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Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2013	Mar. 20, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Trading Symbol	EVOK
Entity Registrant Name	Evoke Pharma Inc
Entity Central Index Key	0001403708
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		6,099,547
Entity Public Float		$ 27,627,705

Balance Sheets - USD ($)	Dec. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 24,196,691	$ 116,013
Prepaid expenses	234,262
Total current assets	24,430,953	116,013
Other assets	555,505
Total assets	24,986,458	116,013
Current Liabilities:
Accounts payable and accrued expenses	284,915	96,798
Accrued compensation	557,399	417,611
Warrant liability		56,000
Current portion of long-term debt	1,442,592
Total current liabilities	2,284,906	570,409
Deferred rent expense	6,830	0
Long-term debt, net of current portion	1,511,461	979,792
Total liabilities	3,803,197	1,550,201
Commitments and contingencies
Stockholders' equity (deficit):
Preferred stock, value
Common stock, $0.0001 par value; authorized shares - 50,000,000 at December 31, 2013 and 20,000,000 at December 31, 2012; issued and outstanding shares - 6,096,752 at December 31, 2013 and 1,242,750 at December 31, 2012	610	124
Additional paid-in capital	43,874,119	195,525
Deficit accumulated during the development stage	(22,691,468)	(19,855,003)
Total stockholders' equity (deficit)	21,183,261	(19,659,354)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$ 24,986,458	116,013
Series A Convertible Preferred Stock [Member]
Stockholders' equity (deficit):
Preferred stock, value		$ 18,225,166

Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2013	Dec. 31, 2012
Preferred stock, par value	$ 0.0001
Preferred stock, shares authorized	5,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,000,000	20,000,000
Common stock, shares issued	6,096,752	1,242,750
Common stock, shares outstanding	6,096,752	1,242,750
Series A Convertible Preferred Stock [Member]
Preferred stock, par value		$ 0.0001
Preferred stock, shares authorized	0	12,305,068
Preferred stock, shares issued	0	12,195,068
Preferred stock, shares outstanding	0	12,195,068
Preferred stock, liquidation preference value	$ 0	$ 18,292,602

Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended			83 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Operating expenses:
Research and development	$ 956,980	$ 1,165,645	$ 1,844,044	$ 16,948,509
General and administrative	1,644,848	836,781	570,524	4,949,381
Purchase of in-process research and development				650,000
Total operating expenses	2,601,828	2,002,426	2,414,568	22,547,890
Loss from operations	(2,601,828)	(2,002,426)	(2,414,568)	(22,547,890)
Other income (expense):
Interest income	7,248	1,690	10,696	221,100
Interest expense	(159,885)	(24,042)	(2,872)	(365,827)
Change in fair value of preferred stock purchase right				(188,587)
Change in fair value of warrant liability	(82,000)	7,250	5,500	(54,264)
Grant income				244,000
Total other income (expense)	(234,637)	(15,102)	13,324	(143,578)
Net loss and comprehensive loss	$ (2,836,465)	$ (2,017,528)	$ (2,401,244)	$ (22,691,468)
Net loss per common share, basic and diluted	$ (1.20)	$ (1.79)	$ (2.18)
Weighted-average shares used to compute basic and diluted net loss per share	2,368,006	1,124,000	1,102,625

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($)	Total	Preferred Stock [Member] Series A Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Deficit Accumulated During the Development Stage [Member]
Beginning Balance at Jan. 29, 2007
Beginning Balance, shares at Jan. 29, 2007
Issuance of restricted common stock for cash	4,580		$ 92	4,488
Issuance of restricted common stock for cash, shares			916,000
Issuance of Series A convertible preferred stock		$ 6,074,501
Issuance of Series A convertible preferred stock, shares		4,195,067
Initial fair value of preferred stock purchase rights issued in connection with Series A financing		$ (848,257)
Estimated fair value of exercised purchase right		80,819
Issuance of common stock upon exercise of stock options	77,358		$ 26	77,332
Issuance of common stock upon exercise of stock options, shares			266,750
Stock-based compensation expense	5,458			5,458
Net loss	(2,009,591)				(2,009,591)
Ending Balance at Dec. 31, 2007	(1,922,195)	$ 5,307,063	$ 118	87,278	(2,009,591)
Ending Balance, shares at Dec. 31, 2007		4,195,067	1,182,750
Beginning Balance at Jan. 29, 2007
Beginning Balance, shares at Jan. 29, 2007
Net loss	(22,691,468)
Ending Balance at Dec. 31, 2013	21,183,261		$ 610	43,874,119	(22,691,468)
Ending Balance, shares at Dec. 31, 2013			6,096,752
Beginning Balance at Dec. 31, 2007	(1,922,195)	$ 5,307,063	$ 118	87,278	(2,009,591)
Beginning Balance, shares at Dec. 31, 2007		4,195,067	1,182,750
Issuance of Series A convertible preferred stock		$ 5,998,145
Issuance of Series A convertible preferred stock, shares		4,000,000
Estimated fair value of exercised purchase right		$ 956,025
Stock-based compensation expense	16,184			16,184
Net loss	(3,227,664)				(3,227,664)
Ending Balance at Dec. 31, 2008	(5,133,675)	$ 12,261,233	$ 118	103,462	(5,237,255)
Ending Balance, shares at Dec. 31, 2008		8,195,067	1,182,750
Stock-based compensation expense	17,803			17,803
Net loss	(5,159,638)				(5,159,638)
Ending Balance at Dec. 31, 2009	(10,275,510)	$ 12,261,233	$ 118	121,265	(10,396,893)
Ending Balance, shares at Dec. 31, 2009		8,195,067	1,182,750
Issuance of Series A convertible preferred stock		$ 5,963,933
Issuance of Series A convertible preferred stock, shares		4,000,001
Issuance of common stock upon exercise of stock options	24,000		$ 6	23,994
Issuance of common stock upon exercise of stock options, shares			60,000
Stock-based compensation expense	15,056			15,056
Net loss	(5,039,338)				(5,039,338)
Ending Balance at Dec. 31, 2010	(15,275,792)	$ 18,225,166	$ 124	160,315	(15,436,231)
Ending Balance, shares at Dec. 31, 2010		12,195,068	1,242,750
Stock-based compensation expense	22,705			22,705
Net loss	(2,401,244)				(2,401,244)
Ending Balance at Dec. 31, 2011	(17,654,331)	$ 18,225,166	$ 124	183,020	(17,837,475)
Ending Balance, shares at Dec. 31, 2011		12,195,068	1,242,750
Stock-based compensation expense	12,505			12,505
Net loss	(2,017,528)				(2,017,528)
Ending Balance at Dec. 31, 2012	$ (19,659,354)	$ 18,225,166	$ 124	195,525	(19,855,003)
Ending Balance, shares at Dec. 31, 2012		12,195,068	1,242,750
Issuance of common stock upon exercise of stock options, shares
Stock-based compensation expense	$ 145,966			145,966
Conversion of shares of preferred stock to common stock	18,225,166	$ (18,225,166)	$ 244	18,224,922
Conversion of shares of preferred stock to common stock, shares		(12,195,068)	2,439,002
Initial public offering of common stock	25,120,948		$ 242	25,120,706
Initial public offering of common stock, shares			2,415,000
Reclassification of warrant liability	187,000			187,000
Net loss	(2,836,465)				(2,836,465)
Ending Balance at Dec. 31, 2013	$ 21,183,261		$ 610	$ 43,874,119	$ (22,691,468)
Ending Balance, shares at Dec. 31, 2013			6,096,752

Statements of Cash Flows - USD ($)	12 Months Ended			83 Months Ended
Statements of Cash Flows - USD ($)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Operating activities
Net loss	$ (2,836,465)	$ (2,017,528)	$ (2,401,244)	$ (22,691,468)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	145,966	12,505	22,705	235,677
Non-cash interest	23,261	4,042	2,426	129,327
Change in fair value of purchase right liability				188,587
Change in fair value of warrant liability	82,000	(7,250)	(5,500)	54,264
Deferred rent expense	6,830			6,830
Change in operating assets and liabilities:
Prepaid expenses and other assets	(234,262)	39,459	76,353	(234,262)
Other assets	(555,505)			(555,505)
Accounts payable and accrued expenses	327,905	218,909	(587,848)	842,314
Net cash used in operating activities	(3,040,270)	(1,749,863)	(2,893,108)	(22,024,236)
Financing activities
Proceeds from convertible promissory note				250,000
Proceeds from bank line of credit and loan advances	2,000,000	1,000,000		5,500,000
Payment on bank line of credit			(277,779)	(2,500,000)
Proceeds from issuance of common stock, net	25,120,948			25,125,528
Proceeds from issuance of preferred stock and purchase rights, net				17,744,041
Proceeds from exercise of stock options				101,358
Net cash provided by (used in) financing activities	27,120,948	1,000,000	(277,779)	46,220,927
Net increase (decrease) in cash and cash equivalents	24,080,678	(749,863)	(3,170,887)	24,196,691
Cash and cash equivalents at beginning of period	116,013	865,876	4,036,763
Cash and cash equivalents at end of period	24,196,691	116,013	865,876	24,196,691
Supplemental disclosures of cash flow information
Interest paid	$ 128,875	$ 20,000	$ 1,346	228,751
Non-cash financing activities
Conversion of convertible promissory note and accrued interest to Series A Convertible Preferred Stock				$ 292,538
Issuance of Series A Convertible Preferred Stock warrants	49,000	24,250		108,486
Conversion of Series A Convertible Preferred Stock to common stock at the initial public offering	$ 18,225,166			$ 18,225,166

Organization and Basis of Presentation

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

Organization and Basis of Presentation

1. Organization and Basis of Presentation

Evoke Pharma, Inc. (the “Company”) was incorporated in the state of Delaware on January 29, 2007 (inception). The Company is a publicly-held specialty pharmaceutical company focused primarily on the development of drugs to treat gastroenterological disorders and disease.

Since its inception, the Company has devoted substantially all of its efforts to product development, raising capital and building infrastructure, and has not realized revenues from its planned principal operations. Accordingly, the Company is considered to be in the development stage.

As reflected in the accompanying financial statements, the Company has a limited operating history and the sales and income potential of the Company’s business are unproven. The Company has experienced net losses since its inception and, as of December 31, 2013 and 2012, had an accumulated deficit of $22,691,468 and $19,855,003, respectively. The Company had a working capital (deficit) of $22,146,047 and $(454,396) as of December 31, 2013 and 2012, respectively.

The Company expects to continue to incur net losses for at least the next several years. Over that period, the Company will need to raise additional debt or equity financing to fund its development. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, and/or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations, financial condition and future prospects.

On June 13, 2013, the Company’s board of directors approved an amendment to the restated certificate of incorporation to effect a one-for-five reverse stock split of the Company’s common stock (the “Reverse Stock Split”). The amendment effecting the Reverse Stock Split was approved by the stockholders on August 29, 2013. The par value and the authorized shares of the common and convertible preferred stock were not adjusted as a result of the Reverse Stock Split. All issued and outstanding common stock and the conversion ratio of the convertible preferred stock have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented. The Reverse Stock Split was effected on August 30, 2013.

Initial Public Offering and Related Transactions

On September 30, 2013, the Company completed its Initial Public Offering (“IPO”) whereby it sold 2,100,000 shares of common stock at a price of $12.00 per share. On October 8, 2013, the underwriters for the Company’s IPO purchased the over-allotment option for an additional 315,000 shares of the Company’s common stock at $12.00 per share. Net proceeds from the IPO, including the exercise of the over-allotment option, were determined as follows:


Gross proceeds (including over-allotment)	$	28,980,000
Underwriting discounts and commissions and non-accountable expense allowance		(2,344,875	)
Total offering costs (excluding value of warrants granted to underwriter of $470,000)		(1,514,177	)

Net proceeds	$	25,120,948

Additionally, upon the closing of the IPO, certain transactions occurred based on a successful completion of the IPO:

•

the conversion of all outstanding shares of convertible preferred stock into 2,439,002 shares of the Company’s common stock;

•

retention payments in the amount of $355,000 became payable to the Company’s executive officers. Such amount was recorded as expense on a straight-line basis from May 22, 2013 (the date of the retention agreements entered into with the executive officers) through December 24, 2013, the date at which the final payment was due based on continued employment. Since the terms of the payment required the occurrence of either a change in control of the Company, or an equity financing, neither of which were considered probable to occur until they happen, a catch-up expense of $202,857 was recorded at the time of the Company’s IPO. The executive officers remained with the Company through December 24, 2013 and received the full retention payment;

•

the issuance of warrants to purchase 84,000 shares of the Company’s common stock to the representative of the underwriters of the Company’s IPO and certain of its affiliates. The warrants will become exercisable at a price of $21.00 per share beginning on September 24, 2014 and will expire on September 24, 2018. The $470,000 initial fair value of the warrants was determined using the Black-Scholes option pricing model and recorded as a cost of the Company’s IPO and charged to additional paid-in capital;

The fair value of the issued warrants was estimated using the Black-Scholes option pricing model with the following assumptions:


Assumed risk-free interest rate	1.44	%
Assumed volatility	71	%
Expected warrant life	5 Years
Expected dividend yield	0.0	%

•

the conversion of warrants to purchase 110,000 shares of convertible preferred stock into warrants to purchase 22,000 shares of the Company’s common stock, and the final remeasurement of fair value and reclassification of the $187,000 warrant liability to additional paid-in capital; and

•

the filing of an amended and restated certificate of incorporation to authorize 50,000,000 shares of common stock and 5,000,000 shares of undesignated preferred stock.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

+ References

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+ Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Use of Estimates

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment operating in the United States.

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking and savings accounts.

Fair Value of Financial Instruments

The carrying amounts of accounts payable and accrued expenses are considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes that the fair value of long-term debt approximates its carrying value. The carrying amount of the warrant liability represents fair value.

Concentrations of Risk

Financial instruments that potentially subject the Company to significant credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in a federally insured financial institution in excess of federally insured limits. The Company has established guidelines designed to maintain safety and liquidity, has not experienced any losses in such accounts and believes the exposure to significant risk to the cash balance is minimal.

In addition, the Company relies on third-party manufacturers for the production of its drug candidate. If the third-party manufacturers are unable to continue manufacturing the Company’s drug candidate, or if the Company loses one of its sole source suppliers used in its manufacturing processes, the Company may not be able to meet clinical trial supply demand for its product candidate and the development of the product candidate could be materially and adversely affected.

Preferred Stock Warrant Liability

Warrants for shares that are puttable and warrants for shares that are contingently redeemable are classified as liabilities on the accompanying balance sheets and carried at their estimated fair value. At the end of each reporting period, any changes in fair value are recorded as a component of other income (expense). At the completion of the IPO, the Company adjusted the carrying value of the warrants and reclassified the liability to additional paid-in capital.

Stock-Based Compensation

Stock-based compensation expense is recorded at the estimated fair value of the award as of the grant date and is recognized as expense on a straight-line basis over the employee’s requisite service period, which is generally the vesting period of the award. Stock-based compensation expense is based on awards ultimately expected to vest, and therefore, the recorded expense includes an estimate of future forfeitures. Forfeitures are to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

Prior to the IPO, the Company granted stock options to purchase common stock to employees with exercise prices equal to the value of the underlying stock, as determined by the board of directors on the date the equity award was granted. The board of directors determined the fair value of the underlying common stock by considering a number of factors, including historical and projected financial results, the risks the Company faced at the time, the preferences of the Company’s preferred stockholders and the lack of liquidity of the Company’s common stock. Subsequent to the IPO, the exercise price of the stock options granted to employees and members of the board of directors of the Company was determined by the Company’s closing market price on the date the stock options were granted.

The fair value of each option award is estimated on the date of grant using the Black-Scholes valuation model using the appropriate risk-free interest rate, expected term and volatility assumptions. The expected life of options was calculated using the simplified method, which calculates the life as the average of the contractual term of the stock option and the vesting period of the option. Due to the Company’s limited historical data as a public company, the estimated volatility is calculated based upon the historical volatility of the Company and comparable companies whose share prices are publicly available for a sufficient period of time. The risk-free interest rate is based upon U.S. Treasury securities with remaining terms similar to the expected term of the stock award being valued. The Company granted 501,500 options in 2013 and no options in 2012.

Research and Development Expenses

Research and development costs are expensed as incurred and primarily include compensation and related benefits, stock-based compensation expense, costs paid to third-party contractors to perform research, conduct clinical trials and develop drug materials and delivery devices. The Company expenses costs relating to the purchase and production of pre-approval inventories as research and development expense in the period incurred until FDA approval is received.

The Company bases its expense accruals related to clinical studies on estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and clinical research organizations , or CROs, that conduct and manage clinical studies on our behalf. The financial terms of these agreements vary from contract to contract and may result in uneven payment flows. Payments under some of these contracts depend on factors, such as the successful enrollment of patients, site initiation and the completion of clinical study milestones. Service providers invoice us monthly in arrears for services performed. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the Company does not identify costs that have begun to be incurred, or if the Company underestimates or overestimates the level of services performed or the costs of these services, actual expenses could differ from estimates. To date, the Company has not experienced significant changes in estimates of accrued research and development expenses after a reporting period. However, due to the nature of estimates, no assurance can be made that changes to the estimates will not be made in the future as the Company becomes aware of additional information about the status or conduct of clinical studies and other research activities.

We do not own or operate manufacturing facilities for the production of EVK-001, nor do we have plans to develop our own manufacturing operations in the foreseeable future. We currently depend on third-party contract manufacturers for all of our required raw materials, drug substance and finished product for our preclinical research and clinical trials. We do not have any current contractual relationships for the manufacture of commercial supplies of EVK-001. If EVK-001 is approved by any regulatory agency, we intend to enter into agreements with third-party contract manufacturers for the commercial production at that time. We currently utilize a third-party consultant, which we engage on an as-needed, hourly basis, to manage our manufacturing contractors.

Income Taxes

The Company accounts for income taxes in accordance with ASC 740, Income Taxes. Under ASC 740, deferred tax assets and liabilities reflect the future tax consequences of the differences between the financial reporting and tax basis of assets and liabilities using current enacted tax rates. The Company provides a valuation allowance against net deferred tax assets unless, based upon the available evidence, it is more likely than not that the deferred tax assets will be realized.

The Company’s policy related to accounting for uncertainty in income taxes prescribes a recognition threshold and measurement attributed criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities.

Comprehensive Income (Loss)

ASC 220, Comprehensive Income, defines comprehensive income (loss) as a change in equity during a period from transactions and other events and circumstances from non-owner sources. Net loss and comprehensive loss were the same for all periods presented.

Net Loss Per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents and adjusted for the weighted-average number of common shares outstanding that are subject to repurchase. The Company has excluded 103,750, 118,750 and 140,125 weighted-average shares subject to repurchase from the weighted-average number of common shares outstanding for the year ended December 31, 2013, 2012 and 2011, respectively. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for the purchase of convertible preferred stock, warrants for the purchase of common stock, and options outstanding under the Company’s equity incentive plans. For the periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.

The following table summarizes the weighted-average anti-dilutive securities excluded from the calculation of diluted net loss per share (in common equivalent shares):


	Year Ended December 31,
	2013		2012		2011
Convertible preferred stock outstanding		—		2,439,002		2,439,002
Warrants for convertible preferred stock		—		14,000		10,000
Warrants for common stock		106,000		—		—
Common stock options		624,750		123,250		123,250

		730,750		2,576,252		2,572,252

Recent Accounting Pronouncements

In February 2013, the Financial Accounting Standards Board issued an accounting standard update to require reclassification adjustments from other comprehensive income to be presented either in the financial statements or in the notes to the financial statements. This accounting standard became effective for the Company beginning in the first quarter of 2013, and its adoption did not have any impact on the Company’s financial statements.

In July 2013, the FASB issued Accounting Standards Update No. 2013-11, presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists (“ASU 2013-11”). The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013, with an option for early adoption. The Company intends to adopt this guidance during the first quarter of 2014, and does not believe the adoption of this standard will have a material impact on the Company’s consolidated financial statements.

Fair Value Measurements

12 Months Ended

Dec. 31, 2013

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The following tables present information about the Company’s financial liabilities measured at fair value on a recurring basis as of December 31, 2013 and 2012 and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value. The Company had no financial liabilities as of December 31, 2013. As a basis for categorizing inputs, the Company uses a three-tier fair value hierarchy, which prioritizes the inputs used to measure fair value from market based assumptions to entity specific assumptions:

Level 1: Observable inputs such as quoted prices in active markets;

Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and

Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

The Company’s Level 3 financial liabilities consisted of warrant liabilities related to warrants to purchase preferred stock. All warrants were measured at fair value utilizing the Black-Scholes option pricing model.

The fair value of the outstanding preferred stock warrants at December 31, 2012 was estimated using the Black-Scholes option pricing model with the following assumptions:


	December 31, 2012
Assumed risk-free-interest rate		0.25% — 1.78%
Assumed volatility		80%
Expected warrant life		2.08 — 9.50 years
Expected dividend yield		0.0%

Liabilities measured at fair value on a recurring basis as of December 31, 2012 are as follows:


			Fair Value Measurements at Reporting Date Using
	Balance as of December 31, 2012		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Liabilities:
Preferred stock warrant liability	$	56,000	$	—	$	—	$	56,000

Total liabilities		56,000	$	—	$	—	$	56,000

The following table is a reconciliation of all the Company’s liabilities measured using significant unobservable inputs (Level 3) for the years ended December 31, 2013 and 2012:


	Warrant Liability
Fair value measurement at December 31, 2011	$	39,000
Warrants issued in connection with loan and security agreement		24,250
Change in fair value of warrant liability		(7,250	)

Fair value measurement at December 31, 2012		56,000
Warrants issues in connection with loan and security agreement		49,000
Change in fair value of warrant liability		82,000
Reclassification to additional paid-in capital at initial public offering		(187,000	)

Fair value measurement at December 31, 2013	$	—

- 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

Debt

12 Months Ended

Dec. 31, 2013

Debt Disclosure [Abstract]

Debt

4. Debt

In June 2012, the Company entered into a $3.0 million loan and security agreement collateralized by the Company’s personal property. Interest on advances under the agreement is at a fixed interest rate equal to 4.50%. The loan and security agreement contains only non-financial covenants. Advances under the loan and security agreement have an interest-only period through December 31, 2013 and a 24-month payback period commences in January 2014. The Company was advanced $1 million and $2 million in July 2012 and January 2013, respectively. As such, as of December 31, 2013 and 2012, the Company had $0 and $2.0 million, respectively, in available credit under the loan and security agreement.

In connection with the loan and security agreement, a warrant was issued for shares of Series A Convertible Preferred Stock that is exercisable in whole, or in part, at any time until the expiration date of June 1, 2022. During July 2012, the Company drew down $1.0 million under the loan and security agreement and the warrant became exercisable for 4,000 shares of Series A Convertible Preferred Stock at an exercise price of $7.50 per share. During January 2013, the Company drew down the remaining $2.0 million under the loan and security agreement and the warrant became exercisable for an additional 8,000 shares of Series A Convertible Preferred Stock at an exercise price of $7.50 per share.

The initial $24,250 fair value of the 4,000 warrant shares earned in July 2012 and the initial $49,000 fair value of the 8,000 warrant shares earned in January 2013 were recorded as a debt discount and are amortized to interest expense over the term of the loan using the effective interest method. As of December 31, 2013 and 2012, the Company had unamortized debt discount of $45,947 and $20,208, respectively, related to the initial fair value of the warrants.

The initial fair value of warrants earned in 2013 and 2012 was estimated using the Black-Scholes option pricing model with the following assumptions:


	January 2013			July 2012
Assumed risk-free interest rate		1.86	%		1.43	%
Assumed volatility		80	%		80	%
Expected warrant life		9.5 Years			10 Years
Expected dividend yield		0.0	%		0.0	%

The aggregate advances under the loan and security agreement and unamortized discount as of December 31, 2013 and 2012 are as follows:


	December 31, 2013			December 31, 2012
Aggregate advances under loan and security agreement	$	3,000,000		$	1,000,000
Less unamortized discount		(45,947	)		(20,208	)

Long-term debt, net of debt discount		2,954,053			979,792
Current portion of unamortized discount		23,260			—
Current portion of long-term debt		(1,465,852	)		—

Long-term debt, net of current portion	$	1,511,461		$	979,792

Maturities of long-term debt as of December 31, 2013, are as follows:


	2014	$	1,572,285
	2015		1,572,285

Total minimum payments			3,144,570
Less amount representing interest			(144,570	)

Total outstanding debt			3,000,000
Less current portion			(1,465,852	)

Long-term portion		$	1,534,148

Total interest incurred under the loan and security agreement for the years ended December 31, 2013 and 2012 (excluding amortization of debt discount) was $136,625 and $20,000, respectively.

Acquisition of Technology

12 Months Ended

Dec. 31, 2013

Business Combinations [Abstract]

Acquisition of Technology

6. Acquisition of Technology

In June 2007, the Company purchased from Questcor Pharmaceuticals, Inc. (“Questcor”) all rights and patents to a development program for the Company’s EVK-001 product candidate, for an upfront payment of $650,000 which was expensed as in-process research and development. In addition to the upfront payment, the Company will be required to make additional milestone payments totaling up to $52,000,000. These milestones include up to $5,000,000 in payments if EVK-001 achieves the following development targets:

•

$500,000 upon the initiation of the first patient dosing in the Company’s planned Phase 3 clinical trial for EVK-001;

•

$1,500,000 upon the U.S. Food and Drug Administration’s (the “FDA”) acceptance for review of a new drug application for EVK-001; and

•

$3,000,000 upon the FDA’s approval of EVK-001.

The remaining $47,000,000 in milestone payments depend on EVK-001’s commercial success and will only apply if EVK-001 receives regulatory approval. In addition, the Company will be required to pay to Questcor a low single digit royalty on net sales of EVK-001. The Company’s obligation to pay such royalties will terminate upon the expiration of the last patent right covering EVK-001, which is expected to occur in 2030.

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit)

12 Months Ended

Dec. 31, 2013

Equity [Abstract]

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit)

7. Convertible Preferred Stock, Common Stock and Stockholders’ Equity (Deficit)

Convertible Preferred Stock

The Company’s convertible preferred stock has been classified as temporary equity in the accompanying balance sheets instead of in stockholders’ equity (deficit) in accordance with authoritative guidance for the classification and measurement of potentially redeemable securities. Upon certain change in control events that are outside of the Company’s control, including liquidation, sale or transfer of control of the Company, holders of the convertible preferred stock were able to cause its redemption.

During June and October 2007, the Company sold an aggregate of 4,000,000 shares of Series A Convertible Preferred Stock at $1.50 per share for gross proceeds of $6,000,000 in cash. In addition, $250,000 in convertible promissory notes issued in an earlier bridge financing and $42,538 in accrued interest thereon converted into 195,067 shares of Series A Convertible Preferred Stock. In connection with the Series A Convertible Preferred Stock issuance, $848,257 of the proceeds were allocated to the preferred stock purchase right liability, and the Company incurred $218,037 of offering costs.

As part of the October 2007 Series A Convertible Preferred Stock transaction, the preferred stock purchase right liability for the second closing was revalued with the $4,132 increase in fair value recorded as other expense on the statement of operations and the then fair value of $80,819 was reclassified to Series A Convertible Preferred Stock. At December 31, 2007, the preferred stock purchase right liability for the third closing was revalued with the $68,955 increase in fair value recorded as other expense on the statement of operations.

During November 2008, the Company sold an additional 4,000,000 shares of Series A Convertible Preferred Stock for gross proceeds of $6,000,000 in cash. In connection with this financing, the Company incurred $1,855 of offering costs. As part of the Series A Convertible Preferred Stock transaction, the preferred stock purchase right liability for the third closing was revalued with the $115,500 increase in fair value recorded as other expense on the statement of operations and the then fair value of $956,025 was reclassified to Series A Convertible Preferred Stock.

During June 2010, the Company sold an additional 4,000,001 shares of Series A Convertible Preferred Stock for gross proceeds of $6,000,002 in cash. In connection with this financing, the Company incurred $36,069 of offering costs.

The holders of the Series A Convertible Preferred Stock were entitled to receive noncumulative dividends at a rate of $0.12 per share per annum. The preferred stock dividends were payable when and if declared by the board of directors. As of December 31, 2012 and June 30, 2013, the board of directors had not declared any dividends. The Series A Convertible Preferred Stock dividends were payable in preference and in priority to any dividends on common stock. At the time of the conversion of the Series A Convertible Preferred Stock, no dividends had been declared.

The holders of the Series A Convertible Preferred Stock were entitled to receive liquidation preferences at the rate of $1.50 per share, plus all declared and unpaid dividends. Liquidation payments to the holders of Series A Convertible Preferred Stock had priority and were made in preference to any payments to the holders of common stock.

The shares of Series A Convertible Preferred Stock were convertible into one share of common stock for each five shares of preferred stock, at the option of the holder, subject to certain anti-dilutive adjustments. Each share of Series A Convertible Preferred Stock was automatically converted into common stock immediately upon the earlier of (i) the Company’s sale of its common stock in a firm commitment underwritten public offering pursuant to a registration statement under the Securities Act of 1933, as amended, in which the per share price is at least $22.50 (as adjusted), and the gross cash proceeds are at least $25,000,000 or (ii) the date specified by written consent or agreement of the holders of not less than 66.66% of the then outstanding shares of Series A Convertible Preferred Stock.

The holders of Series A Convertible Preferred Stock were entitled to one vote for each share of common stock into which such Series A Convertible Preferred Stock could then be converted; and with respect to such vote, such holder had full voting rights and powers equal to the voting rights and powers of the holders of common stock.

The holders of the Series A Convertible Preferred Stock with greater than 250,000 shares were entitled to elect one member each to the Company’s board of directors.

As of December 31, 2013, there were no shares of Series A Convertible Preferred Stock issued or outstanding as all shares, totaling 2,439,002 of Series A Convertible Preferred Stock, converted to 2,439,002 shares of common stock immediately prior to the completion of the IPO.

Under the Company’s amended and restated certificate of incorporation as of December 31, 2013, the Company is authorized to issue 5,000,000 shares of preferred stock with a $0.0001 par value.

Common Stock

As of December 31, 2013, there were 6,096,752 shares of common stock outstanding. Each share of common stock is entitled to one vote. The holders of the common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors of the Company. To date, no dividends have been declared.

Stock Options

The Company adopted the 2007 Equity Incentive Plan (the “2007 Plan”) in May 2007 under which 450,000 shares of common stock were reserved for issuance to employees, nonemployee directors and consultants of the Company. As of December 31, 2012 no options were available for future grant under this plan. In August 2013, the Company adopted the 2013 Equity Incentive Award Plan (the “2013 Plan”) as a successor to the 2007 Plan.

Under the 2013 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, non-employee directors or consultants of the Company. A total of 510,000 shares of common stock were initially reserved for issuance under the 2013 Plan. In addition, the number of shares of common stock available for issuance under the 2013 Plan will be annually increased on the first day of each fiscal year during the term of the 2013 Plan, beginning with the 2014 fiscal year, by an amount equal to the least of: (i) 300,000 shares; (ii) four percent of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company’s board of directors may determine. As of December 31, 2013, 8,500 options remain available for future grant under the 2013 Plan.

Options granted under the 2007 Plan and 2013 Plan have terms ranging from seven to ten years from the date of grant and generally vest over a three to four year period. The exercise price of all options granted during the years ended December 31, 2013, 2012 and 2011 was equal to the market value per share of the Company’s common stock on the date of grant.

A summary of the Company’s stock option activity under the 2007 Plan and 2013 Plan is as follows:


	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		123,250	$	0.40		7.84	$	578
Granted		501,500	$	9.39		9.88		—
Exercised		—		—		—		—
Canceled/Forfeited		—		—		—		—
Outstanding at December 31, 2013		624,750	$	7.61		8.41	$	869,490
Exercisable at December 31, 2013 (1)		90,540	$	0.39		5.01	$	638,881
Vested or expected to vest at December 31, 2013		624,750	$	7.61		8.41	$	869,490

(1)	Includes awards with early exercise provisions that permit optionee to exercise unvested options.

The intrinsic values above represent the aggregate value of the total pre-tax intrinsic value based upon a common stock price of $7.45 and $0.40 at December 31, 2013 and 2012, respectively, and the contractual exercise prices.

The 2007 Plan permits the early exercise of options, but the Company has the option to repurchase any unvested shares at the original purchase price (the exercise price paid by the Purchaser) upon any voluntary or involuntary termination (“Repurchase Option”). The shares of common stock issued from the exercise of stock options are restricted and vest over time or on the achievement of certain milestones. Any unvested shares immediately vest in the event of termination for reasons other than cause, and vesting accelerates in the event of a merger, sale, or other change in control of the Company. Of the total 326,750 stock options exercised, 230,500 and 215,500 were vested as of December 31, 2013 and 2012, respectively.

The total intrinsic value of stock options exercised was $0 for the years ended December 31, 2013, 2012 and 2011, respectively, as there were no options exercised during these years.

Stock-Based Compensation

The estimated fair value of each option award granted was determined on the date of grant using the Black-Scholes option-pricing valuation model with the following weighted-average assumptions for options grants during the three years ended December 31, 2013:


	Year Ended December 31,
	2013	2012		2011
Stock Options
Risk free interest rate	1.75% - 1.8%		—	2.33%
Expected option term	6.0 years		—	5.0 years
Expected volatility of common stock	70.8% - 79.4%		—	80.0%
Expected dividend yield	—%		—	—%

The risk-free interest rate assumption was based on the yield of an applicable rate for U.S. Treasury instruments with maturities similar to those of the expected term of the award being valued. The assumed dividend yield was based on the Company never paying cash dividends and having no expectation of paying cash dividends in the foreseeable future. The weighted average expected term of options was calculated using the simplified method as prescribed by accounting guidance for stock-based compensation. This decision was based on the lack of relevant historical data due to the Company’s limited historical experience. In addition, due to the Company’s limited historical data, the estimated volatility was calculated based upon the Company’s historical volatility, supplemented with historical volatility of comparable companies in the biotechnology industry whose share prices are publicly available for a sufficient period of time.

The weighted average grant date fair value per share of employee stock options granted during the years ended December 31, 2013, 2012 and 2011 was $6.33, $0 and $0.05, respectively.

The Company recognized non-cash stock-based compensation expense to employees and directors in its research and development and its general and administrative functions as follows:


	Year Ended December 31,						Period from January 29, 2007 (Inception) to December 31,
	2013		2012		2011		2013
Research and development	$	39,638	$	10,004	$	15,360	$	93,435
General and administrative		106,328		2,501		7,345		142,243

Total stock-based compensation expense	$	145,966	$	12,505	$	22,705	$	235,678

As of December 31, 2013 and 2012, there was approximately $3,055,000 and $26,000, respectively, of unrecognized compensation costs related to outstanding employee and board of director options, which is expected to be recognized over a weighted average period of 1.84 and 2.0 years, respectively.

Employee Stock Purchase Plan

On June 13, 2013, the Company’s board of directors adopted the Employee Stock Purchase Plan (the “ESPP”), and the Company’s stockholders approved the ESPP on August 29, 2013. The ESPP became effective on the day prior to the effectiveness of the IPO. The ESPP permits participants to purchase common stock through payroll deductions of up to 20% of their eligible compensation. A total of 30,000 shares of common stock will initially be reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be annually increased on the first day of each fiscal year during the term of the ESPP, beginning with the 2014 fiscal year, by an amount equal to the least of: (i) 30,000 shares; (ii) one percent of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company’s board of directors may determine. No shares of common stock have been issues under the ESPP.

Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following at December 31, 2013 and 2012:


	December 31,
	2013		2012
Conversion of preferred stock		—		2,439,002
Stock options issued and outstanding		624,750		123,250
Authorized for future option grants		8,500		—
Warrants for convertible preferred stock		—		14,000
Warrants for common stock		106,000		—
Authorized for Employee Stock Purchase Plan		330,000		—

Total common stock reserved for future issuance		1,069,250		2,576,252

- 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.

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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph d
-Article 4

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Article 4

Reference 18: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

Reference 19: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

+ Details

Income Taxes

12 Months Ended

Dec. 31, 2013

Income Tax Disclosure [Abstract]

Income Taxes

9. Income Taxes

On January 1, 2009, the Company adopted authoritative guidance relating to the accounting for uncertainty in income taxes. The guidance clarified the recognition threshold and measurement attributes for financial statement disclosure of tax positions taken, or expected to be taken, on a tax return. The impact of an uncertain income tax position on the income tax return must be recognized at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain tax position will not be recognized if it has a less than 50% likelihood of being sustained. On the date of adoption, there were no unrecognized tax benefits. Further, there is no unrecognized tax benefit included in the Company’s balance sheets at December 31, 2013 and 2012 that would, if recognized, affect the Company’s effective tax rate.

The Company’s policy is to recognize interest and/or penalties related to income tax matters in income tax expense. The Company had no accrual for interest and penalties on the balance sheets at December 31, 2013 and 2012. The Company is subject to taxation in the United States and state jurisdictions, and as of December 31, 2013, the Company’s tax years beginning 2007 to date are subject to examination by taxing authorities. The Company does not foresee material changes to its gross uncertain income tax position liability within the next twelve months.

A reconciliation of the federal statutory income tax rate and the effective income tax rate is as follows for the years ended December 31:


	December 31,
	2013 (%)			2012 (%)			2011 (%)
Federal statutory rate		34.0			34.0			34.0
Change in valuation allowance		(2.5	)		(4.9	)		(0.2	)
State income taxes, net of federal effect		5.8			5.8			5.8
Research and development credits		4.3			1.5			4.2
Removal of net operating loss and other credits		(39.5	)		(36.4	)		(43.9	)
Other		(2.1	)		(0.0	)		0.1

Effective income tax rate		0.0			0.0			0.0

Pursuant to Internal Revenue Code (IRC) Sections 382 and 383, annual use of the Company’s net operating loss and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has not completed an IRC Section 382/383 analysis regarding the limitation of net operating loss and research and development credit carryforwards. Until this analysis has been completed, the Company has removed the deferred tax assets for net operating losses of approximately $8.4 million and a research and development credit of approximately $931,000 generated through December 31, 2013 from its deferred tax asset schedule, and has recorded a corresponding decrease to its valuation allowance. When this analysis is finalized, the Company plans to update its unrecognized tax benefits accordingly. The Company does not expect this analysis to be completed within the next twelve months and, as a result, the Company does not expect that the unrecognized tax benefits will change within twelve months of this reporting date. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact the Company’s effective tax rate.

Significant components of the Company’s deferred tax assets at December 31, 2013 and 2012 are as follows:


	December 31,
	2013			2012
Deferred tax assets:
Acquired technology	$	147,000		$	164,000
Other, net		290,000			203,000

Total deferred tax assets		437,000			367,000
Less valuation allowance		(437,000	)		(367,000	)

Net deferred tax assets	$	—		$	—

At December 31, 2013, the Company has federal and state net operating loss carryforwards of approximately $21.2 million and $20.7 million, respectively. The federal and state loss carryforwards begin to expire in 2027 and 2017, respectively, unless previously utilized. The Company also has federal and state research tax credit carryforwards of approximately $627,000 and $459,000, respectively. The federal research credit carryforwards will begin expiring in 2027 unless previously utilized. The state research credit will carry forward indefinitely.

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2013
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment operating in the United States.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking and savings accounts.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of accounts payable and accrued expenses are considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates currently available to the Company for loans with similar terms, the Company believes that the fair value of long-term debt approximates its carrying value. The carrying amount of the warrant liability represents fair value.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject the Company to significant credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in a federally insured financial institution in excess of federally insured limits. The Company has established guidelines designed to maintain safety and liquidity, has not experienced any losses in such accounts and believes the exposure to significant risk to the cash balance is minimal. In addition, the Company relies on third-party manufacturers for the production of its drug candidate. If the third-party manufacturers are unable to continue manufacturing the Company’s drug candidate, or if the Company loses one of its sole source suppliers used in its manufacturing processes, the Company may not be able to meet clinical trial supply demand for its product candidate and the development of the product candidate could be materially and adversely affected.
Preferred Stock Warrant Liability	Preferred Stock Warrant Liability Warrants for shares that are puttable and warrants for shares that are contingently redeemable are classified as liabilities on the accompanying balance sheets and carried at their estimated fair value. At the end of each reporting period, any changes in fair value are recorded as a component of other income (expense). At the completion of the IPO, the Company adjusted the carrying value of the warrants and reclassified the liability to additional paid-in capital.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense is recorded at the estimated fair value of the award as of the grant date and is recognized as expense on a straight-line basis over the employee’s requisite service period, which is generally the vesting period of the award. Stock-based compensation expense is based on awards ultimately expected to vest, and therefore, the recorded expense includes an estimate of future forfeitures. Forfeitures are to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Prior to the IPO, the Company granted stock options to purchase common stock to employees with exercise prices equal to the value of the underlying stock, as determined by the board of directors on the date the equity award was granted. The board of directors determined the fair value of the underlying common stock by considering a number of factors, including historical and projected financial results, the risks the Company faced at the time, the preferences of the Company’s preferred stockholders and the lack of liquidity of the Company’s common stock. Subsequent to the IPO, the exercise price of the stock options granted to employees and members of the board of directors of the Company was determined by the Company’s closing market price on the date the stock options were granted. The fair value of each option award is estimated on the date of grant using the Black-Scholes valuation model using the appropriate risk-free interest rate, expected term and volatility assumptions. The expected life of options was calculated using the simplified method, which calculates the life as the average of the contractual term of the stock option and the vesting period of the option. Due to the Company’s limited historical data as a public company, the estimated volatility is calculated based upon the historical volatility of the Company and comparable companies whose share prices are publicly available for a sufficient period of time. The risk-free interest rate is based upon U.S. Treasury securities with remaining terms similar to the expected term of the stock award being valued. The Company granted 501,500 options in 2013 and no options in 2012.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred and primarily include compensation and related benefits, stock-based compensation expense, costs paid to third-party contractors to perform research, conduct clinical trials and develop drug materials and delivery devices. The Company expenses costs relating to the purchase and production of pre-approval inventories as research and development expense in the period incurred until FDA approval is received. The Company bases its expense accruals related to clinical studies on estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and clinical research organizations , or CROs, that conduct and manage clinical studies on our behalf. The financial terms of these agreements vary from contract to contract and may result in uneven payment flows. Payments under some of these contracts depend on factors, such as the successful enrollment of patients, site initiation and the completion of clinical study milestones. Service providers invoice us monthly in arrears for services performed. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the Company does not identify costs that have begun to be incurred, or if the Company underestimates or overestimates the level of services performed or the costs of these services, actual expenses could differ from estimates. To date, the Company has not experienced significant changes in estimates of accrued research and development expenses after a reporting period. However, due to the nature of estimates, no assurance can be made that changes to the estimates will not be made in the future as the Company becomes aware of additional information about the status or conduct of clinical studies and other research activities. We do not own or operate manufacturing facilities for the production of EVK-001, nor do we have plans to develop our own manufacturing operations in the foreseeable future. We currently depend on third-party contract manufacturers for all of our required raw materials, drug substance and finished product for our preclinical research and clinical trials. We do not have any current contractual relationships for the manufacture of commercial supplies of EVK-001. If EVK-001 is approved by any regulatory agency, we intend to enter into agreements with third-party contract manufacturers for the commercial production at that time. We currently utilize a third-party consultant, which we engage on an as-needed, hourly basis, to manage our manufacturing contractors.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC 740, Income Taxes. Under ASC 740, deferred tax assets and liabilities reflect the future tax consequences of the differences between the financial reporting and tax basis of assets and liabilities using current enacted tax rates. The Company provides a valuation allowance against net deferred tax assets unless, based upon the available evidence, it is more likely than not that the deferred tax assets will be realized. The Company’s policy related to accounting for uncertainty in income taxes prescribes a recognition threshold and measurement attributed criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities.
Comprehensive Income (Loss)	Comprehensive Income (Loss) ASC 220, Comprehensive Income, defines comprehensive income (loss) as a change in equity during a period from transactions and other events and circumstances from non-owner sources. Net loss and comprehensive loss were the same for all periods presented.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents and adjusted for the weighted-average number of common shares outstanding that are subject to repurchase. The Company has excluded 103,750, 118,750 and 140,125 weighted-average shares subject to repurchase from the weighted-average number of common shares outstanding for the year ended December 31, 2013, 2012 and 2011, respectively. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for the purchase of convertible preferred stock, warrants for the purchase of common stock, and options outstanding under the Company’s equity incentive plans. For the periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company’s net loss position.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2013, the Financial Accounting Standards Board issued an accounting standard update to require reclassification adjustments from other comprehensive income to be presented either in the financial statements or in the notes to the financial statements. This accounting standard became effective for the Company beginning in the first quarter of 2013, and its adoption did not have any impact on the Company’s financial statements. In July 2013, the FASB issued Accounting Standards Update No. 2013-11, presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists (“ASU 2013-11”). The guidance is effective prospectively for fiscal years, and interim periods within those years, beginning after December 15, 2013, with an option for early adoption. The Company intends to adopt this guidance during the first quarter of 2014, and does not believe the adoption of this standard will have a material impact on the Company’s consolidated financial statements.

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2013

Fair Value Disclosures [Abstract]

Fair Value of Outstanding Preferred Stock Warrants

The fair value of the outstanding preferred stock warrants at December 31, 2012 was estimated using the Black-Scholes option pricing model with the following assumptions:


	December 31, 2012
Assumed risk-free-interest rate		0.25% — 1.78%
Assumed volatility		80%
Expected warrant life		2.08 — 9.50 years
Expected dividend yield		0.0%

Liabilities Measured at Fair Value on Recurring Basis

Liabilities measured at fair value on a recurring basis as of December 31, 2012 are as follows:


			Fair Value Measurements at Reporting Date Using
	Balance as of December 31, 2012		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Liabilities:
Preferred stock warrant liability	$	56,000	$	—	$	—	$	56,000

Total liabilities		56,000	$	—	$	—	$	56,000

Reconciliation of Company's Liabilities Measured Using Significant Unobservable Inputs

The following table is a reconciliation of all the Company’s liabilities measured using significant unobservable inputs (Level 3) for the years ended December 31, 2013 and 2012:


	Warrant Liability
Fair value measurement at December 31, 2011	$	39,000
Warrants issued in connection with loan and security agreement		24,250
Change in fair value of warrant liability		(7,250	)

Fair value measurement at December 31, 2012		56,000
Warrants issues in connection with loan and security agreement		49,000
Change in fair value of warrant liability		82,000
Reclassification to additional paid-in capital at initial public offering		(187,000	)

Fair value measurement at December 31, 2013	$	—

Debt (Tables)

12 Months Ended

Dec. 31, 2013

Debt Disclosure [Abstract]

Assumptions Used in Estimation of Initial Fair Value of Warrants

The initial fair value of warrants earned in 2013 and 2012 was estimated using the Black-Scholes option pricing model with the following assumptions:


	January 2013			July 2012
Assumed risk-free interest rate		1.86	%		1.43	%
Assumed volatility		80	%		80	%
Expected warrant life		9.5 Years			10 Years
Expected dividend yield		0.0	%		0.0	%

Schedule of Aggregate Advances under the Loan and Security Agreement

The aggregate advances under the loan and security agreement and unamortized discount as of December 31, 2013 and 2012 are as follows:


	December 31, 2013			December 31, 2012
Aggregate advances under loan and security agreement	$	3,000,000		$	1,000,000
Less unamortized discount		(45,947	)		(20,208	)

Long-term debt, net of debt discount		2,954,053			979,792
Current portion of unamortized discount		23,260			—
Current portion of long-term debt		(1,465,852	)		—

Long-term debt, net of current portion	$	1,511,461		$	979,792

Schedule of Maturities of Long-Term Debt

Maturities of long-term debt as of December 31, 2013, are as follows:


	2014	$	1,572,285
	2015		1,572,285

Total minimum payments			3,144,570
Less amount representing interest			(144,570	)

Total outstanding debt			3,000,000
Less current portion			(1,465,852	)

Long-term portion		$	1,534,148

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) (Tables)

12 Months Ended

Dec. 31, 2013

Equity [Abstract]

Summary of Stock Option Activity

A summary of the Company’s stock option activity under the 2007 Plan and 2013 Plan is as follows:


	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2012		123,250	$	0.40		7.84	$	578
Granted		501,500	$	9.39		9.88		—
Exercised		—		—		—		—
Canceled/Forfeited		—		—		—		—
Outstanding at December 31, 2013		624,750	$	7.61		8.41	$	869,490
Exercisable at December 31, 2013 (1)		90,540	$	0.39		5.01	$	638,881
Vested or expected to vest at December 31, 2013		624,750	$	7.61		8.41	$	869,490

(1)	Includes awards with early exercise provisions that permit optionee to exercise unvested options.

Summary of Estimated Fair Value of Stock Option Award Granted


	Year Ended December 31,
	2013	2012		2011
Stock Options
Risk free interest rate	1.75% - 1.8%		—	2.33%
Expected option term	6.0 years		—	5.0 years
Expected volatility of common stock	70.8% - 79.4%		—	80.0%
Expected dividend yield	—%		—	—%

Summary of Non-Cash Share-Based Compensation Expense

The Company recognized non-cash stock-based compensation expense to employees and directors in its research and development and its general and administrative functions as follows:


	Year Ended December 31,						Period from January 29, 2007 (Inception) to December 31,
	2013		2012		2011		2013
Research and development	$	39,638	$	10,004	$	15,360	$	93,435
General and administrative		106,328		2,501		7,345		142,243

Total stock-based compensation expense	$	145,966	$	12,505	$	22,705	$	235,678

Summary of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following at December 31, 2013 and 2012:


	December 31,
	2013		2012
Conversion of preferred stock		—		2,439,002
Stock options issued and outstanding		624,750		123,250
Authorized for future option grants		8,500		—
Warrants for convertible preferred stock		—		14,000
Warrants for common stock		106,000		—
Authorized for Employee Stock Purchase Plan		330,000		—

Total common stock reserved for future issuance		1,069,250		2,576,252

Organization and Basis of Presentation - Additional Information (Detail)				12 Months Ended
	Oct. 08, 2013 $ / shares shares	Sep. 30, 2013 $ / shares shares	Jun. 13, 2013	Dec. 31, 2013 USD ($) $ / Warrant shares	Dec. 31, 2012 USD ($) shares
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Date of Incorporation				Jan. 29, 2007
Deficit accumulated during the development stage \| $				$ 22,691,468	$ 19,855,003
Working capital (deficit) \| $				$ 22,146,047	$ (454,396)
Reverse stock split of issued and outstanding shares			One-for-five
Reverse stock split effective date				Aug. 30, 2013
Warrants expiration date				Jun. 01, 2022
Warrant liability to additional paid-in capital \| $				$ 187,000
Common stock authorized				50,000,000	20,000,000
Preferred stock authorized				5,000,000	0
IPO [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares sold		2,100,000
Common stock shares price per share \| $ / shares		$ 12.00
Conversion of convertible preferred stock				2,439,002
IPO [Member] \| Retention bonus expense [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Retention bonuses accounting treatment				Such amount was recorded as expense on a straight-line basis from May 22, 2013 (the date of the retention agreements entered into with the executive officers) through December 24, 2013, the date at which the final payment was due based on continued employment.
IPO [Member] \| Warrants for common stock [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Warrants exercise price per share \| $ / Warrant				21.00
Warrants exercisable start date				Sep. 24, 2014
Warrants expiration date				Sep. 24, 2018
Initial fair value of warrants \| $				$ 470,000
IPO [Member] \| Warrants for Convertible Preferred Stock [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of shares callable by warrants				110,000
IPO [Member] \| Warrants for common stock converted from warrants for preferred stock [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of shares callable by warrants				22,000
Warrant liability to additional paid-in capital \| $				$ 187,000
IPO [Member] \| Executive Officers [Member] \| Retention bonus expense [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Retention bonus payable to executive officers \| $				355,000
IPO [Member] \| Executive Officers [Member] \| Catch-up retention bonus expense [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Retention bonus payable to executive officers \| $				$ 202,857
IPO [Member] \| Underwriters and Affiliates [Member] \| Warrants for common stock [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of shares callable by warrants				84,000
Over-allotment option exercise [Member] \| Underwriters [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Common stock shares sold	315,000
Common stock shares price per share \| $ / shares	$ 12.00

Debt - Additional Information (Detail)	1 Months Ended	12 Months Ended
Debt - Additional Information (Detail)	Jun. 30, 2012 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Jan. 31, 2013 USD ($) $ / Warrant shares	Jul. 31, 2012 USD ($) $ / Warrant shares
Debt Instrument [Line Items]
Loan and security agreement, expiration date		Jun. 01, 2022
Unamortized debt discount, related to the initial fair value of warrants		$ 45,947	$ 20,208
Loan and security agreement [Member]
Debt Instrument [Line Items]
Loan and security agreement, maximum credit	$ 3,000,000
Loan and security agreement, interest rate	4.50%
Loan and security agreement, payback period	24 months
Loan and security agreement, amount drawn				$ 2,000,000	$ 1,000,000
Loan and security agreement, available credit		0	2,000,000
Loan and security agreement, interest incurred		$ 136,625	$ 20,000
Loan and security agreement [Member] \| Warrants for Convertible Preferred Stock [Member]
Debt Instrument [Line Items]
Warrants exercisable, stock issued \| shares				8,000
Warrants exercisable, exercise price \| $ / Warrant				7.50
Loan and security agreement [Member] \| Series A Convertible Preferred Stock [Member] \| Warrants for Convertible Preferred Stock [Member]
Debt Instrument [Line Items]
Warrants exercisable, stock issued \| shares				8,000	4,000
Warrants exercisable, exercise price \| $ / Warrant				7.50	7.50
Initial fair value of warrant issued				$ 49,000	$ 24,250

Debt - Schedule of Aggregate Advances under the Loan and Security Agreement (Detail) - USD ($)	Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Aggregate advances under loan and security agreement	$ 3,000,000	$ 1,000,000
Less unamortized discount	(45,947)	(20,208)
Long-term debt, net of debt discount	2,954,053	979,792
Current portion of unamortized discount	23,260
Current portion of long-term debt	(1,465,852)
Long-term debt, net of current portion	$ 1,511,461	$ 979,792

Acquisition of Technology - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended	83 Months Ended
	Jun. 30, 2007	Dec. 31, 2013	Dec. 31, 2013
Business Acquisition, Contingent Consideration [Line Items]
Upfront payment expensed as in-process research and development	$ 650,000		$ 650,000
Questcor [Member] \| Patents [Member]
Business Acquisition, Contingent Consideration [Line Items]
Milestone payments	52,000,000
Development Target One, Two and Three [Member] \| Questcor [Member] \| Patents [Member]
Business Acquisition, Contingent Consideration [Line Items]
Milestone payments, pegged to development targets	$ 5,000,000
Development Target One [Member] \| Questcor [Member] \| Patents [Member]
Business Acquisition, Contingent Consideration [Line Items]
Milestone payments, pegged to development targets		$ 500,000	500,000
Development targets description		Upon the initiation of the first patient dosing in the Company's planned Phase 3 clinical trial for EVK-001
Development Target Two [Member] \| Questcor [Member] \| Patents [Member]
Business Acquisition, Contingent Consideration [Line Items]
Milestone payments, pegged to development targets		$ 1,500,000	1,500,000
Development targets description		Upon the U.S. Food and Drug Administration's (the "FDA") acceptance for review of a new drug application for EVK-001
Development Target Three [Member] \| Questcor [Member] \| Patents [Member]
Business Acquisition, Contingent Consideration [Line Items]
Milestone payments, pegged to development targets		$ 3,000,000	3,000,000
Development targets description		Upon the FDA's approval of EVK-001
Development Target Four [Member] \| Questcor [Member] \| Patents [Member]
Business Acquisition, Contingent Consideration [Line Items]
Milestone payments, pegged to development targets		$ 47,000,000	$ 47,000,000
Development targets description		Depend on EVK-001's commercial success and will only apply if EVK-001 receives regulatory approval. In addition, the Company will be required to pay to Questcor a low single digit royalty on net sales of EVK-001.
Expected expiration of patent right		2030

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Convertible Preferred Stock - Additional Information (Detail) - USD ($)	1 Months Ended				5 Months Ended	12 Months Ended
	Jun. 30, 2010	Nov. 30, 2008	Dec. 31, 2007	Oct. 31, 2007	Oct. 31, 2007	Dec. 31, 2013	Dec. 31, 2012
Sale Of Stock [Line Items]
Dividends declared						$ 0
Preferred stock, shares authorized						5,000,000	0
Preferred stock, par value						$ 0.0001
Preferred stock shares issued						0	0
Preferred stock shares outstanding						0	0
Common stock, shares outstanding						6,096,752	1,242,750
Convertible promissory notes [Member]
Sale Of Stock [Line Items]
Debt instrument face amount				$ 250,000	$ 250,000
Debt instrument accrued interest					$ 42,538
Conversion of convertible preferred stock					195,067
Common Stock [Member]
Sale Of Stock [Line Items]
Conversion of convertible preferred stock						2,439,002
Shareholders voting power description						Each share of common stock is entitled to one vote. The holders of the common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors of the Company.
Series A Convertible Preferred Stock [Member]
Sale Of Stock [Line Items]
Dividends declared						$ 0
Shareholders voting power description						One vote for each share of common stock into which such Series A Convertible Preferred Stock could then be converted; and with respect to such vote, such holder had full voting rights and powers equal to the voting rights and powers of the holders of common stock.
Preferred stock, shares authorized						0	12,305,068
Preferred stock, par value							$ 0.0001
Preferred stock shares issued						0	12,195,068
Preferred stock shares outstanding						0	12,195,068
Series A Convertible Preferred Stock [Member] \| Convertible promissory notes [Member]
Sale Of Stock [Line Items]
Proceeds from the sale of stock allocated to the preferred stock purchase right liability				848,257	$ 848,257
Offering costs					$ 218,037
Series A Convertible Preferred Stock [Member] \| Purchase right liability [Member]
Sale Of Stock [Line Items]
Increase in fair value recorded as other expense			$ 68,955	4,132
Fair value reclassified to preferred stock				$ 80,819
Private Placement [Member] \| Series A Convertible Preferred Stock [Member]
Sale Of Stock [Line Items]
Number of shares sold in transaction	4,000,001	4,000,000			4,000,000
Sale of stock, price per share	$ 1.50	$ 1.50		$ 1.50	$ 1.50
Gross proceeds from sale of stock	$ 6,000,002	$ 6,000,000			$ 6,000,000
Offering costs	$ 36,069	1,855
Increase in fair value recorded as other expense		115,500
Fair value reclassified to preferred stock		$ 956,025
Noncumulative dividends rate, per share per annum						$ 0.12
Liquidation preferences						$ 1.50
Terms of conversion						The shares of Series A Convertible Preferred Stock are convertible into one share of common stock for each five shares of preferred stock, at the option of the holder, subject to certain anti-dilutive adjustments. Each share of Series A Convertible Preferred Stock is automatically converted into common stock immediately upon the earlier of (i) the Company's sale of its common stock in a firm commitment underwritten public offering pursuant to a registration statement under the Securities Act of 1933, as amended, in which the per share price is at least $22.50 (as adjusted), and the gross cash proceeds are at least $25,000,000 or (ii) the date specified by written consent or agreement of the holders of not less than 66.66% of the then outstanding shares of Series A Convertible Preferred Stock.
Price per share threshold, conversion description						$ 22.50
Gross cash proceeds threshold, conversion description						$ 25,000,000
Shareholders consent percentage threshold, conversion description						66.66%
Shareholders voting power number of shares threshold						250,000

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Stock Options - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 31, 2007
Subsidiary, Sale of Stock [Line Items]
Common stock reserved for issuance	2,576,252	1,069,250	2,576,252
Options available for future grant		501,500	0
Intrinsic value, common stock price		$ 7.45	$ 0.40
Stock options exercised		326,750
Stock options vested		230,500	215,500
Total intrinsic value of stock options exercised		$ 0	$ 0	$ 0
Weighted average grant date fair value per share		$ 6.33	$ 0.00	$ 0.05
Minimum [Member]
Subsidiary, Sale of Stock [Line Items]
Options granted, weighted average term		7 years
Options granted, vesting period		3 years
Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Options granted, weighted average term		10 years
Options granted, vesting period		4 years
2007 Equity Incentive Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock reserved for issuance					450,000
Options available for future grant	0
2013 Equity Incentive Award Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock reserved for issuance		510,000
Additional common stock reserved for issuance		300,000
Shares of common stock available for issuance description		In addition, the number of shares of common stock available for issuance under the 2013 Plan will be annually increased on the first day of each fiscal year during the term of the 2013 Plan, beginning with the 2014 fiscal year, by an amount equal to the least of (i) 300,000 shares; (ii) four percent of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company's board of directors may determine.
Reserve percentage for issuance of shares		4.00%
Options available for future grant		8,500

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Summary of Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding beginning balance	123,250
Shares, Granted	501,500	0
Shares, Exercised
Shares, Canceled/Forfeited
Shares, Outstanding ending balance	624,750	123,250
Shares, Exercisable at December 31, 2013	90,540
Shares, Vested or expected to vest at December 31, 2013	624,750
Weighted Average Exercise Price, Outstanding beginning balance	$ 0.40
Weighted Average Exercise Price, Granted	9.39
Weighted Average Exercise Price, Exercised
Weighted Average Exercise Price, Canceled/Forfeited
Weighted Average Exercise Price, ending balance	7.61	$ 0.40
Weighted Average Exercise Price, Exercisable at December 31, 2013	0.39
Weighted Average Exercise Price, Vested or expected to vest at December 31, 2013	$ 7.61
Weighted Average Remaining Contractual Term (Years), Granted	9 years 10 months 17 days
Weighted Average Remaining Contractual Term (Years), Exercised
Weighted Average Remaining Contractual Term (Years), Canceled/Forfeited
Weighted Average Remaining Contractual Term (Years), Outstanding	8 years 4 months 28 days	7 years 10 months 2 days
Weighted Average Remaining Contractual Term (Years), Exercisable at December 31, 2013	5 years 4 days
Weighted Average Remaining Contractual Term (Years), Vested or expected to vest at December 31, 2013	8 years 4 months 28 days
Aggregate Intrinsic Value, Outstanding beginning balance	$ 578
Aggregate Intrinsic Value, Granted
Aggregate Intrinsic Value, Exercised
Aggregate Intrinsic Value, Canceled/Forfeited
Aggregate Intrinsic Value, Outstanding ending balance	869,490	$ 578
Aggregate Intrinsic Value, Exercisable at December 31, 2013	638,881
Aggregate Intrinsic Value, Vested or expected to vest at December 31, 2013	$ 869,490

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Summary of Estimated Fair Value of Stock Option Award Granted (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk free interest rate, minimum	1.75%
Risk free interest rate, maximum	1.80%
Risk free interest rate			2.33%
Expected option term	6 years		5 years
Expected volatility of common stock, minimum	70.80%
Expected volatility of common stock, maximum	79.40%
Expected volatility of common stock			80.00%
Expected dividend yield

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Stock-Based Compensation and Employee Stock Purchase Plan - Additional Information (Detail) - USD ($)		12 Months Ended
	Jun. 13, 2013	Dec. 31, 2013	Dec. 31, 2012
Subsidiary, Sale of Stock [Line Items]
Unrecognized compensation costs		$ 3,055,000	$ 26,000
Weighted average period		1 year 10 months 2 days	2 years
Shares of common stock available for issuance		1,069,250	2,576,252
Employee Stock Purchase Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Percentage of deduction of eligible compensation	20.00%
Shares of common stock available for issuance	30,000
Shares of common stock available for issuance description		In addition, the number of shares of common stock available for issuance under the ESPP will be annually increased on the first day of each fiscal year during the term of the ESPP, beginning with the 2014 fiscal year, by an amount equal to the least of (i) 30,000 shares; (ii) one percent of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (iii) such other amount as the Company's board of directors may determine.
Reserve percentage for issuance of shares	1.00%
ESPP approval date	Aug. 29, 2013
Shares of common stock issued under ESPP		0

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Jan. 02, 2009
Operating Loss Carryforwards [Line Items]
Likelihood of unfavorable settlement	An uncertain tax position will not be recognized if it has a less than 50% likelihood of being sustained.
Unrecognized tax benefits			$ 0
Unrecognized tax benefits that would affect company's effective tax rate, if recognized	$ 0	$ 0
Accrual on interest and penalties related to income taxes	$ 0	$ 0
Tax years subject to examination by taxing authorities	Beginning 2007 to date
Net operating loss carryforwards	$ 8,400,000
Cumulative change in ownership for limitation of use of net operating loss and research and development credit carryforwards	50.00%
Period of cumulative change of ownership	3 years
Research and development credit	$ 931,000
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 21,200,000
Expiry period of carryforwards	2027
Tax credit carryforwards	$ 627,000
Expiry of federal research credit carryforwards	2027
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 20,700,000
Expiry period of carryforwards	2017
Tax credit carryforwards	$ 459,000

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate and Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Federal statutory rate	34.00%	34.00%	34.00%
Change in valuation allowance	(2.50%)	(4.90%)	(0.20%)
State income taxes, net of federal effect	5.80%	5.80%	5.80%
Research and development credits	4.30%	1.50%	4.20%
Removal of net operating loss and other credits	(39.50%)	(36.40%)	(43.90%)
Other	(2.10%)	0.00%	0.10%
Effective income tax rate	0.00%	0.00%	0.00%

Summarized Quarterly Data - Summarized Quarterly Data (Detail) - USD ($)	3 Months Ended								11 Months Ended	12 Months Ended						83 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2007	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Research and development expense	$ 636,423	$ 78,731	$ 130,846	$ 110,981	$ 318,347	$ 337,003	$ 213,010	$ 297,285		$ 956,980	$ 1,165,645	$ 1,844,044				$ 16,948,509
General and administrative expense	944,359	406,862	72,578	221,049	343,570	140,746	147,328	205,137		1,644,848	836,781	570,524				4,949,381
Net loss	$ (1,616,698)	$ (485,904)	$ (239,871)	$ (493,992)	$ (672,450)	$ (486,254)	$ (358,666)	$ (500,158)	$ (2,009,591)	$ (2,836,465)	$ (2,017,528)	$ (2,401,244)	$ (5,039,338)	$ (5,159,638)	$ (3,227,664)	$ (22,691,468)
Net loss per share, basic and diluted	$ (0.27)	$ (0.41)	$ (0.21)	$ (0.44)	$ (0.60)	$ (0.43)	$ (0.32)	$ (0.45)		$ (1.20)	$ (1.79)	$ (2.18)
Weighted average shares outstanding, basic and diluted	5,971,236	1,190,212	1,137,125	1,133,375	1,129,625	1,125,875	1,122,125	1,118,375		2,368,006	1,124,000	1,102,625

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Net Income
-URI http://asc.fasb.org/extlink&oid=6518256

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.19)
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.18)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.22)
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Other Comprehensive Income
-URI http://asc.fasb.org/extlink&oid=6519514

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e565-108580

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 19
-Article 5

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 20
-Article 9

+ Details

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2013
Postemployment Benefits [Abstract]
Employee Benefit Plan	8. Employee Benefit Plan The Company has established a defined contribution 401(k) plan (the Plan) for all employees who are at least 21 years of age. Employees are eligible to participate in the Plan beginning one year following the date of employment. Under the terms of the Plan, employees may make voluntary contributions as a percentage of compensation. The Company’s contributions to the Plan are discretionary, and no contributions have been made by the Company to date.

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2013
Subsequent Events [Abstract]
Subsequent Events	10. Subsequent Events For the purposes of the financial statements as of December 31, 2013 and the year then ended, the Company has evaluated subsequent events through March 25, 2014, the date the audited annual financial statements were issued. The Company has concluded that no subsequent event has occurred that requires disclosure.

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2013 Segment shares	Dec. 31, 2012 shares	Dec. 31, 2011 shares
Earnings Per Share [Abstract]
Number of operating segment \| Segment	1
Number of stock options granted	501,500	0
Weighted-average shares subject to repurchase from the weighted-average number of common shares outstanding	103,750	118,750	140,125

Commitments - Additional Information (Detail) - USD ($)	12 Months Ended			83 Months Ended
Commitments - Additional Information (Detail) - USD ($)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Lease commencement date	December 1, 2013
Lease expiry date	Dec. 31, 2015
Rent expense	$ 8,886	$ 5,000	$ 12,000	$ 57,686
Deferred rent expense	$ 6,830	$ 0		$ 6,830

Commitments - Future Minimum Lease Payments for Operating Lease (Detail)	Dec. 31, 2013 USD ($)
Commitments And Contingencies Disclosure [Abstract]
2014	$ 75,603
2015	93,399
Total future minimum lease payments	$ 169,002

Organization and Basis of Presentation - Initial Public Offering and Related Transactions (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2013 USD ($)
Equity [Abstract]
Value of warrants granted to underwriters	$ 470,000

Organization and Basis of Presentation - Assumptions Used in Estimation of Fair Value of Issued Warrant (Detail)	1 Months Ended		12 Months Ended
	Jan. 31, 2013	Jul. 31, 2012	Dec. 31, 2013
Accounting Policies [Abstract]
Assumed risk-free interest rate	1.86%	1.43%	1.44%
Assumed volatility	80.00%	80.00%	71.00%
Expected warrant life	9 years 6 months	10 years	5 years
Expected dividend yield	0.00%	0.00%	0.00%

Fair Value Measurements - Additional Information (Detail)	Dec. 31, 2013 USD ($)
Fair Value Disclosures [Abstract]
Financial liabilities	$ 0

Fair Value Measurements - Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	Dec. 31, 2013	Dec. 31, 2012
Liabilities:
Total liabilities	$ 0
Fair value, recurring basis [Member]
Liabilities:
Total liabilities		$ 56,000
Fair value, recurring basis [Member] \| Preferred stock warrant liability [Member]
Liabilities:
Total liabilities		56,000
Fair value, recurring basis [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Liabilities:
Total liabilities
Fair value, recurring basis [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] \| Preferred stock warrant liability [Member]
Liabilities:
Total liabilities
Fair value, recurring basis [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Liabilities:
Total liabilities
Fair value, recurring basis [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Preferred stock warrant liability [Member]
Liabilities:
Total liabilities
Fair value, recurring basis [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Liabilities:
Total liabilities		56,000
Fair value, recurring basis [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Preferred stock warrant liability [Member]
Liabilities:
Total liabilities		$ 56,000

Debt - Schedule of Maturities of Long-Term Debt (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Maturities Of Long Term Debt [Abstract]
2014	$ 1,572,285
2015	1,572,285
Total minimum payments	3,144,570
Less amount representing interest	(144,570)
Total outstanding debt	3,000,000	$ 1,000,000
Less current portion	(1,465,852)
Long-term portion	$ 1,534,148

Convertible Preferred Stock, Common Stock and Stockholders' Equity (Deficit) - Summary of Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Total common stock reserved for future issuance	1,069,250	2,576,252
Conversion of preferred stock [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance		2,439,002
Stock options issued and outstanding [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	624,750	123,250
Authorized for future option grants [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	8,500
Warrants for Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance		14,000
Warrants for common stock [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	106,000
Authorized for Employee Stock Purchase Plan [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	330,000

Employee Benefit Plan - Additional Information (Detail)	12 Months Ended
Employee Benefit Plan - Additional Information (Detail)	Dec. 31, 2013 USD ($)
Postemployment Benefits [Abstract]
Eligible age for employees for participating in the plan	21 years
Company's contributions to employee benefit plan	$ 0

Income Taxes - Summary of Significant Components of Deferred Tax Assets (Detail) - USD ($)	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Acquired technology	$ 147,000	$ 164,000
Other, net	290,000	203,000
Total deferred tax assets	437,000	367,000
Less valuation allowance	(437,000)	(367,000)
Net deferred tax assets