Novo Nordisk, approximately $3.6 million in connection with the Company’s research and development efforts and approximately $4.3 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. Net Loss Per Common Share Basic net income (loss) per common share is calculated by dividing the net income (loss) by the weighted-average number of common shares outstanding during the period, without consideration for potential dilutive common stock equivalents. Diluted net income (loss) per common share is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, convertible promissory notes, warrants and options to purchase common stock are considered potential dilutive common stock equivalents. For the three and nine months ended September 30, 2015 and 2014, diluted net loss per common share was the same as basic net loss per common share since the effect of inclusion of potentially dilutive common stock equivalents would have an antidilutive effect due to the loss reported. The following outstanding common stock equivalents were excluded from the computations of diluted net loss per common share for the periods presented as the effect of including such securities would be antidilutive: September 30, 2015 2014 (unaudited; in shares) Warrants to purchase common stock 72,379 31,674 Options to purchase common stock 956,951 527,619 1,029,330 559,293 Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-03, S implifying the Presentation of Debt Issuance Costs

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	9 Months Ended
	Sep. 30, 2015
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Investments	3. Cash, Cash Equivalents and Investments The following is a summary of the Company’s cash, cash equivalents, and marketable securities investments: September 30, 2015 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair Value (unaudited; in thousands) Cash in bank $ 2,945 $ — $ — $ 2,945 Money market funds 1,930 — — 1,930 Certificates of deposit (restricted) 35 — — 35 Certificates of deposit 7,680 3 (1 ) 7,682 Corporate bonds 11,793 — (12 ) 11,781 U.S. government agency bonds 18,563 1 (6 ) 18,558 Commercial paper 1,000 — — 1,000 $ 43,946 $ 4 $ (19 ) $ 43,931 Classified as: Cash and cash equivalents $ 4,875 Restricted cash 35 Short-term investments in marketable securities 34,098 Long-term investments in marketable securities 4,923 $ 43,931 Contractual maturities of marketable securities: Due within 12 months $ 36,028 Due between 1 year and 2 years 4,923 $ 40,951 December 31, 2014 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair Value (in thousands) Cash in bank $ 1,214 $ — $ — $ 1,214 Certificates of deposit (restricted) 35 — — 35 $ 1,249 $ — $ — $ 1,249 Reported as: Cash and cash equivalents $ 1,214 Restricted cash 35 $ 1,249 For the three and nine months ended September 30, 2015, there were no realized gain and losses on available-for-sale securities. As of September 30, 2015, the maximum contractual maturity of the Company’s available-for-sale investments was within 15 months. The Company does not intend to sell the investments that are in an unrealized loss position, and it is unlikely that the Company will be required to sell the investments before recovery of their amortized cost basis, which may be at maturity. The Company has determined that the gross unrealized losses on its available-for-sale investments as of September 30, 2015 were temporary in nature. All marketable securities with unrealized losses as of September 30, 2015 have been in a loss position for less than five months.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments The Company records its financial assets and liabilities at fair value. 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 establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: • Level 1: Inputs which include quoted prices in active markets for identical assets and liabilities. • Level 2: Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The carrying values of certain assets and liabilities of the Company, such as cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities, approximate fair value due to their relatively short maturities. The carrying value of the Company’s short-term notes payable approximates their fair value as the terms of the borrowing are consistent with current market rates and the duration to maturity is short. The carrying value of the Company’s long-term notes payable approximates fair value because the interest rates approximate market rates that the Company could obtain for debt with similar terms and maturities. The following tables set forth the fair value of the Company’s financial instruments as of September 30, 2015 and December 31, 2014: September 30, 2015 Level 1 Level 2 Level 3 Total (unaudited; in thousands) Financial Assets: Certificates of deposit (restricted cash) $ 35 $ — $ — $ 35 Money market funds 1,930 — — 1,930 Certificates of deposit — 7,682 — 7,682 Corporate bonds — 11,781 — 11,781 U.S. government agency bonds — 18,558 — 18,558 Commercial paper — 1,000 — 1,000 Total financial assets $ 1,965 $ 39,021 $ — $ 40,986 December 31, 2014 Level 1 Level 2 Level 3 Total (in thousands) Financial Assets: Certificates of deposit (restricted cash) $ 35 $ — $ — $ 35 Financial Liabilities: Freestanding warrant liability $ — $ — $ 300 $ 300 The Company’s freestanding warrant liability, which is measured and disclosed at fair value on a recurring basis, is classified within the Level 3 designation. There were no transfers between levels within the fair value hierarchy during the periods presented. The following table presents changes in financial instruments measured at fair value using Level 3 significant unobservable inputs: Warrant (in thousands) Financial liabilities: Balance at December 31, 2014 300 Change in fair value of freestanding warrant liability (1) (48 ) Reclassification to equity (unaudited) (252 ) Balance at September 30, 2015 (unaudited) $ — (1) Change in fair value of the freestanding warrant liability is recorded as other income (expense) in the Company’s condensed consolidated statement of operations.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and Equipment The following summarizes the Company’s property and equipment as of September 30, 2015 and December 31, 2014: September 30, December 31, (unaudited) (in thousands) Laboratory and office equipment $ 1,112 $ 1,043 Manufacturing equipment 10,721 10,712 Computer equipment and software 229 210 Leasehold improvements 15,534 15,838 Construction in progress 1,834 1,437 29,430 29,240 Less: accumulated depreciation (21,394 ) (19,559 ) $ 8,036 $ 9,681 Depreciation and amortization expense was approximately $0.6 million and $0.8 million for the three months ended September 30, 2015 and 2014, respectively, and $1.8 million and $2.3 million for the nine months ended September 30, 2015 and 2014, respectively.

Research and Development Collab

Research and Development Collaboration and License Agreements	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Research and Development Collaboration and License Agreements	6. Research and Development Collaboration and License Agreements Collaboration Agreement with Novo Nordisk Pursuant to a collaboration agreement with Novo Nordisk dated January 31, 2014 related to the development of a transdermal presentation of select Novo Nordisk glucagon-like peptide-1 (GLP-1) analogues, the Company received a non-refundable upfront payment of $1.0 million. The Company evaluated the upfront payment for the license of its technology under the collaboration agreement and determined that the license does not have standalone value apart from the development support services. Accordingly, the license and the development support services are combined as one unit of accounting, and the upfront payment is recorded as deferred revenue in the consolidated balance sheet and recognized as revenue over the performance period that is consistent with the term of performance obligations under the specified feasibility study plan. As of September 30, 2015, all deferred revenue related to the non-refundable upfront payment has been recognized as license fees revenue. In July 2015, the Company announced that Novo Nordisk had notified the Company of its intention to discontinue the collaboration agreement. The termination became effective on October 27, 2015. Upon the termination of the agreement, all technology rights licensed to Novo Nordisk related to the field of GLP-1 products reverted to the Company. The collaboration with Novo Nordisk will no longer be a source of revenue for the Company upon the termination of the agreement. Revenue from the reimbursement of research and development and out-of-pocket expenses was recognized as the related services were performed under the collaboration agreement on a time and material basis. For the three months ended September 30, 2015, no service revenue pursuant to the Novo Nordisk collaboration agreement was recognized. For the three months ended September 30, 2014, the Company recognized $0.2 million as service revenue pursuant to the Novo Nordisk collaboration agreement. For the nine months ended September 30, 2015 and 2014, the Company recognized $46,000 and $0.7 million, respectively, as service revenue pursuant to the Novo Nordisk collaboration agreement. The corresponding cost of service revenue is recorded as research and development expense in the consolidated statements of operations. The Company did not record cost of collaboration service revenue for the three months ended September 30, 2015 in connection with the Novo Nordisk collaboration agreement. For the three months ended September 30, 2014, the Company recorded $0.1 million as cost of collaboration service revenue in connection with the Novo Nordisk collaboration agreement, and for the nine months ended September 30, 2015 and 2014, the Company recorded $53,000 and $0.4 million, respectively, as cost of collaboration service revenue in connection with the Novo Nordisk collaboration agreement.

Debt Financing

Debt Financing	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Debt Financing	7. Debt Financing Conversion of Related Parties Convertible Promissory Notes On January 30, 2015, upon the closing of the Company’s initial public offering, the principal and all unpaid and accrued interest on the September 2013 and February and December 2014 convertible promissory notes outstanding as of January 30, 2015, totaling $7.4 million, were automatically converted into an aggregate of 792,182 shares of common stock at a price equal to 85% of the initial public offering price, resulting in the liability for such notes being reclassified to permanent equity. Senior Secured Term Loan with Hercules In June 2014, the Company entered into a loan and security agreement with Hercules Technology Growth Capital, Inc. (Hercules) which provided the Company $4.0 million in debt financing. In June 2015, the Company entered into a first amendment to the loan and security agreement with Hercules to increase the aggregate principal amount of the loan to $15.0 million (the Hercules Term Loan). Upon the execution of the first amendment to the loan and security agreement, the Company used approximately $11.4 million of the Hercules Term Loan to prepay all amounts owing under the secured promissory note held by BMV Direct SOTRS LP, an affiliate of BioMed Realty Holdings, Inc. The first amendment to the loan and security agreement with Hercules provides that the $15.0 million principal balance will be subject to a 12-month interest-only period beginning July 1, 2015, followed by equal monthly installment payments of principal and interest, with all outstanding amounts due and payable on December 1, 2018. The outstanding principal balance bears interest at a variable rate of the greater of (i) 7.95%, or (ii) 7.95% plus the prime rate as quoted in the Wall Street Journal minus 5.25%. In addition, the Company will be obligated to pay a $100,000 legacy end of term charge on the earlier of June 1, 2017 or the date the Company prepays the Hercules Term Loan and a $351,135 end of term charge on the earlier of loan maturity or at the date the Company prepays the Hercules Term Loan. The Company may prepay all, but not less than all, of the Hercules Term Loan subject to a prepayment charge of 1.0% of the then outstanding principal if prepaid prior to June 23, 2016, or 0.5% of the then outstanding principal if prepaid on or after June 23, 2016 but prior to June 23, 2017, with no prepayment charge if prepaid thereafter. The Hercules Term Loan is secured by a first priority security interest and lien in and to all of the Company’s tangible and intangible properties and assets, including intellectual properties. The amended Hercules Term Loan has substantially different terms than the original loan and in accordance with ASC 470-50, Debt Modifications and Extinguishments In connection with the first amendment to the loan and security agreement with Hercules, the Company issued Hercules a warrant to purchase 40,705 shares of the Company’s common stock at an exercise price of $7.37 per share. The warrant was recorded at fair value on the date of issuance and treated as a debt discount which is being amortized to interest expense over the term of the loan using the effective interest method. (See Note 8 for a discussion of warrants to purchase common stock.) In addition, the Company incurred legal and closing costs totaling $117,000, including an $85,000 upfront loan origination fee paid to Hercules and $32,000 of legal costs, in connection with the first amendment to the loan and security agreement with Hercules. These debt issuance costs have been recorded as a direct deduction from the related debt liability in accordance with ASU 2015-03 and are being amortized to interest expense over the term of the loan using the effective interest method. Given effect to early adoption of ASU 2015-03, the following is a summary of the Company’s long-term debt, net of unamortized debt discount and issuance costs, as of September 30, 2015: September 30, (unaudited; in thousands) Principal amount $ 15,000 Less: unamortized debt issuance costs (104 ) unamortized fair value of freestanding warrant (186 ) Plus: unamortized fair value debt premium 355 accrued terminal interest 58 accrued interest 99 Long-term debt, net of unamortized debt issuance costs and premium, plus accrued interest $ 15,222 Secured Financing with BMR In connection with the recapitalization of the Company in April 2012, the Company renegotiated its lease agreement with its landlord, BioMed Realty Holdings, Inc. and affiliates (BMR Holdings), to include reduced rent obligations. In connection with the rent reduction, the Company issued a secured promissory note (the BMR Note) for the principal amount of approximately $8.6 million to BMR Holdings, which was subsequently assigned to its affiliate BMV Direct SOTRS LP, and all previously accrued interest, unpaid rent, future rent obligations and other fees due to BMR Holdings were either rolled into the BMR Note or eliminated. In June 2015, the Company terminated the BMR Note by prepaying the outstanding principal and all accrued interest as of June 24, 2015, totaling $11.4 million.

Warrants to Purchase Common Sto

Warrants to Purchase Common Stock	9 Months Ended
	Sep. 30, 2015
Text Block [Abstract]
Warrants to Purchase Common Stock	8. Warrants to Purchase Common Stock In connection with the Company’s entry into the loan and security agreement with Hercules in June 2014, the Company issued Hercules a warrant to purchase $280,000 worth of the Company’s stock at a price per share equal to the lower of (i) lowest price per share of stock sold in the Company’s next round of private equity financing resulting in gross proceeds of at least $3.0 million prior to the closing of the Company’s initial public offering, and (ii) $8.84 per share. The warrant was initially recorded on the Company’s consolidated balance sheet at fair value on the date of issuance and treated as a debt discount that is being amortized to interest expense over the debt repayment period using the effective interest method. The warrant liability was revalued at each subsequent balance sheet date through December 31, 2014, with fair value changes recognized as warrant revaluation income (expense) in the accompanying condensed consolidated statements of operations. As a result of the pricing of the Company’s initial public offering on January 27, 2015, the settlement adjustment to the exercise price was effectively fixed, resulting in the warrant being exercisable for 31,674 shares (warrant amount of $280,000 divided by $8.84 per share) of the Company’s common stock. Accordingly, management concluded that the requirements for equity classification under ASC 815-40-25-10 have been met and effected a reclassification of the warrant liability of $0.3 million to equity. The warrant is exercisable at any time, in whole or in part, until five years from the date of the Company’s IPO. For the three and nine months ended September 30, 2015, the Company recorded other income of zero and $48,000, respectively, related to the change in fair value of the warrant before equity reclassification, which was determined by using the Black-Scholes option valuation model with the following assumptions: expected term of 5.00 years; volatility of 89%; risk free interest rate of 1.32%; and no dividend yield. In connection with the Company’s entry into the first amendment to loan and security agreement with Hercules in June 2015, the Company issued Hercules a warrant to purchase 40,705 shares of the Company’s common stock at an exercise price of $7.37 per share. Hercules can exercise its purchase right under the warrant, in whole or in part, at any time until June 23, 2020. The warrant was recorded at fair value on the date of issuance and treated as a debt discount that is being amortized to interest expense over the term of the loan using the effective interest method. The Company classified the warrant as an equity instrument in accordance with ASC 815-40-25-10 and recorded the fair value of the warrant of $212,000 to additional paid-in capital in its consolidated balance sheet. The warrant fair value was determined by using the Black-Scholes option valuation model with the following assumptions: expected term of 5.00 years; volatility of 89%; risk free interest rate of 1.73% and no dividend yield.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies The Company has an operating lease with BMR-34790 Ardentech Court LP, an affiliate of BMR Holdings, for its office, research and development, and manufacturing facilities in Fremont, California. The Company entered into a fifth amendment to the lease in April 2012 which extended the lease term through March 2019 and provided a reduction in annual rents due to a potential reduction of premises from a recapturable premises clause. In June 2015, the Company entered into a sixth amendment to the lease, pursuant to which the landlord’s option to recapture a specified portion of the leased premises (comprising approximately 29,348 square feet of the approximate total 55,588 square feet of leased premises) has been suspended and the Company has the option until December 31, 2015 to extend the term of the lease by an additional 38 months to June 1, 2022 and pay rent on the total leased premises beginning April 1, 2016 at the rates set forth in the sixth amendment. The Company records rent expense under the lease on a straight-line basis over the term of the lease. The difference between the actual lease payments and the expense recognized under the lease, along with the unamortized tenant improvement allowances, resulted in a net deferred rent liability of $40,000 and $98,000 as of September 30, 2015 and December 31, 2014, respectively. For the three months ended September 30, 2015 and 2014, rent expense under operating leases was $0.2 million and $0.2 million, respectively. For the nine months ended September 30, 2015 and 2014, rent expense under operating leases was $0.5 million and $0.5 million, respectively. As of September 30, 2015, future minimum payments under non-cancelable operating leases for each year ending December 31 are as follows: (unaudited; in thousands) 2015 $ 153 2016 626 2017 637 2018 651 2019 163 $ 2,230

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	10. Stock-Based Compensation The Company has reserved 1.4 million shares of common stock for issuance under the 2014 Equity and Incentive Plan (the 2014 Plan). In connection with the Company’s initial public offering of its common stock in January 2015, the Company’s board of directors terminated the Company’s 2012 Stock Incentive Plan (the 2012 Plan) effective as of January 27, 2015 and no further awards may be issued under the 2012 Plan. However, the awards outstanding under the 2012 Plan at January 27, 2015 continue to be governed by the terms of the 2012 Plan. The following table summarizes options and awards activities and related information under the 2012 Plan and 2014 Plan combined: Shares Outstanding of Shares Weighted- Weighted- (In Years) Aggregate (in thousands) Balance at December 31, 2014 28,701 497,753 $ 1.59 6.77 Authorized under 2014 Plan (unaudited) 1,400,000 Granted (unaudited) (527,394 ) 527,394 $ 8.34 Option exercised (unaudited) — (27,017 ) $ 1.38 Restricted stock vested and released (unaudited) — (9,000 ) $ — Cancelled/forfeited (unaudited) 32,179 (32,179 ) $ 1.86 Shares expired under 2012 Plan (unaudited) (58,880 ) Balance at September 30, 2015 (unaudited) 874,606 956,951 $ 5.32 8.69 $ 1,046 Exercisable at September 30, 2015 (unaudited) 285,344 $ 1.54 7.15 $ 696 Vested and expected to vest at September 30, 2015 (unaudited) 894,798 $ 5.14 8.62 $ 1,037 The aggregate intrinsic values of options outstanding and exercisable, vested and expected to vest were calculated as the difference between the exercise price of the options and the closing market value of the Company’s common stock as reported on NASDAQ as of September 30, 2015. The following summarizes the composition of stock options outstanding and exercisable as of September 30, 2015 (unaudited): Options Outstanding and Exercisable Exercise Price Number of Weighted- Life (in years) $1.28 - $1.54 412,256 7.29 $4.52 - $7.92 110,301 9.49 $8.18 - $9.29 434,394 9.81 $1.28 - $9.29 956,951 8.69 Stock-Based Compensation Expense Total stock-based compensation expense recognized was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (unaudited; in thousands) Research and development $ 103 $ 12 $ 166 $ 58 General and administrative 63 24 203 64 Total stock-based compensation expense $ 166 $ 36 $ 369 $ 122 At September 30, 2015, the Company had $3.0 million of total unrecognized stock-based compensation, net of estimated forfeitures, related to outstanding stock options that will be recognized over a weighted-average period of 3.29 years. The Company uses the Black-Scholes model for valuing its options and awards granted to employees and non-employees. Stock-based compensation in connection with non-employee grants was immaterial for the three and nine months ended September 30, 2015 and 2014. The following table illustrates the input assumptions used to value employee stock option grants for the three and nine months ended September 30, 2015 and 2014 (unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Dividend yield 0% 0% 0% 0% Risk-free interest rate 1.07% - 1.73% 2.02% 1.07% - 2.01% 2.02% - 2.12% Expected volatility 89% 89% 89% 89% Expected term (years) 6.08 6.08 6.08 6.08

Summary of Significant Accoun16

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) and as required by Regulation S-X, Rule 10-01 for interim financial reporting. 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 as of the date of the condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying interim condensed consolidated financial statements are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual audited consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for a fair presentation of the financial positions and results of operations for the periods presented. The financial data and other information disclosed in these notes to the interim condensed consolidated financial statements are also unaudited. Since they are interim statements, the accompanying financial statements do not include all of the information and notes required by U.S. GAAP for complete financial statements. The results for the 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 future year. These financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 as filed with the Securities and Exchange Commission.
Consolidation	Consolidation The consolidated financial statements include the accounts of Zosano Pharma Corporation, ZP Opco, Inc., and ZP Group LLC post-termination of the joint venture. Intercompany balances and transactions have been eliminated in consolidation.
Investments in Marketable Securities	Investments in Marketable Securities The Company classifies its investments in marketable securities as available-for-sale. Investments with maturities between three and twelve (12) months are considered short-term investments. Investments with maturities greater than 12 months are considered long-term investments. The Company’s investments classified as available-for-sale are recorded at fair value based upon quoted market prices at period end. Unrealized gains and losses that are deemed temporary in nature are recorded in accumulated other comprehensive income (loss) as a separate component of stockholders’ equity (deficit). A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the corresponding establishment of a new cost basis for the security. Premiums and discounts are amortized (accreted) over the life of the corresponding security as an adjustment to its yield. Dividend and interest income are recognized when earned. Realized gains and losses are included in earnings and are derived using the specific identification method for determining the cost of investments sold.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, consisting of legal, accounting, printing and filing fees totaling approximately $1.8 million related to the initial public offering were capitalized and offset against proceeds from the initial public offering upon the closing of the offering in January 2015. As of December 31, 2014, approximately $1.5 million of expenses related to the initial public offering had been deferred as other long-term assets in the Company’s consolidated balance sheet.
Research and Development Expenses	Research and Development Expenses Research and development costs are charged to expense as incurred and consist of costs related to (i) servicing the Company’s collaborative development efforts with other pharmaceutical companies, (ii) furthering the Company’s research and development efforts, and (iii) designing and manufacturing the Company’s transdermal microneedle patch and applicator for the Company’s clinical and nonclinical studies. For the three months ended September 30, 2015, the Company incurred no research and development costs in support of the Company’s collaborative development services, approximately $3.0 million in connection with the Company’s research and development efforts, and approximately $3.6 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. For the three months ended September 30, 2014, the Company incurred research and development costs of approximately $0.1 million in support of the Company’s collaborative development services to Novo Nordisk A/S (Novo Nordisk), approximately $1.0 million in connection with the Company’s research and development efforts and approximately $1.5 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. For the nine months ended September 30, 2015, the Company incurred research and development costs of approximately $0.1 million in support of the Company’s collaborative development services, approximately $6.3 million in connection with the Company’s research and development efforts, and approximately $8.3 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates. For the nine months ended September 30, 2014, the Company incurred research and development costs of approximately $0.4 million in support of the Company’s collaborative development services to Novo Nordisk, approximately $3.6 million in connection with the Company’s research and development efforts and approximately $4.3 million in the manufacturing of the Company’s microneedle patch system for the development of the Company’s product candidates.
Net Loss Per Common Share	Net Loss Per Common Share Basic net income (loss) per common share is calculated by dividing the net income (loss) by the weighted-average number of common shares outstanding during the period, without consideration for potential dilutive common stock equivalents. Diluted net income (loss) per common share is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, convertible promissory notes, warrants and options to purchase common stock are considered potential dilutive common stock equivalents. For the three and nine months ended September 30, 2015 and 2014, diluted net loss per common share was the same as basic net loss per common share since the effect of inclusion of potentially dilutive common stock equivalents would have an antidilutive effect due to the loss reported.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-03, S implifying the Presentation of Debt Issuance Costs

Summary of Significant Accoun17

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Schedule of Outstanding Common Stock Equivalents Excluded From Computations of Diluted Net Loss per Common Share	The following outstanding common stock equivalents were excluded from the computations of diluted net loss per common share for the periods presented as the effect of including such securities would be antidilutive: September 30, 2015 2014 (unaudited; in shares) Warrants to purchase common stock 72,379 31,674 Options to purchase common stock 956,951 527,619 1,029,330 559,293

Cash, Cash Equivalents and In18

Cash, Cash Equivalents and Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Cash and Cash Equivalents [Abstract]
Summary of Cash, Cash Equivalents, and Marketable Securities Investments	The following is a summary of the Company’s cash, cash equivalents, and marketable securities investments: September 30, 2015 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair Value (unaudited; in thousands) Cash in bank $ 2,945 $ — $ — $ 2,945 Money market funds 1,930 — — 1,930 Certificates of deposit (restricted) 35 — — 35 Certificates of deposit 7,680 3 (1 ) 7,682 Corporate bonds 11,793 — (12 ) 11,781 U.S. government agency bonds 18,563 1 (6 ) 18,558 Commercial paper 1,000 — — 1,000 $ 43,946 $ 4 $ (19 ) $ 43,931 Classified as: Cash and cash equivalents $ 4,875 Restricted cash 35 Short-term investments in marketable securities 34,098 Long-term investments in marketable securities 4,923 $ 43,931 Contractual maturities of marketable securities: Due within 12 months $ 36,028 Due between 1 year and 2 years 4,923 $ 40,951 December 31, 2014 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair Value (in thousands) Cash in bank $ 1,214 $ — $ — $ 1,214 Certificates of deposit (restricted) 35 — — 35 $ 1,249 $ — $ — $ 1,249 Reported as: Cash and cash equivalents $ 1,214 Restricted cash 35 $ 1,249

Fair Value of Financial Instr19

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Instruments	The following tables set forth the fair value of the Company’s financial instruments as of September 30, 2015 and December 31, 2014: September 30, 2015 Level 1 Level 2 Level 3 Total (unaudited; in thousands) Financial Assets: Certificates of deposit (restricted cash) $ 35 $ — $ — $ 35 Money market funds 1,930 — — 1,930 Certificates of deposit — 7,682 — 7,682 Corporate bonds — 11,781 — 11,781 U.S. government agency bonds — 18,558 — 18,558 Commercial paper — 1,000 — 1,000 Total financial assets $ 1,965 $ 39,021 $ — $ 40,986 December 31, 2014 Level 1 Level 2 Level 3 Total (in thousands) Financial Assets: Certificates of deposit (restricted cash) $ 35 $ — $ — $ 35 Financial Liabilities: Freestanding warrant liability $ — $ — $ 300 $ 300
Schedule of Changes in Financial Instruments Measured at Fair Value Using Significant Unobservable Inputs	The following table presents changes in financial instruments measured at fair value using Level 3 significant unobservable inputs: Warrant (in thousands) Financial liabilities: Balance at December 31, 2014 300 Change in fair value of freestanding warrant liability (1) (48 ) Reclassification to equity (unaudited) (252 ) Balance at September 30, 2015 (unaudited) $ — (1) Change in fair value of the freestanding warrant liability is recorded as other income (expense) in the Company’s condensed consolidated statement of operations.

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	The following summarizes the Company’s property and equipment as of September 30, 2015 and December 31, 2014: September 30, December 31, (unaudited) (in thousands) Laboratory and office equipment $ 1,112 $ 1,043 Manufacturing equipment 10,721 10,712 Computer equipment and software 229 210 Leasehold improvements 15,534 15,838 Construction in progress 1,834 1,437 29,430 29,240 Less: accumulated depreciation (21,394 ) (19,559 ) $ 8,036 $ 9,681

Debt Financing (Tables)

Debt Financing (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Summary of Long-Term Debt, Net of Unamortized Debt Discount and Issuance Costs	Given effect to early adoption of ASU 2015-03, the following is a summary of the Company’s long-term debt, net of unamortized debt discount and issuance costs, as of September 30, 2015: September 30, (unaudited; in thousands) Principal amount $ 15,000 Less: unamortized debt issuance costs (104 ) unamortized fair value of freestanding warrant (186 ) Plus: unamortized fair value debt premium 355 accrued terminal interest 58 accrued interest 99 Long-term debt, net of unamortized debt issuance costs and premium, plus accrued interest $ 15,222

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Payments under Non-cancellable Operating Leases	As of September 30, 2015, future minimum payments under non-cancelable operating leases for each year ending December 31 are as follows: (unaudited; in thousands) 2015 $ 153 2016 626 2017 637 2018 651 2019 163 $ 2,230

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Options and Awards Activities	The following table summarizes options and awards activities and related information under the 2012 Plan and 2014 Plan combined: Shares Outstanding of Shares Weighted- Weighted- (In Years) Aggregate (in thousands) Balance at December 31, 2014 28,701 497,753 $ 1.59 6.77 Authorized under 2014 Plan (unaudited) 1,400,000 Granted (unaudited) (527,394 ) 527,394 $ 8.34 Option exercised (unaudited) — (27,017 ) $ 1.38 Restricted stock vested and released (unaudited) — (9,000 ) $ — Cancelled/forfeited (unaudited) 32,179 (32,179 ) $ 1.86 Shares expired under 2012 Plan (unaudited) (58,880 ) Balance at September 30, 2015 (unaudited) 874,606 956,951 $ 5.32 8.69 $ 1,046 Exercisable at September 30, 2015 (unaudited) 285,344 $ 1.54 7.15 $ 696 Vested and expected to vest at September 30, 2015 (unaudited) 894,798 $ 5.14 8.62 $ 1,037
Summary of Stock Options Outstanding and Exercisable	The following summarizes the composition of stock options outstanding and exercisable as of September 30, 2015 (unaudited): Options Outstanding and Exercisable Exercise Price Number of Weighted- Life (in years) $1.28 - $1.54 412,256 7.29 $4.52 - $7.92 110,301 9.49 $8.18 - $9.29 434,394 9.81 $1.28 - $9.29 956,951 8.69
Summary of Stock-Based Compensation Expense	Total stock-based compensation expense recognized was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 (unaudited; in thousands) Research and development $ 103 $ 12 $ 166 $ 58 General and administrative 63 24 203 64 Total stock-based compensation expense $ 166 $ 36 $ 369 $ 122
Schedule of Assumptions for Employee Stock Option Grants	The following table illustrates the input assumptions used to value employee stock option grants for the three and nine months ended September 30, 2015 and 2014 (unaudited): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Dividend yield 0% 0% 0% 0% Risk-free interest rate 1.07% - 1.73% 2.02% 1.07% - 2.01% 2.02% - 2.12% Expected volatility 89% 89% 89% 89% Expected term (years) 6.08 6.08 6.08 6.08

Organization - Additional Infor

Organization - Additional Information (Detail) $ / shares in Units, $ in Thousands	Feb. 27, 2015USD ($)$ / sharesshares	Jan. 30, 2015USD ($)$ / sharesshares	Sep. 30, 2015USD ($)SubsidiariesSegment	Sep. 30, 2014USD ($)
Class of Stock [Line Items]
Number of wholly owned subsidiary | Subsidiaries			2
Number of operating business segment | Segment			1
Net proceeds from issuance of common stock			$ 47,140	$ 0
Debt value converted to financial instruments			7,407	0
Proceeds from a private placement concurrent with the initial public offering, net of private placement fee			$ 14,475	$ 0
Lilly Agreement [Member]
Class of Stock [Line Items]
Proceeds from a private placement concurrent with the initial public offering, net of private placement fee		$ 14,500
Conversion of Related Parties Convertible Promissory Notes [Member]
Class of Stock [Line Items]
Debt value converted to financial instruments		$ 7,400
Percentage price of common stock		85.00%
Common Stock [Member] | Conversion of Related Parties Convertible Promissory Notes [Member]
Class of Stock [Line Items]
Number of shares issued for conversion | shares		792,182
Initial Public Offering [Member]
Class of Stock [Line Items]
Net proceeds from issuance of common stock		$ 44,200
Initial Public Offering [Member] | Common Stock [Member]
Class of Stock [Line Items]
Number of common stock, shares issued | shares		4,500,000
Sale of stock, price per share | $ / shares		$ 11
Overallotment option [Member] | Common Stock [Member]
Class of Stock [Line Items]
Number of common stock, shares issued | shares	110,000
Sale of stock, price per share | $ / shares	$ 11
Net proceeds from issuance of common stock	$ 1,100
Private Placement [Member] | Common Stock [Member] | Lilly Agreement [Member]
Class of Stock [Line Items]
Number of common stock, shares issued | shares		1,363,636

Summary of Significant Accoun25

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jan. 31, 2015	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Research and development expense incurred	$ 6,627,000	$ 2,587,000	$ 14,701,000	$ 8,230,000
Research and development [Member]
Summary Of Significant Accounting Policies [Line Items]
Research and development expense incurred	3,000,000	1,000,000	6,300,000	3,600,000
Microneedle patch system [Member]
Summary Of Significant Accounting Policies [Line Items]
Research and development expense incurred	3,600,000	1,500,000	8,300,000	4,300,000
Collaborative development services [Member]
Summary Of Significant Accounting Policies [Line Items]
Research and development expenses incurred under collaborative agreements	$ 0	$ 100,000	$ 100,000	$ 400,000
Other Long-Term Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred offering cost						$ 1,500,000
Initial Public Offering [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred offering cost					$ 1,800,000

Summary of Significant Accoun26

Summary of Significant Accounting Policies - Schedule of Outstanding Common Stock Equivalents Excluded From Computations of Diluted Net Loss per Common Share (Detail) - shares	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from computation of diluted net loss per share	1,029,330	559,293
Warrants to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from computation of diluted net loss per share	72,379	31,674
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from computation of diluted net loss per share	956,951	527,619

Cash, Cash Equivalents and In27

Cash, Cash Equivalents and Investments - Summary of Cash, Cash Equivalents, and Marketable Securities Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cash and cash equivalents	$ 4,875	$ 1,214	$ 2,303	$ 5,913
Amortized Cost	43,946	1,249
Restricted cash	35	35
Gross Unrealized Gains	4	0
Short-term investments in marketable securities	34,098	0
Gross Unrealized Losses	(19)	0
Long-term investments in marketable securities	4,923	0
Estimated Fair Value	43,931	1,249
Contractual maturities of marketable securities:
Due within 12 months	36,028
Due between 1 year and 2 years	4,923
Total	40,951
Cash in bank [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,945	1,214
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	2,945	1,214
Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,930
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	1,930
Certificates of deposit (restricted) [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	35	35
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	35	$ 35
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,680
Gross Unrealized Gains	3
Gross Unrealized Losses	(1)
Estimated Fair Value	7,682
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,793
Gross Unrealized Gains	0
Gross Unrealized Losses	(12)
Estimated Fair Value	11,781
U.S government agency bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,563
Gross Unrealized Gains	1
Gross Unrealized Losses	(6)
Estimated Fair Value	18,558
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,000
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	$ 1,000

Cash, Cash Equivalents and In28

Cash, Cash Equivalents and Investments - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015
Schedule of Available-for-sale Securities [Line Items]
Realized gain and losses on available-for-sale securities	$ 0	$ 0
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments contractual maturity period		15 months
Marketable securities with unrealized loss position period		5 months

Fair Value of Financial Instr29

Fair Value of Financial Instruments - Schedule of Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financial Assets:
Financial assets fair value	$ 40,986
Certificates of deposit (restricted) [Member]
Financial Assets:
Financial assets fair value	35	$ 35
Money market funds [Member]
Financial Assets:
Financial assets fair value	1,930
Certificates of deposit [Member]
Financial Assets:
Financial assets fair value	7,682
Corporate bonds [Member]
Financial Assets:
Financial assets fair value	11,781
U.S government agency bonds [Member]
Financial Assets:
Financial assets fair value	18,558
Commercial paper [Member]
Financial Assets:
Financial assets fair value	1,000
Common Stock Warrant Liability [Member]
Financial Liabilities:
Financial liabilities fair value		300
Level 1 [Member]
Financial Assets:
Financial assets fair value	1,965
Level 1 [Member] | Certificates of deposit (restricted) [Member]
Financial Assets:
Financial assets fair value	35	35
Level 1 [Member] | Money market funds [Member]
Financial Assets:
Financial assets fair value	1,930
Level 1 [Member] | Certificates of deposit [Member]
Financial Assets:
Financial assets fair value	0
Level 1 [Member] | Corporate bonds [Member]
Financial Assets:
Financial assets fair value	0
Level 1 [Member] | U.S government agency bonds [Member]
Financial Assets:
Financial assets fair value	0
Level 1 [Member] | Commercial paper [Member]
Financial Assets:
Financial assets fair value	0
Level 1 [Member] | Common Stock Warrant Liability [Member]
Financial Liabilities:
Financial liabilities fair value		0
Level 2 [Member]
Financial Assets:
Financial assets fair value	39,021
Level 2 [Member] | Certificates of deposit (restricted) [Member]
Financial Assets:
Financial assets fair value	0	0
Level 2 [Member] | Money market funds [Member]
Financial Assets:
Financial assets fair value	0
Level 2 [Member] | Certificates of deposit [Member]
Financial Assets:
Financial assets fair value	7,682
Level 2 [Member] | Corporate bonds [Member]
Financial Assets:
Financial assets fair value	11,781
Level 2 [Member] | U.S government agency bonds [Member]
Financial Assets:
Financial assets fair value	18,558
Level 2 [Member] | Commercial paper [Member]
Financial Assets:
Financial assets fair value	1,000
Level 2 [Member] | Common Stock Warrant Liability [Member]
Financial Liabilities:
Financial liabilities fair value		0
Level 3 [Member]
Financial Assets:
Financial assets fair value	0
Level 3 [Member] | Certificates of deposit (restricted) [Member]
Financial Assets:
Financial assets fair value	0	0
Level 3 [Member] | Money market funds [Member]
Financial Assets:
Financial assets fair value	0
Level 3 [Member] | Certificates of deposit [Member]
Financial Assets:
Financial assets fair value	0
Level 3 [Member] | Corporate bonds [Member]
Financial Assets:
Financial assets fair value	0
Level 3 [Member] | U.S government agency bonds [Member]
Financial Assets:
Financial assets fair value	0
Level 3 [Member] | Commercial paper [Member]
Financial Assets:
Financial assets fair value	$ 0
Level 3 [Member] | Common Stock Warrant Liability [Member]
Financial Liabilities:
Financial liabilities fair value		$ 300

Fair Value of Financial Instr30

Fair Value of Financial Instruments - Schedule of Changes in Financial Instruments Measured at Fair Value Using Significant Unobservable Inputs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financial Liabilities:
Change in fair value of freestanding warrant liability	$ 0	$ 0	$ 48	$ 0
Common Stock Warrant Liability [Member]
Financial Liabilities:
Balance at December 31, 2014			300
Change in fair value of freestanding warrant liability			(48)
Reclassification to equity			(252)
Balance at September 30, 2015	$ 0		$ 0

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 29,430	$ 29,240
Less: accumulated depreciation	(21,394)	(19,559)
Property and equipment, net	8,036	9,681
Laboratory and office equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,112	1,043
Manufacturing equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,721	10,712
Computer equipment and software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	229	210
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	15,534	15,838
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,834	$ 1,437

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 600	$ 800	$ 1,835	$ 2,278

Research and Development Coll33

Research and Development Collaboration and License Agreements - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Jan. 31, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred Revenue, recorded	$ 0		$ 0		$ 170,000
Collaboration agreement, termination effective date			Oct. 27, 2015
Service revenue	0	$ 374,000	$ 313,000	$ 2,481,000
Novo Nordisk Agreement [Member] | Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred Revenue, recorded						$ 1,000,000
Service revenue	0	200,000	46,000	700,000
Novo Nordisk Agreement [Member] | Collaborative Arrangement [Member] | Research and development [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cost of collaboration service revenue	$ 0	$ 100,000	$ 53,000	$ 400,000

Debt Financing - Additional Inf

Debt Financing - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Debt Instrument [Line Items]
Debt value converted to financial instruments		$ 7,407	$ 0
Conversion of Related Parties Convertible Promissory Notes [Member]
Debt Instrument [Line Items]
Debt value converted to financial instruments	$ 7,400
Percentage price of common stock	85.00%
Conversion of Related Parties Convertible Promissory Notes [Member] | December 2014 Promissory Notes [Member]
Debt Instrument [Line Items]
Debt value converted to financial instruments	$ 7,400
Percentage price of common stock	85.00%
Common Stock [Member] | Conversion of Related Parties Convertible Promissory Notes [Member]
Debt Instrument [Line Items]
Number of shares issued for conversion	792,182
Common Stock [Member] | Conversion of Related Parties Convertible Promissory Notes [Member] | December 2014 Promissory Notes [Member]
Debt Instrument [Line Items]
Number of shares issued for conversion	792,182

Debt Financing - Additional I35

Debt Financing - Additional Information 1 (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Apr. 30, 2012
Debt Instrument [Line Items]
Loss on debt extinguishment		$ 0	$ 0	$ (446,000)	$ 0
Common stock warrants, exercise price per share						$ 8.84
Amended Hercules Secured Term Loan [Member]
Debt Instrument [Line Items]
Common stock warrants issued	40,705
Common stock warrants, exercise price per share	$ 7.37
Senior Subordinated Notes [Member] | Amended Hercules Secured Term Loan [Member]
Debt Instrument [Line Items]
Debt face amount	$ 15,000,000
Debt payment terms				Principal balance will be subject to a 12-month interest-only period beginning July 1, 2015, followed by equal monthly installment payments of principal and interest, with all outstanding amounts due and payable on December 1, 2018.
Debt payment, beginning date				Jul. 1, 2015
Debt payment, due and payable date				Dec. 1, 2018
Debt effective interest rate	7.95%
Debt variable interest rate	7.95%
Debt additional variable interest rate decrease	5.25%
Debt end of term balloon payment	$ 100,000
Debt prepayment penalty description				The Company may prepay all, but not less than all, of the Hercules Term Loan subject to a prepayment charge of 1.0% of the then outstanding principal if prepaid prior to June 23, 2016, or 0.5% of the then outstanding principal if prepaid on or after June 23, 2016 but prior to June 23, 2017, with no prepayment charge if prepaid thereafter.
Debt end of term charge	$ 351,135
Common stock warrants issued	40,705
Common stock warrants, exercise price per share	$ 7.37
Legal and closing costs	$ 117,000
Upfront loan origination fee paid	85,000
Legal costs	$ 32,000
Senior Subordinated Notes [Member] | Amended Hercules Secured Term Loan [Member] | Prior to June 23,2016 [Member]
Debt Instrument [Line Items]
Percentage of prepayment penalty on outstanding principal after lock-in period	1.00%
Senior Subordinated Notes [Member] | Amended Hercules Secured Term Loan [Member] | After June 23,2016 but prior to June 23,2017 [Member]
Debt Instrument [Line Items]
Percentage of prepayment penalty on outstanding principal after lock-in period	0.50%
Senior Subordinated Notes [Member] | Amended Hercules Secured Term Loan [Member] | After June 23, 2017 [Member]
Debt Instrument [Line Items]
Prepayment penalty charge on outstanding principal after lock-in period	$ 0
Senior Subordinated Notes [Member] | Senior Secured Term Loan with Hercules [Member]
Debt Instrument [Line Items]
Debt face amount						$ 4,000,000
Convertible Subordinated Debt [Member] | BMR Secured Note [Member]
Debt Instrument [Line Items]
Debt face amount							$ 8,600,000
Prepayment of outstanding principal and all accrued interest	$ 11,400,000

Debt Financing - Summary of Lon

Debt Financing - Summary of Long-Term Debt, Net of Unamortized Debt Discount and Issuance Costs (Detail) $ in Thousands	Sep. 30, 2015USD ($)
Debt Disclosure [Abstract]
Principal amount	$ 15,000
Less: unamortized debt issuance costs	(104)
unamortized fair value of freestanding warrant	(186)
Plus: unamortized fair value debt premium	355
accrued terminal interest	58
accrued interest	99
Long-term debt, net of unamortized debt issuance costs and premium, plus accrued interest	$ 15,222

Warrants to Purchase Common S37

Warrants to Purchase Common Stock - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jan. 27, 2015
Class of Warrant or Right [Line Items]
Common stock warrants, exercise price per share		$ 8.84
Warrant exercise price description					The Company issued Hercules a warrant to purchase $280,000 worth of the Company's stock at a price per share equal to the lower of (i) lowest price per share of stock sold in the Company's next round of private equity financing resulting in gross proceeds of at least $3.0 million prior to the closing of the Company's initial public offering, and (ii) $8.84 per share.
Initial fair value of warrant issued		$ 280,000
Gross proceeds from private equity financing					$ 14,475,000	$ 0
Warrant exercisable, shares							31,674
Reclassification of warrant liability to equity					$ 252,000	0
Warrants exercisable period from IPO					5 years
Other income related to change in fair value of the warrant			$ 0	$ 0	$ (48,000)	$ 0
Amended Hercules Secured Term Loan [Member]
Class of Warrant or Right [Line Items]
Common stock warrants, exercise price per share	$ 7.37
Warrant exercise price description					In connection with the Company's entry into the first amendment to loan and security agreement with Hercules in June 2015, the Company issued Hercules a warrant to purchase 40,705 shares of the Company's common stock at an exercise price of $7.37 per share. Hercules can exercise its purchase right under the warrant, in whole or in part, at any time until June 23, 2020.
Initial fair value of warrant issued	$ 212,000
Common stock warrants issued	40,705
Minimum [Member]
Class of Warrant or Right [Line Items]
Gross proceeds from private equity financing		$ 3,000,000
Common Stock Warrant Liability [Member]
Class of Warrant or Right [Line Items]
Other income related to change in fair value of the warrant					$ 48,000
Fair value assumptions, expected term			5 years		5 years
Fair value assumptions, expected volatility			89.00%		89.00%
Fair value assumptions, risk free interest rate			1.32%		1.32%
Fair value assumptions, expected dividend yield			0.00%		0.00%
Common Stock Warrant Liability [Member] | Amended Hercules Secured Term Loan [Member]
Class of Warrant or Right [Line Items]
Fair value assumptions, expected term	5 years
Fair value assumptions, expected volatility	89.00%
Fair value assumptions, risk free interest rate	1.73%
Fair value assumptions, expected dividend yield	0.00%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2015ft²	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Other Commitments [Line Items]
Deferred rent liability, net		$ 40		$ 40		$ 98
Operating lease rent expense		$ 200	$ 200	$ 500	$ 500
Sixth Amendment to Lease Agreement [Member]
Other Commitments [Line Items]
Operating lease amendment description				In June 2015, the Company entered into a sixth amendment to the lease, pursuant to which the landlord’s option to recapture a specified portion of the leased premises (comprising approximately 29,348 square feet of the approximate total 55,588 square feet of leased premises) has been suspended and the Company has the option until December 31, 2015 to extend the term of the lease by an additional 38 months to June 1, 2022 and pay rent on the total leased premises beginning April 1, 2016 at the rates set forth in the sixth amendment.
Operating lease optional additional term	38 months
Operating lease agreement expiration date				Jun. 1, 2022
Landlord option to recapture portion of leased premises suspended | ft²	29,348
Operating lease area of premises | ft²	55,588
Lease payment start date				Apr. 1, 2016

Commitments and Contingencies39

Commitments and Contingencies - Schedule of Future Minimum Payments under Non-cancellable Operating Leases (Detail) $ in Thousands	Sep. 30, 2015USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating lease future minimum payments due, 2015	$ 153
Operating lease future minimum payments due, 2016	626
Operating lease future minimum payments due, 2017	637
Operating lease future minimum payments due, 2018	651
Operating lease future minimum payments due, 2019	163
Operating lease future minimum payments due	$ 2,230

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Jan. 27, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation	$ 3
Weighted-average period of unrecognized stock-based compensation	3 years 3 months 15 days
2014 Equity and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	1,400,000
2012 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance		0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Options and Awards Activities (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Beginning balance	28,701
Shares Available for Grant, Granted	(527,394)
Shares Available for Grant, Option exercised	0
Shares Available for Grant, Cancelled/forfeited	32,179
Shares Available for Grant, Ending balance	874,606	28,701
Outstanding Number of Shares, Beginning balance	497,753
Outstanding Number of Shares, Granted	527,394
Outstanding Number of Shares, Option exercised	(27,017)
Outstanding Number of Shares, Cancelled/forfeited	(32,179)
Outstanding Number of Shares, Ending balance	956,951	497,753
Outstanding Number of Shares, Exercisable	285,344
Outstanding Number of Shares, Restricted stock vested and released	894,798
Weighted-Average Exercise Price per Share, Beginning balance	$ 1.59
Weighted-Average Exercise Price per Share, Granted	8.34
Weighted-Average Exercise Price per Share, Option exercised	1.38
Weighted-Average Exercise Price per Share, Cancelled/forfeited	1.86
Weighted-Average Exercise Price per Share, Ending balance	5.32	$ 1.59
Weighted-Average Exercise Price per Share, Exercisable	1.54
Weighted-Average Exercise Price per Share, Vested and expected to vest	$ 5.14
Weighted-Average Remaining Contractual Term	8 years 8 months 9 days	6 years 9 months 7 days
Weighted-Average Remaining Contractual Term, Exercisable	7 years 1 month 24 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest	8 years 7 months 13 days
Aggregate Intrinsic Value, Ending balance	$ 1,046
Aggregate Intrinsic Value, Exercisable	696
Aggregate Intrinsic Value, Aggregate Intrinsic Value, Vested and expected to vest	$ 1,037
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding Number of Shares, Restricted stock vested and released	9,000
2014 Equity and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Authorized under 2014 Plan	1,400,000
2012 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant, Shares expired under 2012 Plan	(58,880)

Stock-Based Compensation - Su42

Stock-Based Compensation - Summary of Stock Options Outstanding and Exercisable (Detail)	9 Months Ended
	Sep. 30, 2015$ / sharesshares
$1.28-$1.54 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable, Exercise Price, Minimum	$ 1.28
Options Outstanding and Exercisable, Exercise Price, Maximum	$ 1.54
Options Outstanding and Exercisable, Number of Shares | shares	412,256
Options Outstanding and Exercisable,Weighted-Average Remaining Contractual Life	7 years 3 months 15 days
$4.52-$7.92 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable, Exercise Price, Minimum	$ 4.52
Options Outstanding and Exercisable, Exercise Price, Maximum	$ 7.92
Options Outstanding and Exercisable, Number of Shares | shares	110,301
Options Outstanding and Exercisable,Weighted-Average Remaining Contractual Life	9 years 5 months 27 days
$8.18-$9.29 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable, Exercise Price, Minimum	$ 8.18
Options Outstanding and Exercisable, Exercise Price, Maximum	$ 9.29
Options Outstanding and Exercisable, Number of Shares | shares	434,394
Options Outstanding and Exercisable,Weighted-Average Remaining Contractual Life	9 years 9 months 22 days
$1.28-$9.29 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding and Exercisable, Exercise Price, Minimum	$ 1.28
Options Outstanding and Exercisable, Exercise Price, Maximum	$ 9.29
Options Outstanding and Exercisable, Number of Shares | shares	956,951
Options Outstanding and Exercisable,Weighted-Average Remaining Contractual Life	8 years 8 months 9 days

Stock-Based Compensation - Su43

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	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, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 166	$ 36	$ 369	$ 122
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	103	12	166	58
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 63	$ 24	$ 203	$ 64

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Assumptions for Employee Stock Option Grants (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Dividend yield	0.00%	0.00%	0.00%	0.00%
Risk-free interest rate, minimum	1.07%		1.07%	2.02%
Risk-free interest rate		2.02%
Risk-free interest rate, maximum	1.73%		2.01%	2.12%
Expected volatility	89.00%	89.00%	89.00%	89.00%
Expected term (years)	6 years 29 days	6 years 29 days	6 years 29 days	6 years 29 days