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Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2016	Oct. 31, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Trading Symbol	CBYL
Entity Registrant Name	CARBYLAN THERAPEUTICS, INC.
Entity Central Index Key	0001348911
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		26,344,104

Condensed Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 35,208	$ 53,723
Prepaid expenses and other current assets	605	1,222
Total current assets	35,813	54,945
Property and equipment, net		805
Restricted cash	50	50
Other assets		991
Total assets	35,863	56,791
Current liabilities:
Accounts payable	431	1,460
Accrued expenses	1,431	1,327
Loan payable		1,455
Deferred licensing revenue	29	29
Total current liabilities	1,891	4,271
Loans payable, net of current portion		3,154
Deferred licensing revenue, net of current portion	35	56
Total liabilities	1,926	7,481
Commitments and contingencies (Note 5)
Stockholders’ equity
Preferred stock, $0.001 par value; 5,000,000 shares authorized as of September 30, 2016 and December 31, 2015: no shares issued and outstanding as of September 30, 2016 and December 31, 2015
Common stock, $0.001 par value; 100,000,000 shares authorized as of September 30, 2016 and December 31, 2015: 26,344,104 shares issued and outstanding as of September 30, 2016 and 26,322,494 shares issued and outstanding as of December 31, 2015	27	27
Additional paid-in capital	122,873	121,904
Accumulated deficit	(88,963)	(72,621)
Total stockholders’ equity	33,937	49,310
Total liabilities and stockholders’ equity	$ 35,863	$ 56,791

Condensed Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	26,344,104	26,322,494
Common stock, shares outstanding	26,344,104	26,322,494

Condensed Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2016

Sep. 30, 2015

Sep. 30, 2016

Sep. 30, 2015

Income Statement [Abstract]

License Revenue

$ 7

$ 21

Operating Expenses:

Research and development

332

3,533

4,812

11,939

General and administrative

2,080

1,373

6,226

3,549

Restructuring and lease termination charges

3,420

Impairment of long-lived assets

1,460

Total operating expenses

2,412

4,906

15,918

15,488

Loss from Operations

(2,405)

(4,899)

(15,897)

(15,467)

Other Income (expense):

Interest income

Interest expense

(95)

(493)

(1,100)

Loss on extinguishment of convertible promissory notes

(3,177)

Other income (expense), net

(2)

553

Net Loss and Comprehensive Loss

$ (2,385)

$ (4,991)

$ (16,342)

$ (19,187)

Net loss per share to common stockholders, basic and diluted

$ (0.09)

$ (0.19)

$ (0.62)

$ (1.15)

^[1]

Weighted average common shares outstanding, basic and diluted

26,343,108

26,322,494

26,338,238

16,642,715

^[1]

[1]	Revised from a net loss of $1.12 per share to common stockholders, basic and diluted, and 17,203,279 weighted average common shares outstanding, basic and diluted, as previously reported for the nine months ended September 30, 2015.

Condensed Statements of Operations and Comprehensive Loss (Parenthetical) (Unaudited)

9 Months Ended

Sep. 30, 2015

$ / shares

Net loss per share to common stockholders, basic and diluted | $ / shares

$ (1.15)

^[1]

Weighted average common shares outstanding, basic and diluted | shares

16,642,715

^[1]

As Previously Reported [Member]

Net loss per share to common stockholders, basic and diluted | $ / shares

$ 1.12

Weighted average common shares outstanding, basic and diluted | shares

17,203,279

[1]	Revised from a net loss of $1.12 per share to common stockholders, basic and diluted, and 17,203,279 weighted average common shares outstanding, basic and diluted, as previously reported for the nine months ended September 30, 2015.

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash Flows from Operating Activities
Net loss	$ (16,342)	$ (19,187)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	34	98
Gain on sale of property and equipment	(23)
Stock based compensation expense	962	444
Change in fair value of preferred stock warrant liability and derivative liability		(520)
Non-cash interest expense	58	192
Amortization of loan and convertible promissory notes discount	83	773
Loss on extinguishment of loans payable	(250)
Loss on extinguishment of convertible promissory notes		3,177
Impairment of long-lived assets	1,460
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	945	(881)
Other assets	59	(39)
Accounts payable	(1,029)	503
Accrued expenses	104	(335)
Deferred licensing revenue	(21)	(21)
Net cash used in operating activities	(13,960)	(15,796)
Cash Flows from Investing Activities
Purchase of property and equipment	(245)	(280)
Sale of property and equipment	183
Net cash used in investing activities	(62)	(280)
Cash Flows from Financing Activities
Proceeds from issuance of common stock upon exercise of options, net	7	149
Proceeds from issuance of common stock, net		67,908
Proceeds from convertible promissory notes		4,000
Repayment of loan payable	(4,500)
Net cash provided by (used in) financing activities	(4,493)	72,057
Net increase (decrease) in cash and cash equivalents	(18,515)	55,981
Cash and cash equivalents at beginning of period	53,723	3,897
Cash and cash equivalents at end of period	35,208	59,878
Supplemental Cash Flow Information
Cash paid for interest	606	45
Supplemental Disclosures of Non-cash Investing Activities
Transfer of long-term deposits to property and equipment	$ 824
Supplemental Disclosures of Non-cash Financing Activities
Conversion of preferred stock warrants to common stock warrants		347
Conversion of preferred stock to common stock		39,556
Derivative related to convertible promissory notes at issuance		1,196
Beneficial conversion feature for convertible promissory notes		$ 519

Formation and Business of the Company

9 Months Ended

Sep. 30, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Formation and Business of the Company

1.	Formation and Business of the Company

Carbylan Therapeutics, Inc. (the “Company”) is a clinical-stage specialty pharmaceutical company. The Company’s initial focus was on the development of Hydros-TA, its proprietary, intra-articular injectable product candidate to treat pain associated with osteoarthritis of the knee. The Company was incorporated in the state of Delaware on March 26, 2004 as Sentrx Surgical, Inc. The name of the Company was changed to Carbylan Biosurgery, Inc. on December 14, 2005. The name of the Company was changed to Carbylan Therapeutics, Inc. on March 7, 2014.

Since commencing operations and until April 2016, the Company has devoted substantially all of its efforts to identifying and developing product candidates for therapeutic markets, recruiting personnel and raising capital. The Company has devoted predominantly all of its resources to the preclinical and clinical development of, and manufacturing capabilities for, Hydros-TA. The Company has never been profitable and has not yet commenced commercial operations. At September 30, 2016, the Company had an accumulated deficit of approximately $89.0 million.

In February 2016, the Company announced topline results of its COR1.1 trial, a Phase 3 clinical trial comparing treatment with Hydros-TA to treatment with Hydros and with TA, on a standalone basis. Hydros-TA met the first of its two primary endpoints but did not meet its second primary endpoint. In March 2016, the Company engaged a financial and strategic advisor, Wedbush PacGrow, to advise it on strategic alternatives. In April 2016, the Company announced that it had suspended further clinical development of Hydros-TA and that it was actively pursuing a strategic transaction, including a merger or acquisition of the Company. In April 2016, the board of directors approved a restructuring plan effective as of April 15, 2016 resulting in a reduction in force affecting 14 of the Company’s 17 employees, including two executive officers. The restructuring plan was intended to reduce operational costs to preserve capital and streamline the Company’s operations as it pursues a strategic transaction. As a result of the restructuring plan, the Company incurred one-time cash severance payments of approximately $0.3 million and an aggregate of $0.7 million in severance expenses, including the severance payments to the two executive officers. The charges associated with the restructuring plan were recorded in the quarter ended June 30, 2016.

In June 2016, the Company entered into a definitive share purchase agreement (“Share Purchase Agreement”), with KalVista Pharmaceuticals Ltd. (“KalVista”), a private company limited by shares incorporated and registered in England and Wales and the shareholders of KalVista, pursuant to which the shareholders of KalVista will become the majority owners of the Company. The number of shares of common stock of the Company to be issued in respect of each KalVista share will be based upon the relative stipulated values of each of the Company and KalVista as determined pursuant to the Share Purchase Agreement. The stipulated value of the Company is subject to downward adjustment based upon the Company’s net cash balance at the closing of the transaction. Assuming that no such adjustment is applicable, immediately following the closing of the transaction, KalVista equity holders are expected to own approximately 81.0% of the outstanding common stock of the Company on a fully-diluted basis. Consummation of the transaction is subject to certain closing conditions, including, among other things, approval by the stockholders of the Company of the transactions contemplated by the Share Purchase Agreement and related matters. The Share Purchase Agreement contains certain termination rights for both the Company and KalVista, and further provides that, upon termination of the Share Purchase Agreement under specified circumstances, the Company may be required to pay KalVista a termination fee of $3.0 million and/or to reimburse certain expenses incurred by KalVista in an amount up to $1.0 million.

In March 2016, the Company determined that it would not occupy the Newark Lease facility. (See Note 5.) As a result, the Company recorded an asset impairment charge consisting primarily of leasehold improvements for the Newark Lease of approximately $1.1 million. In June 2016, the Company entered in to a lease termination agreement with the lessor and agreed to the termination of the lease and to surrender the leased premises by June 30, 2016. The Company paid a one-time termination fee of $2.45 million on June 27, 2016 and surrendered the premises. (See Note 5.)

In June 2016, the Company repaid in full its outstanding loan with Silicon Valley Bank pursuant to its Loan and Security Agreement originally entered into in October 2011, as well as the final interest payment and various fees. The total payment was $4.6 million, and the Loan and Security Agreement has terminated. There are no remaining aggregated annual payments under the Loan and Security Agreement as of September 30, 2016. (See Note 6.)

In July 2016, the Company received a deficiency letter from the Listing Qualifications Department (the “Staff”) of The NASDAQ Stock Market notifying the Company that, for the last 30 consecutive business days, the bid price for the Company’s common stock had closed below the minimum $1.00 per share requirement for continued inclusion on The NASDAQ Global Market pursuant to NASDAQ Listing Rule 5450(a)(1) (the “Rule”). In accordance with NASDAQ Listing Rule 5810(c)(3)(A), the Company was provided an initial period of 180 calendar days, or until January 24, 2017, to regain compliance with the Rule. If, at any time before January 24, 2017, the bid price for the Company’s common stock closes at $1.00 or more for a minimum of 10 consecutive business days as required under Listing Rule 5810(c)(3)(A), the Staff would provide written notification to the Company that it complies with the Rule.

In March 2015, the Company’s board of directors and stockholders approved a 4-for-1 reverse stock split of the Company’s common and preferred stock. The Company filed an amendment to its certificate of incorporation effecting the reverse stock split on March 13, 2015. All share and per share amounts contained in these financial statements and notes thereto, have been adjusted retroactively to reflect the reverse stock split.

On April 8, 2015, the Company’s registration statement on Form S-1 (File No. 333-201278) relating to the initial public offering of its common stock was declared effective by the SEC. The initial public offering closed on April 14, 2015 at which time the Company sold 14,950,000 shares of common stock, which included 1,950,000 shares of common stock purchased by the underwriters upon the full exercise of their option to purchase additional shares of common stock. The Company received cash proceeds of approximately $66.3 million from the initial public offering, net of underwriting discounts and commissions and offering costs paid by the Company.

Prior to the closing of the initial public offering, all outstanding shares of convertible preferred stock converted into 8,268,531 shares of common stock with the related carrying value of $39.6 million reclassified to common stock and additional paid-in capital. In addition, all convertible preferred stock warrants were converted into warrants exercisable for common stock and the convertible promissory notes were converted in to 2,287,120 shares of common stock.

On April 14, 2015, the Company filed its Amended and Restated Certificate of Incorporation, authorizing 105,000,000 shares of capital stock, including 100,000,000 shares of authorized common stock and 5,000,000 shares of authorized undesignated preferred stock. Both the common stock and preferred stock have a par value of $0.001 per share. There are no shares of preferred stock outstanding at September 30, 2016.

Summary of Significant Accounting Policies and Basis of Presentation

9 Months Ended

Sep. 30, 2016

Accounting Policies [Abstract]

Summary of Significant Accounting Policies and Basis of Presentation

2.Summary of Significant Accounting Policies and Basis of Presentation

Basis of Presentation

The accompanying interim condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements and reflect all adjustments which are, in the opinion of management, necessary to a fair statement of the results for the period presented herein. The unaudited interim financial statements have been prepared on the same basis as the annual financial statements. These interim financial results are not necessarily indicative of the results to be expected for the year ending December 31, 2016, or for any other future annual or interim period. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto included in the Company’s Annual Report on Form 10-K filed on March 30, 2016 with the SEC.

Use of Estimates

The preparation of the interim condensed 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 financial statements and the reported amounts of revenues and expenses during the reporting periods. On an ongoing basis, the Company evaluates its estimates, including those related to impairment of long-lived assets, restructuring, lease termination charges, common stock, stock-based compensation expense, warrant liabilities, accruals, derivative liability, deferred tax valuation allowance and revenue recognition. Management bases its estimates on historical experience or on various other assumptions, including information received from its service providers, which it believes to be reasonable under the circumstances. Actual results could differ from those estimates.

Risks and Uncertainties

Medicinal drug product candidates, like those previously being developed by the Company, require approvals from the U.S. Food and Drug Administration (“FDA”) or foreign regulatory agencies prior to commercial sales. There can be no assurance that any product candidates will receive the necessary approvals and any failure to receive approval or delay in approval may have a material adverse impact on the business and financial statements of the sponsoring company.

If the Company’s strategic transaction with KalVista is not consummated and it decides to continue its historical business operations, the Company may require substantial additional funding to operate. There can be no assurance that such financing will be available or will be at terms acceptable by the Company. Additionally, the Company will then be subject to risks common to companies in the pharmaceutical industry with no commercial operating history, including, but not limited to, dependency on the clinical and commercial success of its product candidates, ability to obtain regulatory approval of its product candidates, the need for substantial additional financing to achieve its goals, uncertainty of broad adoption of its approved products, if any, by physicians and consumers, significant competition and untested manufacturing capabilities.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents. The Company invests its excess cash in money market accounts. The Company’s cash and cash equivalents are held by a single financial institution and all cash is held in the United States. Such deposits may, at times, exceed federally insured limits. The Company has not recognized any losses during the periods presented and management does not believe that the Company is exposed to significant credit risk from its cash and cash equivalents.

Segment Reporting

The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company is a specialty pharmaceutical company focused on the development and commercialization of novel and proprietary therapies that address significant unmet medical needs. No product revenue has been generated since inception, and all assets are held in the United States.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with an original maturity date of 90 days or less on the date of purchase to be cash equivalents. The Company invests its cash in bank deposits and money market funds.

Restricted Cash

The Company is required to guarantee the credit limit on its corporate credit card with a certificate of deposit of $50,000. The balance is included as restricted cash on the condensed balance sheets.

Beneficial Conversion Feature

From time to time, the Company may issue convertible promissory notes that have conversion prices that create an embedded beneficial conversion feature on the issuance date. A beneficial conversion feature exists on the date a convertible promissory note is issued when the fair value of the underlying common stock to which the note is convertible into is in excess of the remaining unallocated proceeds of the note after first considering the allocation of a portion of the note proceeds to the fair value of any attached equity instruments, if any related equity instruments were granted with the debt. The intrinsic value of the beneficial conversion feature is recorded as a debt discount with a corresponding amount to additional paid-in capital. The debt discount is amortized to interest expense over the term of the note using the effective interest method.

Embedded Derivatives Related to Convertible Promissory Notes

Embedded derivatives that are required to be bifurcated from the underlying debt instrument (i.e. host) are accounted for and valued as a separate financial instrument. The Company evaluated the terms and features of the convertible promissory notes issued in September 2014 and February 2015 and identified embedded derivatives requiring bifurcation and accounting at fair value because the economic and contractual characteristics of the embedded derivatives met the criteria for bifurcation and separate accounting due to the conversion features (see Note 7 for a description of the conversion features).

Property and Equipment, Net

Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which are as follows:

Computer equipment		3 years
Lab equipment		3 years
Furniture and fixtures		5 years
Machinery and equipment		3 years
Manufacturing equipment		7 years

Leasehold improvements are amortized over the lesser of their useful lives or the term of the lease. Upon sale or retirement of the assets, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is recognized in the accompanying interim condensed statement of operations and comprehensive loss in operating expenses. Maintenance and repairs are charged to operations as incurred.

Long-lived assets

The Company assesses the impairment of long-lived assets whenever events or changes in circumstances indicate that the carrying value of such assets, or asset groups, may not be recoverable. Whenever events or changes in circumstances suggest that the carrying amount of long-lived assets may not be recoverable, the future undiscounted cash flows expected to be generated by the asset, or asset groups from its use or eventual disposition is estimated. If the sum of the expected future undiscounted cash flows is less than the carrying amount of those assets, or asset groups, an impairment loss is recognized based on the excess of the carrying amount over the fair value of the assets, or asset groups.

Pre-clinical and Clinical Trial Accruals

The Company’s clinical trial accruals are based on estimates of patient enrollment and related costs at clinical investigator sites as well as estimates for the services received and efforts expended pursuant to contracts with clinical research organizations that conduct and manage preclinical and clinical trials on the Company’s behalf. If contracts are modified based upon changes in the clinical trial protocol or scope of work to be performed, the Company modifies the estimates of accrued expenses accordingly. To date, there have been no material differences from its estimates to the amount actually incurred.

Preferred Stock Warrant Liability

The Company accounts for its warrants as either equity or liabilities based upon the characteristics and provisions of each instrument. Warrants classified as derivative liabilities are recorded on the Company’s accompanying balance sheets at their fair value on the date of issuance and are revalued at each subsequent balance sheet date, with fair value changes recognized as increases or reductions to other income (expense), net in the statements of operations and comprehensive loss.

Research and Development Expenditures

Costs incurred to further the Company’s research and development include salaries and related employee benefits, stock-based compensation expense, costs associated with clinical studies, nonclinical research and development activities, regulatory activities, research-related overhead expenses and fees paid to external service providers and contract research and manufacturing organizations that conduct certain research and development activities on behalf of the Company.

Stock-Based Compensation

The Company maintains performance incentive plans under which incentive stock options and non-qualified stock options may be granted to employees and non-employees. The Company accounts for stock-based compensation arrangements with employees in accordance with ASC 718, Compensation — Stock Compensation. ASC 718 requires the recognition of compensation expense, using a fair value-based method, for costs related to all share-based payments including stock options.

The Company’s determination of the fair value of stock options on the date of grant utilizes the Black-Scholes option-pricing model, and is impacted by its common stock price as well as changes in assumptions regarding a number of subjective variables. These variables include, but are not limited to, expected term that options will remain outstanding, expected common stock price volatility over the term of the option awards, risk-free interest rates and expected dividends.

The fair value is recognized over the period during which an optionee is required to provide services in exchange for the option award, known as the requisite service period (usually the vesting period), on a straight-line basis. Stock-based compensation expense recognized at fair value includes the impact of estimated forfeitures. The Company estimates future forfeitures at the date of grant and revises the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

Income Taxes

The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.

The Company accounts for uncertain tax positions in accordance with ASC 740-10, Accounting for Uncertainty in Income Taxes. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.

Net Loss per Share Attributable to Common Stockholders

Basic earnings per share to common stockholders is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the periods presented. The computation of diluted earnings per share is similar to the computation of basic earnings per share, except that the denominator is increased for the assumed exercise of dilutive options and other potentially dilutive securities using the treasury stock method unless the effect is antidilutive.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards update (“ASU”) 2014-09, “Revenue from Contracts with Customers,” requiring an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. This guidance is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. This guidance can be adopted either retrospectively to each prior reporting period presented, or retrospectively with a cumulative-effect adjustment recognized as of the date of adoption. The original effective date of this guidance for public entities was for annual reporting period beginning after December 15, 2016. In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606), to defer the effective date of this guidance by one year, to the annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. A reporting entity may choose to early adopt the guidance as of the original effective date. The FASB has issued several updates to the standard which i) defer the original effective date from January 1, 2017 to January 1, 2018, while allowing for early adoption as of January 1, 2017 (ASU 2015-14); ii) clarify the application of the principal versus agent guidance (ASU 2016-08); and iii) clarify the guidance on inconsequential and perfunctory promises and licensing (ASU 2016-10). In May 2016, the FASB issued ASU 2016-12, Revenue from Contracts with Customers (Topic 606) Narrow-Scope Improvements and Practical Expedients, to address certain narrow aspects of the guidance including collectability criterion, collection of sales taxes from customers, noncash consideration, contract modifications and completed contracts. This issuance does not change the core principle of the guidance in the initial topic issued in May 2014. The Company does not anticipate an early adoption of Topic 606, and is currently evaluating the impact of the adoption of this guidance upon the financial statements, including which transition method it will select.

In August 2014, the FASB issued ASU NO. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern, or ASU 2014-15. ASU 2014-15 requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued and provides guidance on determining when and how to disclose going concern uncertainties in the financial statements. Certain disclosures will be required if conditions give rise to substantial doubt about an entity’s ability to continue as a going concern. ASU 2014-15 applies to all entities and is effective for annual and interim reporting periods ending after December 15, 2016, with early adoption permitted. The Company does not anticipate an early adoption, and is currently evaluating the impact on its financial statements upon the adoption of this guidance.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under this guidance, an entity is required to recognize right-of-use assets and lease liabilities on its balance sheet and disclose key information about leasing arrangements. This guidance offers specific accounting guidance for a lessee, a lessor and sale and leaseback transactions. Lessees and lessors are required to disclose qualitative and quantitative information about leasing arrangements to enable a user of the financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. This guidance is effective for annual reporting period beginning after December 15, 2018, including interim periods within that reporting period, and requires a modified retrospective adoption, with early adoption permitted. The Company is currently evaluating the impact on its financial statements upon the adoption of this guidance.

In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation – Stock Compensation (Topic 718). This guidance identifies areas for simplification involving several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, an option to recognize gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the statement of cash flows. This guidance is effective for annual reporting period beginning after December 15, 2016, including interim periods within that reporting period, with early adoption permitted. The Company is currently evaluating the impact on its financial statements upon the adoption of this guidance.

In August 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-15, Statement of Cash Flows, Classification of Certain Cash Receipts and Cash Payments (Topic 230). This guidance addresses specific cash flow issues with the objective of reducing the diversity in practice for the treatment of these issues. The areas identified include: debt prepayment of extinguishment; settlement of zero-coupon debt instruments; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions and application of the predominance principle with respect to separately identifiable cash flows. This guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, with early adoption permitted. The Company is currently evaluating the impact on its financial statements upon the adoption of this guidance.

Fair Value Measurements

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Fair Value Measurements

3.	Fair Value Measurements

The Company follows ASC 820-10, Fair Value Measurements and Disclosures, which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows:

Level 1

Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2

Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.

Level 3

Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model.

The Company’s investments in money market funds are measured at fair value on a recurring basis. These money market funds are actively traded and reported daily through a variety of sources. The fair value of the money market fund investments is classified as Level 1.

The fair value of the certificates of deposit is classified as Level 2 due to the nature of a contractual restriction with a financial institution that requires the certificate of deposit to remain in place as collateral for the credit card, and therefore the ability to liquidate the investment is limited.

There were no transfers between Level 1 and Level 2 during the periods presented.

In certain cases where there is limited activity or less transparency around inputs to valuation, securities are classified as Level 3. During 2014 and through the date of the initial public offering in April 2015, the Company estimated the fair value of the warrant liability. The Company used the Black-Scholes option-pricing method to calculate the fair value of the warrant liability. Generally, increases or decreases in the fair value of the underlying convertible preferred stock resulted in a similar impact in the fair value measurement of the warrant liability.

The fair value of the derivative of the September 2014 and February 2015 convertible promissory notes (see Note 7) was recorded as a derivative liability instrument that is measured at fair value at each reporting period. In connection with the initial public offering, the convertible promissory notes were converted in to shares of common stock, and the derivative liability is therefore not present at September 30, 2016. At March 31, 2015, the Company remeasured the fair value of the derivative for the September 2014 and February 2015 convertible promissory notes by estimating the fair value of the convertible promissory notes with and without the conversion derivative. To calculate the fair value of the convertible promissory notes without the conversion derivative, the Company estimated the present value of the expected cash payments at an assumed discount rate. To calculate the fair value of the convertible promissory notes with the conversion feature, the Company calculated the present value of the convertible promissory notes upon conversion at an initial public offering, and the present value of the convertible promissory notes at an equity financing. The Company applied a probability of occurrence to all of the conversion scenarios and estimated a weighted value of the notes with the conversion feature. The difference between the fair value of the convertible promissory notes with and without the conversion features is the fair value of the derivative. In April 2015, the Company completed the initial public offering, and there was no further re-measurement of derivative.

The following table presents the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring and non-recurring basis:

	Fair Value Measurements as of September 30, 2016 (in thousands)
	Quoted Price in Active Markets for Identical Assets		Significant other Observable Inputs		Significant Unobservable Inputs
	Level 1		Level 2		Level 3		Total
Assets
Money market funds⁽¹⁾	$	34,057	$	—	$	—	$	34,057
Certificate of deposit		—		50		—		50
	$	34,057	$	50	$	—	$	34,107

	Fair Value Measurements as of December 31, 2015 (in thousands)
	Quoted Price in Active Markets for Identical Assets		Significant other Observable Inputs		Significant Unobservable Inputs
	Level 1		Level 2		Level 3		Total
Assets
Money market funds⁽¹⁾	$	53,625	$	—	$	—	$	53,625
Certificate of deposit		—		50		—		50
	$	53,625	$	50	$	—	$	53,675

(1)	Included in cash and cash equivalents in the Company’s condensed balance sheet.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Balance Sheet Components

9 Months Ended

Sep. 30, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Balance Sheet Components

4.	Balance Sheet Components

Property and Equipment, Net

The following table represents the components of property and equipment (in thousands):

	September 30,		December 31,
	2016		2015
Computer equipment	$	-	$	30
Lab equipment		-		697
Furniture and fixtures		-		21
Machinery and equipment		-		262
Leasehold improvements		-		55
Construction in progress		-		368
		-		1,433
Less: Accumulated depreciation and amortization		-		(628	)
Total property and equipment, net	$	-	$	805

Depreciation expense for the nine months ended September 30, 2016 and 2015, was $34,000, and $98,000, respectively.

The Company recorded an impairment charge of $1.5 million during March 2016 in connection with its determination not to occupy the Newark Lease facility and to suspend further clinical development of Hydros-TA. An impairment charge of $1.1 million was recorded, primarily related to leasehold improvements, furniture and fixtures for the Newark Lease facility that have no future use. Additionally, the Company determined that certain equipment used in the development of Hydros-TA was impaired and recorded an impairment charge of $0.4 million. In May 2016, this equipment was sold for $0.2 million, and an immaterial gain on the sale of the assets was recorded in operating expenses. Each of these impairment charges was measured using Level 1 inputs of the fair value hierarchy.

Accrued Liabilities

(in thousands)

	September 30,		December 31,
	2016		2015
Accrued payroll and related expenses	$	365	$	727
Accrued legal expenses		486		77
Accrued research and clinical trial expenses		21		338
Accrued professional services		555		185
Other accrued expenses		4		-
	$	1,431	$	1,327

Commitments and Contingencies

9 Months Ended

Sep. 30, 2016

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

5.	Commitments and Contingencies

Operating Lease

The Company leased its facilities in Palo Alto, California under a noncancelable operating lease which expired May 2016. The terms of the lease agreement required the Company to provide a security deposit of $69,000. The security deposit was included in other assets on the accompanying condensed balance sheets. In June 2016, the Company vacated these premises, and in July 2016, the security deposit was returned to the Company. The Company had a sub-lease agreement with a tenant for approximately thirty-seven percent of the square footage of the corporate headquarters. Under this agreement, the Company received $16,000 per month as rental income which is accounted for as a reduction of rent expense. The sub-lease agreement expired on February 29, 2016.

On July 13, 2015, the Company entered into a lease for an 18,704 square foot facility located in Newark, California (the “Newark Lease”), with office, R&D and laboratory space. Under the Newark Lease, the landlord provided an allowance of $599,000 to fund certain improvements to the facility. The Newark Lease had an initial term of approximately six and a half years, with a monthly rental rate starting at $2.65 per square foot in the first year of the lease, escalating each year by 3.0%. The annual rent obligation was expected to be approximately $599,000 for the first year of the lease. The Company was responsible for certain other costs, such as insurance, taxes, utilities, maintenance and repairs, a property management fee, and reimbursement of certain expenses related to maintenance of common areas. The Company delivered a security deposit of approximately $149,000 in connection with the execution of the Newark Lease, and this amount was recorded in other assets on the condensed balance sheets, until it was returned to the Company in July 2016. In March 2016, the Company determined that it would not occupy the Newark Lease facility and recorded an asset impairment charge consisting primarily of leasehold improvements of approximately $1.1 million. In June 2016, the Company entered in to a lease termination agreement with the lessor and agreed to the termination of the lease and to surrender the leased premises by June 30, 2016. The Company paid a one-time termination fee of $2.45 million on June 27, 2016 and surrendered the premises.

As of September 30, 2016, there are no aggregate future minimum lease payments since there are no current operating leases.

Gross rent expense for the three months ended September 30, 2016 and 2015 was $0 and $110,000, respectively. The rental expense is reduced by the sublease rental income amounts of $0 and $50,000, respectively, for the three months ended September 30, 2016 and 2015. Gross rent expense for the nine months ended September 30, 2016 and 2015 was $507,000 and $328,000, respectively. The rental expense is reduced by the sublease rental income amounts of $37,000 and $147,000, respectively, for the nine months ended September 30, 2016 and 2015.

Indemnification

In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves future claims that may be made against the Company but have not yet been made. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. However, the Company may record charges in the future as a result of these indemnification obligations. No amounts associated with such indemnifications have been recorded to date.

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business activities. The Company accrues a liability for such matters when it is probable that a liability has been incurred and that future expenditures can be reasonably estimated. There have been no contingent liabilities requiring accrual or disclosure at September 30, 2016.

Loan and Security Agreement

9 Months Ended

Sep. 30, 2016

Debt Disclosure [Abstract]

Loan and Security Agreement

6.	Loan and Security Agreement

In October 2011, the Company entered into a loan and security agreement (the “Loan and Security Agreement”) with a financial institution. In September 2014, the Loan and Security Agreement was amended. The interest rate was 3.95% per annum and the loan was repayable in thirty-six equal monthly installments, following an eighteen-month interest only period. The final balloon interest payment was approximately $0.5 million and was accreted over the life of the loan. The amendment was accounted for as a modification, and the unamortized debt discount as of the date of the modification was being amortized over the new loan period, using the effective interest rate method.

In June 2016, the Company repaid the loan in full, as well as the final interest payment and various fees. The total payment was $4.6 million of accrued interest, the final balloon payment and principal, and the Loan and Security Agreement has terminated. There are no remaining aggregated annual payments under the Loan and Security Agreement as of September 30, 2016.

Convertible Promissory Notes

9 Months Ended

Sep. 30, 2016

Long Term Debt [Abstract]

Convertible Promissory Notes

7.	Convertible Promissory Notes

On September 29, 2014 and February 19, 2015, the Company entered into convertible note purchase agreements and issued convertible promissory notes (the “Notes”) in an aggregate principal amount of $5.0 million and $4.0 million, respectively, to several related parties that own more than 10% of the Company’s capital stock. All principal and accrued interest on the Notes was converted to the Company’s common stock upon the completion of the Company’s initial public offering in April 2015. Upon conversion, 2,287,120 shares of common stock were issued.

The Notes provided that upon completion of an initial public offering, the Notes would automatically convert into a number of shares of the Company’s common stock equal to the quotient obtained by dividing the entire principal amount and accrued interest on the Notes by 80% of the initial public offering price per share of the Company’s common stock. The Notes bore interest at a rate of 5% per annum, compounded annually.

Due to the automatic conversion features contained in the Notes, the actual number of shares of common stock or preferred stock that would be required if a conversion of the Notes was made through the issuance of the Company’s common or preferred stock could not be predicted prior to the conversion taking place. In addition, the conversion that would occur upon a change in control of the Company met the definition of a put option and was not closely related to the debt. As a result, the automatic conversion features and put option, exclusive of the Series B conversion feature, required derivative accounting treatment and were bifurcated from the Notes and marked to market each reporting period through the statement of operations and comprehensive loss. The fair value of the automatic conversion features and put option of the Notes, exclusive of the Series B conversion feature, were recorded as a derivative liability instrument and measured at fair value at each reporting period.

As of December 31, 2014, the Company estimated the fair value of the derivative by estimating the fair value of the Notes with and without the conversion derivative. To calculate the fair value of the Notes without the conversion derivative, the Company estimated the present value of the expected cash payments at an assumed discount rate of 8.25%. To calculate the fair value of the Notes with the conversion feature, the Company calculated the present value of the Notes upon conversion at an initial public offering, and the present value of the Notes at an equity financing. The risk-free rate for the assumed discount period is estimated at 0.05% and 0.15% in the respective conversion scenarios. The risk-free rate for the assumed discount period is estimated at 0.05% and 0.12% in the respective conversion scenarios at the valuation date of December 31, 2014. The Company applied a probability of occurrence to all of the conversion scenarios associated with the derivative and estimated a weighted value of the Notes with the conversion feature. The difference between the fair value of the Notes with and without the conversion features is the derivative. The fair value of the derivative was $1,495,000 as of December 31, 2014.

Upon issuance of the February 2015 Notes, the Company calculated the derivative liability using the same methodology and assumptions as those used as of December 31, 2014 because there were not significant changes in the Company or in the operations of the Company that had occurred in that intervening time period. The additional derivative liability recorded upon issuance of the February 2015 Notes was $1,196,000.

At March 31, 2015, the Company remeasured the fair value of the derivative liability for the Notes using a methodology similar to the methodology used at December 31, 2014, with a minimal discount period. The fair value of the derivative was $2,287,000.

The Company determined that the Notes contain a beneficial conversion feature related to the conversion feature of the Notes into Series B convertible preferred stock. The beneficial conversion feature results from the difference between the fair value of the Company’s common stock at the date of issuance and the Series B Preferred Stock Conversion price of $4.8104 at the date of issuance. The beneficial conversion feature amounted to $2,275,000 for the September 2014 Notes and $158,000 for the February 2015 Notes as of the date of issuance of the respective Notes, and was recorded as a debt discount that would be amortized through the maturity date of the Notes.

Convertible Preferred Stock Warrants

9 Months Ended

Sep. 30, 2016

Equity [Abstract]

Convertible Preferred Stock Warrants

8.	Convertible Preferred Stock Warrants

The Company issued warrants to purchase shares of the Company’s convertible preferred stock at various times in connection with loans payable. Immediately prior to the closing of the initial public offering, all convertible preferred stock warrants were converted in to warrants exercisable for common stock.

The fair value of the convertible preferred stock warrant liability was remeasured as of each reporting period end. As of March 31, 2015 (the last reporting period end prior to the initial public offering), the Company remeasured the fair value of the convertible preferred stock warrant liability using a Black-Scholes option-pricing method with the following assumptions: the Company’s initial public offering price of $5.00 per share, a weighted average remaining life of 6.5 years, an expected volatility of 58.3%, a weighted average risk-free interest rate of 1.55% and no expected dividend. The Company evaluated the down-round protection provisions of the warrant agreements by using a Monte Carlo simulation model and determined that the impact of such provisions was immaterial to the fair value of the warrants at each reporting period. The assumptions are further described as follows:

Expected Time to liquidity event — The Company estimated the time to liquidity event based on management’s analysis of the business, market conditions and clinical development.

Expected Volatility — The Company estimates the expected volatility based on the average volatility for comparable publicly traded biopharmaceutical companies over a period equal to the expected time to liquidity event. When selecting the publicly traded biopharmaceutical companies, the Company selected companies with comparable characteristics to it, including enterprise value and risk profiles, and with historical share price information sufficient to meet the time to liquidity event. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available.

Risk-Free Interest Rate — The risk-free interest rate is based on U.S. Treasury zero-coupon issues with remaining terms similar to the expected time to the liquidity event.

Expected Dividend Rate — The Company has never paid any dividends and does not plan to pay dividends in the foreseeable future, and, therefore, used an expected dividend rate of zero in the valuation model.

Common Stock

9 Months Ended

Sep. 30, 2016

Federal Home Loan Banks [Abstract]

Common Stock

9.	Common Stock

As of September 30, 2016 the Company’s Amended and Restated Certificate of Incorporation, as amended, has authorized 100,000,000 shares of common stock at $0.001 par value.

Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to the preferential dividend rights of the holders of the Series A and B convertible preferred stock. As of September 30, 2016, no dividends have been declared.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 4.E)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 10
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 12: http://www.xbrl.org/2003/role/presentationRef
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Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 15: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Stock Option Plan

9 Months Ended

Sep. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Plan

10.	Stock Option Plan

Incentive stock options are granted with exercise prices not less than the estimated fair value of common stock, and non-statutory stock options may be granted with an exercise price of not less than 100% of the estimated fair value of the common stock on the date of grant. Options granted under the Plan expire no later than 10 years from the date of grant. Incentive stock options granted under the Plan vest over periods determined by the Board of Directors, generally over four years. Non-statutory stock options vest based on the terms of the individual agreement, generally from nine months to four years.

As of September 30, 2016, options for 1,420,806 shares have been issued under the 2015 Equity Plan. The number of shares available for issuance under the Company’s 2015 Equity Plan will be increased on the first day of each fiscal year beginning in 2016, by an amount equal to the lessor of (1) 1,200,000 shares of stock and (2) four percent (4%) of the outstanding shares of stock on the last day of the immediately preceding year. The maximum number of shares of the Company’s common stock that may be delivered in satisfaction of awards under the 2015 Equity Plan is 2,585,833 shares, inclusive of 750,000 shares authorized upon creation of the 2015 Plan and 1,053,299 shares added January 1, 2016.

Stock Option Modifications

On April 12, 2016, the Company’s Board of Directors approved a restructuring plan effective as of April 15, 2016 and resulting in a reduction in force of the Company’s employees. As part of the reduction in force, the Company terminated the employment of an executive officer and retained his services as a consultant to the Company through October 15, 2016. The executive officer’s option awards continued to vest during the consulting period. Though vesting ceased October 15, 2016, all options awarded to the executive remain outstanding until the earliest to occur of (1) the consummation of a change of control, (ii) March 8, 2017 and (iii) the original expiration date of the stock option. After the earliest to occur of such dates, all of the stock options will terminate to the extent still outstanding. If a change in control occurs prior to the termination of the stock options, the vesting will accelerate for 100% of the executive’s then-unvested stock options. The incremental fair value that is attributable to the modified options was insignificant.

The Company terminated the employment of another executive as part of the reduction in force described in the preceding paragraph. The executive received accelerated vesting of his option awards that would have vested during the six month period following April 15, 2016. The incremental fair value of the modified awards was insignificant.

As of September 30, 2016, the Company had 2,165,554 shares issuable upon exercise of outstanding option awards.

Total stock-based compensation expense related to options and awards granted was allocated as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Research and Development	$	65	$	86	$	273	$	96
General and administrative		217		203		689		348
Total	$	282	$	289	$	962	$	444

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References + Details

Related Party Transactions

9 Months Ended

Sep. 30, 2016

Related Party Transactions

11.	Related Party Transactions

In September 2014 and February 2015, the Company issued the Notes to several related parties that own more than 10% of the Company’s capital stock (see Note 7). Upon completion of the initial public offering, those Notes were converted in to shares of the Company’s common stock.

Income Taxes

9 Months Ended

Sep. 30, 2016

Income Tax Disclosure [Abstract]

Income Taxes

12.	Income Taxes

The Company’s effective tax rate is 0% for income tax for the three and nine months ended September 30, 2016 and the Company expects that its effective tax rate for the full year 2016 will be 0%. Based on the weight of available evidence, including cumulative losses since inception and expected future losses, the Company has determined that it is more likely than not that the deferred tax asset amount will not be realized and therefore a valuation allowance has been provided on net deferred tax assets.

The Company has substantial net operating loss carry forwards available to offset future taxable income for federal and state income tax purposes. The ability to utilize the net operating losses may be limited due to changes in our ownership as defined by Section 382 of the Internal Revenue Code (the “Code”). Under the provisions of Sections 382 and 383 of the Code, a change of control, as defined in the Code, may impose an annual limitation on the amount of the Company’s net operating loss and tax credit carryforwards, and other tax attributes that can be used to reduce future tax liabilities.

The Company files tax returns for U.S. Federal and State of California. The Company is not currently subject to any income tax examinations. Since the Company’s inception, the Company had incurred losses from operations, which generally allows all tax years to remain open.

The gross amount of unrecognized tax benefits as of September 30, 2016 is approximately $0.8 million related to the reserve on R&D credits, none of which will affect the effective tax rate if recognized due to the valuation allowance. The Company does not expect any material changes in the next twelve months in unrecognized tax benefits.

The Company recognizes interest and/or penalties related to uncertain tax positions. To the extent accrued interest and penalties do not ultimately become payable, amounts accrued will be reduced and reflected in the period that such determination is made. Any interest and penalties are recognized in income tax expense. The Company currently has no interest and penalties related to uncertain tax positions.

Legal Proceedings

9 Months Ended

Sep. 30, 2016

Commitments And Contingencies Disclosure [Abstract]

Legal Proceedings

13.	Legal Proceedings

On September 26, 2016, a purported stockholder class action complaint was filed in the Superior Court of the State of California in and for the County of Alameda (the “Superior Court”) against the Company, the members of the board of directors of the Company, as well as against KalVista, Wedbush Securities Inc. (“Wedbush”) and certain unknown employees of Wedbush, entitled Laidlaw v. Carbylan Therapeutics, Inc., et al. Case No. RG16832665. The complaint alleges that the members of the Company’s board of directors and/or the Company breached their fiduciary duties of care, good faith, loyalty and/or disclosure in connection with the Share Purchase Agreement, dated as of June 15, 2016, by and among the Company, KalVista, and the shareholders of KalVista, and that KalVista and Wedbush aided and abetted such breaches of fiduciary duties. The complaint seeks to enjoin and/or rescind any transaction with KalVista as well as certain other equitable relief, unspecified damages and attorneys’ fees and costs. As of September 30, 2016, the Company has established an accrued liability of $0.3 million in regards to this claim.

On October 31, 2016, the Superior Court approved a voluntary dismissal of the purported stockholder class action complaint (See Note 14).

From time to time the Company is involved in legal proceedings arising in the ordinary course of business. The Company believes there is no other litigation pending that could have, individually or in the aggregate, a material adverse effect on its results of operations or financial condition.

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2016
Subsequent Events [Abstract]
Subsequent Events	14.Subsequent Events On October 31, 2016, the Superior Court of the State of California in and for the County of Alameda approved a voluntary dismissal of the purported stockholder class action complaint filed in the Court on September 26, 2016 against certain members of the board of directors and certain executives of Carbylan Therapeutics, Inc., as well as against KalVista Pharmaceuticals Ltd., Wedbush Securities Inc. and certain unknown employees of Wedbush, entitled Laidlaw v. Carbylan Therapeutics, Inc., et al., Case No. RG16832665. Prior to the court approval of the voluntary dismissal, the parties agreed to a settlement and release of all claims by the named stockholders of the Company. In connection with the settlement, the Company agreed to pay the negotiated plaintiffs’ attorneys’ fee of $0.3 million.

Summary of Significant Accounting Policies and Basis of Presentation (Policies)

9 Months Ended

Sep. 30, 2016

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Risks and Uncertainties

Concentration of Credit Risk

Segment Reporting

Cash and Cash Equivalents

Restricted Cash

Beneficial Conversion Feature

Embedded Derivatives Related to Convertible Promissory Notes

Property and Equipment, Net

Computer equipment		3 years
Lab equipment		3 years
Furniture and fixtures		5 years
Machinery and equipment		3 years
Manufacturing equipment		7 years

Long-lived Assets

Long-lived assets

Pre-clinical and Clinical Trial Accruals

Preferred Stock Warrant Liability

Research and Development Expenditures

Stock-Based Compensation

Income Taxes

Net Loss per Share Attributable to Common Stockholders

Recent Accounting Pronouncements

Summary of Significant Accounting Policies and Basis of Presentation (Tables)

9 Months Ended

Sep. 30, 2016

Accounting Policies [Abstract]

Estimated Useful Life of Property and Equipment

Depreciation is computed using the straight-line method over the estimated useful lives of the assets, which are as follows:

Computer equipment		3 years
Lab equipment		3 years
Furniture and fixtures		5 years
Machinery and equipment		3 years
Manufacturing equipment		7 years

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2016

Fair Value Disclosures [Abstract]

Summary of Fair Value Hierarchy for Assets and Liabilities Measured on a Recurring and Non-Recurring Basis

The following table presents the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring and non-recurring basis:

	Fair Value Measurements as of September 30, 2016 (in thousands)
	Quoted Price in Active Markets for Identical Assets		Significant other Observable Inputs		Significant Unobservable Inputs
	Level 1		Level 2		Level 3		Total
Assets
Money market funds⁽¹⁾	$	34,057	$	—	$	—	$	34,057
Certificate of deposit		—		50		—		50
	$	34,057	$	50	$	—	$	34,107

	Fair Value Measurements as of December 31, 2015 (in thousands)
	Quoted Price in Active Markets for Identical Assets		Significant other Observable Inputs		Significant Unobservable Inputs
	Level 1		Level 2		Level 3		Total
Assets
Money market funds⁽¹⁾	$	53,625	$	—	$	—	$	53,625
Certificate of deposit		—		50		—		50
	$	53,625	$	50	$	—	$	53,675

(1)	Included in cash and cash equivalents in the Company’s condensed balance sheet.

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details

Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2016

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Components of Property and Equipment

The following table represents the components of property and equipment (in thousands):

	September 30,		December 31,
	2016		2015
Computer equipment	$	-	$	30
Lab equipment		-		697
Furniture and fixtures		-		21
Machinery and equipment		-		262
Leasehold improvements		-		55
Construction in progress		-		368
		-		1,433
Less: Accumulated depreciation and amortization		-		(628	)
Total property and equipment, net	$	-	$	805

Schedule of Accrued Liabilities

Accrued Liabilities

(in thousands)

	September 30,		December 31,
	2016		2015
Accrued payroll and related expenses	$	365	$	727
Accrued legal expenses		486		77
Accrued research and clinical trial expenses		21		338
Accrued professional services		555		185
Other accrued expenses		4		-
	$	1,431	$	1,327

Stock Option Plan (Tables)

9 Months Ended

Sep. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Stock-Based Compensation Expense

Total stock-based compensation expense related to options and awards granted was allocated as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Research and Development	$	65	$	86	$	273	$	96
General and administrative		217		203		689		348
Total	$	282	$	289	$	962	$	444

Formation and Business of the Company - Additional Information (Detail)			1 Months Ended				3 Months Ended	9 Months Ended
	Jun. 27, 2016 USD ($)	Apr. 14, 2015 USD ($) $ / shares shares	Jul. 31, 2016 $ / shares	Jun. 30, 2016 USD ($)	Apr. 30, 2016 USD ($) Employee	Mar. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / shares shares
Organization And Basis Of Presentation [Line Items]
Entity Incorporation, State Name								Delaware
Date of incorporation								Mar. 26, 2004
Accumulated deficit								$ 88,963,000		$ 72,621,000
Restructuring plan effective date								Apr. 15, 2016
Restructuring plan, number of positions reduction \| Employee					14
Number of employees \| Employee					17
Severance payments					$ 300,000		$ 700,000
Asset Impairment charge								$ 1,460,000
Termination fee paid	$ 2,450,000
Number of consecutive business days			30 days
Common stock minimum bid price \| $ / shares			$ 1.00
Initial period allowed to regain compliance with listing qualifications			180 days
Minimum bid price per share required to regain compliance with listing qualifications \| $ / shares			$ 1.00
Regain compliance with listing qualifications period end date								Jan. 24, 2017
Reverse stock split, description								In March 2015, the Company’s board of directors and stockholders approved a 4-for-1 reverse stock split of the Company’s common and preferred stock. The Company filed an amendment to its certificate of incorporation effecting the reverse stock split on March 13, 2015. All share and per share amounts contained in these financial statements and notes thereto, have been adjusted retroactively to reflect the reverse stock split.
Reverse Stock Split, Conversion Ratio								0.25
Proceeds from issuance of common stock, net									$ 67,908,000
Carrying value of convertible preferred stock into common stock									$ 39,556,000
Capital stock, shares authorized \| shares		105,000,000
Common stock, shares authorized \| shares		100,000,000						100,000,000		100,000,000
Preferred stock, shares authorized \| shares		5,000,000						5,000,000		5,000,000
Preferred stock, par value \| $ / shares		$ 0.001						$ 0.001		$ 0.001
Common stock, par value \| $ / shares		$ 0.001						$ 0.001		$ 0.001
Preferred stock, shares outstanding \| shares								0		0
Convertible Preferred Stock [Member]
Organization And Basis Of Presentation [Line Items]
Convertible preferred stock converted into common stock \| shares		8,268,531
Carrying value of convertible preferred stock into common stock		$ 39,600,000
Initial Public Offering [Member]
Organization And Basis Of Presentation [Line Items]
Proceeds from issuance of common stock, net		$ 66,300,000
Initial Public Offering [Member] \| Common Stock [Member]
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold \| shares		14,950,000
Over-Allotment Option [Member]
Organization And Basis Of Presentation [Line Items]
Shares of common stock sold \| shares		1,950,000
Loan and Security Agreement [Member]
Organization And Basis Of Presentation [Line Items]
Repayment of loan				$ 4,600,000
Convertible Promissory Notes [Member]
Organization And Basis Of Presentation [Line Items]
Conversion of notes into common stock, shares \| shares		2,287,120
Facility located in Newark, California [Member]
Organization And Basis Of Presentation [Line Items]
Asset Impairment charge						$ 1,500,000
Facility located in Newark, California [Member] \| Leasehold Improvements, Furniture and Fixtures [Member]
Organization And Basis Of Presentation [Line Items]
Asset Impairment charge						$ 1,100,000
Minimum [Member]
Organization And Basis Of Presentation [Line Items]
Number of consecutive business days			10 days
KalVista Pharmaceuticals Ltd [Member] \| Share Purchase Agreement [Member]
Organization And Basis Of Presentation [Line Items]
Expected ownership percentage				81.00%
Agreement termination fee				$ 3,000,000
KalVista Pharmaceuticals Ltd [Member] \| Share Purchase Agreement [Member] \| Maximum [Member]
Organization And Basis Of Presentation [Line Items]
Reimbursable expenses under agreement termination				$ 1,000,000
Executive Officer [Member]
Organization And Basis Of Presentation [Line Items]
Number of employees \| Employee					2

Summary of Significant Accounting Policies Basis of Presentation - Additional Information (Detail) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash	$ 50,000	$ 50,000
Certificate of Deposit [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash	$ 50,000

Summary of Significant Accounting Policies Basis of Presentation - Estimated Useful Life of Property and Equipment (Detail)	9 Months Ended
	Sep. 30, 2016
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment	3 years
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment	3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment	5 years
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment	3 years
Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of property and equipment	7 years

Fair Value Measurements - Additional Information (Detail)	Sep. 30, 2016 USD ($)
Fair Value Disclosures [Abstract]
Transfers between Level 1 and Level 2, Assets	$ 0
Transfers between Level 2 and Level 1, Assets	0
Transfers between Level 1 and Level 2, Liabilities	0
Transfers between Level 2 and Level 1, Liabilities	0
Derivative liability	$ 0

Fair Value Measurements - Summary of Fair Value Hierarchy for Assets and Liabilities Measured on a Recurring and Non-Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	$ 34,107	$ 53,675
Quoted Price in Active Markets for Identical Assets Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	34,057	53,625
Significant other Observable Inputs Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	50	50
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	34,057	53,625
Money Market Funds [Member] \| Quoted Price in Active Markets for Identical Assets Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	34,057	53,625
Certificate of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	50	50
Certificate of Deposit [Member] \| Significant other Observable Inputs Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair value	$ 50	$ 50

Balance Sheet Components - Components of Property and Equipment (Detail) $ in Thousands	Dec. 31, 2015 USD ($)
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,433
Less: Accumulated depreciation and amortization	(628)
Total property and equipment, net	805
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	30
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	697
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	21
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	262
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	55
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 368

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended		9 Months Ended
	May 31, 2016	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Depreciation expense			$ 34	$ 98
Asset Impairment charge			1,460
Sale of equipment			$ 183
Facility located in Newark, California [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment charge		$ 1,500
Facility located in Newark, California [Member] \| Leasehold Improvements, Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment charge		1,100
Facility located in Newark, California [Member] \| Certain Equipment [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment charge		$ 400
Sale of equipment	$ 200

Balance Sheet Components - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Accrued payroll and related expenses	$ 365	$ 727
Accrued legal expenses	486	77
Accrued research and clinical trial expenses	21	338
Accrued professional services	555	185
Other accrued expenses	4
Total accrued liabilities	$ 1,431	$ 1,327

Commitments and Contingencies - Additional Information (Detail)			1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 27, 2016 USD ($)	Jul. 13, 2015 USD ($) ft² $ / ft²	Mar. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Other Commitments [Line Items]
Rental income per month, sub-lease agreement						$ 16,000
Gross rent expense				$ 0	$ 110,000	507,000	$ 328,000
Asset Impairment charge						1,460,000
Termination fee paid	$ 2,450,000
Aggregate future minimum lease payments				0		0
Sublease rental income				0	$ 50,000	37,000	$ 147,000
Indemnification Guarantee [Member]
Other Commitments [Line Items]
Contingent liabilities				0		$ 0
Facility located in Newark, California [Member]
Other Commitments [Line Items]
Area of square foot lease premises \| ft²		18,704
Gross rent expense		$ 599,000
Operating leases, initial term of contract		6 years 6 months
Monthly rental rate per square foot \| $ / ft²		2.65
Annual base rent percentage		3.00%
Asset Impairment charge			$ 1,500,000
Facility located in Newark, California [Member] \| Leasehold Improvements, Furniture and Fixtures [Member]
Other Commitments [Line Items]
Asset Impairment charge			$ 1,100,000
Facility located in Newark, California [Member] \| Maximum [Member]
Other Commitments [Line Items]
Operating leases allowance for improvements		$ 599,000
Other Noncurrent Assets [Member] \| Facility located in Newark, California [Member]
Other Commitments [Line Items]
Security deposit		$ 149,000
Non Cancellable Operating Lease [Member]
Other Commitments [Line Items]
Lease expiration period						2016-05
Non Cancellable Operating Lease [Member] \| Other Noncurrent Assets [Member]
Other Commitments [Line Items]
Security deposit				$ 69,000		$ 69,000
Sublease Agreement [Member]
Other Commitments [Line Items]
Percentage of square footage leased						37.00%
Lease expiration date						Feb. 29, 2016

Loan and Security Agreement - Additional Information (Detail) - Loan and Security Agreement [Member] $ in Millions	1 Months Ended		9 Months Ended
	Jun. 30, 2016 USD ($)	Sep. 30, 2014 USD ($) Installment	Sep. 30, 2016
Debt Instrument [Line Items]
Debt instrument interest rate		3.95%
Loan repayment description			The loan was repayable in thirty-six equal monthly installments, following an eighteen-month interest only period. The final balloon interest payment was approximately $0.5 million and was accreted over the life of the loan.
Number of equal monthly installments \| Installment		36
Interest repayment period		18 months
Frequency of payments			Equal monthly installments
Final balloon interest payment		$ 0.5
Repayment of loan	$ 4.6

Convertible Promissory Notes - Additional Information (Detail) - USD ($)		9 Months Ended	12 Months Ended
	Apr. 14, 2015	Sep. 30, 2016	Dec. 31, 2014	Mar. 31, 2015	Feb. 19, 2015	Sep. 29, 2014
Convertible Promissory Notes [Member]
Debt Instrument [Line Items]
Initial public offering period		April 2015
Conversion of notes into common stock, shares	2,287,120
Debt instrument interest rate		5.00%
Debt instrument payment terms		Annually
Present value of the notes assumed discount rate		8.25%
Derivative liability			$ 1,495,000	$ 2,287,000
Debt instrument conversion price		$ 4.8104
Convertible Promissory Notes [Member] \| Fair Value of Notes With Conversion Derivative [Member]
Debt Instrument [Line Items]
Risk-free interest rate		0.05%	0.05%
Convertible Promissory Notes [Member] \| Fair Value of Notes without Conversion Derivative [Member]
Debt Instrument [Line Items]
Risk-free interest rate		0.15%	0.12%
Convertible Promissory Notes [Member] \| Related Parties that own more than ten percent of the company capital [Member]
Debt Instrument [Line Items]
Convertible debt, aggregate principal amount					$ 4,000,000	$ 5,000,000
Debt instrument conversion rate		80.00%
Convertible Promissory Notes [Member] \| Related Parties that own more than ten percent of the company capital [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Ownership held by related parties		10.00%
February 2015 Notes [Member]
Debt Instrument [Line Items]
Fair value of derivative liability at issuance		$ 1,196,000
Debt instrument, convertible, beneficial conversion feature		158,000
September 2014 Notes [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, beneficial conversion feature		$ 2,275,000

Convertible Preferred Stock Warrants - Additional Information (Detail) - Series B Warrants [Member]	3 Months Ended
	Mar. 31, 2015 $ / shares
Class of Warrant or Right [Line Items]
Weighted average remaining life	6 years 6 months
Expected volatility rate	58.30%
Weighted average risk-free interest rate	1.55%
Expected dividend rate	0.00%
Initial Public Offering [Member]
Class of Warrant or Right [Line Items]
Offering price per share	$ 5.00

Common Stock - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Apr. 14, 2015
Equity [Abstract]
Common stock, par value	$ 0.001	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000	100,000,000
Description of voting rights to shareholders	Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders.
Common stock dividends declared	$ 0

Stock Option Plan - Additional Information (Detail) - shares		9 Months Ended
	Jan. 01, 2016	Sep. 30, 2016
Restructuring Plan [Member] \| Consultant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accelerated vesting percentage of unvested stock options		100.00%
Accelerated vesting description of option awards		all options awarded to the executive remain outstanding until the earliest to occur of (1) the consummation of a change of control, (ii) March 8, 2017 and (iii) the original expiration date of the stock option. After the earliest to occur of such dates, all of the stock options will terminate to the extent still outstanding.
Restructuring Plan [Member] \| Executive [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Accelerated vesting period of option awards		6 months
2004 Stock Option Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, vesting period		4 years
2004 Stock Option Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, expiration period		10 years
2004 Stock Option Plan [Member] \| Non-Statutory Stock Options [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted exercise price, based on percentage of estimated fair value		100.00%
Stock options granted, vesting period		9 months
2004 Stock Option Plan [Member] \| Non-Statutory Stock Options [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted, vesting period		4 years
2015 Equity Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, options, granted		1,420,806
Shares available for future awards		2,585,833
Number of shares authorized		750,000
Number of shares available for issuance		1,200,000
Percentage of maximum outstanding shares of stock		4.00%
Share-based compensation arrangement by share-based payment award, description		The number of shares available for issuance under the Company’s 2015 Equity Plan will be increased on the first day of each fiscal year beginning in 2016, by an amount equal to the lessor of (1) 1,200,000 shares of stock and (2) four percent (4%) of the outstanding shares of stock on the last day of the immediately preceding year.
Number of additional shares authorized	1,053,299
Shares issuable upon exercise of outstanding option awards		2,165,554

Stock Option Plan - Schedule of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock based compensation expense	$ 282	$ 289	$ 962	$ 444
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock based compensation expense	65	86	273	96
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock based compensation expense	$ 217	$ 203	$ 689	$ 348

Related Party Transactions - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2016
Related Parties that own more than ten percent of the company capital [Member] \| Minimum [Member] \| Convertible Promissory Notes [Member]
Related Party Transaction [Line Items]
Ownership held by related parties	10.00%

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Effective income tax rate	0.00%	0.00%
Gross unrecognized tax benefits related to reserve on R&D credits	$ 800,000	$ 800,000
Material changes in the next twelve months in unrecognized tax benefits	$ 0	0
Interest and penalties related to uncertain tax positions		$ 0
Forecast [Member]
Operating Loss Carryforwards [Line Items]
Effective income tax rate			0.00%

Legal Proceedings - Additional Information (Detail) $ in Millions	Sep. 30, 2016 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Accrued liability in purported stockholder class action complaint	$ 0.3

Subsequent Events - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Negotiated plaintiffs’ attorneys’ fee payable		$ 486	$ 77
Subsequent Events [Member]
Subsequent Event [Line Items]
Negotiated plaintiffs’ attorneys’ fee payable	$ 300