Document and Entity Information
| Document and Entity Information - shares | 3 Months Ended | |
| Mar. 31, 2016 | May. 10, 2016 | |
| Document And Entity Information [Abstract] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Mar. 31, 2016 | |
| Document Fiscal Year Focus | 2,016 | |
| Document Fiscal Period Focus | Q1 | |
| Trading Symbol | ITEK | |
| Entity Registrant Name | Inotek Pharmaceuticals Corporation | |
| Entity Central Index Key | 1,281,895 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity Filer Category | Smaller Reporting Company | |
| Entity Common Stock, Shares Outstanding | 26,423,394 |
Consolidated Balance Sheets
| Consolidated Balance Sheets - USD ($) $ in Thousands | Mar. 31, 2016 | Dec. 31, 2015 |
| Current assets: | ||
| Cash and cash equivalents | $ 58,706 | $ 80,042 |
| Short-term investments | 43,559 | 31,238 |
| Prepaid expenses and other current assets | 982 | 1,086 |
| Total current assets | 103,247 | 112,366 |
| Property and equipment, net | 790 | 812 |
| Other assets | 170 | 143 |
| Total assets | 104,207 | 113,321 |
| Current liabilities: | ||
| Accounts payable | 1,376 | 1,633 |
| Accrued expenses and other current liabilities | 3,238 | 2,508 |
| Total current liabilities | 4,614 | 4,141 |
| Other long-term liabilities | 351 | 367 |
| Total liabilities | $ 4,965 | $ 4,508 |
| Commitments and Contingencies (Note 7) | ||
| Stockholders' equity: | ||
| Preferred Stock, $0.001 par value: 5,000,000 shares authorized and no shares issued or outstanding | ||
| Common stock, $0.01 par value: 120,000,000 shares authorized; 26,423,394 shares issued and outstanding at March 31, 2016 and December 31, 2015 | $ 264 | $ 264 |
| Additional paid-in capital | 305,069 | 304,583 |
| Accumulated deficit | (206,091) | (196,023) |
| Accumulated other comprehensive loss | (11) | |
| Total stockholders' equity | 99,242 | 108,813 |
| Total liabilities and stockholders' equity | $ 104,207 | $ 113,321 |
Consolidated Balance Sheets (Pa
| Consolidated Balance Sheets (Parenthetical) - $ / shares | Mar. 31, 2016 | Dec. 31, 2015 |
| Statement of Financial Position [Abstract] | ||
| Preferred stock, par value | $ 0.001 | $ 0.001 |
| Preferred stock, shares authorized | 5,000,000 | 5,000,000 |
| Preferred stock, shares issued | 0 | 0 |
| Preferred stock, shares outstanding | 0 | 0 |
| Common stock, par value | $ 0.01 | $ 0.01 |
| Common stock, shares authorized | 120,000,000 | 120,000,000 |
| Common stock, shares issued | 26,423,394 | 26,423,394 |
| Common stock, shares outstanding | 26,423,394 | 26,423,394 |
Consolidated Statements of Oper
| Consolidated Statements of Operations - USD ($) $ in Thousands | 3 Months Ended | |
| Mar. 31, 2016 | Mar. 31, 2015 | |
| Operating expenses: | ||
| Research and development | $ (7,615) | $ (1,069) |
| General and administrative | (2,522) | (1,980) |
| Loss from operations | (10,137) | (3,049) |
| Interest expense | (474) | |
| Interest income | 69 | |
| Loss on extinguishment of debt | (683) | |
| Change in fair value of warrant liabilities | 267 | |
| Change in fair value of Convertible Bridge Notes redemption rights derivative | 480 | |
| Change in fair value of 2020 Convertible Notes derivative liability | 1,997 | |
| Net loss | $ (10,068) | $ (1,462) |
| Net loss per share attributable to common stockholders-basic and diluted | $ (0.38) | $ (0.21) |
| Weighted-average number of shares outstanding-basic and diluted | 26,423,394 | 7,677,575 |
Consolidated Statements of Comp
| Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands | 3 Months Ended | |
| Mar. 31, 2016 | Mar. 31, 2015 | |
| Statement of Comprehensive Income [Abstract] | ||
| Net loss | $ (10,068) | $ (1,462) |
| Other comprehensive income: | ||
| Net unrealized gain on marketable securities | 11 | |
| Total comprehensive loss | $ (10,057) | $ (1,462) |
Consolidated Statements of Cash
| Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 3 Months Ended | |
| Mar. 31, 2016 | Mar. 31, 2015 | |
| Cash flows from operating activities: | ||
| Net loss | $ (10,068) | $ (1,462) |
| Adjustments to reconcile net loss to cash used in operating activities: | ||
| Noncash interest expense | 274 | |
| Deferred rent and lease incentives | (16) | |
| Loss on extinguishment of debt | 522 | |
| Amortization of premium on marketable securities | 43 | |
| Depreciation | 37 | 0 |
| Change in fair value of warrant liabilities | (267) | |
| Change in fair value of Convertible Bridge Notes redemption rights derivative | (480) | |
| Change in fair value of 2020 Convertible Notes derivative liability | (1,997) | |
| Stock-based compensation | 486 | 1,364 |
| Changes in operating assets and liabilities: | ||
| Prepaid expenses and other assets | 52 | (271) |
| Accounts payable | (257) | 154 |
| Accrued expenses and other current liabilities | 730 | 170 |
| Net cash used in operating activities | (8,993) | (1,993) |
| Cash flows from investing activities: | ||
| Purchases of short-term investments | (24,161) | |
| Proceeds from the maturities of short-term investments | 11,833 | |
| Purchases of property and equipment | (15) | |
| Net cash used in investing activities | (12,343) | |
| Cash flows from financing activities: | ||
| Net proceeds from issuance of common stock in initial public offering | 38,155 | |
| Proceeds from issuance of 2020 Convertible Notes in initial public offering | 21,000 | |
| Payments of 2020 Convertible Notes issuance costs | (1,841) | |
| Principal payments on notes payable | (5,800) | |
| Net cash provided by financing activities | 51,514 | |
| Net change in cash and cash equivalents | (21,336) | 49,521 |
| Cash and cash equivalents, beginning of period | 80,042 | 3,618 |
| Cash and cash equivalents, end of period | 58,706 | 53,139 |
| Supplemental disclosure of cash flow information: | ||
| Cash paid for interest | 89 | |
| Supplemental disclosure of noncash investing and financing activities: | ||
| Net unrealized gain on marketable securities | $ 11 | |
| IPO [Member] | ||
| Supplemental disclosure of noncash investing and financing activities: | ||
| Conversion of Notes into common stock | 2,028 | |
| Reclassification of fair value of warrant liability to equity upon initial public offering | 215 | |
| Reclassification of deferred public offering costs to stockholders' equity | 1,590 | |
| Reclassification of deferred public offering costs to other assets | 256 | |
| Series AA Redeemable Convertible Preferred Stock [Member] | ||
| Supplemental disclosure of noncash investing and financing activities: | ||
| Accretion of Series AA preferred stock to redemption value | 130 | |
| Series AA Redeemable Convertible Preferred Stock [Member] | IPO [Member] | ||
| Supplemental disclosure of noncash investing and financing activities: | ||
| Conversion of preferred stock into common stock upon initial public offering | 46,383 | |
| Series X Redeemable Convertible Preferred Stock [Member] | IPO [Member] | ||
| Supplemental disclosure of noncash investing and financing activities: | ||
| Conversion of preferred stock into common stock upon initial public offering | $ 548 | |
Organization and Operations
| Organization and Operations | 3 Months Ended |
| Mar. 31, 2016 | |
| Accounting Policies [Abstract] | |
| Organization and Operations | 1. Organization and Operations Inotek Pharmaceuticals Corporation (the “Company”) is a clinical-stage biopharmaceutical company advancing molecules with novel mechanisms of action to address significant diseases of the eye. The Company’s business strategy is to develop and progress its product candidates through human clinical trials. The Company’s headquarters are located in Lexington, Massachusetts. The Company has devoted substantially all of its efforts to research and development, including clinical trials of its product candidates. The Company has not completed the development of any product candidates. The Company has no current source of revenue to sustain present activities and does not expect to generate revenue until and unless the Company receives regulatory approval of and successfully commercializes its product candidates. The Company is subject to a number of risks and uncertainties similar to those of other life science companies developing new products, including, among others, the risks related to the necessity to obtain adequate additional financing, to successfully develop product candidates, to obtain regulatory approval of products candidates, to comply with government regulations, to successfully commercialize its potential products, to protect proprietary technology and to the dependence on key individuals. In the first quarter of 2015, the Company completed its initial public offering (the “IPO”) of (i) 6,966,333 shares of common stock, including 299,333 shares from an exercise of the underwriters’ overallotment option at a price of $6.00 per share and (ii) $21,000 aggregate principal amount of 5.0% Convertible Senior Notes due 2020 (the “2020 Convertible Notes”), including $1,000 from an exercise of the underwriters’ overallotment option. Existing stockholders and their affiliated entities purchased approximately 3,005,000 shares of common stock issued in the IPO at the same terms. The Company received net proceeds of $36,495, after deducting underwriting discounts and offering-related costs, from its equity issuances and $18,903 in net proceeds, after deducting underwriting discounts and offering-related costs, from its debt issuances. In July and August 2015, holders of $21,000 principal amount of the 2020 Convertible Notes elected to convert the principal into 3,333,319 shares of common stock. In addition, the Interest Make-Whole Payment (see Note 5) was settled with shares of common stock, at the election of the Company, resulting in the issuance of 530,072 additional shares of common stock. In August 2015, the Company completed an underwritten public offering of its common stock (the “Follow-on Offering”). The Company issued 6,210,000 shares of its common stock at a price of $12.75 per share, including 810,000 shares from the underwriters’ full exercise of their overallotment option, and received net proceeds of $73,965, after deducting underwriting discounts and offering-related costs. As of March 31, 2016, the Company had an accumulated deficit of $206,091 and $102,265 of cash and cash equivalents and short-term investments. The Company will need to expend substantial resources for research and development, including costs associated with the clinical testing of its product candidates and will need to obtain additional financing to fund its operations and to conduct trials for its product candidates. If such products were to receive regulatory approval, the Company would need to prepare for the potential commercialization of its product candidates and fund the commercial launch and continued marketing of its products. The Company expects operating expenses will substantially increase in the future related to additional clinical testing and to support an increased infrastructure to support expanded operations and being a public company. The Company will require additional funding in the future and may not be able to raise such additional funds. The Company expects losses will continue as it conducts research and development activities. The Company will seek to finance future cash needs through public or private equity offerings, license agreements, debt financings, collaborations, strategic alliances, or any combination thereof. The incurrence of indebtedness would result in increased fixed payment obligations and could also result in restrictive covenants, such as limitations on the Company’s ability to incur additional debt, limitations on the Company’s ability to acquire, sell or license intellectual property rights and other operating restrictions that could adversely impact the ability of the Company to conduct its business. If adequate funds are not available, the Company would delay, reduce or eliminate research and development programs and reduce administrative expenses. The Company may seek to access the public or private capital markets whenever conditions are favorable, even if it does not have an immediate need for additional capital at that time. In addition, if the Company raises additional funds through collaborations, strategic alliances or licensing arrangements with third parties, it may have to relinquish valuable rights to its technologies, future revenue streams or product candidates or to grant licenses on terms that may not be favorable to it. If the Company is unable to raise sufficient funding, it may be unable to continue to operate. There is no assurance that the Company will be successful in obtaining sufficient financing on acceptable terms and conditions to fund continuing operations, if at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company’s business, results of operations and financial condition. |
Significant Accounting Policies
| Significant Accounting Policies | 3 Months Ended |
| Mar. 31, 2016 | |
| Accounting Policies [Abstract] | |
| Significant Accounting Policies | 2. Significant Accounting Policies Basis of Presentation Segment Reporting Use of Estimates Comprehensive income (loss) Cash and Cash Equivalents The Company maintains its cash and cash equivalent balances in the form of money market, savings or operating accounts with financial institutions that management believes are creditworthy. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents. Short-term Investments Investments—Debt and Equity Securities The Company reviews short-term investments for other-than-temporary impairment whenever the fair value of a short-term investment is less than the amortized cost and evidence indicates that a short-term investment’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the short-term investment, or if it is more likely than not that the Company will be required to sell the short-term investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period. Short-term investments at March 31, 2016 consist of the following: Cost Basis Unrealized Gains Unrealized Losses Fair Value Current: Certificates of deposit $ 17,932 $ — $ — $ 17,932 Agency bonds 5,502 1 (1 ) 5,502 United States Treasury securities 20,125 2 (2 ) 20,125 $ 43,559 $ 3 $ (3 ) $ 43,559 Short-term investments at December 31, 2015 consist of the following: Cost Basis Unrealized Gains Unrealized Losses Fair Value Current: Certificates of deposit $ 16,160 $ — $ — $ 16,160 Agency bonds 10,036 — (5 ) 10,031 United States Treasury securities 5,053 — (6 ) 5,047 $ 31,249 $ — $ (11 ) $ 31,238 At March 31, 2016 and December 31, 2015, all short-term investments held by the Company had contractual maturities of less than one year. The Company evaluated its securities for other-than-temporary impairment and determined that no such impairment existed at March 31, 2016 and December 31, 2015. Property and Equipment Deferred Public Offering Costs Deferred Financing Costs Research and Development Costs • employee-related expenses including salaries, benefits, travel and stock-based compensation expense for research and development personnel; • expenses incurred under agreements with contract research organizations that conduct clinical and preclinical studies, contract manufacturing organizations and consultants; • costs associated with preclinical and development activities; and • costs associated with regulatory operations. Costs for certain development activities, such as clinical studies, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, and information provided to the Company by its vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the patterns of costs incurred, and are reflected in the financial statements as accrued expenses, or prepaid expenses and other current assets, if the related services have not been provided. Stock-Based Compensation The Company accounts for stock options issued to non-employees in accordance with the provisions of the FASB ASC 505-50, Equity-Based Payments to Non-employees Fair Value Measurements Fair Value Measurements and Disclosures Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The fair value of the Company’s financial instruments, including cash and cash equivalents, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their respective carrying values due to the short-term nature of these instruments. The Company’s assets and liabilities measured at fair value on a recurring basis include its warrant liabilities, convertible notes redemption rights derivative and 2020 Convertible Notes derivative liability (see Note 8). Derivative Financial Instruments Net Loss Per Share Earnings per Share The following table sets forth the computation of basic and diluted earnings (loss) per share attributable to the Company’s common stockholders: For the Three Months Ended March 31, 2016 2015 Numerator: Net loss $ (10,068 ) $ (1,462 ) Accretion and dividends on convertible preferred stock — (130 ) Net loss applicable to common stockholders (10,068 ) (1,592 ) Denominator: Weighted average common shares outstanding - basic and diluted 26,423,394 7,677,575 Net loss per share applicable to common stockholders - basic and diluted $ (0.38 ) $ (0.21 ) The following common stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated as including them would have an anti-dilutive effect: March 31, 2016 2015 Shares issuable upon conversion of the 2020 Convertible Notes — 3,333,333 Warrants for common stock 56,408 56,408 Stock options 2,400,177 911,075 Total 2,456,585 4,300,816 Subsequent Events Recent Accounting Pronouncements Presentation of Financial Statements – Going Concern In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting Compensation – Stock Compensation |
Property and Equipment
| Property and Equipment | 3 Months Ended |
| Mar. 31, 2016 | |
| Property, Plant and Equipment [Abstract] | |
| Property and Equipment | 3. Property and Equipment At March 31, 2016 and December 31, 2015, the Company’s property and equipment consisted of the following: Useful lives March 31, 2016 December 31, 2015 Office equipment 5 years $ 349 $ 334 Computer hardware and software 3 - 7 years 252 252 Laboratory equipment 5 years 43 43 Leasehold improvements 7 years 445 445 1,089 1,074 Less: accumulated depreciation (299 ) (262 ) Property and equipment, net $ 790 $ 812 During the three months ended March 31, 2016 and 2015, the Company recognized $37 and $0 of depreciation expense, respectively. |
Accrued Expenses and Other Curr
| Accrued Expenses and Other Current Liabilities | 3 Months Ended |
| Mar. 31, 2016 | |
| Payables and Accruals [Abstract] | |
| Accrued Expenses and Other Current Liabilities | 4. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities at March 31, 2016 and December 31, 2015 consisted of the following: March 31, 2016 December 31, 2015 Research and development $ 1,394 $ 375 Government payable 457 450 Compensation and benefits 590 999 Professional fees 523 347 Other 274 337 Total $ 3,238 $ 2,508 |
Debt
| Debt | 3 Months Ended |
| Mar. 31, 2016 | |
| Debt Disclosure [Abstract] | |
| Debt | 5. Debt 2020 Convertible Notes On February 23, 2015, the Company issued an aggregate of $20,000 of the 2020 Convertible Notes pursuant to its IPO. On March 24, 2015, the Company issued an additional $1,000 of 2020 Convertible Notes pursuant to the exercise of the underwriters’ overallotment option. The 2020 Convertible Notes had a maturity date of February 15, 2020 (“Maturity Date”), were unsecured and accrued interest at a rate of 5.0% per annum, payable semi-annually on February 15 and August 15 of each year. In connection with the issuance of the 2020 Convertible Notes, the Company incurred $2,097 of financing costs which were recorded in other assets on the balance sheet. Each holder of a 2020 Convertible Note (the “Holder”), had the option to convert all or any portion of such note at an initial conversion rate of 158.7302 shares of the Company’s common stock per $1 principal amount of 2020 Convertible Notes (the “Conversion Rate”). The Conversion Rate was subject to adjustment from time to time upon the occurrence of certain events, including the issuance of stock dividends and payment of cash dividends. For any conversion that occurred on or after July 23, 2015, the Company would, in addition to the other consideration payable, make an interest make-whole payment (the “Interest Make-Whole Payment”) to such converting Holder equal to the sum of the present values of the scheduled payments of interest that would have been made on the 2020 Convertible Notes to be converted had such notes remained outstanding from the date of the conversion (the “Conversion Date”) through the earlier of (i) the date that is three years after the Conversion Date and (ii) the Maturity Date, if the 2020 Convertible Notes had not been so converted or otherwise repurchased. Present values for the Interest Make-Whole Payment would be calculated using a discount rate equal to 2%. The Company could satisfy its obligation to pay any Interest Make-Whole Payment, at its election, in cash, shares of common stock or a combination thereof. The 2020 Convertible Notes were convertible, at the holder’s option, upon a fundamental change (“Fundamental Change”), as defined in the Indenture (“Indenture”). If a holder elected to convert its notes upon a Fundamental Change, the Company would increase the Conversion Rate for the 2020 Convertible Notes so surrendered for conversion by a number of additional shares of common stock by which the Conversion Rate would have increased per $1 principal amount of notes for each stock price and make-whole Fundamental Change effective date as set forth in the Indenture. The additional shares ranged from 7.9364 to 0. Upon a Fundamental Change, each Holder would have the right to require the Company to repurchase for cash all of such Holder’s notes, or any portion thereof that is equal to $1 or an integral multiple of $1. The repurchase price of the 2020 Convertible Notes would equal 100% of the principal amount thereof, plus accrued and unpaid interest thereon. However, if the repurchase occurred after a regular record date for an interest payment, but before the distribution date of that interest payment, the Holder receive the regular interest payment and the repurchase price would equal 100% of the principal amount of the 2020 Convertible Notes to be repurchased. The 2020 Convertible Notes were redeemable at the holder’s option upon an event of default (“Event of Default”). If an Event of Default (other than certain events of bankruptcy, insolvency or reorganization involving the Company) occurred and was continuing, the Trustee by notice to the Company, or the holders of at least 25% in principal amount of the outstanding notes by written notice to the Company and the Trustee, could declare 100% of the principal and accrued and unpaid interest, if any, on all of the 2020 Convertible Notes to be due and payable immediately. Upon the occurrence of certain Events of Default relating to bankruptcy, insolvency or reorganization involving the Company, 100% of the principal and accrued and unpaid interest, if any, on all of the 2020 Convertible Notes would become due and payable automatically. The Indenture provided that, to the extent the Company elected and for up to 180 days, the sole remedy for an Event of Default relating to certain failures by the Company to comply with certain reporting covenants in the Indenture, consisted exclusively of the right to receive additional interest (“Additional Interest”) on the 2020 Convertible Notes. The Additional Interest consisted of interest at an additional rate of 0.25% per annum for the first 90 days after the Event of Default. For the 91st to 180th day after the Event of Default, the Additional Interest would consist of interest at an additional rate of 0.50% per annum. After 180 days, if the Event of Default was not cured or waived, the 2020 Convertible Notes were subject to acceleration as provided in Section 6.02 of the Indenture. The Company determined that the conversion option, Interest Make-Whole Payments and the Additional Interest were embedded derivatives that required bifurcation and separate accounting under FASB ASC 815, Derivatives and Hedging The Company estimated the fair value of the Additional Interest using an income approach, specifically, the risk-neutral debt valuation method that is used to derive the value of a debt instrument using the expected cash flows and the risk-free rate. The significant assumptions used in estimating the expected cash flows were: the market yield used to determine the risk-neutral probability of default and the expected recovery rate upon default. The Company recorded $11,850 as the fair value of the combined embedded derivative liability on February 23, 2015, with a corresponding amount recorded as a discount to the 2020 Convertible Notes, related to the initial issuance of the 2020 Convertible Notes. The Company recorded approximately $573 of additional derivative liability and discount to the 2020 Convertible Notes as the fair value of the combined embedded derivative on March 24, 2015, upon the issuance of additional 2020 Convertible Notes for the exercise of the underwriters’ overallotment option. The deferred financing costs and the debt discount were recorded in other assets and were being amortized to interest expense over the life of the 2020 Convertible Notes using the effective interest method. Changes in the fair value of the combined embedded derivative liability were recorded in earnings in the period in which the changes occurred. The change in the estimated fair value of the combined embedded derivative liability of $1,997 was recorded in earnings in the three months ended March 31, 2015. In July and August 2015, holders of all $21,000 principal amount of the 2020 Convertible Notes elected to convert the principal into 3,333,319 shares of common stock in accordance with the terms of the 2020 Convertible Notes. In addition, the Interest Make-Whole Payment was settled with shares of common stock, at the election of the Company, resulting in the issuance of 530,072 additional shares of common stock. As of December 31, 2015, all $21,000 of the 2020 Convertible Notes were extinguished. Interest expense related to the 2020 Convertible Notes for the three months ended March 31, 2015, was $209, including $15 related to amortization of the issuance costs and $90 related to amortization of the debt discount. Convertible Bridge Notes In December 2014, the Company sold an aggregate of $2,000 of subordinated convertible promissory notes to existing stockholders (the “Convertible Bridge Notes”). The Convertible Bridge Notes were scheduled to mature on June 30, 2015 and accrued interest at the rate of 8% per annum and were subordinate to all other senior indebtedness of the Company. Upon the closing of an IPO of common stock of at least $40,000 in gross proceeds, all outstanding principal and accrued interest thereon would automatically convert into common stock at the IPO price. Pursuant to the IPO in February 2015, the Convertible Bridge Notes were converted into 337,932 shares of common stock based upon the IPO common share offering price of $6.00 per share. During the three months ended March 31, 2015, the Company reflected as interest expense related to the Convertible Bridge Notes (i) $23 related to the 8% coupon rate and (ii) $128 of amortization of the initial fair value of the redemption rights derivative and issuance costs. In connection with the conversion of the Convertible Bridge Notes into common stock, the Company recorded a (i) a $480 gain in change in fair value of the of the Convertible Bridge Notes redemption rights derivative from the write off of the derivative and (ii) a loss on extinguishment of debt of $360 from the acceleration of the unamortized balance of the debt discount and issuance costs. Notes Payable On June 28, 2013, the Company entered into two Loan and Security Agreements (the “Loan Agreements” or “Loans”) with two financial entities (the “Lenders”) pursuant to which the Company issued Loans for $3,500 to each lender and received proceeds of $6,915 net of costs and fees payable to the lenders. The Loans bore interest at a rate per annum of 11.0%. The Loans would mature on October 1, 2016 and required interest-only payments for the initial 12 months and thereafter required repayment of the principal balance with interest in 27 monthly installments. Also, upon full repayment or maturity of the Loans, the Lenders would be due a termination payment of 3.0% of the initial principal amount of the Loans, or $210 (the “Loan Termination Payment”). In connection with the Loan Agreements, the Company issued to the Lenders fully-vested warrants to purchase either, at the election of the warrant holder, (i) 228,906 shares of the Company’s Series AA preferred stock at an exercise price of $1.529 per share, or (ii) $350 of stock in the next round stock, as defined in the Loan Agreements, at a price that is the lowest effective price per share that is offered in the next round. The warrants expire on the earlier of (i) ten years after the date of grant, or (ii) immediately prior to an acquisition transaction, as defined in the warrants. The Company determined that the warrants should initially be classified as a liability based upon the nature of the underlying Series AA preferred stock. In connection with the Company’s IPO in February 2015, the Company exercised its right to terminate the Loan Agreements by paying the $5,347 principal balance due, the $210 Loan Termination Payment, a $160 prepayment fee calculated as 3% of the principal balance due at the time of the termination, plus $23 of interest accrued from February 1, 2015 through the payoff date. The Company made a scheduled principal payment of $243 in January 2015. For the three months ended March 31, 2015, interest expense related to the Loan Agreements was $115, including $26 related to accretion of the debt discount and termination payment. Additionally, in the three months ended March 31, 2015, the Company recorded a charge for loss on extinguishment of debt of $322 related to the write-off of the unamortized debt discount. Subsequent to the Company’s IPO, the warrants issued to the lenders became exercisable for 56,408 shares of common stock at $6.204 per share. The Company calculated the fair value of the warrants at the IPO date using a Black Scholes model using the following assumptions: a fair value of $6.00 per share (the IPO price of the Company’s common stock), 8.4 years to maturity, 1.70% risk-free rate, and 60% volatility. The Company determined the fair value of the warrant liability at the IPO date to be $215 and recorded a gain on change in fair value of warrant liabilities of $267 in the statement of operations for the three months ended March 31, 2015. The Company determined that subsequent to this change, the warrants were exercisable at a fixed number of shares of common stock and qualified for equity classification under the accounting guidance, and the fair value of the $215 was reclassified to additional paid-in capital as of the IPO date. |
Equity
| Equity | 3 Months Ended |
| Mar. 31, 2016 | |
| Equity [Abstract] | |
| Equity | 6. Equity Authorized Shares As of March 31, 2016, the Company’s authorized capital stock consisted of 120,000,000 shares of common stock, par value $0.01 per share, and 5,000,000 shares of undesignated preferred stock, par value $0.001 per share. Preferred Stock During 2014, the Company modified the terms of 558,862 shares of Series X preferred stock such that the Company’s repurchase right relative to those shares expired upon consummation of the IPO. The Company estimated the fair value of the modified award at the modification date to be $950 and recognized this amount as stock-based compensation expense upon completion of the IPO in the three months ended March 31, 2015. Common Stock All preferences, voting powers, relative, participating, optional, or other specific rights and privileges, limitations, or restrictions of the common stock are expressly subject to those that may be fixed with respect to any shares of preferred stock. Common stockholders are entitled to one vote per share, and to receive dividends, when and if declared by the Company’s board of directors. At March 31, 2016 and December 31, 2015, there were 26,423,394 shares common stock outstanding. 2014 Stock Option and Incentive Plan In August 2014, the Company’s board of directors adopted the 2014 Stock Option and Incentive Plan (the “2014 Plan”) for the issuance of incentive and non-qualified stock options, restricted stock, and other equity awards, all for common stock, as determined by the board of directors to employees, officers, directors, consultants, and advisors of the Company and its subsidiaries. Pursuant to the provisions of the 2014 Plan and approval by the board of directors, on January 1, 2016 an additional 1,056,936 shares were added to the 2014 Plan representing 4% of total common shares issued and outstanding at December 31, 2015. There were 833,035 shares issuable under the 2014 Plan as of March 31, 2016. The 2014 Plan expires in August 2024. In the three months ended March 31, 2016, the Company recorded aggregate stock-based compensation expense of $466 for stock options under the 2014 Plan: $269 in general and administrative expense and $197 in research and development expense. In the three months ended March 31, 2015, the Company recorded an aggregate stock-based compensation expense of $414 for stock options under the 2014 Plan: $218 in general and administrative expense and $196 in research and development expense. During the three months ended March 31, 2016, the board of directors granted a total of 796,500 ten-year term stock options to employees of the Company. The fair value of each stock option granted was estimated on the grant date using a Black-Scholes stock option pricing model based on the following assumptions: an expected term of 5.97 to 6.08 years; expected stock price volatility of 77.5% to 77.7%, a risk free rate of 1.47% to 1.90%, and a dividend yield of 0%. The Company will recognize $4,080 of stock-based compensation expense for these stock options on a straight-line basis commencing upon the grant dates through the final vesting dates. The following table summarizes activity for the three months ended March 31, 2016 under the 2014 Plan: Number of Shares Weighted Average Exercise Price Per Share Aggregate Intrinsic Value Options outstanding at December 31, 2015 1,620,760 $ 4.95 $ 10,339 Granted 796,500 $ 7.80 $ — Exercised — $ — $ — Cancelled (28,000 ) $ 6.79 $ — Options outstanding at March 31, 2016 2,389,260 $ 5.87 $ 4,164 Options exercisable at March 31, 2016 515,942 $ 4.52 $ 1,485 Weighted-average years remaining on contractual life 9.19 Unrecognized compensation cost related to non-vested stock options $ 8,200 The weighted-average fair value of all stock options granted for the three months ended March 31, 2016 was $5.25 per share. Aggregate intrinsic value is based on $7.40 per share, the closing price of common stock on March 31, 2016. 2004 Stock Option and Incentive Plan The Company has outstanding stock options pursuant to its 2004 Stock Option and Incentive Plan (the “2004 Plan”). The 2004 Plan has expired but remains effective for all outstanding options under the 2004 Plan. The following table summarizes activity for the three months ended March 31, 2016 under the 2004 Plan: Number of Shares Weighted Average Exercise Price Per Share Aggregate Intrinsic Value Options outstanding at December 31, 2015 10,917 $ 40.58 $ — Granted — $ — $ — Exercised — $ — $ — Expired — $ — $ — Options outstanding at March 31, 2016 10,917 $ 40.58 $ — Options exercisable at March 31, 2016 10,917 $ 40.58 $ — Weighted-average years remaining on contractual life 2.03 Unrecognized compensation cost related to non-vested stock options $ — The exercise prices exceed the $7.40 per share closing price of common stock on March 31, 2016, therefore there is no intrinsic value of the outstanding 2004 Plan stock options. Employee Stock Purchase Plan In November 2014 the Company’s board of directors adopted and the stockholders approved the 2014 Employee Stock Purchase Plan (“ESPP”). The ESPP provides that the number of shares reserved and available for issuance under the ESPP shall be cumulatively increased each January 1, beginning on January 1, 2016, by the lesser of (i) 600,000 shares of common stock or (ii) the number of shares necessary to set the number of shares of Common Stock under the Plan at 1% percent of the outstanding number of shares as of January 1 of the applicable year. However, the board of directors reserves the right to determine that there will be no increase for any year or that any increase will be for a lesser number of shares. As of January 1, 2016, 117,100 shares were added to the ESPP. As of March 31, 2016, there were 264,233 shares available for issuance under the ESPP. As of March 31, 2016, there was $46 withheld from employees that will be used to purchase shares of the Company’s common stock on May 31, 2016, which is the last day of the current offering period. The Company recorded $20 of stock-based compensation expense pursuant to the ESPP during the three months ended March 31, 2016. |
Commitments and Contingencies
| Commitments and Contingencies | 3 Months Ended |
| Mar. 31, 2016 | |
| Commitments and Contingencies Disclosure [Abstract] | |
| Commitments and Contingencies | 7. Commitments and Contingencies Operating leases In May 2015, the Company entered into a lease agreement (the “Office Lease”) for its headquarters in Lexington, Massachusetts. The Company occupied this space in September 2015, at which time its rental obligations commenced. The Company recorded $445 as leasehold improvements for costs incurred to build out the space, and is amortizing those costs to facilities expense over the term of the lease. Rent expense is recognized on a straight-line basis at the average monthly rent over the term of the lease. Deferred rent is included in other current and long-term liabilities on the Company’s consolidated balance sheets. Rent expense related to the Office Lease was $62 for the three months ended March 31, 2016. Rent expense was $15 for the three months ended March 31, 2015, and was related to the Company’s prior lease agreement which expired in September 2015. In February 2016, the Company signed an amendment to the Office Lease, whereby it agreed to rent additional space (the “Lease Amendment”). The Company expects to occupy the additional space in July 2016. The terms of the Lease Amendment follow the terms of the Office Lease. If occupancy occurs on July 1, 2016, the aggregate annual commitments pursuant to the Office Lease and the Lease Amendment are as follows: Year Amount 2016 $ 177 2017 402 2018 411 2019 421 2020 430 Thereafter 959 Total $ 2,800 Indemnification Arrangements As permitted under Delaware law, the Company’s bylaws provide that the Company will indemnify any director, officer, employee or agent of the Company or anyone serving in these capacities. The maximum potential amount of future payments the Company could be required to pay is unlimited. The Company has insurance that reduces its monetary exposure and would enable it to recover a portion of any future amounts paid. As a result, the Company believes that the estimated fair value of these indemnification commitments is minimal. Throughout the normal course of business, the Company has agreements with vendors that provide goods and services required by the Company to run its business. In some instances, vendor agreements include language that requires the Company to indemnify the vendor from certain damages caused by the Company’s use of the vendor’s goods and/or services. The Company has insurance that would allow it to recover a portion of any future amounts that could arise from these indemnifications. As a result, the Company believes that the estimated fair value of these indemnification commitments is minimal. |
Derivative Financial Instrument
| Derivative Financial Instruments | 3 Months Ended |
| Mar. 31, 2016 | |
| Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
| Derivative Financial Instruments | 9. Derivative Financial Instruments The Company determined that certain embedded features related to the 2020 Convertible Notes and the Convertible Bridge Notes are derivative financial instruments. The effect of derivative instruments not designated as hedging instruments on the statement of operations for the three months ended March 31, 2015 consist of the following: Derivative financial instruments not designated as hedging instruments Location of gain or loss recognized in income on derivative financial instrument Amount of gain or (loss) 2020 Convertible Notes derivative liability Change in fair value of 2020 Convertible Notes derivative liability $ 1,997 Convertible Bridge Notes Change in fair value of Convertible Bridge Notes redemption rights derivative $ 480 See Notes 5 and 8 for additional discussion regarding the accounting for and valuation of these derivative financial instruments. |
Subsequent Event
| Subsequent Event | 3 Months Ended |
| Mar. 31, 2016 | |
| Subsequent Events [Abstract] | |
| Subsequent Event | 10. Subsequent Event In April 2016, the Company filed a registration statement on Form S-3 containing two prospectuses: (i) a base prospectus which covers the offering, issuance and sale of up to $200,000 in the aggregate of an indeterminate number of shares of common stock and preferred stock, such indeterminate principal amount of debt securities and such indeterminate number of warrants and units; and (ii) a sales agreement prospectus covering the offering, issuance and sale of up to a maximum aggregate offering price of $50,000 of the Company’s common stock that may be issued and sold under a sales agreement with Cowen and Company, LLC. The sales agreement prospectus amount of $50,000 is included in the base prospectus amount of $200,000. |
Significant Accounting Polici16
| Significant Accounting Policies (Policies) | 3 Months Ended |
| Mar. 31, 2016 | |
| Accounting Policies [Abstract] | |
| Basis of Presentation | Basis of Presentation |
| Segment Reporting | Segment Reporting |
| Use of Estimates | Use of Estimates |
| Comprehensive income (loss) | Comprehensive income (loss) |
| Cash and Cash Equivalents | Cash and Cash Equivalents The Company maintains its cash and cash equivalent balances in the form of money market, savings or operating accounts with financial institutions that management believes are creditworthy. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. The Company believes it is not exposed to any significant credit risk on cash and cash equivalents. |
| Short-term Investments | Short-term Investments Investments—Debt and Equity Securities The Company reviews short-term investments for other-than-temporary impairment whenever the fair value of a short-term investment is less than the amortized cost and evidence indicates that a short-term investment’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the short-term investment, or if it is more likely than not that the Company will be required to sell the short-term investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period. Short-term investments at March 31, 2016 consist of the following: Cost Basis Unrealized Gains Unrealized Losses Fair Value (in thousands) Current: Certificates of deposit $ 17,932 $ — $ — $ 17,932 Agency bonds 5,502 1 (1 ) 5,502 United States Treasury securities 20,125 2 (2 ) 20,125 $ 43,559 $ 3 $ (3 ) $ 43,559 Short-term investments at December 31, 2015 consist of the following: Cost Basis Unrealized Gains Unrealized Losses Fair Value (in thousands) Current: Certificates of deposit $ 16,160 $ — $ — $ 16,160 Agency bonds 10,036 — (5 ) 10,031 United States Treasury securities 5,053 — (6 ) 5,047 $ 31,249 $ — $ (11 ) $ 31,238 At March 31, 2016 and December 31, 2015, all short-term investments held by the Company had contractual maturities of less than one year. The Company evaluated its securities for other-than-temporary impairment and determined that no such impairment existed at March 31, 2016 and December 31, 2015. |
| Property and Equipment | Property and Equipment |
| Deferred Public Offering Costs | Deferred Public Offering Costs |
| Deferred Financing Costs | Deferred Financing Costs |
| Research and Development Costs | Research and Development Costs • employee-related expenses including salaries, benefits, travel and stock-based compensation expense for research and development personnel; • expenses incurred under agreements with contract research organizations that conduct clinical and preclinical studies, contract manufacturing organizations and consultants; • costs associated with preclinical and development activities; and • costs associated with regulatory operations. Costs for certain development activities, such as clinical studies, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, and information provided to the Company by its vendors on their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the patterns of costs incurred, and are reflected in the financial statements as accrued expenses, or prepaid expenses and other current assets, if the related services have not been provided. |
| Stock-Based Compensation | Stock-Based Compensation The Company accounts for stock options issued to non-employees in accordance with the provisions of the FASB ASC 505-50, Equity-Based Payments to Non-employees |
| Fair Value Measurements | Fair Value Measurements Fair Value Measurements and Disclosures Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and unobservable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The fair value of the Company’s financial instruments, including cash and cash equivalents, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their respective carrying values due to the short-term nature of these instruments. The Company’s assets and liabilities measured at fair value on a recurring basis include its warrant liabilities, convertible notes redemption rights derivative and 2020 Convertible Notes derivative liability (see Note 8) |
| Derivative Financial Instruments | Derivative Financial Instruments |
| Net Loss Per Share | Net Loss Per Share Earnings per Share The following table sets forth the computation of basic and diluted earnings (loss) per share attributable to the Company’s common stockholders: For the Three Months Ended March 31, 2016 2015 Numerator: Net loss $ (10,068 ) $ (1,462 ) Accretion and dividends on convertible preferred stock — (130 ) Net loss applicable to common stockholders (10,068 ) (1,592 ) Denominator: Weighted average common shares outstanding - basic and diluted 26,423,394 7,677,575 Net loss per share applicable to common stockholders - basic and diluted $ (0.38 ) $ (0.21 ) The following common stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated as including them would have an anti-dilutive effect: March 31, 2016 2015 Shares issuable upon conversion of the 2020 Convertible Notes — 3,333,333 Warrants for common stock 56,408 56,408 Stock options 2,400,177 911,075 Total 2,456,585 4,300,816 |
| Subsequent Events | Subsequent Events |
| Recent Accounting Pronouncements | Recent Accounting Pronouncements Presentation of Financial Statements – Going Concern In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting Compensation – Stock Compensation |
Significant Accounting Polici17
| Significant Accounting Policies (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Accounting Policies [Abstract] | |
| Schedule of Short-term Investment | Short-term investments at March 31, 2016 consist of the following: Cost Basis Unrealized Gains Unrealized Losses Fair Value Current: Certificates of deposit $ 17,932 $ — $ — $ 17,932 Agency bonds 5,502 1 (1 ) 5,502 United States Treasury securities 20,125 2 (2 ) 20,125 $ 43,559 $ 3 $ (3 ) $ 43,559 Short-term investments at December 31, 2015 consist of the following: Cost Basis Unrealized Gains Unrealized Losses Fair Value Current: Certificates of deposit $ 16,160 $ — $ — $ 16,160 Agency bonds 10,036 — (5 ) 10,031 United States Treasury securities 5,053 — (6 ) 5,047 $ 31,249 $ — $ (11 ) $ 31,238 |
| Schedule of Computation of Basic and Diluted Earnings (Loss) Per Share | The following table sets forth the computation of basic and diluted earnings (loss) per share attributable to the Company’s common stockholders: For the Three Months Ended March 31, 2016 2015 Numerator: Net loss $ (10,068 ) $ (1,462 ) Accretion and dividends on convertible preferred stock — (130 ) Net loss applicable to common stockholders (10,068 ) (1,592 ) Denominator: Weighted average common shares outstanding - basic and diluted 26,423,394 7,677,575 Net loss per share applicable to common stockholders - basic and diluted $ (0.38 ) $ (0.21 ) |
| Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share | The following common stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated as including them would have an anti-dilutive effect: March 31, 2016 2015 Shares issuable upon conversion of the 2020 Convertible Notes — 3,333,333 Warrants for common stock 56,408 56,408 Stock options 2,400,177 911,075 Total 2,456,585 4,300,816 |
Property and Equipment (Tables)
| Property and Equipment (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Property, Plant and Equipment [Abstract] | |
| Schedule of Property and Equipment | At March 31, 2016 and December 31, 2015, the Company’s property and equipment consisted of the following: Useful lives March 31, 2016 December 31, 2015 Office equipment 5 years $ 349 $ 334 Computer hardware and software 3 - 7 years 252 252 Laboratory equipment 5 years 43 43 Leasehold improvements 7 years 445 445 1,089 1,074 Less: accumulated depreciation (299 ) (262 ) Property and equipment, net $ 790 $ 812 |
Accrued Expenses and Other Cu19
| Accrued Expenses and Other Current Liabilities (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Payables and Accruals [Abstract] | |
| Schedule of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities at March 31, 2016 and December 31, 2015 consisted of the following: March 31, 2016 December 31, 2015 Research and development $ 1,394 $ 375 Government payable 457 450 Compensation and benefits 590 999 Professional fees 523 347 Other 274 337 Total $ 3,238 $ 2,508 |
Equity (Tables)
| Equity (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Equity [Abstract] | |
| Summary of Stock Option Activity | The following table summarizes activity for the three months ended March 31, 2016 under the 2014 Plan: Number of Shares Weighted Average Exercise Price Per Share Aggregate Intrinsic Value Options outstanding at December 31, 2015 1,620,760 $ 4.95 $ 10,339 Granted 796,500 $ 7.80 $ — Exercised — $ — $ — Cancelled (28,000 ) $ 6.79 $ — Options outstanding at March 31, 2016 2,389,260 $ 5.87 $ 4,164 Options exercisable at March 31, 2016 515,942 $ 4.52 $ 1,485 Weighted-average years remaining on contractual life 9.19 Unrecognized compensation cost related to non-vested stock options $ 8,200 Aggregate intrinsic value is based on $7.40 per share, the closing price of common stock on March 31, 2016. The following table summarizes activity for the three months ended March 31, 2016 under the 2004 Plan: Number of Shares Weighted Average Exercise Price Per Share Aggregate Intrinsic Value Options outstanding at December 31, 2015 10,917 $ 40.58 $ — Granted — $ — $ — Exercised — $ — $ — Expired — $ — $ — Options outstanding at March 31, 2016 10,917 $ 40.58 $ — Options exercisable at March 31, 2016 10,917 $ 40.58 $ — Weighted-average years remaining on contractual life 2.03 Unrecognized compensation cost related to non-vested stock options $ — |
Commitments and Contingencies (
| Commitments and Contingencies (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Commitments and Contingencies Disclosure [Abstract] | |
| Schedule of Aggregate Annual Commitments Pursuant to Office Lease and Lease Amendment | If occupancy occurs on July 1, 2016, the aggregate annual commitments pursuant to the Office Lease and the Lease Amendment are as follows: Year Amount 2016 $ 177 2017 402 2018 411 2019 421 2020 430 Thereafter 959 Total $ 2,800 |
Fair Value of Assets and Liabil
| Fair Value of Assets and Liabilities Measured on Recurring Basis (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Fair Value Disclosures [Abstract] | |
| Fair Value of Assets and Liabilities Measured on Recurring Basis | The following table sets forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy: Fair Value Measurements at March 31, 2016 Total Level 1 Level 2 Level 3 Assets: Certificates of deposit $ 17,932 $ — $ 17,932 $ — Agency bonds 5,502 — 5,502 — United States Treasury securities 20,125 20,125 — — Short-term investments $ 43,559 $ 20,125 $ 23,434 $ — Fair Value Measurements at December 31, 2015 Total Level 1 Level 2 Level 3 Assets: Certificates of deposit $ 16,160 $ — $ 16,160 $ — Agency bonds 10,031 — 10,031 — United States Treasury securities 5,047 5,047 — — Short-term investments $ 31,238 $ 5,047 $ 26,191 $ — |
Derivative Financial Instrume23
| Derivative Financial Instruments (Tables) | 3 Months Ended |
| Mar. 31, 2016 | |
| Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
| Effect of Derivative Instrument Not Designated as Hedging Instruments on Statement of Operations | The effect of derivative instruments not designated as hedging instruments on the statement of operations for the three months ended March 31, 2015 consist of the following: Derivative financial instruments not designated as hedging instruments Location of gain or loss recognized in income on derivative financial instrument Amount of gain or (loss) 2020 Convertible Notes derivative liability Change in fair value of 2020 Convertible Notes derivative liability $ 1,997 Convertible Bridge Notes Change in fair value of Convertible Bridge Notes redemption rights derivative $ 480 |
Organization and Operations - A
| Organization and Operations - Additional Information (Detail) - USD ($) | 1 Months Ended | 3 Months Ended | ||||||
| Aug. 31, 2015 | Jul. 31, 2015 | Mar. 31, 2015 | Mar. 31, 2016 | Dec. 31, 2015 | Mar. 24, 2015 | Feb. 23, 2015 | Jun. 28, 2013 | |
| Schedule Of Description Of Business [Line Items] | ||||||||
| Net proceeds from issuance of equity | $ 73,965,000 | $ 36,495,000 | ||||||
| Net proceeds from issuance of debts | $ 18,903,000 | |||||||
| Accumulated deficit | $ (206,091,000) | $ (196,023,000) | ||||||
| Aggregate cash and cash equivalents and marketable securities | $ 102,265,000 | |||||||
| 2020 Convertible Notes [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Convertible senior notes, interest rate, stated percentage | 5.00% | |||||||
| Aggregate principal amount | $ 21,000,000 | $ 21,000,000 | $ 1,000,000 | $ 20,000,000 | ||||
| Convertible Notes converted into shares | 3,333,319 | 3,333,319 | ||||||
| Additional shares of common stock | 530,072 | 530,072 | ||||||
| Senior Notes [Member] | 2020 Convertible Notes [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Convertible senior notes, interest rate, stated percentage | 5.00% | |||||||
| Aggregate principal amount | $ 21,000,000 | |||||||
| Notes Payable [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Aggregate principal amount | $ 21,000,000 | $ 21,000,000 | $ 3,500,000 | |||||
| Convertible Notes converted into shares | 3,333,319 | 3,333,319 | ||||||
| Additional shares of common stock | 530,072 | 530,072 | ||||||
| IPO [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Initial public offering common stock, shares | 6,966,333 | |||||||
| IPO [Member] | Affiliated Entity [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Initial public offering common stock, shares | 3,005,000 | |||||||
| Over-Allotment Option [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Initial public offering common stock, shares | 810,000 | 299,333 | ||||||
| Initial public offering common stock, per shares | $ 6 | |||||||
| Aggregate principal amount | $ 1,000,000 | |||||||
| Secondary Public Offering [Member] | ||||||||
| Schedule Of Description Of Business [Line Items] | ||||||||
| Initial public offering common stock, shares | 6,210,000 | |||||||
| Initial public offering common stock, per shares | $ 12.75 | |||||||
Significant Accounting Polici25
| Significant Accounting Policies - Additional Information (Detail) | 3 Months Ended | ||
| Mar. 31, 2016USD ($)Segment | Mar. 31, 2015USD ($) | Dec. 31, 2015USD ($) | |
| Accounting Policies [Abstract] | |||
| Number of operating segments | Segment | 1 | ||
| Realized gains or losses on short-term investment | $ 0 | $ 0 | |
| Unrealized gains (losses) on short-term investment | 11,000 | 0 | |
| Other than temporary impairment evaluated | 0 | $ 0 | |
| Deferred public offering costs | $ 182,000 | $ 0 | |
| Amortization of deferred financing costs | $ 44,000 | ||
Significant Accounting Polici26
| Significant Accounting Policies - Schedule of Short-term Investment (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended |
| Mar. 31, 2016 | Dec. 31, 2015 | |
| Schedule of Available-for-sale Securities [Line Items] | ||
| Available-for-sale securities, Cost Basis | $ 43,559 | $ 31,249 |
| Available-for-sale securities, Unrealized Gains | 3 | |
| Available-for-sale securities, Unrealized Losses | (3) | (11) |
| Available-for-sale securities, Fair Value | 43,559 | 31,238 |
| Certificates of Deposit [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Available-for-sale securities, Cost Basis | 17,932 | 16,160 |
| Available-for-sale securities, Fair Value | 17,932 | 16,160 |
| Agency Bonds [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Available-for-sale securities, Cost Basis | 5,502 | 10,036 |
| Available-for-sale securities, Unrealized Gains | 1 | |
| Available-for-sale securities, Unrealized Losses | (1) | (5) |
| Available-for-sale securities, Fair Value | 5,502 | 10,031 |
| United States Treasury Securities [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Available-for-sale securities, Cost Basis | 20,125 | 5,053 |
| Available-for-sale securities, Unrealized Gains | 2 | |
| Available-for-sale securities, Unrealized Losses | (2) | (6) |
| Available-for-sale securities, Fair Value | $ 20,125 | $ 5,047 |
Significant Accounting Polici27
| Significant Accounting Policies - Schedule of Computation of Basic and Diluted Earnings (Loss) Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | |
| Mar. 31, 2016 | Mar. 31, 2015 | |
| Numerator: | ||
| Net loss | $ (10,068) | $ (1,462) |
| Accretion and dividends on convertible preferred stock | (130) | |
| Net loss applicable to common stockholders | $ (10,068) | $ (1,592) |
| Denominator: | ||
| Weighted average common shares outstanding - basic and diluted | 26,423,394 | 7,677,575 |
| Net loss per share applicable to common stockholders - basic and diluted | $ (0.38) | $ (0.21) |
Significant Accounting Polici28
| Significant Accounting Policies - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares | 3 Months Ended | |
| Mar. 31, 2016 | Mar. 31, 2015 | |
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 2,456,585 | 4,300,816 |
| Shares Issuable Upon Conversion of the 2020 Convertible Notes [Member] | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 3,333,333 | |
| Warrants Exercisable for Common Stock [Member] | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 56,408 | 56,408 |
| Stock Options [Member] | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Antidilutive securities excluded from computation of earnings per share | 2,400,177 | 911,075 |
Property and Equipment - Schedu
| Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands | 3 Months Ended | |
| Mar. 31, 2016 | Dec. 31, 2015 | |
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Gross | $ 1,089 | $ 1,074 |
| Less: accumulated depreciation | (299) | (262) |
| Property and equipment, net | $ 790 | 812 |
| Office Equipment [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Useful lives | 5 years | |
| Property and equipment, Gross | $ 349 | 334 |
| Computer Hardware and Software [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Gross | $ 252 | 252 |
| Computer Hardware and Software [Member] | Minimum [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Useful lives | 3 years | |
| Computer Hardware and Software [Member] | Maximum [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Useful lives | 7 years | |
| Laboratory Equipment [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Useful lives | 5 years | |
| Property and equipment, Gross | $ 43 | 43 |
| Leasehold Improvements [Member] | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, Useful lives | 7 years | |
| Property and equipment, Gross | $ 445 | $ 445 |
Property and Equipment - Additi
| Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | |
| Mar. 31, 2016 | Mar. 31, 2015 | |
| Property, Plant and Equipment, Net [Abstract] | ||
| Depreciation expense | $ 37 | $ 0 |
Accrued Expenses and Other Cu31
| Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands | Mar. 31, 2016 | Dec. 31, 2015 |
| Payables and Accruals [Abstract] | ||
| Research and development | $ 1,394 | $ 375 |
| Government payable | 457 | 450 |
| Compensation and benefits | 590 | 999 |
| Professional fees | 523 | 347 |
| Other | 274 | 337 |
| Total | $ 3,238 | $ 2,508 |
Debt - 2020 Convertible Notes -
| Debt - 2020 Convertible Notes - Additional Information (Detail) | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||
| Aug. 31, 2015USD ($)shares | Jul. 31, 2015USD ($)shares | Mar. 31, 2016USD ($)$ / shares | Mar. 31, 2015USD ($) | Dec. 31, 2015USD ($) | Mar. 24, 2015USD ($) | Feb. 23, 2015USD ($) | |
| Debt Instrument [Line Items] | |||||||
| Interest expense | $ 474,000 | ||||||
| 2020 Convertible Notes [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Debt instrument principal amount | $ 21,000,000 | $ 21,000,000 | $ 1,000,000 | $ 20,000,000 | |||
| Debt instrument maturity date | Feb. 15, 2020 | ||||||
| Convertible notes, interest rate, stated percentage | 5.00% | ||||||
| Financing costs incurred by the company | $ 2,097,000 | ||||||
| Number of shares, note gets converted into | 158.7302 | ||||||
| Principal amount | $ 1 | ||||||
| Discount rate | 2.00% | ||||||
| Holdings in debt outstanding | 25.00% | ||||||
| Number of days after default | 180 days | ||||||
| Fair value of combined embedded derivative liability | $ 11,850,000 | ||||||
| Derivative liabilities and discount recorded | $ 573,000 | ||||||
| Change in estimated fair value of combined embedded derivative liability | $ 1,997,000 | ||||||
| Convertible Notes converted into shares | shares | 3,333,319 | 3,333,319 | |||||
| Additional shares of common stock | shares | 530,072 | 530,072 | |||||
| Extinguishment of debt | $ 21,000,000 | ||||||
| Interest expense | $ 209,000 | ||||||
| Amortization of financing costs and discounts | 15,000 | ||||||
| Amortization of debt discount | $ 90,000 | ||||||
| 2020 Convertible Notes [Member] | First 90 Days [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Additional interest rate | 0.25% | ||||||
| 2020 Convertible Notes [Member] | 91 to 180 Days [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Additional interest rate | 0.50% | ||||||
| 2020 Convertible Notes [Member] | Fundamental Change [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Percentage of principal amount of notes to be purchased | 100.00% | ||||||
| Repurchase price description | Upon a Fundamental Change, each Holder would have the right to require the Company to repurchase for cash all of such Holder's notes, or any portion thereof that is equal to $1 or an integral multiple of $1. | ||||||
| Repurchase price | $ / shares | $ 1 | ||||||
| 2020 Convertible Notes [Member] | Fundamental Change [Member] | Maximum [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Number of shares, note gets converted into | 0 | ||||||
| 2020 Convertible Notes [Member] | Fundamental Change [Member] | Minimum [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Number of shares, note gets converted into | 7.9364 | ||||||
Debt - Convertible Bridge Notes
| Debt - Convertible Bridge Notes - Additional Information (Detail) - USD ($) | 1 Months Ended | 3 Months Ended | ||
| Feb. 28, 2015 | Dec. 31, 2014 | Mar. 31, 2016 | Mar. 31, 2015 | |
| Debt Instrument [Line Items] | ||||
| Amortization of financing costs | $ 44,000 | |||
| Losses on extinguishment of debt | $ (522,000) | |||
| 2014 Convertible Bridge Notes [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Debt instrument, face amount | $ 2,000,000 | |||
| Debt instrument maturity date | Jun. 30, 2015 | |||
| Debt instrument annual interest rate | 8.00% | 8.00% | ||
| Debt instrument, interest expense to coupon rate | $ 23,000 | |||
| Amortization of financing costs | 128,000 | |||
| Losses on extinguishment of debt | (360,000) | |||
| Debt converted into shares of common stock | 337,932 | |||
| Share offering price | $ 6 | |||
| Gain in change in fair value | $ 480,000 | |||
| 2014 Convertible Bridge Notes [Member] | Minimum [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Gross proceeds | $ 40,000,000 | |||
Debt - Notes Payable - Addition
| Debt - Notes Payable - Additional Information (Detail) | Jun. 28, 2013USD ($)AgreementEntity | Feb. 28, 2015USD ($) | Mar. 31, 2016USD ($)Installment$ / sharesshares | Mar. 31, 2015USD ($) | Aug. 31, 2015USD ($) | Jul. 31, 2015USD ($) | Jan. 31, 2015USD ($) |
| Debt Instrument [Line Items] | |||||||
| Losses on extinguishment of debt | $ (522,000) | ||||||
| Change in fair value of warrant liabilities | (267,000) | ||||||
| Notes Payable [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Number of loan and security agreements | Agreement | 2 | ||||||
| Number of financial entities | Entity | 2 | ||||||
| Debt instrument principal balance | $ 3,500,000 | $ 21,000,000 | $ 21,000,000 | ||||
| Proceeds from loans issued | $ 6,915,000 | ||||||
| Interest rate | 11.00% | ||||||
| Loan maturity date | Oct. 1, 2016 | ||||||
| Interest only payments for initial | 12 months | ||||||
| Number of installments | Installment | 27 | ||||||
| Termination payment percentage | 3.00% | 3.00% | |||||
| Loan termination payment | $ 210,000 | $ 210,000 | |||||
| Warrant or right securities called by warrants, amount | $ 350,000 | ||||||
| Warrant expiration date | The warrants expire on the earlier of (i) ten years after the date of grant, or (ii) immediately prior to an acquisition transaction, as defined in the warrants. | ||||||
| Repaying principal amount | 5,347,000 | ||||||
| Prepayment fee | 160,000 | ||||||
| Interest accrued | $ 23,000 | ||||||
| Debt instrument, principal payments | $ 243,000 | ||||||
| Interest expense related to loan agreements | 115,000 | ||||||
| Accretion of debt discounts and loan termination payment | 26,000 | ||||||
| Losses on extinguishment of debt | (322,000) | ||||||
| Warrants issued to lenders exercisable to common shares | shares | 56,408 | ||||||
| Warrants issued to lenders exercisable to common shares, price per share | $ / shares | $ 6.204 | ||||||
| Change in fair value of warrant liabilities | 267,000 | ||||||
| Reclassification of fair value of warrant liability to equity upon initial public offering | $ 215,000 | ||||||
| Notes Payable [Member] | Warrants Exercisable for Common Stock [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| IPO price of the Company's common stock | $ / shares | $ 6 | ||||||
| Fair value assumptions, expected term | 8 years 4 months 24 days | ||||||
| Fair value assumptions, risk free interest rate | 1.70% | ||||||
| Fair value assumptions, expected volatility rate | 60.00% | ||||||
| Fair value of the warrant liability | $ 215,000 | ||||||
| Notes Payable [Member] | Series AA Preferred Stock [Member] | |||||||
| Debt Instrument [Line Items] | |||||||
| Preferred stock issued to lenders | shares | 228,906 | ||||||
| Preferred stock issued to lenders, price per share | $ / shares | $ 1.529 |
Equity - Additional Information
| Equity - Additional Information (Detail) - USD ($) | Mar. 31, 2016 | Mar. 31, 2016 | Mar. 31, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Jan. 01, 2016 |
| Stockholders Equity [Line Items] | ||||||
| Common stock, shares authorized | 120,000,000 | 120,000,000 | 120,000,000 | |||
| Common stock, par value | $ 0.01 | $ 0.01 | $ 0.01 | |||
| Preferred stock, shares authorized | 5,000,000 | 5,000,000 | 5,000,000 | |||
| Preferred stock, par value | $ 0.001 | $ 0.001 | $ 0.001 | |||
| Stock-based compensation expense | $ 950,000 | |||||
| Common stock voting rights description | One vote per share | |||||
| Common stock, shares outstanding | 26,423,394 | 26,423,394 | 26,423,394 | |||
| Common Stock [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Amount withheld from employees | $ 46,000 | |||||
| 2014 Stock Option and Incentive Plan [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock-based compensation expense | $ 466,000 | 414,000 | ||||
| Number of shares reserved for future issuance | 833,035 | 833,035 | 1,056,936 | |||
| Percentage of outstanding common stock increased to shares available for grant | 4.00% | |||||
| Stock options, dividend yield | 0.00% | |||||
| Stock options granted | 796,500 | |||||
| Expiration period of stock options | 10 years | |||||
| Stock options, intrinsic value | $ 4,164,000 | $ 4,164,000 | $ 10,339,000 | |||
| Weighted-average fair value of stock options granted | $ 5.25 | |||||
| 2014 Stock Option and Incentive Plan [Member] | Minimum [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock options, expected term | 5 years 11 months 19 days | |||||
| Stock options, expected stock price volatility | 77.50% | |||||
| Stock options, risk free rate | 1.47% | |||||
| 2014 Stock Option and Incentive Plan [Member] | Maximum [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock options, expected term | 6 years 29 days | |||||
| Stock options, expected stock price volatility | 77.70% | |||||
| Stock options, risk free rate | 1.90% | |||||
| 2014 Stock Option and Incentive Plan [Member] | General and Administrative Expense [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock-based compensation expense | $ 269,000 | 218,000 | ||||
| 2014 Stock Option and Incentive Plan [Member] | Research and Development Expense [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock-based compensation expense | 197,000 | $ 196,000 | ||||
| 2004 Stock Option Plan [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock options, intrinsic value | $ 0 | $ 0 | ||||
| Closing price of common stock | $ 7.40 | $ 7.40 | ||||
| Employee Stock Purchase Plan [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Stock-based compensation expense | $ 20,000 | |||||
| Number of shares reserved for future issuance | 600,000 | 600,000 | 117,100 | |||
| Percentage of outstanding common stock increased to shares available for grant | 1.00% | |||||
| Number of shares available for issuance | 264,233 | 264,233 | ||||
| Series X Redeemable Convertible Preferred Stock [Member] | ||||||
| Stockholders Equity [Line Items] | ||||||
| Preferred stock shares vested | 558,862 |
Equity - Summary of Stock Optio
| Equity - Summary of Stock Option Activity (Detail) | 3 Months Ended |
| Mar. 31, 2016USD ($)$ / sharesshares | |
| 2004 Stock Option Plan [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of Shares Outstanding, Beginning Balance | shares | 10,917 |
| Number of Shares , Exercised | shares | 0 |
| Number of Shares, Expired | shares | 0 |
| Number of Shares Outstanding, Ending Balance | shares | 10,917 |
| Number of Shares, Options Exercisable | shares | 10,917 |
| Weighted-average years remaining on contractual life | 2 years 11 days |
| Weighted Average Exercise Price Per Share, Beginning Balance | $ / shares | $ 40.58 |
| Weighted Average Exercise Price Per Share, Exercised | $ / shares | 0 |
| Weighted Average Exercise Price Per Share, Expired | $ / shares | 0 |
| Weighted Average Exercise Price Per Share, Ending Balance | $ / shares | 40.58 |
| Weighted Average Exercise Price Per Share, Options Exercisable | $ / shares | $ 40.58 |
| Aggregate Intrinsic Value, Granted | $ | $ 0 |
| Aggregate Intrinsic Value, Exercised | $ | 0 |
| Aggregate Intrinsic Value, Expired | $ | 0 |
| Aggregate Intrinsic Value, Outstanding Ending Balance | $ | $ 0 |
| 2014 Stock Option and Incentive Plan [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of Shares Outstanding, Beginning Balance | shares | 1,620,760 |
| Number of Shares , Granted | shares | 796,500 |
| Number of Shares , Exercised | shares | 0 |
| Number of Shares , Cancelled | shares | (28,000) |
| Number of Shares Outstanding, Ending Balance | shares | 2,389,260 |
| Number of Shares, Options Exercisable | shares | 515,942 |
| Weighted-average years remaining on contractual life | 9 years 2 months 9 days |
| Unrecognized compensation cost related to non-vested stock options | $ | $ 8,200,000 |
| Weighted Average Exercise Price Per Share, Beginning Balance | $ / shares | $ 4.95 |
| Weighted Average Exercise Price Per Share, Granted | $ / shares | 7.80 |
| Weighted Average Exercise Price Per Share, Exercised | $ / shares | 0 |
| Weighted Average Exercise Price Per Share, Cancelled | $ / shares | 6.79 |
| Weighted Average Exercise Price Per Share, Ending Balance | $ / shares | 5.87 |
| Weighted Average Exercise Price Per Share, Options Exercisable | $ / shares | $ 4.52 |
| Aggregate Intrinsic Value, Outstanding Beginning Balance | $ | $ 10,339,000 |
| Aggregate Intrinsic Value, Granted | $ | 0 |
| Aggregate Intrinsic Value, Exercised | $ | 0 |
| Aggregate Intrinsic Value, Outstanding Ending Balance | $ | 4,164,000 |
| Aggregate Intrinsic Value, Options Exercisable | $ | $ 1,485,000 |
Commitments and Contingencies -
| Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | |
| May. 31, 2015 | Mar. 31, 2016 | Mar. 31, 2015 | |
| Operating Leased Assets [Line Items] | |||
| Commencement date of lease | 2015-09 | ||
| Acquisition of leasehold improvements | $ 445 | ||
| Operating leases, rent expenses | $ 15 | ||
| Leased Office Building [Member] | |||
| Operating Leased Assets [Line Items] | |||
| Operating leases, rent expenses | $ 62 | ||
Commitments and Contingencies38
| Commitments and Contingencies - Schedule of Aggregate Annual Commitments Pursuant to Office Lease and Lease Amendment (Detail) $ in Thousands | Mar. 31, 2016USD ($) |
| Commitments and Contingencies Disclosure [Abstract] | |
| 2,016 | $ 177 |
| 2,017 | 402 |
| 2,018 | 411 |
| 2,019 | 421 |
| 2,020 | 430 |
| Thereafter | 959 |
| Total | $ 2,800 |
Fair Value of Financial Measure
| Fair Value of Financial Measurements - Fair Value of Assets and Liabilities Measured on Recurring Basis (Detail) - Fair Value Measurements, Recurring [Member] - USD ($) $ in Thousands | Mar. 31, 2016 | Dec. 31, 2015 |
| Certificates of Deposit [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | $ 17,932 | $ 16,160 |
| Agency Bonds [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 5,502 | 10,031 |
| United States Treasury Securities [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 20,125 | 5,047 |
| Short-term Investments [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 43,559 | 31,238 |
| Level 1 [Member] | United States Treasury Securities [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 20,125 | 5,047 |
| Level 1 [Member] | Short-term Investments [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 20,125 | 5,047 |
| Level 2 [Member] | Certificates of Deposit [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 17,932 | 16,160 |
| Level 2 [Member] | Agency Bonds [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | 5,502 | 10,031 |
| Level 2 [Member] | Short-term Investments [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Short-term investments fair value disclosure | $ 23,434 | $ 26,191 |
Fair Value of Financial Measu40
| Fair Value of Financial Measurements - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended |
| Mar. 31, 2015 | Dec. 31, 2014 | |
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Derivative, Gain (Loss) on Derivative, Net | $ 1,997 | |
| Convertible Notes Redemption Rights Derivative [Member] | ||
| Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ||
| Fair value of embedded derivative | $ 480 | |
| Notes converted in to shares | 337,932 | |
| Derivative, Gain (Loss) on Derivative, Net | $ 480 |
Derivative Financial Instrume41
| Derivative Financial Instruments - Effect of Derivative Instrument Not Designated as Hedging Instruments on Statement of Operations (Detail) $ in Thousands | 3 Months Ended |
| Mar. 31, 2015USD ($) | |
| Change in Fair Value of 2020 Convertible Notes Derivative [Member] | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of gain or (loss) recognized in income on derivative financial instrument | $ 1,997 |
| Change in Fair Value of Convertible Bridge Notes Redemption Rights Derivative [Member] | |
| Derivative Instruments, Gain (Loss) [Line Items] | |
| Amount of gain or (loss) recognized in income on derivative financial instrument | $ 480 |
Subsequent Event - Additional I
| Subsequent Event - Additional Information (Detail) - Subsequent Event [Member] - Maximum [Member] | Apr. 30, 2016USD ($) |
| Subsequent Event [Line Items] | |
| Amount of stock transactions | $ 200,000,000 |
| Amount of common stock transactions | $ 50,000,000 |