Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2017 | Mar. 12, 2018 | Jun. 30, 2017 | |
Document And Entity Information [Abstract] | |||
Entity Registrant Name | Clearside Biomedical, Inc. | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2017 | ||
Document Fiscal Year Focus | 2,017 | ||
Document Fiscal Period Focus | FY | ||
Trading Symbol | CLSD | ||
Document Type | 10-K | ||
Entity Central Index Key | 1,539,029 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Filer Category | Accelerated Filer | ||
Entity Common Stock, Shares Outstanding | 31,913,113 | ||
Entity Public Float | $ 153,311,000 |
Balance Sheets
Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Current assets: | ||
Cash and cash equivalents | $ 9,224 | $ 34,824 |
Short-term investments | 28,416 | 48,807 |
Prepaid expenses | 1,445 | 396 |
Other current assets | 116 | 290 |
Total current assets | 39,201 | 84,317 |
Property and equipment, net | 885 | 94 |
Restricted cash | 360 | 360 |
Other assets | 47 | 42 |
Total assets | 40,493 | 84,813 |
Current liabilities: | ||
Accounts payable | 5,384 | 2,594 |
Accrued liabilities | 4,716 | 2,791 |
Current portion of long-term debt | 3,200 | |
Current portion of deferred rent | 199 | 3 |
Other current liabilities | 20 | 20 |
Total current liabilities | 13,519 | 5,408 |
Long-term debt | 4,809 | 7,586 |
Deferred rent | 610 | |
Deferred revenue | 140 | 160 |
Total liabilities | 19,078 | 13,154 |
Commitments and contingencies | ||
Stockholders’ equity: | ||
Preferred stock, $0.001 par value; 10,000,000 shares authorized and no shares issued at December 31, 2017 and 2016 | ||
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2017 and 2016; 25,354,651 and 24,573,033 shares issued and outstanding at December 31, 2017 and 2016, respectively | 25 | 25 |
Additional paid-in capital | 145,618 | 136,892 |
Accumulated deficit | (124,220) | (65,245) |
Accumulated other comprehensive loss | (8) | (13) |
Total stockholders’ equity | 21,415 | 71,659 |
Total liabilities and stockholders’ equity | $ 40,493 | $ 84,813 |
Balance Sheets (Parenthetical)
Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2017 | Dec. 31, 2016 |
Statement Of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 10,000,000 | 10,000,000 |
Preferred stock, shares issued | 0 | 0 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 100,000,000 | 100,000,000 |
Common stock, shares, issued | 25,354,651 | 24,573,033 |
Common stock, shares outstanding | 25,354,651 | 24,573,033 |
Statements of Operations and Co
Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Income Statement [Abstract] | |||
License and collaboration revenue | $ 345 | $ 520 | |
Operating expenses: | |||
Research and development | 49,053 | 19,455 | $ 10,762 |
General and administrative | 9,700 | 6,263 | 6,555 |
Total operating expenses | 58,753 | 25,718 | 17,317 |
Loss from operations | (58,408) | (25,198) | (17,317) |
Other expense | (567) | (684) | (322) |
Net loss | $ (58,975) | $ (25,882) | $ (17,639) |
Net loss per share of common stock — basic and diluted | $ (2.33) | $ (1.97) | $ (7.54) |
Weighted average shares outstanding — basic and diluted | 25,311,614 | 13,111,067 | 2,338,950 |
Net loss | $ (58,975) | $ (25,882) | $ (17,639) |
Unrealized gain (loss) on available-for-sale investments | 5 | (13) | |
Comprehensive loss | $ (58,970) | $ (25,895) | $ (17,639) |
Statement of Stockholders' Equi
Statement of Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | Redeemable Convertible Preferred Stock | Common Stock | Additional Paid-In-Capital | Additional Paid-In-CapitalRedeemable Convertible Preferred Stock | Accumulated Deficit | Accumulated Other Comprehensive Loss |
Beginning balance at Dec. 31, 2014 | $ (19,213) | $ 2 | $ 2,509 | $ (21,724) | |||
Beginning balance, shares at Dec. 31, 2014 | 1,816,467 | ||||||
Exercise of stock options | 14 | 14 | |||||
Exercise of stock options, shares | 50,980 | ||||||
Vesting of restricted stock, shares | 14,203 | ||||||
Issuance of common stock upon exercise of warrants | (1) | $ 1 | (2) | ||||
Issuance of common stock upon exercise of warrants, Shares | 777,612 | ||||||
Accretion of stock issuance costs | (525) | (525) | |||||
Share-based compensation expense | 705 | 705 | |||||
Net loss | (17,639) | (17,639) | |||||
Ending balance at Dec. 31, 2015 | (36,659) | $ 3 | 2,701 | (39,363) | |||
Ending balance, shares at Dec. 31, 2015 | 2,659,262 | ||||||
Exercise of stock options | 31 | 31 | |||||
Exercise of stock options, shares | 10,724 | ||||||
Vesting of restricted stock, shares | 6,485 | ||||||
Issuance of common stock upon exercise of warrants | 410 | 410 | |||||
Issuance of common stock upon exercise of warrants, Shares | 133,560 | ||||||
Issuance of common stock in initial public offering | 51,377 | $ 8 | 51,369 | ||||
Issuance of common stock in initial public offering, Shares | 8,148,843 | ||||||
Issuance of common stock in follow-on offering | 33,459 | $ 4 | 33,455 | ||||
Issuance of common stock in follow-on offering, Shares | 4,000,000 | ||||||
Conversion of preferred stock to common stock | 48,198 | $ 10 | 48,188 | ||||
Conversion of preferred stock to common stock, Shares | 9,614,159 | ||||||
Issuance of warrants to purchase common stock | 308 | 308 | |||||
Accretion of stock issuance costs | $ (884) | $ (884) | |||||
Share-based compensation expense | 1,314 | 1,314 | |||||
Net loss | (25,882) | (25,882) | |||||
Other comprehensive gain (loss) | (13) | $ (13) | |||||
Ending balance at Dec. 31, 2016 | 71,659 | $ 25 | 136,892 | (65,245) | (13) | ||
Ending balance, shares at Dec. 31, 2016 | 24,573,033 | ||||||
Issuance of common shares under employee stock purchase plan | 66 | 66 | |||||
Issuance of common shares under employee stock purchase plan, shares | 9,692 | ||||||
Exercise of stock options | 239 | 239 | |||||
Exercise of stock options, shares | 171,926 | ||||||
Issuance of common stock in follow-on offering | 5,057 | 5,057 | |||||
Issuance of common stock in follow-on offering, Shares | 600,000 | ||||||
Share-based compensation expense | 3,364 | 3,364 | |||||
Net loss | (58,975) | (58,975) | |||||
Other comprehensive gain (loss) | 5 | 5 | |||||
Ending balance at Dec. 31, 2017 | $ 21,415 | $ 25 | $ 145,618 | $ (124,220) | $ (8) | ||
Ending balance, shares at Dec. 31, 2017 | 25,354,651 |
Statements of Cash Flows
Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Operating activities | |||
Net loss | $ (58,975) | $ (25,882) | $ (17,639) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation | 182 | 65 | 60 |
Share-based compensation expense | 3,364 | 1,314 | 705 |
Non-cash interest expense | 211 | 283 | 104 |
Accretion of debt discount | 212 | 108 | 60 |
Change in fair value of warrant liability | 156 | 52 | |
Amortization and accretion on available-for-sale investments, net | (31) | (43) | |
Loss on sale of fixed assets | 15 | ||
Changes in operating assets and liabilities: | |||
Prepaid expenses and other current assets | (833) | (487) | (145) |
Other assets | (5) | 882 | 1,763 |
Accounts payable and accrued liabilities | 4,715 | 1,424 | 632 |
Deferred revenue | (20) | (520) | 500 |
Deferred rent | 97 | (9) | (9) |
Net cash used in operating activities | (51,083) | (22,709) | (13,902) |
Investing activities | |||
Purchase of available-for-sale investments | (48,116) | (54,485) | |
Maturities of available-for-sale-investments | 68,543 | 5,708 | |
Change in restricted cash | (360) | ||
Acquisition of property and equipment | (306) | (3) | (32) |
Proceeds from the sale of fixed assets | 4 | ||
Net cash provided by (used in) investing activities | 20,121 | (49,140) | (28) |
Financing activities | |||
Proceeds from follow-on offering, net of issuance costs | 5,057 | 33,456 | |
Proceeds from initial public offering, net of issuance costs | 51,376 | ||
Proceeds from exercise of stock options | 239 | 31 | 14 |
Proceeds from shares issued under employee stock purchase plan | 66 | ||
Proceeds from issuance of long-term debt | 7,857 | 5,976 | |
Principal payments made on long-term debt | (6,330) | ||
Net cash provided by financing activities | 5,362 | 86,390 | 25,944 |
Net (decrease) increase in cash and cash equivalents | (25,600) | 14,541 | 12,014 |
Cash and cash equivalents, beginning of period | 34,824 | 20,283 | 8,269 |
Cash and cash equivalents, end of period | 9,224 | 34,824 | 20,283 |
Supplemental disclosure | |||
Interest paid | 653 | 250 | 100 |
Tenant improvements paid by landlord | $ 637 | ||
Conversion of convertible preferred stock to common stock | 48,198 | ||
Reclassification of deferred initial public offering costs | 1,597 | ||
Issuance of warrants to purchase common stock | 308 | ||
Issuance of warrant to purchase Series B preferred stock | 164 | ||
Accretion of redeemable convertible preferred stock to redemption value | 884 | 525 | |
Unpaid initial public offering costs in accounts payable and accrued expenses | $ 507 | 410 | |
Series C Preferred Stock | |||
Financing activities | |||
Proceeds from the issuance of Preferred Stock, net of issuance costs | $ 19,954 |
The Company
The Company | 12 Months Ended |
Dec. 31, 2017 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
The Company | 1. The Company Clearside Biomedical, Inc. (the “Company”) is a late-stage clinical biopharmaceutical company developing first-in-class drug therapies to treat blinding diseases of the eye. The Company’s current product candidates focus on treatments for diseases affecting the retina and choroid, especially diseases associated with macular edema, and are injected into the suprachoroidal space (“SCS”) using its proprietary SCS Microinjector. Incorporated in the State of Delaware on May 26, 2011, the Company has its corporate headquarters in Alpharetta, Georgia. The Company’s activities since inception have primarily consisted of developing product and technology rights, raising capital and performing research and development activities. The Company has no current source of revenue to sustain present activities, and does not expect to generate meaningful 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 at a similar stage of development, including, among others, the need to obtain adequate additional financing, successful development efforts including regulatory approval of products, compliance with government regulations, successful commercialization of potential products, protection of proprietary technology and dependence on key individuals. Liquidity On June 1, 2016, the Company’s registration statement on Form S-1 relating to its initial public offering of its common stock (the “IPO”) was declared effective by the Securities and Exchange Commission (“SEC”). The IPO closed on June 7, 2016 and the Company sold 7,200,000 shares of common stock at a price to the public of $7.00 per share, for net proceeds of $45.3 million. On June 30, 2016, the underwriters of the IPO partially exercised their option to purchase additional shares, and on July 6, 2016, the Company sold 948,843 additional shares of common stock at a price to the public of $7.00 per share, for net proceeds of $6.1 million. The Company paid to the underwriters underwriting discounts and commissions of $4.0 million in connection with the IPO, including the underwriters’ exercise of their option to purchase additional shares. In addition, the Company incurred expenses of $1.6 million in connection with the IPO. Thus, the aggregate net offering proceeds to the Company, after deducting underwriting discounts and commissions and offering expenses, were $51.4 million. On December 9, 2016, the Company’s registration statement on Form S-1 relating to its follow-on public offering of its common stock was declared effective by the SEC. The follow-on public offering closed on December 14, 2016 and the Company sold 4,000,000 share of common stock at a price to the public of $9.00 per share, for net proceeds of $33.4 million. On December 30, 2016, the underwriters of the follow-on public offering exercised their option to purchase additional shares and on January 6, 2017, the Company sold 600,000 additional shares of common stock at a price to the public of $9.00 per share, for net proceeds of $5.1 million. The Company paid to the underwriters underwriting discounts and commissions of $2.5 million in connection with the follow-on public offering, including the underwriters’ exercise of their option to purchase additional shares, and incurred expenses of $0.4 million in connection with the follow-on public offering. On June 30, 2017, the Company entered into an at-the-market sales agreement with Cowen and Company LLC (“Cowen”), under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock having an aggregate offering price of up to $50.0 million through Cowen acting as its sales agent. As of the date of this report, the Company has not sold any shares of its common stock under the at-the-market facility. On March 12, 2018, the Company closed a follow-on public offering in which it sold 6,538,462 shares of common stock at a public offering price of $13.00 per share, resulting in net proceeds of $79.6 million after deducting underwriting discounts and commissions and estimated offering expenses. Prior to the IPO, the Company had funded its operations primarily through the sale of convertible preferred stock and the issuance of long-term debt, resulting in aggregate proceeds of approximately $53.9 million. Even with the completion of the IPO and the subsequent public offerings of common stock, the Company will continue to need to obtain additional financing to fund future operations, including completing the development and commercialization of its primary product candidates. The Company will need to expend substantial resources for research and development, including costs associated with the clinical testing of its product candidates. The Company will also need to obtain additional financing to conduct additional trials for the regulatory approval of its drug candidates if requested by regulatory bodies, and completing the development of any additional product candidates that might be acquired. 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 of the products, if the Company decides to commercialize the products on its own. Moreover, the Company’s fixed expenses such as rent and other contractual commitments are substantial and are expected to increase in the future. The Company had cash, cash equivalents and short-term investments of $37.6 million as of December 31, 2017. In the absence of product or other revenues, the amount, timing, nature or source of which cannot be predicted, the Company’s losses will continue as it conducts its research and development activities. Until the Company can generate sufficient revenue, the Company may finance future cash needs through public or private equity offerings, license agreements, debt financings, collaborations, strategic alliances and marketing or distribution arrangements. The Company has incurred losses and negative cash flows since inception and expects operating losses and negative cash flows to continue into the foreseeable future. However, the Company is able to control spending on development activities while proceeding with a new drug application and still advancing clinical trials for key drug candidates and the Company expects that the cash on hand as of the filing date, March 16, 2018, will be sufficient to fund its operations for at least the next 12 months from that date. |
Significant Accounting Policies
Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2017 | |
Accounting Policies [Abstract] | |
Significant Accounting Policies | 2. Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include the accounting for useful lives to calculate depreciation and amortization, clinical trial accruals, share-based compensation expense and income tax valuation allowance. Actual results could differ from these estimates. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment. Property and Equipment, Net Property and equipment is recorded at historical cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, or for leasehold improvement the lesser of the useful life or remaining lease term . Repairs and maintenance are expensed when incurred. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in the determination of net income. Debt Discount All debt discounts are recorded against the related debt obligation and are amortized using the effective interest rate method over the term of the underlying debt obligation and reflected in interest expense. Fair Value Measurements The Company records certain financial assets and liabilities at fair value in accordance with the provisions of Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures Income Taxes Deferred tax assets or liabilities are recorded for temporary differences between financial statement and tax basis of assets and liabilities, using enacted rates in effect for the year in which the differences are expected to reverse. A valuation allowance is recorded if it is more likely than not that a deferred tax asset will not be realized. The Company has provided a full valuation allowance on its deferred tax assets, which primarily consist of cumulative net operating losses of $28.0 million for the period from May 26, 2011 (inception) to December 31, 2017. Due to its history of operating losses since inception and losses expected to be incurred in the foreseeable future, a full valuation allowance was considered necessary. Reverse Stock Split On May 11, 2016, the Company effected a 1-for-2.2 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 the Company’s 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. The adjustment to the conversion ratio for the Series C convertible preferred stock also included an anti-dilution adjustment based on the initial public offering price of the Company’s common stock. Research and Development Costs Research and development costs are charged to expense as incurred and include: • employee-related expenses, including salaries, benefits, travel and share-based compensation expense for research and development personnel; • expenses incurred under agreements with contract research organizations, contract manufacturing organizations and consultants that conduct clinical and preclinical studies; • costs associated with nonclinical and development activities; • costs associated with technology and intellectual property licenses; • costs for the Company’s research and development facility; and • depreciation expense for assets used in research and development activities. 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, or 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 prepaid or accrued liabilities No material adjustments to these estimates have been recorded in these financial statements. Share-Based Compensation Compensation cost related to share-based awards granted to employees is measured based on the estimated fair value of the award at the grant date. The Company estimates the fair value of stock options using a Black-Scholes option pricing model. Compensation expense for options granted to non-employees is determined as the fair value of consideration received or the fair value of the equity instruments issued, whichever is more reliably measured. The fair value of awards granted to non-employees is re-measured each period until the related service is complete. Share-based compensation costs are expensed on a straight-line basis (net of estimated forfeitures) over the relevant vesting period. Compensation cost related to shares purchased through the Company’s employee stock purchase plan, which is considered compensatory, is based on the estimated fair value of the shares on the offering date, including consideration of the discount and the look back period. The Company estimates the fair value of the shares using a Black-Scholes option pricing model. Compensation expense is recognized over the six month withholding period prior to the purchase date. All share-based compensation costs are recorded in general and administrative or research and development costs in the statements of operations based upon the underlying employees’ roles within the Company. Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with an original term of three months or less at the date of purchase. Short-Term Investments Short-term investments are investments with original maturities of between 90 and 365 days when purchased and are comprised of certificates of deposit, commercial paper, corporate and government bonds and treasury bills. The Company classifies its short-term investments as available-for-sale securities. Short-term investments are recorded at fair value and unrealized gains and losses are recorded within accumulated other comprehensive loss until realized. In addition, the Company evaluates the short-investments with unrealized losses to determine whether such losses are other-than-temporary. Restricted Cash The Company is required to maintain a stand-by letter of credit as a security deposit for its facility lease in Alpharetta, Georgia. The Company’s bank requires the Company to maintain a restricted cash balance to serve as collateral for the letter of credit issued to the landlord by the bank. As of December 31, 2017, the restricted cash balance was invested in a commercial money market account. Concentration of Credit Risk Arising From Cash Deposits in Excess of Insured Limits The Company maintains its cash in bank deposits that at times may exceed federally insured limits. The Company has not experienced any loss in such accounts. The Company believes it is not exposed to any significant risks with respect to its cash balances. Recent Accounting Pronouncements Accounting Pronouncements Recently Adopted In August 2016, Financial Accounting Standards Board (“FASB”) Statement of Cash Flows Classification of Certain Cash Receipts and Cash Payments In November 2016, the FASB issued ASU 2016-18, Restricted Cash, Recent Accounting Pronouncements Not Yet Adopted In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers The Company plans to adopt the standard using the modified retrospective transition method. After evaluating its current and prior license agreements, as well as its other collaboration agreements, the Company does not expect that the adoption of ASU 2014-09 will not have a material impact on its financial statements and related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842), |
Property and Equipment, Net
Property and Equipment, Net | 12 Months Ended |
Dec. 31, 2017 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment, Net | 3. Property and Equipment, Net Property and equipment, net consisted of the following (dollar amounts in thousands): Estimated Useful Lives (Years) December31, 2017 2016 Furniture and fixtures 5 $ 303 $ 69 Machinery and equipment 5 121 121 Computer equipment 3 41 27 Leasehold improvements Lesser of useful life remaining lease term 667 45 Total property and equipment 1,132 262 Less: Accumulated depreciation (247 ) (168 ) Property and equipment, net $ 885 $ 94 |
Accrued Liabilities
Accrued Liabilities | 12 Months Ended |
Dec. 31, 2017 | |
Payables And Accruals [Abstract] | |
Accrued Liabilities | 4. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 2017 2016 Accrued research and development $ 3,360 $ 1,153 Accrued bonuses 920 870 Accrued professional fees 62 410 Accrued vacation 113 72 Accrued interest payable 58 52 Accrued expense 203 234 $ 4,716 $ 2,791 |
Long-Term Debt
Long-Term Debt | 12 Months Ended |
Dec. 31, 2017 | |
Debt Disclosure [Abstract] | |
Long-Term Debt | 5. Long-Term Debt Loan and Security Agreements In April 2015, the Company entered into a loan agreement (the “original loan agreement”) with Silicon Valley Bank (“SVB”) for borrowings up to $6.0 million, with a floating interest rate equal to the Wall Street Journal’s prime rate minus 0.50%. Under the terms of the original loan agreement, an initial tranche of $4.0 million was advanced on April 15, 2015 and an additional tranche of $2.0 million was advanced on May 15, 2015. The Company was required to pay accrued interest only for a period of 12 months from the date of each advance, followed by 30 equal monthly payments of principal and accrued interest. A final payment of $0.3 million, or 5.50% of the aggregate borrowed amount, was due at maturity of the loan in 2018 and was being accreted in long-term debt over the life of the loan. Closing costs of $24,000 were recorded against the long-term debt liability and were also being accreted over the life of the loan. In September 2016, the Company entered into an amended and restated loan and security agreement, which was subsequently amended on October 31, 2017 (as amended, the “loan agreement”) with SVB, MidCap Funding XII Trust and MidCap Financial Trust (together, “MidCap” and collectively with SVB, the “Lenders”), which amended and restated in its entirety the Company’s original loan agreement. The loan agreement provides for new term loans of up to $15.0 million, with a floating interest rate equal to 7% plus the greater of (i) the 30-day U.S. LIBOR, reported in the Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue, or (ii) 0.50%. Under the terms of the loan agreement, an initial tranche of $8.0 million was advanced on September 28, 2016. The Company may draw the remaining $7.0 million through March 31, 2018. The Company was required to pay accrued interest only through December 31, 2017 on the outstanding amount, followed by 30 equal payments of principal and accrued interest. The Company has the option to prepay the outstanding balance of the term loans in full, subject to a prepayment fee of 2% of the original principal amount of the aggregate term loans for any prepayment through May 31, 2020. A final payment of $0.5 million, or 6.50% of the aggregate borrowed amount, is due at maturity of the loan on June 1, 2020, or upon the prepayment of the facility or the acceleration of amounts due under the facility as a result of an event of default, and is being accreted in long-term debt over the life of the loan. Of the initial $8.0 million advanced on September 28, 2016, $5.3 million was used to repay all amounts outstanding under the original loan agreement. Closing costs incurred in the refinancing portion of the loan were recorded as expense while the financing costs for the new portion of the loan are recorded in long-term debt and being accreted over the life of the loan. Upon repayment of the original loan agreement, all remaining closing costs associated with the original loan agreement are being accreted to long-term debt over the life of the new loan. The term loans under the loan agreement are secured by substantially all of the Company’s assets, except that the collateral does not include any of the Company’s intellectual property. However, pursuant to the terms of a negative pledge arrangement, the Company has agreed not to encumber any of its intellectual property. Interest expense on the borrowings under the original loan agreement and the loan agreement was $653,000, $287,000 and $115,000 for the years ended December 31, 2017, 2016 and 2015, respectively. Accretion of the scheduled final payment under the original loan agreement and the loan agreement was $211,000, $283,000 and $101,000 for the years ended December 31, 2017, 2016 and 2015, respectively. Accretion of the deferred closing costs under the original loan agreement and the loan agreement was $62,000, $17,000 and $7,400 for the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, the scheduled payments for the loan agreement, including the scheduled final payment in 2020, were as follows (in thousands): Year Ending December 31, Principal Interest and Final Total 2018 $ 3,200 $ 476 $ 3,676 2019 3,200 234 3,434 2020 1,600 545 2,145 $ 8,000 $ 1,255 $ 9,255 |
Convertible Shareholder Notes P
Convertible Shareholder Notes Payable | 12 Months Ended |
Dec. 31, 2017 | |
Equity [Abstract] | |
Convertible Shareholder Notes Payable | 6. Convertible Shareholder Notes Payable In April 2014, the Company authorized the sale of convertible promissory notes (the “Bridge Notes”) to its existing stockholders, including two of its executive officers and one of its directors in their individual capacities, in the aggregate principal amount of $6.0 million. In April 2014, the Company issued $3.0 million in aggregate principal amount of Bridge Notes. The outstanding notes accrued interest at a rate of 7%, with principal plus interest due upon maturity in April 2015, unless earlier converted. The Bridge Notes were convertible upon the occurrence of a qualified financing which occurred in August 2014, and accordingly the principal and interest under all of the Bridge Notes was converted automatically into an aggregate of 1,137,652 shares of Series B convertible preferred stock in connection with the financing. In connection with the issuance of the Bridge Notes, the Company also issued warrants to the lenders to purchase an aggregate of 112,802 shares of common stock at an exercise price of $0.02 per share. These warrants, which would have otherwise expired upon the closing of the IPO, were automatically net exercised for an aggregate of 112,441 shares of common stock upon the closing of the IPO. |
Convertible Preferred Stock
Convertible Preferred Stock | 12 Months Ended |
Dec. 31, 2017 | |
Temporary Equity Disclosure [Abstract] | |
Convertible Preferred Stock | 7. Convertible Preferred Stock As of December 31, 2015, the Company had authorized an aggregate of 20,913,331 shares of Series A, A-1, B and C convertible preferred stock, par value $0.001 per share. Upon the closing of the Company’s IPO, all 20,839,633 shares of the Company’s convertible preferred stock that were issued and outstanding on that date were automatically converted into an aggregate of 9,614,159 shares of its common stock. The following table summarizes the activity of convertible preferred stock (in thousands, except per share amounts): Total Series A Series A-1 Series B Series C Convertible Preferred Stock Preferred Stock Preferred Stock Preferred Stock Preferred Shares Amount Shares Amount Shares Amount Shares Amount Stock Balance at January 1, 2016 5,198,826 $ 4,086 4,356,931 $ 7,900 6,009,202 $ 15,372 5,274,674 $ 19,956 $ 47,314 Accretion of redeemable convertible preferred stock to redemption value — — — — — 840 — 44 884 Conversion of preferred stock to common stock at closing of IPO (5,198,826 ) (4,086 ) (4,356,931 ) (7,900 ) (6,009,202 ) (16,212 ) (5,274,674 ) (20,000 ) (48,198 ) Balance at December 31, 2016 — $ — — $ — — $ — — $ — $ — As of December 31, 2017 and 2016, there were 10,000,000 shares of preferred stock authorized, none of which were issued and outstanding. |
Common Stock
Common Stock | 12 Months Ended |
Dec. 31, 2017 | |
Equity [Abstract] | |
Common Stock | 8. Common Stock The Company’s amended and restated certificate of incorporation authorizes the Company to issue 100,000,000 shares of $0.001 par value common stock. As of December 31, 2017 and 2016, there were 25,354,651 and 24,573,033 shares of common stock outstanding, respectively. |
Stock Purchase Warrants
Stock Purchase Warrants | 12 Months Ended |
Dec. 31, 2017 | |
Stock Purchase Warrants [Abstract] | |
Stock Purchase Warrants | 9. Stock Purchase Warrants Preferred Stock Warrants During 2013, in connection with a loan agreement, the Company issued a warrant to the lender to purchase up to 16,550 shares of Series A-1 preferred stock at a price per share of $1.8132. The term of the warrant extended until 10 years from the grant date and the warrant was exercisable at any time during that 10-year period. This warrant was outstanding at December 31, 2015 and had a weighted average remaining life of 6.8 years and a fair value of $58,000. The warrant was automatically converted to a common stock warrant and was net exercised on June 6, 2016, in connection with the IPO, resulting in the issuance of 3,236 shares of common stock. In April 2015, in connection with the original loan agreement, the Company issued a warrant to the lenders to purchase up to 57,143 shares of Series B preferred stock at a price per share of $3.50. The term of the warrant extends until 10 years from the grant date and the warrant is exercisable at any time during that 10-year period. The warrant was automatically converted into a warrant to purchase 25,974 shares of common stock at an exercise price of $7.70 upon the closing of the IPO. This warrant was outstanding at December 31, 2015 and had a weighted average remaining life of 9.25 years and a fair value of $0.2 million. This warrant was net exercised on October 12, 2016, resulting in the issuance of 17,883 shares of common stock. Common Stock Warrants During 2014, in connection with the sale of convertible promissory notes in connection with a preferred stock financing, the Company issued warrants to the lenders to purchase up to an aggregate of 112,802 shares of common stock at a price per share of $0.02. These warrants were outstanding at December 31, 2015 and had a remaining life of 8.2 years. These warrants, which would have otherwise expired upon the closing of the IPO, were automatically net exercised for an aggregate of 112,441 shares of common stock upon the closing of the IPO. In September 2016, in connection with the loan agreement, the Company issued warrants to the Lenders to purchase up to 29,796 shares of common stock at a price per share of $10.74. The warrants expire in September 2026, or earlier upon the occurrence of specified mergers or acquisitions of the Company, and are immediately exercisable . |
Share-Based Compensation
Share-Based Compensation | 12 Months Ended |
Dec. 31, 2017 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Share-Based Compensation | 10. Share-Based Compensation Stock Options In January 2016, the Company’s board of directors adopted and approved the Clearside Biomedical, Inc. 2016 Equity Incentive Plan (the “2016 Plan”) which became effective on June 1, 2016. The 2016 Plan provides for the grant of share-based awards to employees, directors and consultants of the Company. The Company reserved 1,818,182 shares of common stock for issuance under the 2016 Plan. The 2016 Plan provides for the grant of incentive stock options to employees, and for the grant of nonqualified stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, performance stock awards and other forms of stock compensation to the Company’s employees, directors, and non-employee third parties. The number of shares of common stock reserved for issuance under the 2016 Plan will automatically increase on January 1 each year, for a period of ten years, from January 1, 2017 through January 1, 2026, by 4% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Company’s board of directors. At December 31, 2017, under the 2016 Plan, options to purchase 2,044,400 shares of the Company’s common stock were outstanding at a weighted average price of $7.98 per share and 751,078 shares remained available for future grant. As of January 1, 2018, the number of shares of common stock that may be issued under the 2016 Plan was automatically increased by 1,014,186 shares, representing 4% of the total number of shares of common stock outstanding on December 31, 2017, increasing the number of shares of common stock available for issuance under the 2016 Plan as of that date to 1,765,264 shares. As a result of the adoption of the 2016 Plan, no further grants may be made under the Company’s 2011 Stock Incentive Plan (the “2011 Plan”). The 2011 Plan provided for the grant of share-based awards to employees, directors and consultants of the Company. At December 31, 2017, options to purchase 1,013,713 shares of the Company’s common stock were outstanding under the 2011 Plan at a weighted average exercise price of $2.47 per share. The Company has granted stock option awards to employees, directors and consultants. The total share-based compensation expense recognized is reflected in the statements of operations as follows (in thousands): Year Ended December 31, 2017 2016 2015 Research and development $ 1,348 $ 539 $ 327 General and administrative 1,988 775 378 Total $ 3,336 $ 1,314 $ 705 Share-based compensation is accounted for in accordance with the provisions of ASC 718, Compensation-Stock Compensation The following table sets forth the weighted average assumptions utilized in the fair value calculation for the underlying common stock for the years ended December 31, 2017, 2016 and 2015. Year Ended December 31, 2017 2016 2015 Expected term (years) 7.00 7.00 7.00 Expected stock price volatility 96.85 % 97.45 % 86.63 % Risk-free interest rate 2.20 % 2.20 % 2.09 % Expected dividend yield 0.00 % 0.00 % 0.00 % Expected term (in years): The Company utilized the guidance set forth in ASC 718 to determine the expected term of options. The Company utilized the simplified method as prescribed by ASC 718, as the Company does not have sufficient historical exercise and post-vesting termination data to provide a reasonable basis upon which to estimate the expected term of stock options granted to employees. Risk-free interest rate : The risk-free interest rate is based on the yields of U.S. Treasury securities with maturities similar to the expected time to a possible liquidity event. Expected dividend yield : The Company has not paid and does not anticipate paying any dividends in the foreseeable future. Expected stock price volatility : The volatility assumption is based on the historical volatilities of the stock of several public entities that are similar to the Company, as the Company does not have sufficient historical transactions in its own shares on which to base expected volatility. A similar peer group of companies was utilized for 2017 and 2016. Forfeitures: As of January 1, 2017, upon adopting ASU 2016-09, the Company began recording forfeitures as they occurred. In prior years, the Company had estimated its forfeiture rate to be zero for the periods presented and any expense true-ups for terminated employees have been immaterial. The following table summarizes the activity related to stock options during the year ended December 31, 2017: Weighted Number of Average Shares Exercise Price Options outstanding at January 1, 2017 2,243,575 $ 5.78 Granted 1,127,950 6.45 Exercised (171,926 ) 1.37 Cancelled/Forfeited (124,250 ) 8.40 Options outstanding at December 31, 2017 3,075,349 6.17 Options exercisable at December 31, 2016 789,120 1.55 Options exercisable at December 31, 2017 1,114,286 3.94 The following table provides additional information about the Company’s stock options that were outstanding and exercisable at December 31, 2017 (aggregate intrinsic values in thousands): Weighted Weighted Weighted Average Weighted Average Average Aggregate Remaining Average Aggregate Remaining Exercise Options Exercise Intrinsic Contractual Options Exercise Intrinsic Contractual Price Outstanding Price Value Life (Years) Exercisable Price Value Life (Years) $0.02 - $0.40 465,265 5.4 465,265 5.4 $3.08 - $5.89 1,385,871 8.9 356,632 7.2 $6.16 - $8.90 1,105,921 8.9 264,161 8.2 $9.11 - $20.84 118,292 9.0 28,228 8.9 3,075,349 $ 6.17 $ 5,598 8.4 1,114,286 $ 3.94 $ 4,180 6.7 As of December 31, 2017, the Company had $11.6 million of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted average period of 3.1 years. The weighted-average fair values of all stock options granted for the years ended December 31, 2017, 2016 and 2015 was $5.25 per share, $7.89 per share and $5.72 per share, respectively. The intrinsic value is calculated as the difference between the fair market value and the exercise price per share of the stock options. The fair market value per share of common stock as of December 29, 2017 was $7.00, which was the closing sale price of the Company’s common stock on the Nasdaq Global Market on that date. Employee Stock Purchase Plan In January 2016, the Company’s board of directors adopted and approved the Clearside Biomedical, Inc. 2016 Employee Stock Purchase Plan (the “2016 ESPP”) which became effective on June 1, 2016. The 2016 ESPP permits employees to purchase shares of the Company’s common stock through payroll deductions up to 15% of their earnings. The Company reserved 181,818 shares of common stock for issuance under the 2016 ESPP. Additionally, the number of shares reserved for issuance under the 2016 ESPP will automatically increase for a period of ten years, from January 1, 2017 through January 1, 2026, by the lesser of (i) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (ii) 454,545 shares of common stock or (iii) a lesser number of shares as may be determined by the Company’s board of directors. As of January 1, 2018, the number of shares of common stock that may be issued under the 2016 ESPP was automatically increased by 253,546 shares, representing 1% of the total number of shares of common stock outstanding on December 31, 2017, increasing the number of shares of common stock available for issuance under the 2016 ESPP as of that date to 671,402 shares. The first offering period for the 2016 ESPP commenced on January 1, 2017. The 2016 ESPP is considered a compensatory plan and the fair value of the discount and the look-back period are estimated using the Black-Scholes option pricing model and expense is recognized over the six month withholding period prior to the purchase date. During the year ended December 31, 2017, the Company issued 9,692 shares of common stock purchased under the 2016 ESPP, and $21,000 and $7,000 of share-based compensation expense was recorded in general and administration expense and research and development expense, respectively. |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2017 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 11. Income Taxes No provision for U.S. federal or state income taxes has been recorded as the Company has incurred net operating losses since inception. Significant components of the Company’s net deferred income tax assets consist of the following (in thousands): December 31, 2017 2016 2015 Deferred tax asset (liability) Net operating loss carryforwards $ 27,999 $ 23,391 $ 14,119 Non-deductible accrued expenses 248 358 230 Deferred rent 49 1 4 Deferred revenue 38 69 77 Stock compensation expense 387 101 88 Depreciation differences (18 ) (13 ) (28 ) Federal tax credits 3,437 1,232 850 State tax credits 524 301 262 Charitable contributions 6 6 3 Valuation allowance (32,670 ) (25,446 ) (15,605 ) Net deferred tax asset $ — $ — $ — A reconciliation of the statutory tax rates and the effective tax rates is as follows: Year Ended December 31, 2017 2016 2015 U.S. federal tax rate 34.00 % 34.00 % 34.00 % State tax rate 2.42 3.79 4.54 Permanent difference and other (2.84 ) (1.98 ) (1.26 ) Tax credit 3.97 1.62 2.66 Valuation allowance (12.42 ) (37.43 ) (39.94 ) Impact of federal rate change (25.13 ) — — 0.00 % 0.00 % 0.00 % In December 2017, the 2017 Tax Cuts and Jobs Act (the “2017 Tax Act”) was signed into law. The 2017 Tax Act significantly revises the U.S. corporate income tax by, among other things, lowering the statutory corporate tax rate from 34% to 21%, eliminating certain deductions, imposing a mandatory one-time tax on accumulated earnings of foreign subsidiaries, introducing new tax regimes, and changing how foreign earnings are subject to U.S. tax. The 2017 Tax Act also enhanced and extended through 2026 the option to claim accelerated depreciation deductions on qualified property. The Company has not completed its determination of the accounting implications of the 2017 Tax Act on its tax accruals. However, the Company has reasonably estimated the effects of the 2017 Tax Act and recorded provisional amounts in its financial statements as of December 31, 2017. The Company recorded a provisional tax expense of the impact of the 2017 Tax Act of approximately $14.9 million. This amount is primarily comprised of the re-measurement of federal deferred tax liabilities resulting from the permanent reduction in the U.S. statutory corporate tax rate to 21% from 34%. As the Company completes its analysis of the 2017 Tax Act, collects and prepares necessary data, and interprets any additional guidance issued by the U.S. Treasury Department, the IRS, and other standard-setting bodies, the Company may make adjustments to the provisional amounts. Those adjustments may materially impact the Company’s provision for income taxes in the period in which the adjustments are made. Based on the Company’s history of net operating losses, any benefit that is being or will be derived from the 2017 Tax Act will be offset by a full valuation allowance, as discussed further below. Realization of the future tax benefits is dependent on the Company’s ability to generate sufficient taxable income within the carryforward period. Due to the Company’s history of operating losses, the deferred tax assets arising from the aforementioned future tax benefits are currently not likely to be realized and, accordingly, are offset by a full valuation allowance. The income tax provision varies from the expected provision determined by applying the federal statutory income tax rate to income (loss). The difference in the expected provision, as determined by applying the federal statutory income tax rate to income (loss) is primarily due to the increase in the deferred income tax valuation allowance of $7.2 million, $9.8 million and $7.0 million for the years ended December 31, 2017, 2016 and 2015, respectively, and in 2017, the impact of the federal rate change because of the 2017 Tax Act. As of December 31, 2017, the Company had net deferred tax assets primarily related to net operating loss carryforwards of $28.0 million, which expire through 2037. Utilization of the net operating loss carryforwards and credits may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. The effect of an ownership change could be an imposition of an annual limitation on the use of net operating loss carryforwards attributable to periods before the change. The U.S. federal statute of limitations remains open for the periods from inception and forward. The Company has not been the subject of examination by the taxing authorities. The Company has no uncertain tax positions. |
Commitment and Contingencies
Commitment and Contingencies | 12 Months Ended |
Dec. 31, 2017 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 12. Commitments and Contingencies Lease Commitment Summary The Company had previously leased office space under non-cancelable operating leases which expired in March 2017. In November 2016, the Company signed a new office lease agreement to lease approximately 20,000 square feet of office space in Alpharetta, Georgia for its corporate headquarters. The lease agreement is for a six and one-half year term with a renewal option for one additional five-year term. Rental payments are $35,145 per month subject to an increase of 3% per year. Rent expense under this lease is recognized on a straight-line basis over the term of the lease. In addition, the lease agreement requires payment of the pro-rata share of the annual operating expenses associated with the premises. The Company relocated to this new space in March 2017. Minimum lease payments were as follows at December 31, 2017 (in thousands): Year ending December 31, 2018 $ 431 2019 444 2020 458 2021 472 2022 487 Thereafter 373 Total minimum lease payments $ 2,665 Rent expense was $214,000, $81,000 and $150,000 for the years ended December 31, 2017, 2016 and 2015, respectively. Contract Service Providers In the course of the Company’s normal business operations, it has agreements with contract service providers to assist in the performance of its research and development, clinical research and manufacturing. Substantially all of these contracts are on an as needed basis. |
License and Collaboration Agree
License and Collaboration Agreements | 12 Months Ended |
Dec. 31, 2017 | |
License And Collaboration Agreements [Abstract] | |
License and Collaboration Agreements | 13. License and Collaboration Agreements In August 2014, the Company entered into a royalty-bearing license agreement with NovaMedica LLC (“NovaMedica”). Under this agreement, the Company granted to NovaMedica the right to use the Company’s intellectual property to develop and commercialize the intended products (the “Covered Products”) and to have the exclusive right to sell those products in Russia and specified adjacent territories involving the use of the corticosteroid triamcinolone acetonide as the sole active pharmaceutical ingredient for administration in the SCS. In connection with this royalty-bearing license, NovaMedica made an upfront payment to the Company of $200,000. The Company is currently developing product candidates that when completed would be subject to this license giving NovaMedica the exclusive right to then sell the products in the specified geographic territories. In mid-December 2015, the Company received positive results from the Phase 2 clinical trial relating to the product candidate and determined, based on these results, that the intellectual property could become commercially feasible. Beginning in the first quarter ended March 31, 2016, the Company began recognizing the $200,000 to revenue over the period of time to complete clinical development and commercialization of the Covered Products and the beginning of the first set of patent expirations in 2027. The Company recorded $20,000 of license revenue during each of the years ended December 31, 2017 and 2016 for this license agreement. NovaMedica is jointly owned by Rusnano MedInvest LLC (“Rusnano MedInvest”) and Domain Russia Investments Limited. RMI Investments, which beneficially owned approximately 6% of the Company’s voting securities as of December 31, 2017, is a wholly owned subsidiary of Rusnano MedInvest. In April 2015, the Company entered into a license and collaboration agreement (the “Spark Agreement”) with Spark Therapeutics, Inc. (“Spark”) under which Spark could acquire the exclusive rights to license the Company’s microinjector technology and access to the SCS within the eye for development and ultimate commercialization of Spark’s gene therapy treatments to be delivered via the microinjector. In conjunction with executing the Spark Agreement, Spark made an upfront, non-refundable payment to the Company of $500,000. In February 2016, the initial study was completed and Spark elected not to extend the arrangement nor license the technology which terminated the Spark Agreement in accordance with the agreement terms. During the quarter ended March 31, 2016, the Company recorded as revenue the $500,000 upfront payment as the amount was non-refundable and the Company had no further obligations under the Spark Agreement. The Company has periodically entered into other short-term collaboration agreements to evaluate the potential use of its proprietary SCS microinjector with third-party product candidates for the treatment of various diseases. Funds received from these collaboration agreements are recognized as revenue over the term of the agreement. The Company recorded $325,000 of revenue from these collaboration agreements during the year ended December 31, 2017. |
Available-for-Sale Investments
Available-for-Sale Investments | 12 Months Ended |
Dec. 31, 2017 | |
Investments Debt And Equity Securities [Abstract] | |
Available-for-Sale Investments | 14. Available-for-Sale Investments The following table summarizes the Company’s available-for-sale investments as of December 31, 2017 (in thousands): December 31, 2017 Amortized Unrealized Fair Cost Loss Value Government bonds and agency obligations $ 11,241 $ (3 ) $ 11,238 Commercial paper 10,154 — 10,154 Corporate bonds 5,069 (5 ) 5,064 Certificates of deposit 1,960 — 1,960 Total available-for-sale investments $ 28,424 $ (8 ) $ 28,416 |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2017 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 15. Fair Value Measurements The Company records certain financial assets and liabilities at fair value in accordance with the provisions of ASC Topic 820, Fair Value Measurements and Disclosures • Level 1—Unadjusted quoted prices in active, accessible markets for identical assets or liabilities. • Level 2—Other inputs that are directly or indirectly observable in the marketplace. • Level 3—Unobservable inputs that are supported by little or no market activity. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The Company’s material financial instruments at December 31, 2017 and 2016 consisted primarily of cash and cash equivalents, short-term investments and long-term debt and stock purchase warrant liabilities. The fair value of cash and cash equivalents, government bonds, other current assets and accounts payable approximate their respective carrying values due to the short term nature of these instruments and are classified as Level 1 in the fair hierarchy. The fair value of long-term debt approximates the carrying value due to variable interest rates that correspond to market rates. The Company has determined its short-term investments, comprised of certificates of deposit, corporate bonds, commercial paper, treasury bills and agency obligations, to be Level 2 in the fair value hierarchy. The fair value was determined using a market approach, based on prices and other relevant information generated by market transactions involving similar assets. The short-term investments consist of investments with original maturity dates from date of acquisition of 90 to 365 days and are classified as available-for-sale. The Company has determined its stock purchase warrants liability to be Level 3 in the fair value hierarchy. There were no significant transfers between Levels 1, 2 and 3 during the years ended December 31, 2017 and 2016. The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy (in thousands): December 31, 2017 Level 1 Level 2 Level 3 Recorded Value Financial Assets: Cash and money markets $ 9,224 $ — $ — $ 9,224 Restricted cash money market 360 — — 360 Government bonds and treasury bills 11,238 — — 11,238 Certificates of deposit — 1,960 — 1,960 Corporate bonds — 5,064 — 5,064 Commercial paper — 10,154 — 10,154 Total financial assets $ 20,822 $ 17,178 $ — $ 38,000 December 31, 2016 Level 1 Level 2 Level 3 Recorded Value Financial Assets: Cash and money markets $ 29,928 $ — $ — $ 29,928 Restricted cash money market 360 — — 360 Government bonds 19,027 — — 19,027 Certificates of deposit — 6,579 — 6,579 Agency obligations — 4,179 — 4,179 Corporate bonds — 7,262 — 7,262 Commercial paper — 16,656 — 16,656 Total financial assets $ 49,315 $ 34,676 $ — $ 83,991 Prior to the IPO, the Company estimated the fair value of its warrants to purchase preferred stock using an option pricing model that included three valuation scenarios, a non-IPO scenario and two IPO scenarios. Under the IPO scenarios, the Company calculated the value of the warrant based on a call option of the common share at IPO (assuming the underlying preferred stock would convert to common stock) given the time to exit and the term of the warrants stipulated in the contract. The Company then applied a discount for lack of marketability. Subsequent to the IPO, the Company used the Black-Scholes option pricing model to estimate the fair value of the remaining warrants. The estimates in the Black-Scholes option pricing model are based, in part, on assumptions related to the volatility of comparable public companies, the expected life of the warrants, the risk-free interest rate and the fair value of the underlying warrants. Changes in the fair value of the stock purchase warrants were recorded in other expense, net in the statements of operations. The following table summarizes the changes in fair value of the Level 3 liability, stock purchase warrants (in thousands): Level 3 Liabilities Year Ended December 2016 Stock purchase warrants Balance at beginning of period $ 258 Issuance of stock purchase warrants — Exercise of stock purchase warrants (414 ) Net increase in fair value remeasurement 156 Balance at end of period $ — |
Net Loss per Share
Net Loss per Share | 12 Months Ended |
Dec. 31, 2017 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 16. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration of the dilutive effect of potential common stock equivalents. Diluted net loss per share gives effect to all dilutive potential shares of common stock outstanding during this period. For all periods presented, the Company’s potential common stock equivalents, which included convertible preferred stock, stock options, unvested restricted stock and stock purchase warrants, have been excluded from the computation of diluted net loss per share as their inclusion would have the effect of reducing the net loss per share. Therefore, the denominator used to calculate both basic and diluted net loss per share is the same in all periods presented. The Company’s potential common stock equivalents that have been excluded from the computation of diluted net loss per share for all periods presented because of their antidilutive effect consisted of the following: Year Ended December 31, 2017 2016 2015 Convertible preferred stock — — 9,472,530 Outstanding stock options 3,075,349 2,243,575 1,261,637 Unvested restricted stock — — 6,485 Stock purchase warrants 29,796 29,796 146,298 3,105,145 2,273,371 10,886,950 |
Quarterly Financial Information
Quarterly Financial Information (Unaudited) | 12 Months Ended |
Dec. 31, 2017 | |
Quarterly Financial Data [Abstract] | |
Quarterly Financial Information (Unaudited) | 17. Quarterly Financial Information (unaudited) Summarized quarterly financial information for each of the years ended December 31, 2017 and 2016 are as follows (in thousands except per share data): Quarter Ended March 31, 2017 June 30, 2017 September 30, 2017 December 31, 2017 Operating expenses $ (10,261 ) $ (13,768 ) $ (18,348 ) $ (16,376 ) Net loss $ (10,373 ) $ (13,773 ) $ (18,336 ) $ (16,493 ) Net loss per share of common stock — basic and diluted $ (0.41 ) $ (0.54 ) $ (0.72 ) $ (0.65 ) Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Operating expenses $ (5,862 ) $ (5,183 ) $ (5,311 ) $ (9,362 ) Net loss $ (5,449 ) $ (5,102 ) $ (5,645 ) $ (9,686 ) Net loss per share of common stock — basic and diluted $ (2.05 ) $ (0.62 ) $ (0.28 ) $ (0.45 ) |
Subsequent Events
Subsequent Events | 12 Months Ended |
Dec. 31, 2017 | |
Subsequent Events [Abstract] | |
Subsequent Events | 18. Subsequent Events On March 12, 2018, the Company closed a follow-on public offering in which it sold 6,538,462 shares of common stock at a public offering price of $13.00 per share, resulting in net proceeds of $79.6 million after deducting underwriting discounts and commissions and estimated offering expenses. The Company has granted the underwriters of the offering an option, exercisable through April 6, 2018, to purchase up to an additional 980,769 shares of common stock at the public offering price. |
Significant Accounting Polici25
Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2017 | |
Accounting Policies [Abstract] | |
Basis of Presentation | Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include the accounting for useful lives to calculate depreciation and amortization, clinical trial accruals, share-based compensation expense and income tax valuation allowance. Actual results could differ from these estimates. |
Segment Information | Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating segment. |
Property and Equipment, Net | Property and Equipment, Net Property and equipment is recorded at historical cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, or for leasehold improvement the lesser of the useful life or remaining lease term . Repairs and maintenance are expensed when incurred. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in the determination of net income. |
Debt Discount | Debt Discount All debt discounts are recorded against the related debt obligation and are amortized using the effective interest rate method over the term of the underlying debt obligation and reflected in interest expense. |
Fair Value Measurements | Fair Value Measurements The Company records certain financial assets and liabilities at fair value in accordance with the provisions of Accounting Standards Codification (“ASC”) Topic 820, Fair Value Measurements and Disclosures |
Income Taxes | Income Taxes Deferred tax assets or liabilities are recorded for temporary differences between financial statement and tax basis of assets and liabilities, using enacted rates in effect for the year in which the differences are expected to reverse. A valuation allowance is recorded if it is more likely than not that a deferred tax asset will not be realized. The Company has provided a full valuation allowance on its deferred tax assets, which primarily consist of cumulative net operating losses of $28.0 million for the period from May 26, 2011 (inception) to December 31, 2017. Due to its history of operating losses since inception and losses expected to be incurred in the foreseeable future, a full valuation allowance was considered necessary. |
Reverse Stock Split | Reverse Stock Split On May 11, 2016, the Company effected a 1-for-2.2 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 the Company’s 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. The adjustment to the conversion ratio for the Series C convertible preferred stock also included an anti-dilution adjustment based on the initial public offering price of the Company’s common stock. |
Research and Development Costs | Research and Development Costs Research and development costs are charged to expense as incurred and include: • employee-related expenses, including salaries, benefits, travel and share-based compensation expense for research and development personnel; • expenses incurred under agreements with contract research organizations, contract manufacturing organizations and consultants that conduct clinical and preclinical studies; • costs associated with nonclinical and development activities; • costs associated with technology and intellectual property licenses; • costs for the Company’s research and development facility; and • depreciation expense for assets used in research and development activities. 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, or 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 prepaid or accrued liabilities No material adjustments to these estimates have been recorded in these financial statements. |
Share-Based Compensation | Share-Based Compensation Compensation cost related to share-based awards granted to employees is measured based on the estimated fair value of the award at the grant date. The Company estimates the fair value of stock options using a Black-Scholes option pricing model. Compensation expense for options granted to non-employees is determined as the fair value of consideration received or the fair value of the equity instruments issued, whichever is more reliably measured. The fair value of awards granted to non-employees is re-measured each period until the related service is complete. Share-based compensation costs are expensed on a straight-line basis (net of estimated forfeitures) over the relevant vesting period. Compensation cost related to shares purchased through the Company’s employee stock purchase plan, which is considered compensatory, is based on the estimated fair value of the shares on the offering date, including consideration of the discount and the look back period. The Company estimates the fair value of the shares using a Black-Scholes option pricing model. Compensation expense is recognized over the six month withholding period prior to the purchase date. All share-based compensation costs are recorded in general and administrative or research and development costs in the statements of operations based upon the underlying employees’ roles within the Company. |
Cash Equivalents | Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with an original term of three months or less at the date of purchase. |
Short-Term Investments | Short-Term Investments Short-term investments are investments with original maturities of between 90 and 365 days when purchased and are comprised of certificates of deposit, commercial paper, corporate and government bonds and treasury bills. The Company classifies its short-term investments as available-for-sale securities. Short-term investments are recorded at fair value and unrealized gains and losses are recorded within accumulated other comprehensive loss until realized. In addition, the Company evaluates the short-investments with unrealized losses to determine whether such losses are other-than-temporary. |
Restricted Cash | Restricted Cash The Company is required to maintain a stand-by letter of credit as a security deposit for its facility lease in Alpharetta, Georgia. The Company’s bank requires the Company to maintain a restricted cash balance to serve as collateral for the letter of credit issued to the landlord by the bank. As of December 31, 2017, the restricted cash balance was invested in a commercial money market account. |
Concentration of Credit Risk Arising From Cash Deposits in Excess of Insured Limits | Concentration of Credit Risk Arising From Cash Deposits in Excess of Insured Limits The Company maintains its cash in bank deposits that at times may exceed federally insured limits. The Company has not experienced any loss in such accounts. The Company believes it is not exposed to any significant risks with respect to its cash balances. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements Accounting Pronouncements Recently Adopted In August 2016, Financial Accounting Standards Board (“FASB”) Statement of Cash Flows Classification of Certain Cash Receipts and Cash Payments In November 2016, the FASB issued ASU 2016-18, Restricted Cash, Recent Accounting Pronouncements Not Yet Adopted In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers The Company plans to adopt the standard using the modified retrospective transition method. After evaluating its current and prior license agreements, as well as its other collaboration agreements, the Company does not expect that the adoption of ASU 2014-09 will not have a material impact on its financial statements and related disclosures. In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842), |
Property and Equipment, Net (Ta
Property and Equipment, Net (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Property Plant And Equipment [Abstract] | |
Schedule of Property and Equipment, Net | Property and equipment, net consisted of the following (dollar amounts in thousands): Estimated Useful Lives (Years) December31, 2017 2016 Furniture and fixtures 5 $ 303 $ 69 Machinery and equipment 5 121 121 Computer equipment 3 41 27 Leasehold improvements Lesser of useful life remaining lease term 667 45 Total property and equipment 1,132 262 Less: Accumulated depreciation (247 ) (168 ) Property and equipment, net $ 885 $ 94 |
Accrued Liabilities (Tables)
Accrued Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Payables And Accruals [Abstract] | |
Schedule of Accrued Liabilities | Accrued liabilities consisted of the following (in thousands): December 2017 2016 Accrued research and development $ 3,360 $ 1,153 Accrued bonuses 920 870 Accrued professional fees 62 410 Accrued vacation 113 72 Accrued interest payable 58 52 Accrued expense 203 234 $ 4,716 $ 2,791 |
Long-Term Debt (Tables)
Long-Term Debt (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Debt Disclosure [Abstract] | |
Scheduled Payments for the Loan Agreement | As of December 31, 2017, the scheduled payments for the loan agreement, including the scheduled final payment in 2020, were as follows (in thousands): Year Ending December 31, Principal Interest and Final Total 2018 $ 3,200 $ 476 $ 3,676 2019 3,200 234 3,434 2020 1,600 545 2,145 $ 8,000 $ 1,255 $ 9,255 |
Convertible Preferred Stock (Ta
Convertible Preferred Stock (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Temporary Equity Disclosure [Abstract] | |
Activity Convertible Preferred Stock | The following table summarizes the activity of convertible preferred stock (in thousands, except per share amounts): Total Series A Series A-1 Series B Series C Convertible Preferred Stock Preferred Stock Preferred Stock Preferred Stock Preferred Shares Amount Shares Amount Shares Amount Shares Amount Stock Balance at January 1, 2016 5,198,826 $ 4,086 4,356,931 $ 7,900 6,009,202 $ 15,372 5,274,674 $ 19,956 $ 47,314 Accretion of redeemable convertible preferred stock to redemption value — — — — — 840 — 44 884 Conversion of preferred stock to common stock at closing of IPO (5,198,826 ) (4,086 ) (4,356,931 ) (7,900 ) (6,009,202 ) (16,212 ) (5,274,674 ) (20,000 ) (48,198 ) Balance at December 31, 2016 — $ — — $ — — $ — — $ — $ — |
Share-Based Compensation (Table
Share-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Share-based Compensation Expense | The total share-based compensation expense recognized is reflected in the statements of operations as follows (in thousands): Year Ended December 31, 2017 2016 2015 Research and development $ 1,348 $ 539 $ 327 General and administrative 1,988 775 378 Total $ 3,336 $ 1,314 $ 705 |
Weighted Average Assumptions Used in Fair Value Calculation for Underlying Common Stock | The following table sets forth the weighted average assumptions utilized in the fair value calculation for the underlying common stock for the years ended December 31, 2017, 2016 and 2015. Year Ended December 31, 2017 2016 2015 Expected term (years) 7.00 7.00 7.00 Expected stock price volatility 96.85 % 97.45 % 86.63 % Risk-free interest rate 2.20 % 2.20 % 2.09 % Expected dividend yield 0.00 % 0.00 % 0.00 % |
Summary of Activity Related to Stock Options | The following table summarizes the activity related to stock options during the year ended December 31, 2017: Weighted Number of Average Shares Exercise Price Options outstanding at January 1, 2017 2,243,575 $ 5.78 Granted 1,127,950 6.45 Exercised (171,926 ) 1.37 Cancelled/Forfeited (124,250 ) 8.40 Options outstanding at December 31, 2017 3,075,349 6.17 Options exercisable at December 31, 2016 789,120 1.55 Options exercisable at December 31, 2017 1,114,286 3.94 |
Additional Information about the Stock Option Outstanding and Exercisable | The following table provides additional information about the Company’s stock options that were outstanding and exercisable at December 31, 2017 (aggregate intrinsic values in thousands): Weighted Weighted Weighted Average Weighted Average Average Aggregate Remaining Average Aggregate Remaining Exercise Options Exercise Intrinsic Contractual Options Exercise Intrinsic Contractual Price Outstanding Price Value Life (Years) Exercisable Price Value Life (Years) $0.02 - $0.40 465,265 5.4 465,265 5.4 $3.08 - $5.89 1,385,871 8.9 356,632 7.2 $6.16 - $8.90 1,105,921 8.9 264,161 8.2 $9.11 - $20.84 118,292 9.0 28,228 8.9 3,075,349 $ 6.17 $ 5,598 8.4 1,114,286 $ 3.94 $ 4,180 6.7 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Income Tax Disclosure [Abstract] | |
Schedule of Net Deferred Tax Assets | Significant components of the Company’s net deferred income tax assets consist of the following (in thousands): December 31, 2017 2016 2015 Deferred tax asset (liability) Net operating loss carryforwards $ 27,999 $ 23,391 $ 14,119 Non-deductible accrued expenses 248 358 230 Deferred rent 49 1 4 Deferred revenue 38 69 77 Stock compensation expense 387 101 88 Depreciation differences (18 ) (13 ) (28 ) Federal tax credits 3,437 1,232 850 State tax credits 524 301 262 Charitable contributions 6 6 3 Valuation allowance (32,670 ) (25,446 ) (15,605 ) Net deferred tax asset $ — $ — $ — |
Schedule of Statutory and Effective Income Tax Rate Reconciliation | A reconciliation of the statutory tax rates and the effective tax rates is as follows: Year Ended December 31, 2017 2016 2015 U.S. federal tax rate 34.00 % 34.00 % 34.00 % State tax rate 2.42 3.79 4.54 Permanent difference and other (2.84 ) (1.98 ) (1.26 ) Tax credit 3.97 1.62 2.66 Valuation allowance (12.42 ) (37.43 ) (39.94 ) Impact of federal rate change (25.13 ) — — 0.00 % 0.00 % 0.00 % |
Commitment and Contingencies (T
Commitment and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Commitments And Contingencies Disclosure [Abstract] | |
Future Minimum Commitments Due Under Non-Cancelable Operating Leases | Minimum lease payments were as follows at December 31, 2017 (in thousands): Year ending December 31, 2018 $ 431 2019 444 2020 458 2021 472 2022 487 Thereafter 373 Total minimum lease payments $ 2,665 |
Available-for-Sale Investments
Available-for-Sale Investments (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Investments Debt And Equity Securities [Abstract] | |
Summary of Company's Available-For-Sale Investments | The following table summarizes the Company’s available-for-sale investments as of December 31, 2017 (in thousands): December 31, 2017 Amortized Unrealized Fair Cost Loss Value Government bonds and agency obligations $ 11,241 $ (3 ) $ 11,238 Commercial paper 10,154 — 10,154 Corporate bonds 5,069 (5 ) 5,064 Certificates of deposit 1,960 — 1,960 Total available-for-sale investments $ 28,424 $ (8 ) $ 28,416 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Fair Value Disclosures [Abstract] | |
Summary of Assets and Liabilities Measured at Fair Value | The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy (in thousands): December 31, 2017 Level 1 Level 2 Level 3 Recorded Value Financial Assets: Cash and money markets $ 9,224 $ — $ — $ 9,224 Restricted cash money market 360 — — 360 Government bonds and treasury bills 11,238 — — 11,238 Certificates of deposit — 1,960 — 1,960 Corporate bonds — 5,064 — 5,064 Commercial paper — 10,154 — 10,154 Total financial assets $ 20,822 $ 17,178 $ — $ 38,000 December 31, 2016 Level 1 Level 2 Level 3 Recorded Value Financial Assets: Cash and money markets $ 29,928 $ — $ — $ 29,928 Restricted cash money market 360 — — 360 Government bonds 19,027 — — 19,027 Certificates of deposit — 6,579 — 6,579 Agency obligations — 4,179 — 4,179 Corporate bonds — 7,262 — 7,262 Commercial paper — 16,656 — 16,656 Total financial assets $ 49,315 $ 34,676 $ — $ 83,991 |
Summarizes the Changes in Fair Value of the Level 3 Liability, Stock Purchase Warrants | The following table summarizes the changes in fair value of the Level 3 liability, stock purchase warrants (in thousands): Level 3 Liabilities Year Ended December 2016 Stock purchase warrants Balance at beginning of period $ 258 Issuance of stock purchase warrants — Exercise of stock purchase warrants (414 ) Net increase in fair value remeasurement 156 Balance at end of period $ — |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Earnings Per Share [Abstract] | |
Potential Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share | The Company’s potential common stock equivalents that have been excluded from the computation of diluted net loss per share for all periods presented because of their antidilutive effect consisted of the following: Year Ended December 31, 2017 2016 2015 Convertible preferred stock — — 9,472,530 Outstanding stock options 3,075,349 2,243,575 1,261,637 Unvested restricted stock — — 6,485 Stock purchase warrants 29,796 29,796 146,298 3,105,145 2,273,371 10,886,950 |
Quarterly Financial Informati36
Quarterly Financial Information (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2017 | |
Quarterly Financial Data [Abstract] | |
Summary of Quarterly Financial Information | Summarized quarterly financial information for each of the years ended December 31, 2017 and 2016 are as follows (in thousands except per share data): Quarter Ended March 31, 2017 June 30, 2017 September 30, 2017 December 31, 2017 Operating expenses $ (10,261 ) $ (13,768 ) $ (18,348 ) $ (16,376 ) Net loss $ (10,373 ) $ (13,773 ) $ (18,336 ) $ (16,493 ) Net loss per share of common stock — basic and diluted $ (0.41 ) $ (0.54 ) $ (0.72 ) $ (0.65 ) Quarter Ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Operating expenses $ (5,862 ) $ (5,183 ) $ (5,311 ) $ (9,362 ) Net loss $ (5,449 ) $ (5,102 ) $ (5,645 ) $ (9,686 ) Net loss per share of common stock — basic and diluted $ (2.05 ) $ (0.62 ) $ (0.28 ) $ (0.45 ) |
The Company - Additional Inform
The Company - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | Mar. 12, 2018 | Jun. 30, 2017 | Jan. 06, 2017 | Dec. 14, 2016 | Jun. 07, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Jul. 06, 2016 |
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Entity incorporation date | May 26, 2011 | |||||||
Common stock, Sale of shares | 25,354,651 | 24,573,033 | ||||||
Common stock, Share offering price | $ 9 | |||||||
Underwriting discounts and commissions | $ 2,500 | |||||||
Offering expense | $ 400 | |||||||
Public offering closing date | Dec. 14, 2016 | |||||||
Issuance of common stock for follow-on public offering, shares | 4,000,000 | |||||||
Issuance of common stock for follow-on public offering, value | $ 33,400 | $ 5,057 | $ 33,459 | |||||
Issuance of common stock in initial public offering | $ 51,377 | |||||||
Proceeds from Issuance of convertible preferred stock and long-term debt | 53,900 | |||||||
Cash, cash equivalents and short-term investments | $ 37,600 | |||||||
Subsequent Event | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Common stock, Share offering price | $ 13 | |||||||
Public offering closing date | Mar. 12, 2018 | |||||||
Issuance of common stock for follow-on public offering, shares | 6,538,462 | |||||||
Net proceeds after deducting underwriting discounts and commissions and estimated offering expenses | $ 79,600 | |||||||
Common Stock | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Common stock, Sale of shares | 8,148,843 | |||||||
Issuance of common stock for follow-on public offering, shares | 600,000 | 4,000,000 | ||||||
Issuance of common stock for follow-on public offering, value | $ 4 | |||||||
Issuance of common stock in initial public offering | $ 8 | |||||||
IPO | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
IPO, closing date | Jun. 7, 2016 | |||||||
Common stock, Sale of shares | 7,200,000 | |||||||
Common stock, Share offering price | $ 7 | |||||||
Net proceeds from issuance of stock | $ 45,300 | |||||||
Underwriting discounts and commissions | $ 4,000 | |||||||
Offering expense | 1,600 | |||||||
Net offering proceeds after deducting underwriting discount and commission and offering expenses | $ 51,400 | |||||||
Over-allotment option by underwriters | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Common stock, Sale of shares | 600,000 | 948,843 | ||||||
Common stock, Share offering price | $ 9 | $ 7 | ||||||
Net proceeds from issuance of stock | $ 5,100 | $ 6,100 | ||||||
Over-allotment option by underwriters | Subsequent Event | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Common stock, Share offering price | $ 13 | |||||||
Issuance of common stock for follow-on public offering, shares | 6,538,462 | |||||||
Net proceeds after deducting underwriting discounts and commissions and estimated offering expenses | $ 79,600 | |||||||
At-the-market sales agreement | Cowen and Company LLC | Common Stock | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Number of shares sold under facility | 0 | |||||||
At-the-market sales agreement | Cowen and Company LLC | Common Stock | Maximum | ||||||||
Organization Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ||||||||
Issuance of common stock in initial public offering | $ 50,000 |
Significant Accounting Polici38
Significant Accounting Policies - Additional Information (Detail) $ in Millions | May 11, 2016 | Dec. 31, 2017USD ($)Segment |
Accounting Policies [Abstract] | ||
Number of operating segments | Segment | 1 | |
Cumulative net operating losses | $ | $ 28 | |
Reverse split of common stock | 0.4545 | |
Reverse stock split ratio | On May 11, 2016, the Company effected a 1-for-2.2 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 the Company’s convertible preferred stock. | |
Short-term investments maturity start period | 90 days | |
Short-term investments maturity end period | 365 days |
Property and Equipment, Net - S
Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | |
Property Plant And Equipment [Line Items] | ||
Property and Equipment, gross | $ 1,132 | $ 262 |
Less: Accumulated depreciation | (247) | (168) |
Property and equipment, net | 885 | 94 |
Furniture and Fixtures | ||
Property Plant And Equipment [Line Items] | ||
Property and Equipment, gross | $ 303 | 69 |
Estimated Useful Lives (Years) | 5 years | |
Machinery and Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and Equipment, gross | $ 121 | 121 |
Estimated Useful Lives (Years) | 5 years | |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and Equipment, gross | $ 41 | 27 |
Estimated Useful Lives (Years) | 3 years | |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Property and Equipment, gross | $ 667 | $ 45 |
Estimated Useful Lives (Years) | Lesser of useful life or remaining lease term |
Accrued Liabilities - Schedule
Accrued Liabilities - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Payables And Accruals [Abstract] | ||
Accrued research and development | $ 3,360 | $ 1,153 |
Accrued bonuses | 920 | 870 |
Accrued professional fees | 62 | 410 |
Accrued vacation | 113 | 72 |
Accrued interest payable | 58 | 52 |
Accrued expense | 203 | 234 |
Accrued liabilities, current | $ 4,716 | $ 2,791 |
Long-Term Debt - Additional Inf
Long-Term Debt - Additional Information (Details) - USD ($) | Sep. 28, 2016 | Sep. 30, 2016 | Apr. 30, 2015 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | May 15, 2015 | Apr. 15, 2015 | Apr. 01, 2015 |
Debt Instrument [Line Items] | |||||||||
Long term debt | $ 8,000,000 | ||||||||
Interest expense on borrowings | 653,000 | $ 287,000 | $ 115,000 | ||||||
Accretion of scheduled final payment | 211,000 | 283,000 | 101,000 | ||||||
Accretion of deferred closing costs | $ 62,000 | $ 17,000 | $ 7,400 | ||||||
Silicon Valley Bank | |||||||||
Debt Instrument [Line Items] | |||||||||
Line of credit facility, maximum borrowing capacity | $ 6,000,000 | ||||||||
Long term debt | $ 2,000,000 | $ 4,000,000 | |||||||
Long term debt, maturity year | 2,018 | ||||||||
Debt Instrument, Payment Terms | The Company was required to pay accrued interest only for a period of 12 months from the date of each advance, followed by 30 equal monthly payments of principal and accrued interest. | ||||||||
Final payment during maturity | $ 300,000 | ||||||||
Final payment during maturity, percentage | 5.50% | ||||||||
Closing costs recorded in the long-term debt liability | $ 24,000 | ||||||||
Silicon Valley Bank , MidCap Funding XII Trust and MidCap Financial Trust | |||||||||
Debt Instrument [Line Items] | |||||||||
Long term debt | $ 8,000,000 | ||||||||
Debt Instrument, Payment Terms | The Company was required to pay accrued interest only through December 31, 2017 on the outstanding amount, followed by 30 equal payments of principal and accrued interest. | ||||||||
Final payment during maturity | $ 500,000 | ||||||||
Final payment during maturity, percentage | 6.50% | ||||||||
Line of credit facility, remaining borrowing capacity | $ 7,000,000 | ||||||||
Debt instrument, maturity date | Jun. 1, 2020 | ||||||||
Repay all the amount outstanding under the original loan agreement | $ 5,300,000 | ||||||||
Silicon Valley Bank , MidCap Funding XII Trust and MidCap Financial Trust | Prepayments Through May 31, 2020 | |||||||||
Debt Instrument [Line Items] | |||||||||
Prepayment fee percentage of the original principal amount of the aggregate term loans | 2.00% | ||||||||
Silicon Valley Bank , MidCap Funding XII Trust and MidCap Financial Trust | Amended and Restated Loan and Security Agreement | |||||||||
Debt Instrument [Line Items] | |||||||||
Line of credit facility, maximum borrowing capacity | $ 15,000,000 | ||||||||
Interest rate | 0.50% | ||||||||
Debt instrument, description of variable rate basis | 30-day U.S. LIBOR | ||||||||
Prime Rate | Silicon Valley Bank | |||||||||
Debt Instrument [Line Items] | |||||||||
Interest rate | 0.50% | ||||||||
Floating Interest Rate | Silicon Valley Bank , MidCap Funding XII Trust and MidCap Financial Trust | Amended and Restated Loan and Security Agreement | |||||||||
Debt Instrument [Line Items] | |||||||||
Interest rate | 7.00% |
Long-Term Debt - Scheduled Paym
Long-Term Debt - Scheduled Payments for Loan Agreement (Details) $ in Thousands | Dec. 31, 2017USD ($) |
Debt Disclosure [Abstract] | |
Principal, 2018 | $ 3,200 |
Principal, 2019 | 3,200 |
Principal, 2020 | 1,600 |
Principal | 8,000 |
Interest and Final Payment, 2018 | 476 |
Interest and Final Payment, 2019 | 234 |
Interest and Final Payment, 2020 | 545 |
Interest and Final Payment | 1,255 |
Total, 2018 | 3,676 |
Total, 2019 | 3,434 |
Total, 2020 | 2,145 |
Total | $ 9,255 |
Convertible Shareholder Notes43
Convertible Shareholder Notes Payable (Detail) - The Bridge Notes | 1 Months Ended | |
Aug. 31, 2014$ / sharesshares | Apr. 30, 2014USD ($)Stockholder | |
Class Of Stock [Line Items] | ||
Convertible notes principal amount authorized | $ | $ 6,000,000 | |
Issuance of promissory notes | $ | $ 3,000,000 | |
Debt instrument annual interest rate | 7.00% | |
Debt instrument, maturity date | Apr. 30, 2015 | |
Warrants issued to purchase common stock shares | 112,802 | |
Class of warrant Exercise | $ / shares | $ 0.02 | |
Series B Preferred Stock | ||
Class Of Stock [Line Items] | ||
Debt converted into shares of convertible preferred stock | 1,137,652 | |
Convertible Stock Warrant | ||
Class Of Stock [Line Items] | ||
Number of shares, exercised | 112,441 | |
Executive Officer | ||
Class Of Stock [Line Items] | ||
Number of stockholders | Stockholder | 2 | |
Director | ||
Class Of Stock [Line Items] | ||
Number of stockholders | Stockholder | 1 |
Convertible Preferred Stock - A
Convertible Preferred Stock - Additional Information (Detail) - $ / shares | Dec. 31, 2017 | Dec. 31, 2016 | Jun. 07, 2016 | Dec. 31, 2015 |
Class Of Stock [Line Items] | ||||
Preferred stock convertible into common stock | 9,614,159 | |||
Preferred stock, shares authorized | 10,000,000 | 10,000,000 | ||
Preferred stock, shares issued | 0 | 0 | ||
Preferred stock, shares outstanding | 0 | 0 | ||
Series A, A-1, B and C Preferred Stock | ||||
Class Of Stock [Line Items] | ||||
Convertible preferred stock, shares authorized | 20,913,331 | |||
Convertible preferred stock, par value | $ 0.001 | |||
Convertible Preferred Stock | IPO | ||||
Class Of Stock [Line Items] | ||||
Convertible preferred stock, shares issued | 20,839,633 | |||
Convertible preferred stock, shares outstanding | 20,839,633 |
Convertible Preferred Stock (De
Convertible Preferred Stock (Detail) $ in Thousands | 12 Months Ended |
Dec. 31, 2016USD ($)shares | |
Class Of Stock [Line Items] | |
Beginning balance | $ 47,314 |
Accretion of redeemable convertible preferred stock to redemption value | 884 |
Conversion of preferred stock to common stock at closing of IPO | (48,198) |
Series A | |
Class Of Stock [Line Items] | |
Beginning balance | $ 4,086 |
Beginning balance, shares | shares | 5,198,826 |
Conversion of preferred stock to common stock at closing of IPO | $ (4,086) |
Conversion of preferred stock to common stock at closing of IPO, shares | shares | (5,198,826) |
Series A-1 Preferred Stock | |
Class Of Stock [Line Items] | |
Beginning balance | $ 7,900 |
Beginning balance, shares | shares | 4,356,931 |
Conversion of preferred stock to common stock at closing of IPO | $ (7,900) |
Conversion of preferred stock to common stock at closing of IPO, shares | shares | (4,356,931) |
Series B | |
Class Of Stock [Line Items] | |
Beginning balance | $ 15,372 |
Beginning balance, shares | shares | 6,009,202 |
Accretion of redeemable convertible preferred stock to redemption value | $ 840 |
Conversion of preferred stock to common stock at closing of IPO | $ (16,212) |
Conversion of preferred stock to common stock at closing of IPO, shares | shares | (6,009,202) |
Series C | |
Class Of Stock [Line Items] | |
Beginning balance | $ 19,956 |
Beginning balance, shares | shares | 5,274,674 |
Accretion of redeemable convertible preferred stock to redemption value | $ 44 |
Conversion of preferred stock to common stock at closing of IPO | $ (20,000) |
Conversion of preferred stock to common stock at closing of IPO, shares | shares | (5,274,674) |
Common Stock - Additional Infor
Common Stock - Additional Information (Detail) - $ / shares | Dec. 31, 2017 | Dec. 31, 2016 |
Equity [Abstract] | ||
Common stock, shares authorized | 100,000,000 | 100,000,000 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares outstanding | 25,354,651 | 24,573,033 |
Stock Purchase Warrants - Addit
Stock Purchase Warrants - Additional Information (Details) - USD ($) | Oct. 12, 2016 | Jun. 06, 2016 | Sep. 30, 2016 | Apr. 30, 2015 | Dec. 31, 2017 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 |
Preferred Stock Warrants | Series A-1 Preferred Stock | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Class of warrant Exercise | $ 1.8132 | |||||||
Warrant exercisable term | 10 years | |||||||
Weighted average remaining life of warrants | 6 years 9 months 18 days | |||||||
Fair value of warrant | $ 58,000 | |||||||
Number of shares, exercised | 3,236 | |||||||
Preferred Stock Warrants | Series B Preferred Stock | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Class of warrant Exercise | $ 3.50 | |||||||
Warrant exercisable term | 10 years | |||||||
Weighted average remaining life of warrants | 9 years 3 months | |||||||
Fair value of warrant | $ 200,000 | |||||||
Number of shares, exercised | 17,883 | |||||||
Preferred Stock Warrants | Series B Preferred Stock | Convertible Warrant | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Number of stock that can be purchased by each warrant | 25,974 | |||||||
Class of warrant Exercise | $ 7.70 | |||||||
Preferred Stock Warrants | Maximum | Series A-1 Preferred Stock | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Number of stock that can be purchased by each warrant | 16,550 | |||||||
Preferred Stock Warrants | Maximum | Series B Preferred Stock | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Number of stock that can be purchased by each warrant | 57,143 | |||||||
Convertible Stock Warrant | Convertible Promissory Note | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Class of warrant Exercise | $ 0.02 | |||||||
Weighted average remaining life of warrants | 8 years 2 months 12 days | |||||||
Number of shares, exercised | 112,441 | |||||||
Convertible Stock Warrant | Amended and Restated Loan And Security Agreement | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Class of warrant Exercise | $ 10.74 | |||||||
Weighted average remaining life of warrants | 8 years 9 months | |||||||
Warrants expiration term | 2026-09 | |||||||
Convertible Stock Warrant | Maximum | Convertible Promissory Note | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Number of stock that can be purchased by each warrant | 112,802 | |||||||
Convertible Stock Warrant | Maximum | Amended and Restated Loan And Security Agreement | ||||||||
Class Of Warrant Or Right [Line Items] | ||||||||
Number of stock that can be purchased by each warrant | 29,796 |
Share-Based Compensation - Addi
Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands | Jan. 01, 2018 | Jan. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 29, 2017 |
2016 Stock Incentive Plan | Subsequent Event | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares common stock reserved for issuance | 1,765,264 | |||||
Annual increase of common stock reserved for issuance | 4.00% | |||||
Increase in common stock for future issuance, shares | 1,014,186 | |||||
2016 Employee Stock Purchase Plan | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares common stock reserved for issuance | 181,818 | |||||
Share based compensation arrangement description | the number of shares reserved for issuance under the 2016 ESPP will automatically increase for a period of ten years, from January 1, 2017 through January 1, 2026, by the lesser of (i) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (ii) 454,545 shares of common stock or (iii) a lesser number of shares as may be determined by the Company’s board of directors. | |||||
Annual increase of common stock reserved for issuance | 1.00% | |||||
Employee payroll deductions, percent | 15.00% | |||||
Number of shares reserved for issuance increase in years | 10 years | |||||
Addition of common stock shares reserved for future issuance | 454,545 | |||||
Common stock purchased | 9,692 | |||||
2016 Employee Stock Purchase Plan | General and Administrative Expense | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Share-based compensation expense | $ 21,000 | |||||
2016 Employee Stock Purchase Plan | Research and Development Expense | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Share-based compensation expense | $ 7,000 | |||||
2016 Employee Stock Purchase Plan | Subsequent Event | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares common stock reserved for issuance | 671,402 | |||||
Annual increase of common stock reserved for issuance | 1.00% | |||||
Addition of common stock shares reserved for future issuance | 253,546 | |||||
Stock Options | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of shares grants | 1,127,950 | |||||
Option to purchase common stock shares outstanding | 3,075,349 | 2,243,575 | ||||
Weighted average exercise price | $ 6.17 | $ 5.78 | ||||
Unrecognized compensation expense related to unvested stock options | $ 11,600 | |||||
Expected to be recognized over a weighted average period | 3 years 1 month 6 days | |||||
Weighted-average fair values granted | $ 5.25 | $ 7.89 | $ 5.72 | |||
Fair market value per share of common stock | $ 7 | |||||
Share-based compensation expense | $ 3,336 | $ 1,314 | $ 705 | |||
Stock Options | General and Administrative Expense | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Share-based compensation expense | 1,988 | 775 | 378 | |||
Stock Options | Research and Development Expense | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Share-based compensation expense | $ 1,348 | $ 539 | $ 327 | |||
Stock Options | 2016 Stock Incentive Plan | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Shares common stock reserved for issuance | 1,818,182 | |||||
Share based compensation arrangement description | The number of shares of common stock reserved for issuance under the 2016 Plan will automatically increase on January 1 each year, for a period of ten years, from January 1, 2017 through January 1, 2026, by 4% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Company’s board of directors. | |||||
Annual increase of common stock reserved for issuance | 4.00% | |||||
Option to purchase common stock shares outstanding | 2,044,400 | |||||
Weighted average exercise price | $ 7.98 | |||||
Shares available for future grant | 751,078 | |||||
Stock Options | 2011 Stock Incentive Plan | ||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||
Number of shares grants | 0 | |||||
Option to purchase common stock shares outstanding | 1,013,713 | |||||
Weighted average exercise price | $ 2.47 |
Share-Based Compensation - Summ
Share-Based Compensation - Summary of Share-based Compensation Expense (Details) - Stock Options - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Share-based compensation expense | $ 3,336 | $ 1,314 | $ 705 |
Research and Development | |||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Share-based compensation expense | 1,348 | 539 | 327 |
General and Administrative | |||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Share-based compensation expense | $ 1,988 | $ 775 | $ 378 |
Share-Based Compensation - Weig
Share-Based Compensation - Weighted Average Assumptions Used in Fair Value Calculation for Underlying Common Stock (Details) - Stock Options | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Expected term (years) | 7 years | 7 years | 7 years |
Expected stock price volatility | 96.85% | 97.45% | 86.63% |
Risk-free interest rate | 2.20% | 2.20% | 2.09% |
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Share-Based Compensation - Su51
Share-Based Compensation - Summary of Activity Related to Stock Options (Details) - Stock Options - $ / shares | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Number of Shares, Options outstanding, Beginning balance | 2,243,575 | |
Number of Shares, Granted | 1,127,950 | |
Number of Shares, Exercised | (171,926) | |
Number of Shares, Cancelled/Forfeited | (124,250) | |
Number of Shares, Options outstanding, Ending balance | 3,075,349 | 2,243,575 |
Number of Shares, Options exercisable | 1,114,286 | 789,120 |
Weighted Average Exercise Price, Options outstanding, Beginning balance | $ 5.78 | |
Weighted Average Exercise Price, Granted | 6.45 | |
Weighted Average Exercise Price, Exercised | 1.37 | |
Weighted Average Exercise Price, Cancelled/Forfeited | 8.40 | |
Weighted Average Exercise Price, Options outstanding, Ending balance | 6.17 | $ 5.78 |
Weighted Average Exercise Price, Options exercisable | $ 3.94 | $ 1.55 |
Share-Based Compensation - Ad52
Share-Based Compensation - Additional Information about the Stock Option Outstanding and Exercisable (Details) - Stock Options - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ||
Options Outstanding | 3,075,349 | 2,243,575 |
Weighted Average Exercise Price | $ 6.17 | $ 5.78 |
Aggregate Intrinsic Value | $ 5,598 | |
Weighted Average Remaining Contractual Life (Years) | 8 years 4 months 24 days | |
Options Exercisable | 1,114,286 | 789,120 |
Weighted Average Exercise Price | $ 3.94 | $ 1.55 |
Aggregate Intrinsic Value | $ 4,180 | |
Weighted Average Remaining Contractual Life (Years) | 6 years 8 months 12 days | |
$0.02 - $0.40 | ||
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ||
Exercise Price Lower Range Limit | $ 0.02 | |
Exercise Price Upper Range Limit | $ 0.40 | |
Options Outstanding | 465,265 | |
Weighted Average Remaining Contractual Life (Years) | 5 years 4 months 24 days | |
Options Exercisable | 465,265 | |
Weighted Average Remaining Contractual Life (Years) | 5 years 4 months 24 days | |
$3.08 - $5.89 | ||
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ||
Exercise Price Lower Range Limit | $ 3.08 | |
Exercise Price Upper Range Limit | $ 5.89 | |
Options Outstanding | 1,385,871 | |
Weighted Average Remaining Contractual Life (Years) | 8 years 10 months 24 days | |
Options Exercisable | 356,632 | |
Weighted Average Remaining Contractual Life (Years) | 7 years 2 months 12 days | |
$6.16 - $8.90 | ||
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ||
Exercise Price Lower Range Limit | $ 6.16 | |
Exercise Price Upper Range Limit | $ 8.90 | |
Options Outstanding | 1,105,921 | |
Weighted Average Remaining Contractual Life (Years) | 8 years 10 months 24 days | |
Options Exercisable | 264,161 | |
Weighted Average Remaining Contractual Life (Years) | 8 years 2 months 12 days | |
$9.11 - $20.84 | ||
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ||
Exercise Price Lower Range Limit | $ 9.11 | |
Exercise Price Upper Range Limit | $ 20.84 | |
Options Outstanding | 118,292 | |
Weighted Average Remaining Contractual Life (Years) | 9 years | |
Options Exercisable | 28,228 | |
Weighted Average Remaining Contractual Life (Years) | 8 years 10 months 24 days |
Income Tax - Additional Informa
Income Tax - Additional Information (Detail) - USD ($) | 12 Months Ended | |||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Income Tax Disclosure [Line Items] | ||||
U.S. federal tax rate | 34.00% | 34.00% | 34.00% | |
Tax Cuts and Jobs Act of 2017,Provisional Income Tax Expense | $ 14,900,000 | |||
Increase in deferred income tax valuation allowance | 7,200,000 | $ 9,800,000 | $ 7,000,000 | |
Net deferred tax assets related to net operating loss carryforwards | $ 27,999,000 | $ 23,391,000 | $ 14,119,000 | |
Net deferred tax assets related to net operating loss carryforwards expiration year | 2,037 | |||
Scenario, Plan | ||||
Income Tax Disclosure [Line Items] | ||||
U.S. federal tax rate | 21.00% | |||
U.S. Federal or State Income Taxes [Member] | ||||
Income Tax Disclosure [Line Items] | ||||
Provision for income taxes | $ 0 |
Schedule of Net Deferred Tax As
Schedule of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 |
Deferred tax asset (liability) | |||
Net operating loss carryforwards | $ 27,999 | $ 23,391 | $ 14,119 |
Deferred tax asset (liability) Non-deductible accrued expenses | 248 | 358 | 230 |
Deferred rent | 49 | 1 | 4 |
Deferred revenue | 38 | 69 | 77 |
Stock compensation expense | 387 | 101 | 88 |
Depreciation differences | (18) | (13) | (28) |
Charitable contributions | 6 | 6 | 3 |
Valuation allowance | (32,670) | (25,446) | (15,605) |
Federal | |||
Deferred tax asset (liability) | |||
Tax credits | 3,437 | 1,232 | 850 |
State | |||
Deferred tax asset (liability) | |||
Tax credits | $ 524 | $ 301 | $ 262 |
Schedule of Statutory and Effec
Schedule of Statutory and Effective Income Tax Rate Reconciliation (Detail) | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |||
U.S. federal tax rate | 34.00% | 34.00% | 34.00% |
State tax rate | 2.42% | 3.79% | 4.54% |
Permanent difference and other | (2.84%) | (1.98%) | (1.26%) |
Tax credit | 3.97% | 1.62% | 2.66% |
Valuation allowance | (12.42%) | (37.43%) | (39.94%) |
Impact of federal rate change | (25.13%) | ||
Total income tax provision (benefit) | 0.00% | 0.00% | 0.00% |
Commitment and Contingencies -
Commitment and Contingencies - Additional Information (Details) | 1 Months Ended | 12 Months Ended | ||
Nov. 30, 2016USD ($)ft² | Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | Dec. 31, 2015USD ($) | |
Commitment And Contingencies [Line Items] | ||||
Non-cancelable operating leases, expiration date | 2017-03 | |||
Rent expense | $ 214,000 | $ 81,000 | $ 150,000 | |
GEORGIA | ||||
Commitment And Contingencies [Line Items] | ||||
Area of office leased | ft² | 20,000 | |||
Operating lease agreement term | 6 years 6 months | |||
Operating lease agreement renewal option term | 5 years | |||
Minimum monthly lease payments | $ 35,145 | |||
Percentage of increase per year | 3.00% |
Commitment and Contingencies 57
Commitment and Contingencies - Future Minimum Commitments Due Under Non-Cancelable Operating Leases (Details) $ in Thousands | Dec. 31, 2017USD ($) |
Commitments And Contingencies Disclosure [Abstract] | |
2,018 | $ 431 |
2,019 | 444 |
2,020 | 458 |
2,021 | 472 |
2,022 | 487 |
Thereafter | 373 |
Total minimum lease payments | $ 2,665 |
License and Collaboration Agr58
License and Collaboration Agreements - Additional Information (Detail) - USD ($) | 3 Months Ended | 12 Months Ended | |||
Mar. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Apr. 30, 2015 | Aug. 31, 2014 | |
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
Revenue from collaborative agreements | $ 325,000 | ||||
NovaMedica | |||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
License revenue | $ 20,000 | $ 20,000 | |||
Patent expirations period | 2,027 | ||||
NovaMedica | Upfront payment | |||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
Deferred revenue | $ 200,000 | $ 200,000 | |||
Spark Therapeutics, Inc. | Upfront payment | |||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
License revenue | $ 500,000 | ||||
Upfront, non-refundable payment | $ 500,000 | ||||
Rusnano MedInvest LLC | |||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
Percentage of voting securities owned subsidiary | 6.00% |
Available-for-Sale Investment59
Available-for-Sale Investments - Summary of Company's Available-For-Sale Investments (Details) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 28,424 | |
Unrealized Loss | (8) | |
Fair Value | 28,416 | $ 48,807 |
Government Bonds and Agency Obligations | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 11,241 | |
Unrealized Loss | (3) | |
Fair Value | 11,238 | |
Commercial Paper | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 10,154 | |
Fair Value | 10,154 | |
Certificates of Deposit | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 1,960 | |
Fair Value | 1,960 | |
Corporate Bonds | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 5,069 | |
Unrealized Loss | (5) | |
Fair Value | $ 5,064 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Detail) - USD ($) | 12 Months Ended | |
Dec. 31, 2017 | Dec. 31, 2016 | |
Fair Value Disclosures [Abstract] | ||
Short-term investments maturity start period | 90 days | |
Short-term investments maturity end period | 365 days | |
Significant transfers between Levels 1, 2 and 3 | $ 0 | $ 0 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 |
Financial Assets: | ||
Total financial assets | $ 38,000 | $ 83,991 |
Government Bonds and Treasury Bills | ||
Financial Assets: | ||
Total financial assets | 11,238 | |
Corporate Bonds | ||
Financial Assets: | ||
Total financial assets | 5,064 | 7,262 |
Commercial Paper | ||
Financial Assets: | ||
Total financial assets | 10,154 | 16,656 |
Level 1 | ||
Financial Assets: | ||
Total financial assets | 20,822 | 49,315 |
Level 1 | Government Bonds and Treasury Bills | ||
Financial Assets: | ||
Total financial assets | 11,238 | |
Level 2 | ||
Financial Assets: | ||
Total financial assets | 17,178 | 34,676 |
Level 2 | Corporate Bonds | ||
Financial Assets: | ||
Total financial assets | 5,064 | 7,262 |
Level 2 | Commercial Paper | ||
Financial Assets: | ||
Total financial assets | 10,154 | 16,656 |
Cash and Money Markets | ||
Financial Assets: | ||
Total financial assets | 9,224 | 29,928 |
Cash and Money Markets | Level 1 | ||
Financial Assets: | ||
Total financial assets | 9,224 | 29,928 |
Restricted Cash Money Market | ||
Financial Assets: | ||
Total financial assets | 360 | 360 |
Restricted Cash Money Market | Level 1 | ||
Financial Assets: | ||
Total financial assets | 360 | 360 |
Certificates of Deposit | ||
Financial Assets: | ||
Total financial assets | 1,960 | 6,579 |
Certificates of Deposit | Level 2 | ||
Financial Assets: | ||
Total financial assets | $ 1,960 | 6,579 |
Government Bonds | ||
Financial Assets: | ||
Total financial assets | 19,027 | |
Government Bonds | Level 1 | ||
Financial Assets: | ||
Total financial assets | 19,027 | |
Agency Obligations | ||
Financial Assets: | ||
Total financial assets | 4,179 | |
Agency Obligations | Level 2 | ||
Financial Assets: | ||
Total financial assets | $ 4,179 |
Fair Value Measurements - Sum62
Fair Value Measurements - Summarizes the Changes in Fair Value of the Level 3 Liability, Stock Purchase Warrants (Detail) - Stock Purchase Warrants $ in Thousands | 12 Months Ended |
Dec. 31, 2016USD ($) | |
Stock purchase warrants | |
Balance at beginning of period | $ 258 |
Exercise of stock purchase warrants | (414) |
Net increase in fair value remeasurement | $ 156 |
Net Loss Per Share - Potential
Net Loss Per Share - Potential Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Details) - shares | 12 Months Ended | ||
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 3,105,145 | 2,273,371 | 10,886,950 |
Outstanding Stock Options | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 3,075,349 | 2,243,575 | 1,261,637 |
Unvested Restricted Stock | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 6,485 | ||
Stock Purchase Warrants | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 29,796 | 29,796 | 146,298 |
Convertible Preferred Stock | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 9,472,530 |
Quarterly Financial Informati64
Quarterly Financial Information (Unaudited) - Summary of Quarterly Financial Information - (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | |
Quarterly Financial Data [Abstract] | |||||||||||
Operating expenses | $ (16,376) | $ (18,348) | $ (13,768) | $ (10,261) | $ (9,362) | $ (5,311) | $ (5,183) | $ (5,862) | $ (58,753) | $ (25,718) | $ (17,317) |
Net loss | $ (16,493) | $ (18,336) | $ (13,773) | $ (10,373) | $ (9,686) | $ (5,645) | $ (5,102) | $ (5,449) | $ (58,975) | $ (25,882) | $ (17,639) |
Net loss per share of common stock — basic and diluted | $ (0.65) | $ (0.72) | $ (0.54) | $ (0.41) | $ (0.45) | $ (0.28) | $ (0.62) | $ (2.05) | $ (2.33) | $ (1.97) | $ (7.54) |
Subsequent Events - Additional
Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions | Mar. 12, 2018 | Dec. 14, 2016 | Jan. 06, 2017 | Jul. 06, 2016 |
Subsequent Event [Line Items] | ||||
Issuance of common stock for follow-on public offering, shares | 4,000,000 | |||
Common stock, Share offering price | $ 9 | |||
Over-allotment option by underwriters | ||||
Subsequent Event [Line Items] | ||||
Common stock, Share offering price | $ 9 | $ 7 | ||
Subsequent Event | ||||
Subsequent Event [Line Items] | ||||
Issuance of common stock for follow-on public offering, shares | 6,538,462 | |||
Common stock, Share offering price | $ 13 | |||
Net proceeds after deducting underwriting discounts and commissions and estimated offering expenses | $ 79.6 | |||
Subsequent Event | Over-allotment option by underwriters | ||||
Subsequent Event [Line Items] | ||||
Issuance of common stock for follow-on public offering, shares | 6,538,462 | |||
Common stock, Share offering price | $ 13 | |||
Net proceeds after deducting underwriting discounts and commissions and estimated offering expenses | $ 79.6 | |||
Common stock exercisable date | Apr. 6, 2018 | |||
Subsequent Event | Over-allotment option by underwriters | Maximum | ||||
Subsequent Event [Line Items] | ||||
Additional shares of common stock issuable to underwriters | 980,769 |