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Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2015	Jul. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Trading Symbol	OCUL
Entity Registrant Name	Ocular Therapeutix, Inc.
Entity Central Index Key	0001393434
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		24,719,725

Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 78,686	$ 37,393
Marketable securities	45,036	37,435
Accounts receivable, net	164	329
Inventory	145	133
Prepaid expenses and other current assets	2,608	893
Total current assets	126,639	76,183
Property and equipment, net	2,603	1,782
Restricted cash	228	228
Total assets	129,470	78,193
Current liabilities:
Accounts payable	2,812	1,316
Accrued expenses	2,284	3,016
Deferred revenue	125	188
Notes payable, net of discount, current	4,370	1,354
Total current liabilities	9,591	5,874
Deferred rent, long-term	94	112
Notes payable, net of discount, long-term	10,673	13,511
Total liabilities	20,358	19,497
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $0.0001 par value; 5,000,000 authorized at June 30, 2015 and December 31, 2014, no shares issued or outstanding at June 30, 2015 and December 31, 2014
Common stock, $0.0001 par value; 100,000,000 shares authorized at June 30, 2015 and December 31, 2014, respectively; 24,719,225 and 21,333,507 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively	2	2
Additional paid-in capital	216,133	148,122
Accumulated deficit	(107,015)	(89,428)
Accumulated other comprehensive loss	(8)
Total stockholders' equity	109,112	58,696
Total liabilities and stockholders' equity	$ 129,470	$ 78,193

Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	24,719,225	21,333,507
Common stock, shares outstanding	24,719,225	21,333,507

Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue:
Product revenue	$ 334	$ 97	$ 572	$ 124
Collaboration revenue	125		313
Total revenue:	459	97	885	124
Operating expenses:
Cost of product revenue	80	20	136	29
Research and development	6,743	4,292	11,462	9,250
Selling and marketing	1,041	535	1,911	845
General and administrative	2,230	1,196	4,124	2,771
Total operating expenses	10,094	6,043	17,633	12,895
Loss from operations	(9,635)	(5,946)	(16,748)	(12,771)
Other income (expense):
Interest income	28	1	68	2
Interest expense	(405)	(257)	(910)	(300)
Other income (expense), net	3	(190)	3	(331)
Total other expense, net	(374)	(446)	(840)	(629)
Net loss	(10,009)	(6,392)	(17,587)	(13,400)
Accretion of redeemable convertible preferred stock to redemption value		(5)		(11)
Net loss attributable to common stockholders	$ (10,009)	$ (6,397)	$ (17,587)	$ (13,411)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.45)	$ (2.10)	$ (0.81)	$ (4.54)
Weighted average common shares outstanding, basic and diluted	22,167,274	3,044,605	21,765,087	2,952,689
Comprehensive loss:
Net loss	$ (10,009)	$ (6,392)	$ (17,587)	$ (13,400)
Other comprehensive loss:
Unrealized loss on marketable securities	(8)		(8)
Total other comprehensive loss	(8)		(8)
Total comprehensive loss	$ (10,017)	$ (6,392)	$ (17,595)	$ (13,411)

Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net loss	$ (17,587)	$ (13,400)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	2,073	1,060
Licensing and consultant fees paid in common stock		2,364
Non-cash interest expense	74	25
Depreciation and amortization expense	360	244
Revaluation of preferred stock warrants		272
Loss on extinguishment of debt		57
(Gain)/loss on disposal of property and equipment	(3)	4
Purchase of premium on marketable securities	25
Amortization of premium on marketable securities	39
Changes in operating assets and liabilities:
Accounts receivable from related party		18
Accounts receivable	165	190
Prepaid expenses and other current assets	(749)	(49)
Inventory	(12)	(109)
Accounts payable	651	345
Accrued expenses and deferred rent	(380)	442
Deferred revenue	(63)
Net cash used in operating activities	(15,407)	(8,537)
Cash flows from investing activities:
Purchases of property and equipment	(1,229)	(545)
Purchases of investments	(17,500)
Proceeds from sale of property and equipment	7
Maturities of investments	9,826
Net cash used in investing activities	(8,896)	(545)
Cash flows from financing activities:
Proceeds from issuance of notes payable and preferred stock warrants, net of issuance costs		14,877
Proceeds from exercise of common stock options	144	24
Proceeds from issuance of public offering, net	65,646
Proceeds from issuance of common stock pursuant to employee stock purchase plan	148
Repayments of notes payable		(2,273)
Payments of initial public offering costs		(1,107)
Payments of insurance costs financed by a third-party	(342)
Net cash provided by financing activities	65,596	11,521
Net increase in cash and cash equivalents	41,293	2,439
Cash and cash equivalents at beginning of period	37,393	17,505
Cash and cash equivalents at end of period	78,686	19,944
Supplemental disclosure of cash flow information:
Cash paid for interest	625	210
Supplemental disclosure of non-cash investing and financing activities:
Accretion of redeemable convertible preferred stock to redemption value		11
Deferred offering costs included in accounts payable and accrued expenses	5	1,090
Additions to property and equipment included in accounts payable at balance sheet dates	$ 134	87
Fair value of preferred stock warrants at grant date		$ 326

Nature of the Business and Basis of Presentation	6 Months Ended
Nature of the Business and Basis of Presentation	Jun. 30, 2015
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Ocular Therapeutix, Inc. (the “Company”) was incorporated on September 12, 2006 under the laws of the State of Delaware. The Company is a biopharmaceutical company focused on the development and commercialization of innovative therapies for diseases and conditions of the eye using its proprietary hydrogel platform technology. The Company’s bioresorbable hydrogel-based product candidates are designed to provide sustained delivery of therapeutic agents to the eye. Since inception, the Company’s operations have been primarily focused on organizing and staffing the Company, acquiring rights to intellectual property, business planning, raising capital, developing its technology, identifying potential product candidates, undertaking preclinical studies and clinical trials, manufacturing initial quantities of its products and product candidates and, beginning in the first quarter of 2014, commercializing ReSure Sealant. In the first quarter of 2014, the Company began recognizing revenue from sales of ReSure Sealant, which was approved in January 2014 by the U.S. Food and Drug Administration (“FDA”) as a product to close clear corneal incisions following cataract surgery. The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations, regulatory approval, uncertainty of market acceptance of products and the need to obtain additional financing. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. As of June 30, 2015, the Company’s lead product candidates were in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval and adequate reimbursement or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees and consultants. The Company does not expect to generate significant revenue from sales of any product for several years, if at all. Accordingly, the Company will need to obtain additional capital to finance its operations. If the Company is unable to raise capital when needed or on attractive terms, the Company could be forced to delay, reduce or eliminate its research and development programs or any future commercialization efforts or to relinquish valuable rights to its technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to the Company. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. The Company believes that its existing cash and cash equivalents and marketable securities will enable it to fund its operating expenses, debt service obligations and capital expenditure requirements at least through the third quarter of 2017. The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). On July 30, 2014 the Company completed an initial public offering (“IPO”) of its common stock, through the issuance and sale of 5,000,000 shares of its common stock at a public offering price of $13.00 per share, resulting in net proceeds of approximately $57,337 after deducting underwriting discounts and other offering costs. Upon the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were automatically converted into 12,440,205 shares of the Company’s common stock and all outstanding warrants for the Company’s redeemable convertible preferred stock were automatically converted into warrants for the Company’s common stock. In August 2014, the underwriters of the Company’s IPO exercised their over-allotment option to purchase an additional 750,000 shares of common stock at the initial public offering price of $13.00 per share, less underwriting discounts, resulting in additional net proceeds of approximately $9,068 after deducting underwriting discounts (Note 8). In June 2015 the Company completed a follow-on offering of its common stock, through at a public offering price of $22.00 per share. The offering consisted of 4,600,000 shares of common stock, of which 3,200,000 shares were issued and sold by the Company and 1,400,000 shares were sold by certain stockholders of the Company, including those shares sold in connection with the exercise by the underwriters of their option to purchase additional shares. The Company received net proceeds from the follow-on offering of approximately $65,646 after deducting underwriting discounts and other offering expenses (Note 8). *Unaudited Interim Financial Information* The balance sheet at December 31, 2014 was derived from audited financial statements, but does not include all disclosures required by GAAP. The accompanying unaudited financial statements as of June 30, 2015 and for the three and six months ended June 30, 2015 and 2014 have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission, or SEC, for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K on file with the SEC. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair presentation of the Company’s financial position as of June 30, 2015 and results of operations and cash flows for the six months ended June 30, 2015 and 2014 have been made. The results of operations for the six months ended June 30, 2015 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2015.

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2015

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, revenue recognition, the accrual of research and development expenses and the valuation of common stock and stock-based awards and preferred stock warrants. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

Inventory Valuation

Inventory is valued at the lower of cost or market, determined by the first-in, first-out (“FIFO”) method.

Prior to approval by the FDA or other regulatory agencies of the Company’s products, the Company expenses inventory costs in the period incurred as research and development expenses. After such time as the product receives approval, the Company begins to capitalize the inventory costs related to the product. The Company also reviews its inventories for potential obsolescence.

The Company had an inventory balance of $145 and $133, respectively, as of June 30, 2015 and December 31, 2014, which consisted primarily of raw materials.

Restricted Cash

As of June 30, 2015 and December 31, 2014, the Company held a certificate of deposit to collateralize a credit card account with its bank of $60. This amount is included in prepaid expenses and other current assets on the Company’s balance sheet. As of June 30, 2015 and December 31, 2014, the Company also held a certificate of deposit of $228, which is a security deposit for the lease of the Company’s corporate headquarters. The Company has classified this as long-term restricted cash on its balance sheet.

Fair Value Measurements

Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

•

Level 1—Quoted prices in active markets for identical assets or liabilities.

•

Level 2—Observable inputs (other than Level 1 quoted prices) such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

•

Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques.

The Company’s cash equivalents and marketable securities at June 30, 2015 and December 31, 2014, were carried at fair value determined according to the fair value hierarchy described above (see Note 3). The carrying value of accounts receivable, accounts payable and accrued expenses approximate their fair value due to the short-term nature of these assets and liabilities. The carrying value of the Company’s outstanding notes payable (see Note 7) approximates fair value (a level 2 fair value measurement), using a discounted cash flow analysis, reflecting discount rates currently available by the Company.

Marketable Securities

The Company’s marketable securities are classified as available-for-sale and are carried at fair value with the unrealized gains and losses reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses and declines in value judged to be other than temporary are included as a component of other income (expense), net based on the specific identification method. Fair value is determined based on quoted market prices. At June 30, 2015, marketable securities by security type consisted of:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
United States treasury notes	$	10,017	$	—		(3	)	$	10,014
Agency bonds		35,027		—		(5	)		35,022

Total	$	45,044	$	—	$	(8	)	$	45,036

At December 31, 2014, marketable securities by security type consisted of:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
United States treasury notes	$	10,026	$	—	$	—	$	10,026
Agency bonds		27,409		—		—		27,409

Total	$	37,435	$	—	$	—	$	37,435

At June 30, 2015 marketable securities consisted of investments that mature within one year.

Segment Data

The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is on advancing its bioresorable hydrogel-based product candidates exclusively for ophthalmology. All tangible assets are held in the United States.

Comprehensive Loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders.

Net Income (Loss) Per Share

Prior to the closing of its IPO of common stock, the Company followed the two-class method when computing net income (loss) per share, as the Company had outstanding shares that met the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed.

Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities, including outstanding stock options, unvested restricted common stock, common stock warrants and warrants for the purchase of redeemable convertible preferred stock. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of outstanding stock options and unvested restricted common stock.

Prior to the closing of the IPO, the Company’s redeemable convertible preferred stock contractually entitled the holders of such shares to participate in dividends but did not contractually require the holders of such shares to participate in losses of the Company. Similarly, restricted stock awards granted by the Company entitle the holder of such awards to dividends declared or paid by the board of directors, regardless of whether such awards are unvested, as if such shares were outstanding common shares at the time of the dividend. However, the unvested restricted stock awards are not entitled to share in the residual net assets (deficit) of the Company. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the three and six months ended June 30, 2015 and 2014.

The following common stock equivalents outstanding as of June 30, 2015 and 2014 were excluded from the computation of diluted net loss per share for the three and six months ended June 30, 2015 and 2014, because they had an anti-dilutive impact:


	As of June 30,
	2015		2014
Options to purchase common stock		2,098,388		1,576,231
Non-vested restricted stock		14,219		75,785
Warrants for the purchase of redeemable convertible preferred stock		—		89,708
Warrants for the purchase of common stock		18,939		—
Redeemable convertible preferred stock		—		12,440,205

Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock		2,131,546		14,181,929

Recently Issued and Adopted Accounting Pronouncements

In August 2014, the FASB issued Accounting Standards Update (“ASU”) 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40). The new guidance addresses management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. Management’s evaluation should be based on relevant conditions and events that are known and reasonably knowable at the date that the financial statements are issued. The standard will be effective for the first interim period within annual reporting periods beginning after December 15, 2016. Early adoption is permitted. The Company is evaluating the effect that this guidance will have on its financial statements and footnote disclosures.

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), (“ASU 2014-09”). ASU 2014-09 outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This new revenue recognition model provides a five-step analysis in determining when and how revenue is recognized. The new model will require revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration a company expects to receive in exchange for those goods or services. In July 2015, the FASB finalized the one year delay in the effective date of ASU 2014-09. The standard will be effective for public entities for annual reporting periods beginning after December 15, 2017 and interim periods within those periods. Early adoption is permitted, but it cannot be any earlier than 2017 for calendar year-end entities. Companies may use either a full retrospective or a modified retrospective approach to adopt ASU 2014-09. The Company is currently assessing the impact that adopting this new accounting guidance will have on its financial statements and footnote disclosures.

In April 2015, the FASB issued ASU No. 2015-03, “Interest—Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs (“ASU 2015-03”). ASU 2015-03 requires debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt liability, consistent with the presentation of a debt discount. Prior to the issuance of the standard, debt issuance costs were required to be presented in the balance sheet as an asset. The Company is currently assessing the impact that adopting this new accounting guidance will have on its consolidated financial statements and footnote disclosures. ASU 2015-03 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015.

Fair Value of Financial Assets and Liabilities

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Fair Value of Financial Assets and Liabilities

3. Fair Value of Financial Assets and Liabilities

The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis as of June 30, 2015 and December 31, 2014 and indicate the level of the fair value hierarchy utilized to determine such fair value:


	Fair Value Measurements as of June 30, 2015 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	—	$	78,519	$	—	$	78,519
Marketable securities:
United States treasury notes		—		10,014		—		10,014
Agency bonds		—		35,022		—		35,022

Total	$	—	$	123,555	$	—	$	123,555


	Fair Value Measurements as of December 31, 2014 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	—	$	29,103	$	—	$	29,103
Agency bonds		—		7,599		—		7,599
Marketable securities:
United States treasury notes		—		10,026		—		10,026
Agency bonds		—		27,409		—		27,409

Total	$	—	$	74,137	$	—	$	74,137

As of June 30, 2015 and December 31, 2014, the Company’s cash equivalents that were invested in money market funds were valued based on Level 2 inputs. During the three months ended June 30, 2015, there were no transfers between Level 1 and Level 2.

- 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

Accrued Expenses

6 Months Ended

Jun. 30, 2015

Payables and Accruals [Abstract]

Accrued Expenses

4. Accrued Expenses

Accrued expenses consisted of the following:


	June 30, 2015		December 31, 2014
Accrued compensation and related expenses	$	975	$	1,495
Accrued professional fees		321		338
Accrued research and development expenses		523		540
Accrued insurance		47		389
Accrued other		418		254

	$	2,284	$	3,016

As of June 30, 2015, the Company’s accrued insurance represents premiums for the period from July 2014 through June 2015 which the Company financed with a third-party.

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	5. Income Taxes The Company did not provide for any income taxes in its statement of operations for the three and six month periods ended June 30, 2015 or 2014. The Company has provided a valuation allowance for the full amount of its net deferred tax assets because, at June 30, 2015 and December 31, 2014, it was more likely than not that any future benefit from deductible temporary differences and net operating loss and tax credit carryforwards would not be realized. The Company has not recorded any amounts for unrecognized tax benefits as of June 30, 2015 or December 31, 2014. As of June 30, 2015 and December 31, 2014, the Company had no accrued interest or tax penalties recorded. The Company’s income tax return reporting periods since December 31, 2011 are open to income tax audit examination by the federal and state tax authorities. In addition, because the Company has net operating loss carryforwards, the Internal Revenue Service is permitted to audit earlier years and propose adjustments up to the amount of net operating losses generated in those years.

Feasibility Agreements	6 Months Ended
Feasibility Agreements	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Feasibility Agreements	6. Feasibility Agreements In September 2013, the Company entered into a feasibility agreement with a biopharmaceutical company. Under this agreement, the biopharmaceutical company will pay up to $500 for completing certain tasks and achieving certain milestones. In the event that the agreement is terminated in advance of the completion of the tasks/achievement of the milestones, the Company would be required to refund portions of the amounts received, based on the actual work completed/milestones achieved as of the date of termination. In the fourth quarter of 2014, the Company completed the tasks related to the first milestone at which time the $250 became non-refundable and therefore the Company recorded revenue of $250. The biopharmaceutical company has indicated that they will not proceed with the second phase of the agreement. The Company does not have any further obligations in connection with this agreement. In October 2014, the Company entered into a feasibility agreement with a biotechnology company. Under this agreement, the biotechnology company will pay up to $700, of which $250 is a non-refundable payment due upon contract execution and $450 is due upon the achievement of certain milestones. The Company is recognizing the non-contingent revenue of $250 on a straight-line basis over the twelve-month period expected to complete the Company’s performance obligations. If and when a contingent milestone payment is earned, the additional consideration to be received will be added to the total expected payments under the contract. In January 2015, the Company achieved the first milestone under the feasibility agreement triggering a payment due of $250. As of June 30, 2015, the Company has recognized revenue of $375 and has deferred revenue of $125. As of December 31, 2014, the Company had deferred revenue of $187 and had $250 in accounts receivable related to this agreement.

Notes Payable

6 Months Ended

Jun. 30, 2015

Debt Disclosure [Abstract]

Notes Payable

7. Notes Payable

The Company entered into a credit agreement with a lending institution in 2011 (the “2011 Modification Agreement”) which had a total borrowing capacity of $5,000 which was fully drawn down. Borrowings under the agreement were required to be repaid in 33 monthly installments commencing July 1, 2012 of $152, plus interest on the principal balance at a rate of the greater of (i) 4.75% above the lender’s prime rate or (ii) 8% per annum. In addition to these principal payments, the Company was required to make a final payment of $225 in March 2015 (or upon earlier termination of the agreement) to the lender, which amount was being accreted to the carrying value of the debt, using the effective interest method. The effective annual interest rate of the outstanding debt under the 2011 Modification Agreement was approximately 11%.

On April 17, 2014, the Company entered into a credit and security agreement (the “2014 Credit Facility”) and terminated the 2011 Modification Agreement. The 2014 Credit Facility provides for initial borrowings of $15,000 under a term loan (“Tranche 1 loan”) and additional borrowings of up to $5,000 under a term loan (“Tranche 2 loan”), for a maximum of $20,000. On that same date, the Company received proceeds of $15,000 through the issuance of promissory notes to the lenders under the Tranche 1 loan. Upon the completion of the IPO in July 2014, borrowings under the Tranche 2 loan became available through December 31, 2014. The Company did not draw down the $5,000 available under the Tranche 2 loan prior to its expiration, and this amount is no longer available to the Company. All promissory notes issued under the 2014 Credit Facility mature on April 1, 2018 and are collateralized by substantially all of the Company’s personal property, other than its intellectual property. There are no financial covenants associated with the 2014 Credit Facility; however, there are negative covenants restricting the Company’s activities, including limitations on dispositions, mergers or acquisitions; encumbering its intellectual property; incurring indebtedness or liens; paying dividends; making certain investments; and engaging in certain other business transactions. The obligations under the 2014 Credit Facility are subject to acceleration upon the occurrence of specified events of default, including a material adverse change in the Company’s business, operations or financial or other condition.

The Company is obligated to make monthly, interest-only payments on the Tranche 1 loan funded under the 2014 Credit Facility until September 30, 2015 and, thereafter, to pay 30 consecutive, equal monthly installments of principal from October 1, 2015 through March 1, 2018 plus interest. The Tranche 1 loan under the 2014 Credit Facility bears interest at an annual rate of 8.25%. In addition, a final payment equal to 3.75% of any amounts drawn under the 2014 Credit Facility is due upon its maturity date.

In April 2014, in connection with the Tranche 1 loan, the lenders received warrants to purchase 100,000 shares of the Company’s Series D-1 redeemable convertible preferred stock with an exercise price of $3.00 per share, which are exercisable until April 2021. The fair value of the warrants as of the issuance date totaling $326 was recorded as a preferred stock warrant liability. Of this amount, $290 was allocated to the 2014 Credit Facility and recorded as debt discount and $36 was allocated to the 2011 Modification Agreement and recorded as loss on extinguishment of debt (see below). Upon the closing of our IPO in July 2014, the preferred stock warrants became exercisable for 37,878 common stock warrants at an exercise price of $7.92 and the fair value of the warrant liability became fixed as of that date and was reclassified to additional paid-in capital. As of June 30, 2015, the effective annual interest rate of the outstanding debt under the 2014 Credit Facility was approximately 11%.

The terms of the 2014 Credit Facility required that the existing outstanding borrowings be repaid. Accordingly, on April 17, 2014, the Company used $1,898 of proceeds from the Tranche 1 loan to repay all amounts then due under the 2011 Modification Agreement, consisting of $1,667 of principal, $6 of interest and $225 of a final payment.

In the second quarter of 2014, the Company accounted for the termination of the 2011 Modification Agreement as an extinguishment in accordance with the guidance in ASC 470-50, Debt and the total amount of unamortized debt discount of $10 was reflected as a loss on extinguishment of debt and included in other expense within the statements of operations and comprehensive loss. Additionally, fees paid to the lenders that were allocated to the existing debt and treated as an extinguishment, inclusive of the value of warrants issued and debt issuance costs paid, totaling $47, was also reflected as a loss on extinguishment of debt included in other expense within the statements of operations and comprehensive loss.

As of June 30, 2015, the annual repayment requirements for the 2014 Credit Facility, inclusive of the final payment of $563 due at expiration, were as follows:


Year Ending December 31,	Principal		Interest and Final Payment		Total
2015	$	1,500	$	619	$	2,119
2016		6,000		902		6,902
2017		6,000		397		6,397
2018		1,500		583		2,083

	$	15,000	$	2,501	$	17,501

Common Stock and Preferred Stock	6 Months Ended
Common Stock and Preferred Stock	Jun. 30, 2015
Equity [Abstract]
Common Stock and Preferred Stock	8. Common Stock and Preferred Stock On April 14, 2014, the Company effected an increase in the number of authorized shares of its common stock from 45,000,000 shares to 47,500,000 shares and an increase in the number of authorized shares of its preferred stock from 33,979,025 shares to 34,229,025 shares. On July 10, 2014, the Company effected a 1-for-2.64 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of redeemable convertible preferred stock. Accordingly, all share and per share amounts for all periods presented in these financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios. On July 30, 2014 the Company completed its IPO, which resulted in the sale of 5,000,000 shares of its common stock at a public offering price of $13.00 per share. Upon closing the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were automatically converted into 12,440,205 shares of common stock. Additionally upon closing the IPO, the Company adopted an amended and restated certificate of incorporation increasing the number of its authorized shares of its common stock to 100,000,000 shares. This amended and restated certificate of incorporation also authorizes the Company to issue 5,000,000 shares of preferred stock, $0.0001 par value, all of which is undesignated. On August 19, 2014, the Company completed the sale of an additional 750,000 shares of common stock at the initial public offering price of $13.00 per share to the underwriters of the Company’s IPO pursuant to the exercise of their over-allotment option. The Company received additional net proceeds of approximately $9,068 after deducting underwriting discounts. In June 2015, the Company completed a follow-on offering of its common stock at a public offering price of $22.00 per share. The offering consisted of 4,600,000 shares of common stock, of which 3,200,000 shares were issued and sold by the Company and 1,400,000 shares were sold by certain stockholders of the Company, including those shares sold in connection with the exercise by the underwriters of their option to purchase additional shares. The Company received net proceeds from the follow-on offering of approximately $65,646 after deducting underwriting discounts and offering expenses.

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

+ Details

Warrants	6 Months Ended
Warrants	Jun. 30, 2015
Text Block [Abstract]
Warrants	9. Warrants The Company’s outstanding preferred stock warrants for the purchase of 236,836 shares of preferred stock were converted to warrants for the purchase of 89,708 shares of common stock at a weighted average exercise price of $6.32 per share. During the six months ended June 30, 2015, warrants covering 70,769 shares were exercised via net share settlement and the Company issued 54,010 shares of common stock as a result of the exercise. Warrants for the purchase of 18,939 shares of common stock remain outstanding at June 30, 2015 at a weighted average exercise price of $7.92 per share.

Stock-Based Awards

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Awards

10. Stock-Based Awards

2006 Stock Option Plan

The Company’s 2006 Stock Option Plan, as amended (the “2006 Plan”), provides for the Company to sell or issue common stock or restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the board of directors and consultants of the Company. The 2006 Plan is administered by the board of directors, or at the discretion of the board of directors, by a committee of the board. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or their committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant and the term of stock options may not be greater than ten years.

Stock options granted under the 2006 Plan generally vest over four years and expire after ten years, although options have been granted with vesting terms less than four years.

On July 30, 2014, the Company’s 2014 Stock Incentive Plan (the “2014 Plan”) became effective and no further stock options or other awards will be made under the 2006 Plan. Shares of common stock that were available for grant under the 2006 Plan as of July 30, 2014 as well as any shares of common stock subject to awards under the 2006 Plan that expire, terminate, or are otherwise surrendered, canceled, forfeited or repurchased without having been fully exercised or resulting in any common stock being issued will become available for issuance under the 2014 Plan, up to a specified number of shares.

2014 Stock Incentive Plan

On June 19, 2014, the Company’s stockholders approved the 2014 Plan, which became effective immediately prior to the closing of the Company’s IPO on July 30, 2014. The 2014 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units, stock appreciation rights and other stock-based awards. The number of shares originally reserved for issuance under the 2014 Plan, inclusive of shares from the 2006 Plan, was 1,336,907. On December 23, 2014, the board of directors adopted a resolution to increase the number available under the 2014 Plan by an additional 790,000 shares effective as of January 1, 2015. As of June 30, 2015, 1,472,694 shares remain available for issuance under the 2014 Plan. The number of shares of common stock that may be issued under the 2014 Plan is subject to increase on the first day of each fiscal year, beginning on January 1, 2015 and ending on December 31, 2024, equal to the least of 1,659,218 shares of the Company’s common stock, 4% of the number of shares of the Company’s common stock outstanding on the first day of the applicable fiscal year, and an amount determined by the Company’s board of directors.

The Company generally grants stock-based awards with service conditions only (“service-based” awards).

As required by the 2006 Plan and 2014 Plan, the exercise price for stock options granted is not to be less than the fair value of common shares as of the date of grant. Prior to the IPO, the value of common stock was determined by the board of directors by taking into consideration its most recently available valuation of common shares performed by management and the board of directors as well as additional factors which might have changed since the date of the most recent contemporaneous valuation through the date of grant.

2014 Employee Stock Purchase Plan

On June 19, 2014, the Company’s stockholders approved the 2014 Employee Stock Purchase Plan (the “ESPP”). A total of 207,402 shares of common stock are reserved for issuance under this plan. The ESPP became effective immediately prior to the closing of the Company’s IPO on July 30, 2014. In addition, the number of shares of common stock that may be issued under the ESPP will automatically increase on the first day of each fiscal year, commencing on January 1, 2015 and ending on December 31, 2024, in an amount equal to the least of 207,402 shares of the Company’s common stock, 0.5% of the number of shares of the Company’s common stock outstanding on the first day of the applicable fiscal year, and an amount determined by the Company’s board of directors. The Company’s first offering period commenced October 1, 2014 and closed on December 31, 2014 at which time 5,395 shares of common stock were issued for total proceeds of $64. On December 23, 2014, the board of directors adopted a resolution to increase the number of authorized under the ESPP by an additional 25,000 shares effective as of January 1, 2015. The Company’s second offering period commenced January 1, 2015 and closed on June 30, 2015 at which time 8,277 shares of common stock were issued for total proceeds of $148. As of June 30, 2015, 218,730 shares of common stock remain available for issuance

Stock Option Valuation

The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. Prior to the Company’s IPO in July 2014, the Company had been a private company and lacked company-specific historical and implied volatility information. Therefore, it estimated its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to nonemployees is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

The assumptions that the Company used to determine the fair value of the stock options granted to employees and directors are as follows, presented on a weighted average basis:


	Three Months ended June 30,						Six Months ended June 30,
	2015			2014			2015			2014
Risk-free interest rate		2.03	%		2.17	%		1.64	%		2.24	%
Expected term (in years)		6.00			6.00			6.00			5.95
Expected volatility		66.4	%		76.7	%		71.6	%		76.5	%
Expected dividend yield		0	%		0	%		0	%		0	%

As of June 30, 2015, there were outstanding unvested service-based stock options held by nonemployees for the purchase of 7,300 shares of common stock.

Stock-based Compensation

The Company recorded stock-based compensation expense related to stock options and restricted common stock in the following expense categories of its statements of operations:


	Three Months Ended June 30,				Six Months Ended June 30.
	2015		2014		2015		2014
Research and development	$	415	$	109	$	717	$	139
Selling and marketing		95		18		158		23
General and administrative		642		430		1,198		898

	$	1,152	$	557	$	2,073	$	1,060

As of June 30, 2015, the Company had an aggregate of $13,667 of unrecognized stock-based compensation cost, which is expected to be recognized over a weighted average period of 3.2 years.

Commitments and Contingencies

6 Months Ended

Jun. 30, 2015

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

11. Commitments and Contingencies

Leases

The Company leases office, laboratory and manufacturing space in Bedford, Massachusetts and certain office equipment under non-cancelable operating leases that expire in June 2017 and June 2018.

Future minimum lease payments for its operating leases as of June 30, 2015 are as follows:


Years Ending December 31,
2015	$	406
2016		820
2017		676
2018		262

Total	$	2,164

During the three months ended June 30, 2015 and 2014, the Company recognized $195 and $149, respectively, of rental expense, related to its office, laboratory and manufacturing space and office equipment. During the six months ended June 30, 2015 and 2014, the Company recognized $390 and $259, respectively, of rental expense, related to its office, laboratory and manufacturing space and office equipment.

Intellectual Property Licenses

The Company has a license agreement with Incept, LLC (“Incept”) (Note 12) to use and develop certain patent rights (the “Incept License”). Under the Incept License, as amended and restated, the Company was granted a worldwide, perpetual, exclusive license to develop and commercialize products that are delivered to or around the human eye for diagnostic, therapeutic or prophylactic purposes relating to ophthalmic diseases or conditions. The Company is obligated to pay low single-digit royalties on net sales of commercial products developed using the licensed technology, commencing with the date of the first commercial sale of such products and until the expiration of the last to expire of the patents covered by the license. Any of the Company’s sublicensees also will be obligated to pay Incept a royalty equal to a low single-digit percentage of net sales made by it and will be bound by the terms of the agreement to the same extent as the Company. The Company is obligated to reimburse Incept for its share of the reasonable fees and costs incurred by Incept in connection with the prosecution of the patent applications licensed to the Company under the Incept License. Through June 30, 2015, royalties payable under this agreement related to product sales were not material.

On February 12, 2014, the Company issued to Incept 189,393 shares of its common stock in connection with the expansion of the scope of the license to include back-of-the-eye technology held by Incept (Note 12).

Indemnification Agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its financial statements as of December 31, 2014 or June 30, 2015.

Purchase Commitments

Purchase commitments represent non-cancelable contractual commitments associated with certain clinical trial activities within our clinical research organization.

Manufacturing Commitments

Manufacturing contracts generally provide for termination on notice, and therefore are cancelable contracts but are contracts that we are likely to continue, regardless of the fact that they are cancelable.

Related Party Transactions	6 Months Ended
Related Party Transactions	Jun. 30, 2015
Related Party Transactions [Abstract]
Related Party Transactions	12. Related Party Transactions The Company has a license agreement with Incept to use and develop certain patent rights that it entered into in 2007. Royalties incurred and payable to Incept have not been material to date. On February 12, 2014, the Company issued 189,393 shares of its common stock to Incept in connection with the expansion of the scope of the Incept License to include back-of-the-eye technology held by Incept. In the three months ended March 31, 2014, the fair value of the shares of $1,665 as of the issuance date was recorded as research and development expense. Incept and certain owners of Incept participated in the Company’s Series A, Series B and Series C preferred stock financing and have also been granted shares of common stock and redeemable convertible preferred stock of the Company. In addition, certain employees of the Company are shareholders of Incept. The Company’s President and Chief Executive Officer is a general partner of Incept. On February 12, 2014, the Company issued 79,545 shares of common stock to a former member of the Company’s board of directors and current stockholder of Incept for consulting services rendered. In the three months ended March 31, 2014, the fair value of the shares of $699 as of the issuance date was recorded as general and administrative expense. During the three and six months ended June 30, 2015, the Company invoiced Augmenix, Inc. (“Augmenix”) $0 and $5, respectively, for consulting and other services. During the three and six months ended June 30, 2014, the Company invoiced Augmenix $9 and $76, respectively for consulting and other services. Certain shareholders of Augmenix were holders of the Company’s redeemable convertible preferred stock and common stock which is now entirely common stock. In addition, certain employees of the Company are shareholders of Augmenix. The Company’s President and Chief Executive Officer was also the Chief Executive Officer of Augmenix up until April 2014. The Company’s President and Chief Executive Officer is the Chairman of the board of directors of Augmenix.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2015

Accounting Policies [Abstract]

Use of Estimates

Use of Estimates

Inventory Valuation

Inventory Valuation

Inventory is valued at the lower of cost or market, determined by the first-in, first-out (“FIFO”) method.

The Company had an inventory balance of $145 and $133, respectively, as of June 30, 2015 and December 31, 2014, which consisted primarily of raw materials.

Restricted Cash

Restricted Cash

Fair Value Measurements

Fair Value Measurements

•

Level 1—Quoted prices in active markets for identical assets or liabilities.

•

Marketable Securities

Marketable Securities


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
United States treasury notes	$	10,017	$	—		(3	)	$	10,014
Agency bonds		35,027		—		(5	)		35,022

Total	$	45,044	$	—	$	(8	)	$	45,036

At December 31, 2014, marketable securities by security type consisted of:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
United States treasury notes	$	10,026	$	—	$	—	$	10,026
Agency bonds		27,409		—		—		27,409

Total	$	37,435	$	—	$	—	$	37,435

At June 30, 2015 marketable securities consisted of investments that mature within one year.

Segment Data

Segment Data

Comprehensive Loss

Comprehensive Loss

Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders.

Net Income (Loss) Per Share

Net Income (Loss) Per Share


	As of June 30,
	2015		2014
Options to purchase common stock		2,098,388		1,576,231
Non-vested restricted stock		14,219		75,785
Warrants for the purchase of redeemable convertible preferred stock		—		89,708
Warrants for the purchase of common stock		18,939		—
Redeemable convertible preferred stock		—		12,440,205

Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock		2,131,546		14,181,929

Recently Issued and Adopted Accounting Pronouncements

Recently Issued and Adopted Accounting Pronouncements

Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2015

Accounting Policies [Abstract]

Summary of Marketable Securities by Security Type

At June 30, 2015, marketable securities by security type consisted of:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
United States treasury notes	$	10,017	$	—		(3	)	$	10,014
Agency bonds		35,027		—		(5	)		35,022

Total	$	45,044	$	—	$	(8	)	$	45,036

At December 31, 2014, marketable securities by security type consisted of:


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
United States treasury notes	$	10,026	$	—	$	—	$	10,026
Agency bonds		27,409		—		—		27,409

Total	$	37,435	$	—	$	—	$	37,435

Schedule of Antidilutive Securities, Excluded from Computation of Diluted Net Loss per Share


	As of June 30,
	2015		2014
Options to purchase common stock		2,098,388		1,576,231
Non-vested restricted stock		14,219		75,785
Warrants for the purchase of redeemable convertible preferred stock		—		89,708
Warrants for the purchase of common stock		18,939		—
Redeemable convertible preferred stock		—		12,440,205

Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock		2,131,546		14,181,929

Fair Value of Financial Assets and Liabilities (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis


	Fair Value Measurements as of June 30, 2015 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	—	$	78,519	$	—	$	78,519
Marketable securities:
United States treasury notes		—		10,014		—		10,014
Agency bonds		—		35,022		—		35,022

Total	$	—	$	123,555	$	—	$	123,555


	Fair Value Measurements as of December 31, 2014 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	—	$	29,103	$	—	$	29,103
Agency bonds		—		7,599		—		7,599
Marketable securities:
United States treasury notes		—		10,026		—		10,026
Agency bonds		—		27,409		—		27,409

Total	$	—	$	74,137	$	—	$	74,137

Accrued Expenses (Tables)

6 Months Ended

Jun. 30, 2015

Payables and Accruals [Abstract]

Schedule of Accrued Expenses

Accrued expenses consisted of the following:


	June 30, 2015		December 31, 2014
Accrued compensation and related expenses	$	975	$	1,495
Accrued professional fees		321		338
Accrued research and development expenses		523		540
Accrued insurance		47		389
Accrued other		418		254

	$	2,284	$	3,016

Notes Payable (Tables)

6 Months Ended

Jun. 30, 2015

Debt Disclosure [Abstract]

Schedule of Annual Repayment Requirements for Credit Facility

As of June 30, 2015, the annual repayment requirements for the 2014 Credit Facility, inclusive of the final payment of $563 due at expiration, were as follows:


Year Ending December 31,	Principal		Interest and Final Payment		Total
2015	$	1,500	$	619	$	2,119
2016		6,000		902		6,902
2017		6,000		397		6,397
2018		1,500		583		2,083

	$	15,000	$	2,501	$	17,501

Stock-Based Awards (Tables)

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Fair Value of Stock Options Weighted Average

The assumptions that the Company used to determine the fair value of the stock options granted to employees and directors are as follows, presented on a weighted average basis:


	Three Months ended June 30,						Six Months ended June 30,
	2015			2014			2015			2014
Risk-free interest rate		2.03	%		2.17	%		1.64	%		2.24	%
Expected term (in years)		6.00			6.00			6.00			5.95
Expected volatility		66.4	%		76.7	%		71.6	%		76.5	%
Expected dividend yield		0	%		0	%		0	%		0	%

Schedule of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock

The Company recorded stock-based compensation expense related to stock options and restricted common stock in the following expense categories of its statements of operations:


	Three Months Ended June 30,				Six Months Ended June 30.
	2015		2014		2015		2014
Research and development	$	415	$	109	$	717	$	139
Selling and marketing		95		18		158		23
General and administrative		642		430		1,198		898

	$	1,152	$	557	$	2,073	$	1,060

Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2015

Commitments and Contingencies Disclosure [Abstract]

Summary of Future Minimum Lease Payments for Operating Leases

Future minimum lease payments for its operating leases as of June 30, 2015 are as follows:


Years Ending December 31,
2015	$	406
2016		820
2017		676
2018		262

Total	$	2,164

Nature of the Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands				1 Months Ended	6 Months Ended
	Jun. 10, 2015	Aug. 19, 2014	Jul. 30, 2014	Aug. 31, 2014	Jun. 30, 2015
Class of Stock [Line Items]
Proceeds from issuance of shares					$ 65,646
IPO [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Initial public offering, shares issued			5,000,000
Common stock, price per share			$ 13.00
Proceeds from issuance of shares			$ 57,337
Number of common shares issued on conversion of redeemable convertible preferred stock			12,440,205
Over-allotment Option [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Initial public offering, shares issued		750,000		750,000
Common stock, price per share		$ 13.00		$ 13.00
Proceeds from issuance of shares		$ 9,068		$ 9,068
Follow-on Offering [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Initial public offering, shares issued	4,600,000
Common stock, price per share	$ 22.00
Proceeds from issuance of shares	$ 65,646
Number of shares offered by company	3,200,000
Number of shares offered by stockholders	1,400,000

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Inventory	$ 145	$ 133
Certificate of deposit	$ 228	228
Maturity period for marketable securities classified as available-for-sale	1 year
Certificates of Deposit [Member]
Summary Of Significant Accounting Policies [Line Items]
Certificate of deposit	$ 60	60
Certificate of deposit	$ 228	$ 228

Summary of Significant Accounting Policies - Summary of Marketable Securities by Security Type (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 45,044	$ 37,435
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(8)
Estimated Fair Value	45,036	37,435
United States Treasury Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,017	10,026
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(3)
Estimated Fair Value	10,014	10,026
Agency Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	35,027	27,409
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(5)
Estimated Fair Value	$ 35,022	$ 27,409

Summary of Significant Accounting Policies - Schedule of Antidilutive Securities, Excluded from Computation of Diluted Net Loss per Share (Detail) - shares	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock	2,131,546	14,181,929
Equity Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock	2,098,388	1,576,231
Non Vested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock	14,219	75,785
Warrants for the Purchase of Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock		89,708
Warrants for the Purchase of Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock	18,939
Series A, B, C, D and D-1 Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total options, warrants and redeemable convertible preferred stock exercisable or convertible into common stock and restricted stock		12,440,205

Fair Value of Financial Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets:
Marketable securities	$ 45,036	$ 37,435
Recurring Basis [Member]
Assets:
Total assets at fair value	123,555	74,137
Recurring Basis [Member] \| United States Treasury Notes [Member]
Assets:
Marketable securities	10,014	10,026
Recurring Basis [Member] \| Agency Bonds [Member]
Assets:
Cash equivalents		7,599
Marketable securities	35,022	27,409
Money Market Funds [Member] \| Recurring Basis [Member]
Assets:
Cash equivalents	78,519	29,103
Level 2 [Member] \| Recurring Basis [Member]
Assets:
Total assets at fair value	123,555	74,137
Level 2 [Member] \| Recurring Basis [Member] \| United States Treasury Notes [Member]
Assets:
Marketable securities	10,014	10,026
Level 2 [Member] \| Recurring Basis [Member] \| Agency Bonds [Member]
Assets:
Cash equivalents		7,599
Marketable securities	35,022	27,409
Level 2 [Member] \| Money Market Funds [Member] \| Recurring Basis [Member]
Assets:
Cash equivalents	$ 78,519	$ 29,103

Fair Value of Financial Assets and Liabilities - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Transfers between fair value measurement levels	$ 0

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued compensation and related expenses	$ 975	$ 1,495
Accrued professional fees	321	338
Accrued research and development expenses	523	540
Accrued insurance	47	389
Accrued other	418	254
Total	$ 2,284	$ 3,016

Income Taxes - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0	$ 0
Accrued interest or tax penalties	$ 0	$ 0
Income tax examination, year under examination	2011

Feasibility Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended
	Oct. 31, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2015	Jun. 30, 2015	Jan. 31, 2015	Sep. 30, 2013
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 125,000		$ 313,000
Deferred revenue		125,000	$ 188,000	125,000	$ 125,000
Accounts receivable		164,000	329,000	164,000	164,000
Feasibility Agreement [Member] \| Biopharmaceutical [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum revenue that could be recognized							$ 500,000
Non-Refundable revenue			250,000
Revenue recognized			250,000
Feasibility Agreement [Member] \| Biotechnology [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum revenue that could be recognized	$ 450,000
Revenue recognized					375,000
Potential agreement revenue	700,000
Non-Refundable revenue	$ 250,000
Non-contingent revenue				250,000
Deferred revenue		$ 125,000	187,000	$ 125,000	$ 125,000
Accounts receivable			$ 250,000
Milestone payment due						$ 250,000

Notes Payable - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended	6 Months Ended
	Apr. 17, 2014	Apr. 30, 2014	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jul. 31, 2014
Line of Credit Facility [Line Items]
Grant date fair value of warrants granted as preferred stock warrant liability					$ 326,000
Loss on extinguishment of debt					(57,000)
IPO [Member] \| Tranche 1 Loan [Member]
Line of Credit Facility [Line Items]
Exercise price of warrants granted						$ 7.92
Warrants to purchase common stock converted from warrants to purchase redeemable convertible preferred stock						37,878
2011 Modification Agreement [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under the agreement	$ 5,000,000
Credit facility, Monthly repayment period				33 monthly installments
Outstanding borrowings, Monthly repayment amount	$ 152,000
Outstanding borrowings, Interest rate above prime lending rate	4.75%
Outstanding borrowings, Interest rate	8.00%
Outstanding borrowings, Effective annual interest rate	11.00%
Proceeds from (repayments of) lines of credit	$ (1,898,000)
Loss on extinguishment of debt		$ 36,000
Outstanding borrowings, Principal	1,667,000
Outstanding borrowings, Interest	6,000
Additional final payment	225,000
2011 Modification Agreement [Member] \| Extinguishment of Debt [Member]
Line of Credit Facility [Line Items]
Debt discount			$ 10,000		$ 10,000
Fees paid to lenders			$ 47,000
2014 Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under the agreement	20,000,000
Outstanding borrowings, Monthly repayment amount				$ 15,000,000
Outstanding borrowings, Effective annual interest rate				11.00%
Loan and Security Agreement date				Apr. 17, 2014
Credit facility, Final payment percent of amounts drawn under the facility				3.75%
Outstanding borrowings, Interest				$ 2,501,000
Additional final payment				$ 563,000
2014 Credit Facility [Member] \| Promissory Notes [Member]
Line of Credit Facility [Line Items]
Debt instrument, Maturity date				Apr. 01, 2018
2014 Credit Facility [Member] \| Tranche 1 Loan [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under the agreement	15,000,000
Credit facility, Monthly repayment period				30 consecutive, equal monthly installments
Outstanding borrowings, Interest rate				8.25%
Last installment payment				Mar. 01, 2018
First date of principal repayment				Oct. 01, 2015
Warrants to purchase shares of redeemable convertible preferred stock		100,000
Exercise price of warrants granted		$ 3.00
Warrants, Date from which warrants or rights exercisable		Apr. 30, 2021
Grant date fair value of warrants granted as preferred stock warrant liability		$ 326,000
Debt discount		$ 290,000
2014 Credit Facility [Member] \| Tranche 1 Loan [Member] \| Promissory Notes [Member]
Line of Credit Facility [Line Items]
Proceeds from (repayments of) lines of credit	15,000,000
2014 Credit Facility [Member] \| Tranche 2 Loan [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under the agreement	$ 5,000,000

Notes Payable - Schedule of Annual Repayment Requirements for Credit Facility (Detail) - 2014 Credit Facility [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Line of Credit Facility [Line Items]
Credit Facility, Principal	$ 15,000
Credit Facility, Interest and Final Payment	2,501
Credit Facility, Total	17,501
2015 [Member]
Line of Credit Facility [Line Items]
Credit Facility, Principal	1,500
Credit Facility, Interest and Final Payment	619
Credit Facility, Total	2,119
2016 [Member]
Line of Credit Facility [Line Items]
Credit Facility, Principal	6,000
Credit Facility, Interest and Final Payment	902
Credit Facility, Total	6,902
2017 [Member]
Line of Credit Facility [Line Items]
Credit Facility, Principal	6,000
Credit Facility, Interest and Final Payment	397
Credit Facility, Total	6,397
2018 [Member]
Line of Credit Facility [Line Items]
Credit Facility, Principal	1,500
Credit Facility, Interest and Final Payment	583
Credit Facility, Total	$ 2,083

Common Stock and Preferred Stock - Additional Information (Detail) $ / shares in Units, $ in Thousands					1 Months Ended	6 Months Ended
	Jun. 10, 2015 USD ($) $ / shares shares	Aug. 19, 2014 USD ($) $ / shares shares	Jul. 30, 2014 USD ($) $ / shares shares	Jul. 10, 2014	Aug. 31, 2014 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares	Dec. 31, 2014 $ / shares shares	Apr. 14, 2014 shares
Class of Stock [Line Items]
Common stock, shares authorized						100,000,000	100,000,000
Reverse stock split conversion description						the Company effected a 1-for-2.64 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of Redeemable Preferred Stock.
Reverse stock split ratio				0.378
Reverse stock split, effective date				Jul. 10, 2014
Preferred stock, shares authorized						5,000,000	5,000,000
Preferred stock, par value \| $ / shares						$ 0.0001	$ 0.0001
Proceeds from issuance of shares \| $						$ 65,646
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized			100,000,000
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized			5,000,000
Preferred stock, par value \| $ / shares			$ 0.0001
IPO [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Number of shares issued			5,000,000
Sale price per share \| $ / shares			$ 13.00
Number of common shares issued on conversion of redeemable convertible preferred stock			12,440,205
Proceeds from issuance of shares \| $			$ 57,337
Over-allotment Option [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Number of shares issued		750,000			750,000
Sale price per share \| $ / shares		$ 13.00			$ 13.00
Proceeds from issuance of shares \| $		$ 9,068			$ 9,068
Follow-on Offering [Member] \| Common Stock [Member]
Class of Stock [Line Items]
Number of shares issued	4,600,000
Sale price per share \| $ / shares	$ 22.00
Proceeds from issuance of shares \| $	$ 65,646
Number of shares offered by company	3,200,000
Number of shares offered by stockholders	1,400,000
Minimum [Member]
Class of Stock [Line Items]
Common stock, shares authorized								45,000,000
Minimum [Member] \| Series A, B, C, D and D-1 Redeemable Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Redeemable convertible preferred stock, shares authorized								33,979,025
Maximum [Member]
Class of Stock [Line Items]
Common stock, shares authorized								47,500,000
Maximum [Member] \| Series A, B, C, D and D-1 Redeemable Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Redeemable convertible preferred stock, shares authorized								34,229,025

Warrants - Additional Information (Detail)	6 Months Ended
Warrants - Additional Information (Detail)	Jun. 30, 2015 $ / shares shares
Class of Warrant or Right [Line Items]
Shares covered under warrants exercised	70,769
Warrants for Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares callable by warrants	236,836
Warrants for Common Stock Converted from Warrants for Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares callable by warrants	89,708
Warrants for Common Stock Converted from Warrants for Preferred Stock [Member] \| Weighted Average [Member]
Class of Warrant or Right [Line Items]
Weighted average exercise price to purchase common stock \| $ / shares	$ 6.32
Warrants for Common Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares callable by warrants	18,939
Warrants for Common Stock [Member] \| Weighted Average [Member]
Class of Warrant or Right [Line Items]
Weighted average exercise price to purchase common stock \| $ / shares	$ 7.92
Warrant [Member] \| Common Stock [Member]
Class of Warrant or Right [Line Items]
Common Stock Issued	54,010

Stock-Based Awards - Additional Information (Detail) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
	Jan. 01, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 19, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested service-based stock options held by nonemployees		7,300
Unrecognized stock-based compensation cost		$ 13,667
Weighted average period of unrecognized stock-based compensation cost expected to be recognized		3 years 2 months 12 days
2006 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercise price, description		The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or their committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant and the term of stock options may not be greater than ten years.
Minimum percentage of stock option exercise price at grant date fair value		100.00%
Stock options expiration period		10 years
Stock options vesting period		4 years
2006 Stock Option Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options expiration period		10 years
2014 Stock Incentive Plan [Member] \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock authorized for issuance	1,659,218			1,336,907
Additional number of shares authorized for issuance	790,000
Number of shares of common stock available for issuance		1,472,694
Additional number of shares of common stock , percentage	4.00%
2014 Employee Stock Purchase Plan [Member] \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock authorized for issuance		207,402		207,402
Additional number of shares authorized for issuance	25,000
Number of shares of common stock available for issuance		218,730
Additional number of shares of common stock , percentage	0.50%
Issuance of common stock in connection with employee stock purchase plan, shares		8,277	5,395
Issuance of common stock in connection with employee stock purchase plan		$ 148	$ 64

Stock-Based Awards - Schedule of Fair Value of Stock Options Weighted Average (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	2.03%	2.17%	1.64%	2.24%
Expected term (in years)	6 years	6 years	6 years	5 years 11 months 12 days
Expected volatility	66.40%	76.70%	71.60%	76.50%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Awards - Schedule of Stock-Based Compensation Expense Related to Stock Options and Restricted Common Stock (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,152	$ 557	$ 2,073	$ 1,060
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	415	109	717	139
Selling and Marketing Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	95	18	158	23
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 642	$ 430	$ 1,198	$ 898

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Feb. 12, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Commitments And Contingencies [Line Items]
Non-cancelable operating leases expiration				June 2017 and June 2018
Rental expense		$ 195	$ 149	$ 390	$ 259
Incept [Member] \| Common Stock [Member]
Commitments And Contingencies [Line Items]
Common stock, shares issued	189,393

Commitments and Contingencies - Summary of Future Minimum Lease Payments for Operating Leases (Detail) $ in Thousands	Jun. 30, 2015 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2015	$ 406
2016	820
2017	676
2018	262
Total	$ 2,164

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
	Feb. 12, 2014	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Receivables [Member]
Related Party Transaction [Line Items]
Invoiced consulting and other services		$ 0	$ 9		$ 5	$ 76
General and Administrative Expense [Member] \| Common Stock [Member] \| Former Board of Director [Member]
Related Party Transaction [Line Items]
Common stock, shares issued	79,545
Fair value of shares issued				$ 699
Incept [Member] \| Common Stock [Member]
Related Party Transaction [Line Items]
Common stock, shares issued	189,393
Incept [Member] \| Research and Development Expense [Member] \| Common Stock [Member]
Related Party Transaction [Line Items]
Common stock, shares issued	189,393
Fair value of shares issued				$ 1,665