April

2,

2015,

1

7.5

troactively to give effect to the -for- reverse stock split.

April

2015,

5,090,909

$11.00

May

2015,

763,636

$11.00

s’ exercise of their option to purchase additional shares, were million, after deducting underwriting discounts and commissions of million. In addition, offering expenses totaled million. Upon completion of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock were converted or reclassified into shares of common stock and all outstanding warrants to acquire shares of the Company’s redeemable convertible preferred stock became warrants to acquire the Company’s common stock. In connection with the IPO, the Company amended and restated its Amended and Restated Certificate of Incorporation to change the authorized capital stock to shares, designated as common stock, and shares, designated as preferred stock, each with a par value of per share.

October

3,

2016,

ATM Agreement”) with Cowen and Company (“Cowen”) under which the Company offer and sell, from time to time, in its sole discretion, shares of common stock having an aggregate offering price of up to through Cowen as the Company's sales agent. The registration statement on Form S- included a prospectus covering the offering up to of shares of common stock in accordance with the ATM Agreement.

’s registration statement on Form S- contemplated under the ATM Agreement was declared effective by the SEC on

may

 ATM Agreement by any method permitted by law deemed to be an “at the market offering” as defined in Rule of the Securities Act, including without limitation sales made by means of ordinary brokers’ transactions on The NASDAQ Global Market or otherwise at market prices prevailing at the time of sale, in block transactions, or as otherwise directed by the Company. Cowen will use commercially reasonable efforts to sell the common stock from time to time, based upon instructions from the Company (including any price, time or size limits or other customary parameters or conditions the Company impose). The Company will pay Cowen a commission of up to percent of the gross sales proceeds of any common stock sold through Cowen under the ATM Agreement, and also has provided Cowen with customary indemnification rights.

 ATM Agreement. The offering of shares of common stock pursuant to the ATM Agreement will terminate upon the earlier of (i) the sale of all common stock subject to the ATM Agreement, or (ii) termination of the ATM Agreement in accordance with its terms.

  the Company had deferred offering costs recorded within other long-term assets in the amount of million.

first

2016

, the Company adopted Accounting Standards Update (“ASU”) - (“ASU - which requires the debt issuance costs related to a recognized debt liability be presented in the balance sheet as direct deduction from the carrying amount of that debt liability, consistent with the presentation of debt discounts. The adoption of ASU - reduced the Company’s assets and liabilities by the amount of the debt issuance costs, which was million at This reclassification had no effect on reported net loss or cash flows.

the Company to concentrations of credit risk consist principally of cash on deposit with multiple financial institutions, the balances of which frequently exceed insured limits.

zed gains and losses included in other income (expense) on the statements of operations. The securities primarily consist of certificates of deposit, U.S. Treasury securities and U.S. government-sponsored agency securities. As of and respectively, the Company held marketable securities and long-term investments with an aggregate fair value of million and million that contained aggregate unrealized losses of and respectively. These marketable securities and long-term investments have been in a continuous unrealized loss position for less than months and the Company expects these investments to fully recovery prior to their maturity.  

ed over the life of the respective financing arrangement using the effective interest method.

impairment whenever events or changes in circumstances indicate that the carrying amounts of the assets not be recoverable. When such events occur, the Company compares the carrying amounts of the assets to their undiscounted expected future cash flows. If the undiscounted cash flows are insufficient to recover the carrying values, an impairment loss is recorded for the difference between the carrying values and fair values of the asset. such impairment occurred for the years ended  and

ical trials and related clinical manufacturing, costs of drug development, costs of materials and supplies, facilities cost, overhead costs, regulatory and compliance costs, and fees paid to consultants and other entities that conduct certain research and development activities on the Company’s behalf. Costs incurred in research and development are expensed as incurred.

expenses are recognized as expense in the statements of operations as the Company receives the related goods or services.

as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using the tax rates that are expected to apply to taxable income for the years in which those tax assets and liabilities are expected to be realized or settled. Valuation allowances are recorded to reduce deferred tax assets to the amount the Company believes is more likely than not to be realized.

t the tax position will be upheld on examination by the taxing authorities based on the merits of the position. The Company recognizes interest and penalties, if any, related to unrecognized income tax uncertainties in income tax expense. The Company did not have any accrued interest or penalties associated with uncertain tax positions as of  and 

the Company is no longer subject to U.S. federal and state and local income tax examinations for years prior to although carryforward attributes that were generated prior to still be adjusted upon examination by the Internal Revenue Service if used in a future period. No income tax returns are currently under examination by taxing authorities.

two

entitle the holders to participate in dividends and earnings of the Company. The -class method requires earnings for the period to be allocated between common stock and participating securities based upon their respective rights to receive distributed and undistributed earnings. Holders of each series of the Company’s redeemable convertible preferred stock are entitled to participate in distributions, when and if declared by the board of directors, that are made to common stockholders and, as a result, are considered participating securities.

April

5,

2012,

JOBS Act”) into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an emerging growth company. As an emerging growth company, the Company elect to adopt new or revised accounting standards when they become effective for non-public companies, which typically is later than public companies must adopt the standards. The Company has elected not to take advantage of the extended transition period afforded by the JOBS Act and, as a result, will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies.

June

2014,

issued ASU - (Topic (“ASU - The amendments require that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. ASU - is effective for annual periods and interim periods within those annual periods beginning after Entities apply ASU - either (a) prospectively to all awards granted or modified after the effective date or (b) retrospectively to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter. The Company prospectively adopted ASU - effective The adoption of ASU - did not have a material impact on the financial statements as the Company does not have any performance-based awards whereby performance could be achieved after the requisite service period.

August

2014,

2014

15,

(“ASU - which amends ASC Subtopic - to provide guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosures. Specifically, the amendments provide a definition of the term “substantial doubt,” require an evaluation every reporting period, provide principles for considering the mitigating effect of management’s plans, require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, require an express statement and other disclosures when substantial doubt is not alleviated and require an assessment for a period of year after the date that financial statements are issued. ASU - is effective for fiscal years ending after and for annual periods and interim periods thereafter.

2014

15

’s financial statements as the Company determined there was no substantial doubt about its ability to continue as a going concern as of

January

2015,

2015

01,

, which eliminates from GAAP the concept of extraordinary items, stating that the concept causes uncertainty because it is unclear when an item should be considered both unusual and infrequent and users do not find the classification and presentation necessary to identify those events and transactions. ASU - is effective for fiscal years, and interim periods within those fiscal years, beginning after The Company adopted ASU - effective The adoption of ASU - did not have a material impact on the Company’s financial statements as the Company had no extraordinary and/or unusual items recorded in prior periods.

April

2015,

2015

03,

d to a recognized debt liability be presented in the balance sheet as direct deduction from the carrying amount of that debt liability, consistent with the presentation of debt discounts. This guidance is effective for financial statements issued for fiscal years beginning after and interim periods within those fiscal years. The adoption of ASU - reduced the Company’s assets and liabilities by the amount of the debt issuance costs, which was million at This reclassification had no effect on reported net loss or cash flows.