Document and Entity Information
Document and Entity Information - shares | 3 Months Ended | |
Mar. 31, 2018 | Apr. 30, 2018 | |
Document And Entity Information [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Mar. 31, 2018 | |
Document Fiscal Year Focus | 2,018 | |
Document Fiscal Period Focus | Q1 | |
Trading Symbol | UMRX | |
Entity Registrant Name | UNUM THERAPEUTICS INC. | |
Entity Central Index Key | 1,622,229 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Non-accelerated Filer | |
Entity Common Stock, Shares Outstanding | 29,839,086 |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
Current assets: | ||
Cash and cash equivalents | $ 25,704 | $ 28,270 |
Marketable securities | 6,696 | 12,691 |
Accounts receivable | 1,601 | 830 |
Prepaid expenses and other current assets | 1,176 | 513 |
Restricted cash | 50 | 75 |
Total current assets | 35,227 | 42,379 |
Property and equipment, net | 3,902 | 4,108 |
Restricted cash | 1,255 | 1,255 |
Deferred offering costs | 2,612 | 1,373 |
Other assets | 419 | |
Total assets | 43,415 | 49,115 |
Current liabilities: | ||
Accounts payable | 3,083 | 1,346 |
Accrued expenses and other current liabilities | 2,358 | 2,953 |
Deferred revenue | 17,519 | 6,891 |
Total current liabilities | 22,960 | 11,190 |
Deferred rent | 902 | 906 |
Deferred revenue, net of current portion | 3,655 | 8,714 |
Total liabilities | 27,517 | 20,810 |
Commitments and contingencies (Note 11) | ||
Redeemable convertible preferred stock (Series A and B), $0.001 par value; 20,791,407 shares authorized at March 31, 2018 and December 31, 2017; 20,771,850 shares issued and outstanding at March 31, 2018 and December 31, 2017; liquidation preference of $77,297 at March 31, 2018 and December 31, 2017 | 77,167 | 77,151 |
Stockholders' deficit: | ||
Common stock, $0.001 par value; 60,040,000 shares authorized at March 31, 2018 and December 31, 2017; 10,208,058 shares and 10,201,690 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively | 10 | 10 |
Additional paid-in capital | 2,990 | 2,499 |
Accumulated other comprehensive loss | (7) | (16) |
Accumulated deficit | (64,262) | (51,339) |
Total stockholders' deficit | (61,269) | (48,846) |
Total liabilities, redeemable convertible preferred stock and stockholders' deficit | $ 43,415 | $ 49,115 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
Statement of Financial Position [Abstract] | ||
Redeemable convertible preferred stock (Series A and B), Par value | $ 0.001 | $ 0.001 |
Redeemable convertible preferred stock (Series A and B), Shares authorized | 20,791,407 | 20,791,407 |
Redeemable convertible preferred stock (Series A and B), Shares issued | 20,771,850 | 20,771,850 |
Redeemable convertible preferred stock (Series A and B), Shares outstanding | 20,771,850 | 20,771,850 |
Redeemable convertible preferred stock (Series A and B), Liquidation preference | $ 77,297 | $ 77,297 |
Common stock, Par value | $ 0.001 | $ 0.001 |
Common stock, Shares authorized | 60,040,000 | 60,040,000 |
Common stock, Shares issued | 10,208,058 | 10,201,690 |
Common stock, Shares outstanding | 10,208,058 | 10,201,690 |
Consolidated Statements of Oper
Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | |
Income Statement [Abstract] | ||
Collaboration revenue | $ 2,220 | $ 1,827 |
Operating expenses: | ||
Research and development | 8,142 | 6,952 |
General and administrative | 1,064 | 944 |
Total operating expenses | 9,206 | 7,896 |
Loss from operations | (6,986) | (6,069) |
Other income (expense): | ||
Interest income | 81 | 90 |
Other income, net | 170 | 40 |
Total other income, net | 251 | 130 |
Net loss | (6,735) | (5,939) |
Accretion of redeemable convertible preferred stock to redemption value | (16) | (16) |
Net loss attributable to common stockholders | $ (6,751) | $ (5,955) |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.66) | $ (0.58) |
Weighted average common shares outstanding, basic and diluted | 10,204,591 | 10,190,228 |
Comprehensive loss: | ||
Net loss | $ (6,735) | $ (5,939) |
Other comprehensive income (loss): | ||
Unrealized gains (losses) on marketable securities, net of tax of $0 | 9 | (12) |
Total other comprehensive income (loss) | 9 | (12) |
Comprehensive loss | $ (6,726) | $ (5,951) |
Consolidated Statements of Ope5
Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | |
Income Statement [Abstract] | ||
Unrealized gains (losses) on marketable securities, net of tax | $ 0 | $ 0 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | |
Cash flows from operating activities: | |||
Net loss | $ (6,735) | $ (5,939) | $ 25,500 |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation and amortization expense | 314 | 278 | |
Stock-based compensation expense | 479 | 300 | |
Premiums paid on marketable securities | (14) | ||
Net amortization of premiums on marketable securities | 4 | 2 | |
Non-cash interest expense | 5 | 4 | |
Changes in operating assets and liabilities: | |||
Accounts receivable | (771) | 41 | |
Prepaid expenses and other current assets | (668) | (185) | |
Other assets | (419) | ||
Accounts payable | 1,341 | (61) | |
Accrued expenses and other current liabilities | (908) | (761) | |
Deferred rent | (4) | 8 | |
Deferred revenue | (619) | (941) | |
Net cash used in operating activities | (7,981) | (7,268) | |
Cash flows from investing activities: | |||
Purchases of property and equipment | (75) | (320) | |
Purchases of marketable securities | (4,500) | ||
Maturities and sales of marketable securities | 6,000 | 4,000 | |
Net cash provided by (used in) investing activities | 5,925 | (820) | |
Cash flows from financing activities: | |||
Proceeds from issuance of common stock upon stock option exercises | 28 | ||
Payments of initial public offering costs | (563) | ||
Net cash used in financing activities | (535) | ||
Net decrease in cash, cash equivalents and restricted cash | (2,591) | (8,088) | |
Cash, cash equivalents and restricted cash at beginning of period | 29,600 | 42,576 | 42,576 |
Cash, cash equivalents and restricted cash at end of period | 27,009 | 34,488 | $ 29,600 |
Supplemental disclosure of noncash investing and financing information: | |||
Purchases of property and equipment included in accounts payable | 108 | ||
Deferred offering costs included in accounts payable and accrued expenses | 956 | ||
Accretion of redeemable convertible preferred stock to redemption value | $ 16 | $ 16 |
Nature of the Business and Basi
Nature of the Business and Basis of Presentation | 3 Months Ended |
Mar. 31, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Nature of the Business and Basis of Presentation | 1. Nature of the Business and Basis of Presentation Unum Therapeutics Inc. (“Unum” or the “Company”) is a clinical-stage biopharmaceutical company focused on the development and commercialization of novel immunotherapy products designed to harness the power of a patient’s immune system to cure cancer. The Company’s proprietary technology, called antibody-coupled T cell receptor (“ACTR”), is a universal, engineered cell therapy that is intended to be used in combination with a wide range of tumor-specific antibodies to target different tumor types. Unum was incorporated in March 2014 under the laws of the State of Delaware . The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. On March 16, 2018, the Company effected a one-for-1.5701314513884 On April 3, 2018, the Company completed an initial public offering (“IPO”) of its common stock and issued and sold 5,770,000 shares of common stock at a public offering price of $12.00 per share, resulting in net proceeds of $64.4 million after deducting underwriting discounts and commissions but before deducting offering costs. In addition, Seattle Genetics, Inc. (“Seattle Genetics”) purchased from the Company, concurrently with the IPO in a private placement, $5.0 million of shares of common stock at a price per share equal to the initial public offering price, or 416,666 shares (the “concurrent private placement”). The shares of common stock sold to Seattle Genetics in the concurrent private placement are not registered under the Securities Act of 1933, as amended, and are subject to a 180-day lock-up Upon closing of the IPO, the Company’s outstanding redeemable convertible preferred stock automatically converted into shares of common stock (see Note 7). Upon conversion of the redeemable convertible preferred stock, the Company reclassified the carrying value of the redeemable convertible preferred stock to common stock and additional paid-in On April 25, 2018, the Company issued and sold an additional 215,000 shares of its common stock at the IPO price of $12.00 per share pursuant to the underwriters’ partial exercise of their option to purchase additional shares of common stock, resulting in additional net proceeds of $2.4 million after deducting underwriting discounts and commissions. The accompanying consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has funded its operations with the sales of redeemable convertible preferred stock, payments received in connection with a collaboration agreement, and most recently, with proceeds from the IPO and concurrent private placement completed in April 2018. The Company has incurred recurring losses since inception, including net losses attributable to the Company of $6.7 million for the three months ended March 31, 2018 and $25.5 million for the year ended December 31, 2017. As of March 31, 2018, the Company had an accumulated deficit of $64.3 million. The Company expects to continue to generate operating losses in the foreseeable future. As of May 14, 2018, the issuance date of the interim consolidated financial statements, the Company expects that its cash, cash equivalents and marketable securities, including net proceeds it received from the completion of its IPO and concurrent private placement in April 2018, will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance date of the interim consolidated financial statements, without considering available borrowings under the Company’s loan and security agreement. The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany accounts and transactions have been eliminated in consolidation. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 3 Months Ended |
Mar. 31, 2018 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Unaudited Interim Financial Information The consolidated balance sheet at December 31, 2017 was derived from audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of March 31, 2018 and for the three months ended March 31, 2018 and 2017 have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s Registration Statement on Form S-1, No. 333-223414 Concentrations of Credit Risk and of Significant Suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains most of its cash and cash equivalents at three accredited financial institutions. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company is dependent on third-party vendors for its product candidates. In particular, the Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and process its product candidates for its development programs. These programs could be adversely affected by a significant interruption in the manufacturing process. Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents consisted of money market funds at March 31, 2018 and December 31, 2017. Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of the Company’s accounts receivable, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. Marketable Securities The Company’s marketable securities are classified as available-for-sale and The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations and comprehensive loss. No such adjustments were necessary during the periods presented. Classification and Accretion of Redeemable Convertible Preferred Stock The Company has classified redeemable convertible preferred stock outside of stockholders’ equity (deficit) because the shares contain certain redemption features that are not solely within the control of the Company. The carrying values of the redeemable convertible preferred stock are accreted to their respective redemption values from the date of issuance through the earliest date of redemption. Collaboration Agreements The Company follows the accounting guidance for collaboration agreements, which requires that certain transactions between the Company and collaborators be recorded in its consolidated statements of operations and comprehensive loss on either a gross basis or net basis, depending on the characteristics of the collaborative relationship, and requires enhanced disclosure of collaborative relationships. The Company evaluates its collaboration agreements for proper classification in its consolidated statements of operations and comprehensive loss based on the nature of the underlying activity. If payments to and from collaborative partners are not within the scope of other authoritative accounting literature, the consolidated statements of operations classification for the payments is based on a reasonable, rational analogy to authoritative accounting literature that is applied in a consistent manner. When the Company has concluded that it has a customer relationship with one of its collaborators, such as that with Seattle Genetics (see Note 5), the Company follows the guidance in Accounting Standards Codification (“ASC”) Topic 606, Revenue From Contracts With Customers Revenue Recognition of Collaboration Agreements On January 1, 2018, the Company adopted the new revenue standard, discussed below under the heading “Recently Adopted Accounting Pronouncements”, which amended revenue recognition principles and provides a single, comprehensive set of criteria for revenue recognition within and across all industries. The new revenue standard provides a five-step framework whereby revenue is recognized when control of promised goods or services is transferred to a customer at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of the new revenue standard, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when collectability of the consideration to which the Company is entitled in exchange for the goods or services it transfers to the customer is determined to be probable. At contract inception, once the contract is determined to be within the scope of the new revenue standard, the Company assesses whether the goods or services promised within each contract are distinct and, therefore, represent a separate performance obligation. Goods and services that are determined not to be distinct are combined with other promised goods and services until a distinct bundle is identified. In determining whether goods or services are distinct, management evaluates certain criteria, including whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (capable of being distinct) and (ii) the good or service is separately identifiable from other goods or services in the contract (distinct in the context of the contract). At the inception of an arrangement that includes options for a customer to purchase additional services or products at agreed upon prices in the future, the Company evaluates whether each option provides a material right. An option that provides a material right will be accounted for as a separate performance obligation. The Company then determines the transaction price, which is the amount of consideration it expects to be entitled from a customer in exchange for the promised goods or services, for each performance obligation and recognizes the associated revenue as each performance obligation is satisfied. The Company’s estimate of the transaction price for each contract includes all variable consideration to which it expects to be entitled. Variable consideration includes payments in the form of collaboration payments, regulatory milestone payments, commercial milestone payments, and royalty payments. For collaboration, regulatory milestone, and commercial milestone payments the Company evaluates whether it is probable that the consideration associated with each milestone will not be subject to a significant reversal in the cumulative amount of revenue recognized. Amounts that meet this threshold are included in the transaction price using the most likely amount method, whereas amounts that do not meet this threshold are considered constrained and excluded from the transaction price until they meet this threshold. At the end of each subsequent reporting period, the Company re-evaluates catch-up The new revenue standard requires the Company to allocate the arrangement consideration on a relative standalone selling price basis for each performance obligation after determining the transaction price of the contract and identifying the performance obligations to which that amount should be allocated. The relative standalone selling price is defined in the new revenue standard as the price at which an entity would sell a promised good or service separately to a customer. If other observable transactions in which the Company has sold the same performance obligation separately are not available, the Company is required to estimate the standalone selling price of each performance obligation. Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. A performance obligation is satisfied and revenue is recognized when “control” of the promised good or service is transferred, either over time or at a point in time, to the customer. A customer obtains control of a good or service if it has the ability to (1) direct its use and (2) obtain substantially all of the remaining benefits from it. If a contract should be accounted for as a combined performance obligation, the Company determines the period over which the performance obligations will be performed and revenue will be recognized. The Company will recognize revenue using the cost-to-cost cost-to-cost catch-up Amounts received prior to satisfying the revenue recognition criteria listed above are recorded as deferred revenue in the accompanying consolidated balance sheets. Amounts expected to be recognized as revenue within 12 months of the balance sheet date are classified as current deferred revenue. Amounts not expected to be recognized as revenue within the following 12 months of the balance sheet date are classified as deferred revenue, net of current portion. At March 31, 2018, the Company had current deferred revenue and deferred revenue, net of current portion of $17.5 million and $3.7 million, respectively, related to its collaboration. The Company recognized revenue of $2.2 million during three months ended March 31, 2018 from the deferred revenue balance at January 1, 2018. The Company recognizes deferred revenue by first allocating from the beginning deferred revenue balance to the extent the beginning deferred revenue balance exceeds the revenue to be recognized. Billings during the period are added to the deferred revenue balance to be recognized in future periods. To the extent that the beginning deferred revenue balance is less than revenue to be recognized during the period, billings during the period are allocated to revenue. In the event that a collaboration agreement was to be terminated and the Company had no further performance obligations, the Company would recognize as revenue any portion of the upfront payment and other payments that had not previously been recorded as revenue and were classified as deferred revenue at the date of such termination. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less or the amount is immaterial. At March 31, 2018, the Company has not capitalized any costs to obtain its contract. Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) 2014-09”), 2014-09 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date 2014-09 No. 2014-09 2014-09, On January 1, 2018, the Company adopted the new revenue standard by applying the modified retrospective method to its collaboration agreement with Seattle Genetics (see Note 5) which was not completed as of January 1, 2018. As a result, while reporting periods beginning on the Company’s adoption of the new revenue standard are presented under the new revenue standard, prior period amounts have not been adjusted and continue to be presented under the revenue standard in effect prior to January 1, 2018. The following table summarizes the cumulative effect to the Company’s consolidated balance sheet upon the adoption of the new revenue standard on January 1, 2018 (in thousands): Balance at December 31, 2017 Adjustments Balance at January 1, 2018 Deferred revenue, current and net of current portion $ 15,605 $ 6,188 $ 21,793 Accumulated deficit $ (51,339 ) $ (6,188 ) $ (57,527 ) The $6.2 million adjustment is the result of the application of the new revenue standard regarding how entities should measure progress in satisfying performance obligations and the contract’s transaction price. Under ASC 606, the Company will recognize revenue using the cost-to-cost The Company will account for the license, research and development services, and steering committee services under ASC 606 as a single performance obligation under the collaboration agreement, just as it accounted for those items as a single unit of accounting under the previous standard. The options held by Seattle Genetics are expected to continue to be accounted for separately as they do not represent material rights based on the criteria of ASC 606. Further, ASC 606 will not have an impact on the Company’s current accounting for milestone or royalty payments. In accordance with the new revenue standard requirements, the following tables summarize the impact of adoption on the Company’s consolidated balance sheets, consolidated statements of operations and comprehensive loss, and consolidated statements of cash flows (in thousands): Consolidated Balance Sheets At March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Deferred revenue, current portion $ 17,519 $ 7,222 $ 10,297 Deferred revenue, net of current portion $ 3,655 $ 7,323 $ (3,668 ) Accumulated deficit $ (64,262 ) $ (57,633 ) $ (6,629 ) Consolidated Statements of Operations and Comprehensive Loss Three Months Ended March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Collaboration revenue $ 2,220 $ 2,661 $ (441 ) Net loss $ (6,735 ) $ (6,294 ) $ (441 ) Net loss attributable to common stockholders $ (6,751 ) $ (6,310 ) $ (441 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.66 ) $ (0.62 ) $ (0.04 ) Comprehensive loss $ (6,726 ) $ (6,285 ) $ (441 ) Consolidated Statements of Cash Flows Three Months Ended March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Net loss $ (6,735 ) $ (6,294 ) $ (441 ) Change in deferred revenue $ (619 ) $ (1,060 ) $ 441 In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments 2016-15”), In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows, Restricted Cash beginning-of-period end-of-period In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09”), Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2016-02”), right-of-use 2016-02 In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception 2017-11”) . 2017-11 2017-11 |
Fair Value of Financial Assets
Fair Value of Financial Assets and Liabilities | 3 Months Ended |
Mar. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair Value of Financial Assets and Liabilities | 3. Fair Value of Financial Assets and Liabilities Marketable securities by security type consisted of the following (in thousands): March 31, 2018 Amortized Gross Gross Fair U.S. Treasury notes (due within one year) $ 4,003 $ — $ (5 ) $ 3,998 U.S. government agency bonds (due within one year) 2,700 — (2 ) 2,698 $ 6,703 $ — $ (7 ) $ 6,696 December 31, 2017 Amortized Gross Gross Fair U.S. Treasury notes (due within one year) $ 5,007 $ — $ (10 ) $ 4,997 U.S. government agency bonds (due within one year) 7,700 — (6 ) 7,694 $ 12,707 $ — $ (16 ) $ 12,691 The following tables present information about the Company’s assets that are measured at fair value on a recurring basis (in thousands): Fair Value Measurements at March 31, 2018 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 22,293 $ — $ 22,293 Marketable securities: U.S. Treasury notes 3,998 — — 3,998 U.S. government agency bonds — 2,698 — 2,698 $ 3,998 $ 24,991 $ — $ 28,989 Fair Value Measurements at December 31, 2017 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 24,196 $ — $ 24,196 Marketable securities: U.S. Treasury notes 4,997 — — 4,997 U.S. government agency bonds — 7,694 — 7,694 $ 4,997 $ 31,890 $ — $ 36,887 During the three months ended March 31, 2018 and 2017, there were no transfers between Level 1, Level 2 and Level 3. |
Accrued Expenses and Other Curr
Accrued Expenses and Other Current Liabilities | 3 Months Ended |
Mar. 31, 2018 | |
Payables and Accruals [Abstract] | |
Accrued Expenses and Other Current Liabilities | 4. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): March 31, 2018 December 31, 2017 Accrued employee compensation and benefits $ 357 $ 1,315 Accrued professional fees 964 980 Accrued external research and development expense 806 478 Accrued other 231 180 $ 2,358 $ 2,953 |
Collaboration Agreement
Collaboration Agreement | 3 Months Ended |
Mar. 31, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Collaboration Agreement | 5. Collaboration Agreement The Company has a collaboration agreement with Seattle Genetics, entered into in 2015, whereby the parties agreed to jointly develop two product candidates incorporating the Company’s ACTR platform and Seattle Genetics’ antibodies. Under the collaboration agreement, the Company conducts preclinical research and clinical development activities related to the two specified product candidates through Phase I clinical development, and Seattle Genetics provides the funding for those activities. Under the collaboration agreement, the Company recognized revenue of $2.2 million and $1.8 million for the three months ended March 31, 2018 and 2017, respectively, related to research and clinical development activities performed. As of March 31, 2018 and December 31, 2017, deferred revenue of $21.2 million and $15.6 million, respectively, was recorded related to this agreement. As noted in Note 2 above, deferred revenue was increased by $6.2 million as of January 1, 2018 upon adoption of ASC 606. As of March 31, 2018, the aggregate amount of the transaction price allocated to the remaining performance obligation for preclinical research and clinical development activities related to the two specified product candidates through Phase I is estimated to be $76.0 million, which is expected to be recognized as revenue through December 31, 2022. |
Loan and Security Agreement
Loan and Security Agreement | 3 Months Ended |
Mar. 31, 2018 | |
Debt Disclosure [Abstract] | |
Loan and Security Agreement | 6. Loan and Security Agreement In January 2017, the Company entered into a loan and security agreement (the “Loan Agreement”) with Pacific Western Bank (“PWB”), which provides for term loan borrowings of up to $15.0 million through January 19, 2019. Borrowings under the Loan Agreement bear interest at a variable annual rate equal to the greater of (i) the prime rate plus 0.25% or (ii) 3.75%, and are payable over an interest-only period until January 19, 2019, followed by a 24-month In connection with the Loan Agreement, the Company agreed to enter into warrant agreements with PWB pursuant to which warrants will be issued to purchase a number of shares of the Company’s capital stock equal to 1% of the amount of each term loan borrowing under the Loan Agreement, divided by the applicable exercise price. No amounts have been borrowed as term loans under the Loan Agreement as of March 31, 2018. Borrowings under the Loan Agreement are collateralized by substantially all of the Company’s assets, except for its intellectual property. Under the Loan Agreement, the Company has agreed to affirmative and negative covenants to which it will remain subject until maturity. These covenants include limitations on the Company’s ability to incur additional indebtedness and engage in certain fundamental business transactions, such as mergers or acquisitions of other businesses. There are no financial covenants associated with the Loan Agreement. Events of default under the Loan Agreement include failure to make payments when due, insolvency events, failure to comply with covenants and material adverse effects with respect to the Company. |
Redeemable Convertible Preferre
Redeemable Convertible Preferred Stock | 3 Months Ended |
Mar. 31, 2018 | |
Equity [Abstract] | |
Redeemable Convertible Preferred Stock | 7. Redeemable Convertible Preferred Stock The Company issued Series A redeemable convertible preferred stock (the “Series A preferred stock”) and Series B redeemable convertible preferred stock (the “Series B preferred stock”). The Series A preferred stock and the Series B preferred stock are collectively referred to as the “Preferred Stock”. The Preferred Stock converted to shares of common stock on a 1:1.5701314513884 basis upon the closing of the IPO. As of each balance sheet date, the Preferred Stock consisted of the following (in thousands, except share amounts): As of March 31, 2018 Preferred Stock Preferred Carrying Value Liquidation Common Stock Series A preferred stock 12,297,276 12,297,276 $ 12,271 $ 12,297 7,832,001 Series B preferred stock 8,494,131 8,474,574 64,896 65,000 5,397,361 20,791,407 20,771,850 $ 77,167 $ 77,297 13,229,362 As of December 31, 2017 Preferred Stock Preferred Carrying Value Liquidation Common Stock Series A preferred stock 12,297,276 12,297,276 $ 12,267 $ 12,297 7,832,001 Series B preferred stock 8,494,131 8,474,574 64,884 65,000 5,397,361 20,791,407 20,771,850 $ 77,151 $ 77,297 13,229,362 Prior to the closing of the IPO, the holders of the Preferred Stock had the following rights and preferences: Voting The holders of Preferred Stock are entitled to vote, together with the holders of common stock, on matters submitted to stockholders for a vote. The holders of Preferred Stock are entitled to the number of votes equal to the number of common shares into which each such share of Preferred Stock could convert. In addition, the holders of Series A preferred stock, voting exclusively and as a separate class, are entitled to elect two directors of the Company. The holders of Series B preferred stock, voting exclusively and as a separate class, are entitled to elect one director of the Company. Conversion Each share of Preferred Stock is convertible at the option of the holder at any time after the date of issuance. Each share of Preferred Stock will be automatically converted into shares of common stock at the applicable conversion ratio then in effect upon the closing of a firm commitment public offering with at least $50.0 million of gross proceeds to the Company. Shares of Series A preferred stock will be automatically converted into shares of common stock at the applicable conversion ratio then in effect upon written consent of the holders of at least 65% of the then-outstanding shares of Series A preferred stock. Shares of Series B preferred stock will be automatically converted into shares of common stock at the applicable conversion ratio then in effect upon written consent of the holders of at least a majority of the then-outstanding shares of Series B preferred stock. The conversion ratio of each series of Preferred Stock is determined by dividing the Original Issue Price of each series by the Conversion Price of each series. The Original Issue Price is $1.00 per share for Series A preferred stock and $7.67 per share for Series B preferred stock. The Conversion Price at issuance was $1.570131 per share for Series A preferred stock and $12.042908 per share for Series B preferred stock, subject to appropriate adjustment in the event of any stock split, stock dividend, combination or other similar recapitalization and other adjustments as set forth in the Company’s certificate of incorporation, as amended and restated. Dividends The holders of Preferred Stock are entitled to receive noncumulative dividends if and when declared by the Company’s board of directors. The Company may not declare, pay or set aside any dividends on shares of any other series of capital stock of the Company, other than dividends on common stock payable in common stock, unless the holders of the Series A and Series B preferred stock first receive, or simultaneously receive, a dividend on each outstanding share of Series A and Series B preferred stock in an amount at least equal to the greater of (i) $0.08 per share in the case of Series A preferred stock and $0.61 per share in the case of Series B preferred stock, each subject to appropriate adjustment in the event of any stock split, stock dividend, combination or other similar recapitalization with respect to such shares, and (ii) (A) in the case of a dividend on common stock or any class or series of stock that is convertible into common stock, that dividend per share of Preferred Stock as would equal the product of (1) the dividend payable on each share of such class or series determined, if applicable, as if all shares of such class or series had been converted into common stock and (2) the number of shares of common stock issuable upon conversion of each share of Preferred Stock, or (B) in the case of a dividend on any class or series that is not convertible into common stock, at a rate per share of Preferred Stock determined by (1) dividing the amount of the dividend payable on each share of such class or series of capital stock by the Original Issue Price of such class or series of capital stock (subject to appropriate adjustment in the event of any stock dividend, stock split, combination of or other similar recapitalization affecting such shares) and (2) multiplying such fraction by an amount equal to the Original Issue Price of each series of Preferred Stock. If the Company declares, pays or sets aside, on the same date, a dividend on shares of more than one class or series of capital stock of the Company, the dividend payable to the holders of the Preferred Stock shall be calculated based upon the dividend on the class or series of capital stock that would result in the highest Preferred Stock dividend. Stockholders are not entitled to any accruing dividends. Through March 31, 2018 and December 31, 2017, no dividends were declared or paid. Liquidation In the event of any voluntary or involuntary liquidation, dissolution or winding-up Unless the holders of at least two-thirds as-converted Redemption At any time on or after June 10, 2020, shares of each of the Series A and Series B preferred stock are subject to mandatory redemption by the Company in three equal annual installments beginning 60 days after receipt of a notice of redemption from the holders of at least two-thirds |
Common Stock
Common Stock | 3 Months Ended |
Mar. 31, 2018 | |
Equity [Abstract] | |
Common Stock | 8. Common Stock Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are not entitled to receive dividends, unless declared by the board of directors. |
Stock-Based Compensation
Stock-Based Compensation | 3 Months Ended |
Mar. 31, 2018 | |
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
Stock-Based Compensation | 9. Stock-Based Compensation 2015 Stock Incentive Plan The Company’s 2015 Stock Incentive Plan (the “2015 Plan”) provides for the Company to grant incentive stock options or nonqualified stock options, restricted stock, restricted stock units and other equity awards to employees, directors and consultants of the Company. The 2015 Plan is administered by the board of directors or, at the discretion of the board of directors, by a committee of the board of directors. The board of directors may also delegate to one or more officers of the Company the power to grant awards to employees and certain officers of the Company. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or its committee if so delegated. Stock options granted under the 2015 Plan with service-based vesting conditions generally vest over four years and expire after ten years. The total number of shares of common stock that may be issued under the 2015 Plan was 4,144,876 shares as of March 31, 2018. Upon effectiveness of the Company’s 2018 Stock Option and Incentive Plan, the (“2018 Plan”) in March 2018, the remaining 1,041,700 shares available under the 2015 Plan became available for issuance under the 2018 Plan and no future issuance will be made under the 2015 Plan. Additionally, outstanding options under the 2015 Plan that are expired, terminated, surrendered or canceled without having been fully exercised will be available for future awards under the 2018 Plan. The exercise price for stock options granted is not less than the fair value of common shares as determined by the board of directors as of the date of grant. The Company’s board of directors values the Company’s common stock, taking into consideration its most recently available valuation of common stock performed by third parties as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant. 2018 Stock Option and Incentive Plan On March 16, 2018, the Company’s stockholders approved the 2018 Plan, which became effective on March 27, 2018. The 2018 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights. The number of shares initially reserved for issuance under the 2018 Plan is 2,800,721 plus the 1,041,700 shares of common stock remaining available for issuance under the 2015 Plan. The number of shares reserved shall be cumulatively increased on January 1, 2019 and each January 1 thereafter by 4% of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or a lesser number of shares determined by the Company’s board of directors. The shares of common stock underlying any awards that are forfeited, canceled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, repurchased or are otherwise terminated by the Company under the 2018 Plan or the 2015 Plan will be added back to the shares of common stock available for issuance under the 2018 Plan. As of March 31, 2018, 3,065,350 shares remained available for future issuance under the 2018 Plan. 2018 Employee Stock Purchase Plan On March 16, 2018, the Company’s stockholders approved the 2018 Employee Stock Purchase Plan (the “ESPP”), which became effective on March 28, 2018. A total of 314,000 shares of common stock were reserved for issuance under this plan. In addition, the number of shares of common stock that may be issued under the ESPP will automatically increase on January 1, 2019, and each January 1 thereafter through January 1, 2027, by the least of (i) 500,000 shares of common stock, (ii) 1% of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or (iii) such lesser number of shares as determined by the ESPP administrator. Stock Option Issuances During the three months ended March 31, 2018, the Company granted options to employees, consultants and directors for the purchase of 777,071 shares of common stock with exercise prices of $12.00 per share and a weighted average grant-date fair value of $6.28 per share. Stock-Based Compensation The Company recorded stock-based compensation expense in the following expense categories of its consolidated statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2018 2017 Research and development expenses $ 401 $ 260 General and administrative expenses 78 40 Total $ 479 $ 300 As of March 31, 2018, total unrecognized compensation cost related to the unvested stock-based awards was $9.8 million, which is expected to be recognized over a weighted average period of 3.0 years. |
Income Taxes
Income Taxes | 3 Months Ended |
Mar. 31, 2018 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 10. Income Taxes 2017 U.S. Tax Reform On December 22, 2017, the Tax Cuts and Jobs Act (the “TCJA”) was signed into United States law. The TCJA includes a number of changes to existing tax law, including, among other things, a permanent reduction in the federal corporate income tax rate from 34% to 21%, effective as of January 1, 2018, as well as limitation of the deduction for net operating losses to 80% of annual taxable income and elimination of net operating loss carrybacks, in each case, for losses arising in taxable years beginning after December 31, 2017 (though any such net operating losses may be carried forward indefinitely). The tax rate change resulted in (i) a reduction in the gross amount of the Company’s deferred tax assets recorded as of December 31, 2017, without an impact on the net amount of its deferred tax assets, which are recorded with a full valuation allowance, and (ii) no income tax expense or benefit being recognized as of the enactment date of the TCJA. In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) which allows the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. Since the Act was passed late in the fourth quarter of 2017, and ongoing guidance and accounting interpretation are expected over the next 12 months, the Company considers the accounting for the effect of the TCJA to be provisional in accordance with SAB 118 at March 31, 2018. Income Taxes During the three months ended March 31, 2018 and 2017, the Company recorded no income tax benefits for the net operating losses incurred or for the research and development tax credits generated in each year due to its uncertainty of realizing a benefit from those items. The Company has provided a valuation allowance for the full amounts of its net deferred tax assets because, at March 31, 2018 and December 31, 2017, it was more likely than not that any future benefit from deductible temporary differences and net operating loss and tax credit carryforwards would not be realized. As of March 31, 2018 and December 31, 2017, the Company had not recorded any amounts for unrecognized tax benefits. The Company files income tax returns in the U.S. and Massachusetts. The statute of limitations for assessment by the Internal Revenue Service and Massachusetts tax authorities remains open for all years since 2014. No federal or state tax audits are currently in process. |
Commitments and Contingencies
Commitments and Contingencies | 3 Months Ended |
Mar. 31, 2018 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 11. Commitments and Contingencies Operating Leases The Company leases its facility under a non-cancelable cash securing this letter of credit has been classified as non-current The following table summarizes the future minimum payments due under the operating leases as of March 31, 2018 (in thousands): Year Ending December 31, 2018 (nine months ending December 31) $ 1,378 2019 1,878 2020 1,933 2021 1,989 2022 2,046 Thereafter 689 $ 9,913 Rent expense for the three months ended March 31, 2018 and 2017 was $0.4 million and $0.4 million, respectively. In January 2017, the Company entered into a 12-month 12-month License Agreement Under its license agreement with National University of Singapore and St. Jude Children’s Research Hospital, Inc. (collectively the “Licensors”) entered into in 2014, the Company is obligated to pay license maintenance fees on each anniversary of the effective date of the agreement that escalate from less than $0.1 million for each of the first seven years to $0.1 million on the eighth anniversary and each year thereafter. The Company is also obligated to make aggregate milestone payments of up to 5.5 million Singapore dollars (equivalent to approximately $4.2 million as of March 31, 2018) upon the achievement of specified clinical and regulatory milestones and to pay tiered royalties ranging in the low single-digit percentages on annual net sales of licensed products sold by the Company or its sublicensees. The royalties are payable on a product-by-product country-by-country The license agreement will expire on a country-by-country Manufacturing Commitment As of March 31, 2018, the Company had non-cancelable Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and its executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of March 31, 2018 or December 31, 2017. Legal Proceedings The Company is not currently party to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses as incurred the costs related to such legal proceedings. |
Net Loss Per Share
Net Loss Per Share | 3 Months Ended |
Mar. 31, 2018 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 12. Net Loss Per Share Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2018 2017 Numerator: Net loss $ (6,735 ) $ (5,939 ) Accretion of redeemable convertible preferred stock to redemption value (16 ) (16 ) Net loss attributable to common stockholders $ (6,751 ) $ (5,955 ) Denominator: Weighted average common shares outstanding, basic and diluted 10,204,591 10,190,228 Net loss per share attributable to common stockholders, basic and diluted $ (0.66 ) $ (0.58 ) The Company’s potential dilutive securities have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: March 31, 2018 2017 Redeemable convertible preferred shares (as converted to common stock) 13,229,362 13,229,362 Stock options to purchase common stock 3,873,879 2,549,808 17,103,241 15,779,170 |
Defined contribution plan
Defined contribution plan | 3 Months Ended |
Mar. 31, 2018 | |
Retirement Benefits [Abstract] | |
Defined contribution plan | 13. Retirement Plan The Company has a defined-contribution plan under Section 401(k) of the Internal Revenue Code (the “401(k) Plan”). The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax |
Subsequent Events
Subsequent Events | 3 Months Ended |
Mar. 31, 2018 | |
Subsequent Events [Abstract] | |
Subsequent Events | 14. Subsequent Events On April 3, 2018, the Company completed an IPO of its common stock, and issued and sold 5,770,000 shares of common stock at a public offering price of $12.00 per share, resulting in net proceeds of $64.4 million after deducting underwriting discounts and commissions but before deducting offering costs. On April 3, 2018, concurrent with the IPO, the Company completed the sale of $5.0 million of shares of common stock at the public offering price of $12.00 per share, or 416,666 shares, to Seattle Genetics in a concurrent private placement. These shares are not registered under the Securities Act of 1933, as amended, and are subject to a 180-day lock-up Upon closing of the IPO on April 3, 2018, the Company’s outstanding redeemable convertible preferred stock automatically converted into shares of common stock (see Note 7). Upon conversion of the redeemable convertible preferred stock, the Company reclassified the carrying value of the Preferred Stock to common stock and additional paid-in On April 25, 2018, in connection with the IPO, the Company issued and sold an additional 215,000 shares of its common stock at the IPO price of $12.00 per share, less underwriting discounts and commissions, pursuant to the underwriters’ partial exercise of their option to purchase additional shares of common stock, resulting in additional net proceeds to the Company of approximately $2.4 million after deducting underwriting discounts and commissions. |
Summary of Significant Accoun21
Summary of Significant Accounting Policies (Policies) | 3 Months Ended |
Mar. 31, 2018 | |
Accounting Policies [Abstract] | |
Unaudited Interim Financial Information | Unaudited Interim Financial Information The consolidated balance sheet at December 31, 2017 was derived from audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of March 31, 2018 and for the three months ended March 31, 2018 and 2017 have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s Registration Statement on Form S-1, No. 333-223414 |
Concentrations of Credit Risk and of Significant Suppliers | Concentrations of Credit Risk and of Significant Suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains most of its cash and cash equivalents at three accredited financial institutions. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company is dependent on third-party vendors for its product candidates. In particular, the Company relies, and expects to continue to rely, on a small number of vendors to manufacture supplies and process its product candidates for its development programs. These programs could be adversely affected by a significant interruption in the manufacturing process. |
Cash Equivalents | Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents consisted of money market funds at March 31, 2018 and December 31, 2017. |
Fair Value Measurements | Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of the Company’s accounts receivable, accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. |
Marketable Securities | Marketable Securities The Company’s marketable securities are classified as available-for-sale and The Company evaluates its marketable securities with unrealized losses for other-than-temporary impairment. When assessing marketable securities for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations and comprehensive loss. No such adjustments were necessary during the periods presented. |
Classification and Accretion of Redeemable Convertible Preferred Stock | Classification and Accretion of Redeemable Convertible Preferred Stock The Company has classified redeemable convertible preferred stock outside of stockholders’ equity (deficit) because the shares contain certain redemption features that are not solely within the control of the Company. The carrying values of the redeemable convertible preferred stock are accreted to their respective redemption values from the date of issuance through the earliest date of redemption. |
Collaboration Agreements | Collaboration Agreements The Company follows the accounting guidance for collaboration agreements, which requires that certain transactions between the Company and collaborators be recorded in its consolidated statements of operations and comprehensive loss on either a gross basis or net basis, depending on the characteristics of the collaborative relationship, and requires enhanced disclosure of collaborative relationships. The Company evaluates its collaboration agreements for proper classification in its consolidated statements of operations and comprehensive loss based on the nature of the underlying activity. If payments to and from collaborative partners are not within the scope of other authoritative accounting literature, the consolidated statements of operations classification for the payments is based on a reasonable, rational analogy to authoritative accounting literature that is applied in a consistent manner. When the Company has concluded that it has a customer relationship with one of its collaborators, such as that with Seattle Genetics (see Note 5), the Company follows the guidance in Accounting Standards Codification (“ASC”) Topic 606, Revenue From Contracts With Customers |
Revenue Recognition of Collaboration Agreements | Revenue Recognition of Collaboration Agreements On January 1, 2018, the Company adopted the new revenue standard, discussed below under the heading “Recently Adopted Accounting Pronouncements”, which amended revenue recognition principles and provides a single, comprehensive set of criteria for revenue recognition within and across all industries. The new revenue standard provides a five-step framework whereby revenue is recognized when control of promised goods or services is transferred to a customer at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To determine revenue recognition for arrangements that the Company determines are within the scope of the new revenue standard, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when collectability of the consideration to which the Company is entitled in exchange for the goods or services it transfers to the customer is determined to be probable. At contract inception, once the contract is determined to be within the scope of the new revenue standard, the Company assesses whether the goods or services promised within each contract are distinct and, therefore, represent a separate performance obligation. Goods and services that are determined not to be distinct are combined with other promised goods and services until a distinct bundle is identified. In determining whether goods or services are distinct, management evaluates certain criteria, including whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (capable of being distinct) and (ii) the good or service is separately identifiable from other goods or services in the contract (distinct in the context of the contract). At the inception of an arrangement that includes options for a customer to purchase additional services or products at agreed upon prices in the future, the Company evaluates whether each option provides a material right. An option that provides a material right will be accounted for as a separate performance obligation. The Company then determines the transaction price, which is the amount of consideration it expects to be entitled from a customer in exchange for the promised goods or services, for each performance obligation and recognizes the associated revenue as each performance obligation is satisfied. The Company’s estimate of the transaction price for each contract includes all variable consideration to which it expects to be entitled. Variable consideration includes payments in the form of collaboration payments, regulatory milestone payments, commercial milestone payments, and royalty payments. For collaboration, regulatory milestone, and commercial milestone payments the Company evaluates whether it is probable that the consideration associated with each milestone will not be subject to a significant reversal in the cumulative amount of revenue recognized. Amounts that meet this threshold are included in the transaction price using the most likely amount method, whereas amounts that do not meet this threshold are considered constrained and excluded from the transaction price until they meet this threshold. At the end of each subsequent reporting period, the Company re-evaluates catch-up The new revenue standard requires the Company to allocate the arrangement consideration on a relative standalone selling price basis for each performance obligation after determining the transaction price of the contract and identifying the performance obligations to which that amount should be allocated. The relative standalone selling price is defined in the new revenue standard as the price at which an entity would sell a promised good or service separately to a customer. If other observable transactions in which the Company has sold the same performance obligation separately are not available, the Company is required to estimate the standalone selling price of each performance obligation. Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. A performance obligation is satisfied and revenue is recognized when “control” of the promised good or service is transferred, either over time or at a point in time, to the customer. A customer obtains control of a good or service if it has the ability to (1) direct its use and (2) obtain substantially all of the remaining benefits from it. If a contract should be accounted for as a combined performance obligation, the Company determines the period over which the performance obligations will be performed and revenue will be recognized. The Company will recognize revenue using the cost-to-cost cost-to-cost catch-up Amounts received prior to satisfying the revenue recognition criteria listed above are recorded as deferred revenue in the accompanying consolidated balance sheets. Amounts expected to be recognized as revenue within 12 months of the balance sheet date are classified as current deferred revenue. Amounts not expected to be recognized as revenue within the following 12 months of the balance sheet date are classified as deferred revenue, net of current portion. At March 31, 2018, the Company had current deferred revenue and deferred revenue, net of current portion of $17.5 million and $3.7 million, respectively, related to its collaboration. The Company recognized revenue of $2.2 million during three months ended March 31, 2018 from the deferred revenue balance at January 1, 2018. The Company recognizes deferred revenue by first allocating from the beginning deferred revenue balance to the extent the beginning deferred revenue balance exceeds the revenue to be recognized. Billings during the period are added to the deferred revenue balance to be recognized in future periods. To the extent that the beginning deferred revenue balance is less than revenue to be recognized during the period, billings during the period are allocated to revenue. In the event that a collaboration agreement was to be terminated and the Company had no further performance obligations, the Company would recognize as revenue any portion of the upfront payment and other payments that had not previously been recorded as revenue and were classified as deferred revenue at the date of such termination. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that the Company would have recognized is one year or less or the amount is immaterial. At March 31, 2018, the Company has not capitalized any costs to obtain its contract. |
Recently Adopted and Issued Accounting Pronouncements | Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) 2014-09”), 2014-09 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date 2014-09 No. 2014-09 2014-09, On January 1, 2018, the Company adopted the new revenue standard by applying the modified retrospective method to its collaboration agreement with Seattle Genetics (see Note 5) which was not completed as of January 1, 2018. As a result, while reporting periods beginning on the Company’s adoption of the new revenue standard are presented under the new revenue standard, prior period amounts have not been adjusted and continue to be presented under the revenue standard in effect prior to January 1, 2018. The following table summarizes the cumulative effect to the Company’s consolidated balance sheet upon the adoption of the new revenue standard on January 1, 2018 (in thousands): Balance at December 31, 2017 Adjustments Balance at January 1, 2018 Deferred revenue, current and net of current portion $ 15,605 $ 6,188 $ 21,793 Accumulated deficit $ (51,339 ) $ (6,188 ) $ (57,527 ) The $6.2 million adjustment is the result of the application of the new revenue standard regarding how entities should measure progress in satisfying performance obligations and the contract’s transaction price. Under ASC 606, the Company will recognize revenue using the cost-to-cost The Company will account for the license, research and development services, and steering committee services under ASC 606 as a single performance obligation under the collaboration agreement, just as it accounted for those items as a single unit of accounting under the previous standard. The options held by Seattle Genetics are expected to continue to be accounted for separately as they do not represent material rights based on the criteria of ASC 606. Further, ASC 606 will not have an impact on the Company’s current accounting for milestone or royalty payments. In accordance with the new revenue standard requirements, the following tables summarize the impact of adoption on the Company’s consolidated balance sheets, consolidated statements of operations and comprehensive loss, and consolidated statements of cash flows (in thousands): Consolidated Balance Sheets At March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Deferred revenue, current portion $ 17,519 $ 7,222 $ 10,297 Deferred revenue, net of current portion $ 3,655 $ 7,323 $ (3,668 ) Accumulated deficit $ (64,262 ) $ (57,633 ) $ (6,629 ) Consolidated Statements of Operations and Comprehensive Loss Three Months Ended March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Collaboration revenue $ 2,220 $ 2,661 $ (441 ) Net loss $ (6,735 ) $ (6,294 ) $ (441 ) Net loss attributable to common stockholders $ (6,751 ) $ (6,310 ) $ (441 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.66 ) $ (0.62 ) $ (0.04 ) Comprehensive loss $ (6,726 ) $ (6,285 ) $ (441 ) Consolidated Statements of Cash Flows Three Months Ended March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Net loss $ (6,735 ) $ (6,294 ) $ (441 ) Change in deferred revenue $ (619 ) $ (1,060 ) $ 441 In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments 2016-15”), In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows, Restricted Cash beginning-of-period end-of-period In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09”), Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) 2016-02”), right-of-use 2016-02 In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception 2017-11”) . 2017-11 2017-11 |
Summary of Significant Accoun22
Summary of Significant Accounting Policies (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Accounting Policies [Abstract] | |
Summary of Cumulative Effect to Consolidated Balance Sheet upon Adoption of New Revenue Standard | The following table summarizes the cumulative effect to the Company’s consolidated balance sheet upon the adoption of the new revenue standard on January 1, 2018 (in thousands): Balance at December 31, 2017 Adjustments Balance at January 1, 2018 Deferred revenue, current and net of current portion $ 15,605 $ 6,188 $ 21,793 Accumulated deficit $ (51,339 ) $ (6,188 ) $ (57,527 ) |
Summary of Impact of Adoption of New Revenue Standard Requirements on Company's Financial Statements | In accordance with the new revenue standard requirements, the following tables summarize the impact of adoption on the Company’s consolidated balance sheets, consolidated statements of operations and comprehensive loss, and consolidated statements of cash flows (in thousands): Consolidated Balance Sheets At March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Deferred revenue, current portion $ 17,519 $ 7,222 $ 10,297 Deferred revenue, net of current portion $ 3,655 $ 7,323 $ (3,668 ) Accumulated deficit $ (64,262 ) $ (57,633 ) $ (6,629 ) Consolidated Statements of Operations and Comprehensive Loss Three Months Ended March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Collaboration revenue $ 2,220 $ 2,661 $ (441 ) Net loss $ (6,735 ) $ (6,294 ) $ (441 ) Net loss attributable to common stockholders $ (6,751 ) $ (6,310 ) $ (441 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.66 ) $ (0.62 ) $ (0.04 ) Comprehensive loss $ (6,726 ) $ (6,285 ) $ (441 ) Consolidated Statements of Cash Flows Three Months Ended March 31, 2018 Under Topic 606 Under Topic 605 Effect of Change Net loss $ (6,735 ) $ (6,294 ) $ (441 ) Change in deferred revenue $ (619 ) $ (1,060 ) $ 441 |
Fair Value of Financial Asset23
Fair Value of Financial Assets and Liabilities (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Schedule of Marketable Securities by Type | Marketable securities by security type consisted of the following (in thousands): March 31, 2018 Amortized Gross Gross Fair U.S. Treasury notes (due within one year) $ 4,003 $ — $ (5 ) $ 3,998 U.S. government agency bonds (due within one year) 2,700 — (2 ) 2,698 $ 6,703 $ — $ (7 ) $ 6,696 December 31, 2017 Amortized Gross Gross Fair U.S. Treasury notes (due within one year) $ 5,007 $ — $ (10 ) $ 4,997 U.S. government agency bonds (due within one year) 7,700 — (6 ) 7,694 $ 12,707 $ — $ (16 ) $ 12,691 |
Schedule of Assets Measured at Fair Value on Recurring Basis | The following tables present information about the Company’s assets that are measured at fair value on a recurring basis (in thousands): Fair Value Measurements at March 31, 2018 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 22,293 $ — $ 22,293 Marketable securities: U.S. Treasury notes 3,998 — — 3,998 U.S. government agency bonds — 2,698 — 2,698 $ 3,998 $ 24,991 $ — $ 28,989 Fair Value Measurements at December 31, 2017 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ — $ 24,196 $ — $ 24,196 Marketable securities: U.S. Treasury notes 4,997 — — 4,997 U.S. government agency bonds — 7,694 — 7,694 $ 4,997 $ 31,890 $ — $ 36,887 |
Accrued Expenses and Other Cu24
Accrued Expenses and Other Current Liabilities (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Payables and Accruals [Abstract] | |
Schedule of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities consisted of the following (in thousands): March 31, 2018 December 31, 2017 Accrued employee compensation and benefits $ 357 $ 1,315 Accrued professional fees 964 980 Accrued external research and development expense 806 478 Accrued other 231 180 $ 2,358 $ 2,953 |
Redeemable Convertible Prefer25
Redeemable Convertible Preferred Stock (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Equity [Abstract] | |
Summary of Preferred Stock | As of each balance sheet date, the Preferred Stock consisted of the following (in thousands, except share amounts): As of March 31, 2018 Preferred Stock Preferred Carrying Value Liquidation Common Stock Series A preferred stock 12,297,276 12,297,276 $ 12,271 $ 12,297 7,832,001 Series B preferred stock 8,494,131 8,474,574 64,896 65,000 5,397,361 20,791,407 20,771,850 $ 77,167 $ 77,297 13,229,362 As of December 31, 2017 Preferred Stock Preferred Carrying Value Liquidation Common Stock Series A preferred stock 12,297,276 12,297,276 $ 12,267 $ 12,297 7,832,001 Series B preferred stock 8,494,131 8,474,574 64,884 65,000 5,397,361 20,791,407 20,771,850 $ 77,151 $ 77,297 13,229,362 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Disclosure of Compensation Related Costs, Share-based Payments [Abstract] | |
Schedule of Stock Based Compensation Expense | The Company recorded stock-based compensation expense in the following expense categories of its consolidated statements of operations and comprehensive loss (in thousands): Three Months Ended March 31, 2018 2017 Research and development expenses $ 401 $ 260 General and administrative expenses 78 40 Total $ 479 $ 300 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Commitments and Contingencies Disclosure [Abstract] | |
Summary of Future Minimum Payments Due under Operating Leases | The following table summarizes the future minimum payments due under the operating leases as of March 31, 2018 (in thousands): Year Ending December 31, 2018 (nine months ending December 31) $ 1,378 2019 1,878 2020 1,933 2021 1,989 2022 2,046 Thereafter 689 $ 9,913 |
Net Loss Per Share (Tables)
Net Loss Per Share (Tables) | 3 Months Ended |
Mar. 31, 2018 | |
Earnings Per Share [Abstract] | |
Schedule of Earnings Per Share Basic and Diluted | Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2018 2017 Numerator: Net loss $ (6,735 ) $ (5,939 ) Accretion of redeemable convertible preferred stock to redemption value (16 ) (16 ) Net loss attributable to common stockholders $ (6,751 ) $ (5,955 ) Denominator: Weighted average common shares outstanding, basic and diluted 10,204,591 10,190,228 Net loss per share attributable to common stockholders, basic and diluted $ (0.66 ) $ (0.58 ) |
Summary of Potential Dilutive Securities | The Company’s potential dilutive securities have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: March 31, 2018 2017 Redeemable convertible preferred shares (as converted to common stock) 13,229,362 13,229,362 Stock options to purchase common stock 3,873,879 2,549,808 17,103,241 15,779,170 |
Nature of the Business and Ba29
Nature of the Business and Basis of Presentation - Additional Information (Detail) $ / shares in Units, $ in Thousands | Apr. 25, 2018USD ($)$ / sharesshares | Apr. 03, 2018USD ($)$ / sharesshares | Mar. 16, 2018 | Mar. 31, 2018USD ($) | Mar. 31, 2017USD ($) | Dec. 31, 2017USD ($) |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||
Reverse stock split description | One-for-1.5701314513884 reverse stock split | |||||
Reverse stock split ratio | 0.636889 | |||||
Net loss | $ (6,735) | $ (5,939) | $ 25,500 | |||
Accumulated deficit | $ (64,262) | $ (51,339) | ||||
Funding term of borrowings for operating expense and capital expenditure requirement | 12 months | |||||
Subsequent Event [Member] | Common Stock [Member] | IPO [Member] | ||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||
Shares of common stock issued and sold | shares | 215,000 | 5,770,000 | ||||
Public offering price, per share | $ / shares | $ 12 | $ 12 | ||||
Net proceeds from initial public offering | $ 2,400 | $ 64,400 | ||||
Subsequent Event [Member] | Common Stock [Member] | Private Placement [Member] | ||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||
Public offering price, per share | $ / shares | $ 12 | |||||
Sale of stock, consideration received on transaction | $ 5,000 | |||||
Sale of stock, number of shares issued in transaction | shares | 416,666 | |||||
Period of lock-up agreement | 180 days |
Summary of Significant Accoun30
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) | 3 Months Ended | ||
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | |
Significant Accounting Policies [Line Items] | |||
Deferred revenue | $ 17,519,000 | $ 6,891,000 | |
Deferred revenue, net of current portion | 3,655,000 | $ 8,714,000 | |
Revenue recognized | $ 2,200,000 | ||
New accounting pronouncement revenue recognition timing | The Company recognized revenue of $2.2 million during three months ended March 31, 2018 from the deferred revenue balance at January 1, 2018. The Company recognizes deferred revenue by first allocating from the beginning deferred revenue balance to the extent the beginning deferred revenue balance exceeds the revenue to be recognized. Billings during the period are added to the deferred revenue balance to be recognized in future periods. To the extent that the beginning deferred revenue balance is less than revenue to be recognized during the period, billings during the period are allocated to revenue | ||
Capitalized contract costs | $ 0 | ||
Maximum [Member] | |||
Significant Accounting Policies [Line Items] | |||
Expenses incremental costs expiration period | 1 year | ||
Period of Transfer of promised goods or services to customer | 1 year | ||
ASU 2016-18 [Member] | |||
Significant Accounting Policies [Line Items] | |||
Increase in restricted cash | $ 1,300,000 | $ 1,300,000 | |
ASU 2014-09 [Member] | |||
Significant Accounting Policies [Line Items] | |||
Deferred revenue | 17,519,000 | ||
Deferred revenue, net of current portion | 3,655,000 | ||
ASU 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | |||
Significant Accounting Policies [Line Items] | |||
Adjustment due to application of the new revenue standards | $ 6,200,000 |
Summary of Significant Accoun31
Summary of Significant Accounting Policies - Summary of Cumulative Effect to Consolidated Balance Sheet upon Adoption of New Revenue Standard (Detail) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Accumulated deficit | $ (64,262) | $ (51,339) |
ASU 2014-09 [Member] | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Accumulated deficit | (64,262) | |
Scenario, Previously Reported [Member] | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Deferred revenue, current and net of current portion | 15,605 | |
Accumulated deficit | (51,339) | |
Effect of Change [Member] | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Accumulated deficit | $ (6,629) | |
Effect of Change [Member] | ASU 2014-09 [Member] | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Deferred revenue, current and net of current portion | 6,188 | |
Accumulated deficit | (6,188) | |
Scenario As Restated [Member] | ||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | ||
Deferred revenue, current and net of current portion | 21,793 | |
Accumulated deficit | $ (57,527) |
Summary of Significant Accoun32
Summary of Significant Accounting Policies - Summary of Impact of Adoption of New Revenue Standard Requirements on Company's Financial Statements (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Deferred revenue, current portion | $ 17,519 | $ 6,891 | |
Deferred revenue, net of current portion | 3,655 | 8,714 | |
Accumulated deficit | (64,262) | (51,339) | |
Collaboration revenue | 2,220 | $ 1,827 | |
Net loss | (6,735) | (5,939) | 25,500 |
Net loss attributable to common stockholders | $ (6,751) | $ (5,955) | |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.66) | $ (0.58) | |
Comprehensive loss | $ (6,726) | $ (5,951) | |
Net loss | (6,735) | (5,939) | 25,500 |
Change in deferred revenue | (619) | $ (941) | |
Effect of Change [Member] | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Deferred revenue, current portion | 10,297 | ||
Deferred revenue, net of current portion | (3,668) | ||
Accumulated deficit | (6,629) | ||
Collaboration revenue | (441) | ||
Net loss | (441) | ||
Net loss attributable to common stockholders | $ (441) | ||
Net loss per share attributable to common stockholders, basic and diluted | $ (0.04) | ||
Comprehensive loss | $ (441) | ||
Net loss | (441) | ||
Change in deferred revenue | 441 | ||
ASU 2014-09 [Member] | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Deferred revenue, current portion | 17,519 | ||
Deferred revenue, net of current portion | 3,655 | ||
Accumulated deficit | (64,262) | ||
Collaboration revenue | 2,220 | ||
Net loss | (6,735) | ||
Net loss attributable to common stockholders | $ (6,751) | ||
Net loss per share attributable to common stockholders, basic and diluted | $ (0.66) | ||
Comprehensive loss | $ (6,726) | ||
Net loss | (6,735) | ||
Change in deferred revenue | (619) | ||
ASU 2014-09 [Member] | Effect of Change [Member] | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Accumulated deficit | $ (6,188) | ||
Under Topic 605 [Member] | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Deferred revenue, current portion | 7,222 | ||
Deferred revenue, net of current portion | 7,323 | ||
Accumulated deficit | (57,633) | ||
Collaboration revenue | 2,661 | ||
Net loss | (6,294) | ||
Net loss attributable to common stockholders | $ (6,310) | ||
Net loss per share attributable to common stockholders, basic and diluted | $ (0.62) | ||
Comprehensive loss | $ (6,285) | ||
Net loss | (6,294) | ||
Change in deferred revenue | $ (1,060) |
Fair Value of Financial Asset33
Fair Value of Financial Assets and Liabilities - Schedule of Marketable Securities by Type (Detail) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 6,703 | $ 12,707 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | (7) | (16) |
Fair Value | 6,696 | 12,691 |
U.S. Treasury Notes [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 4,003 | 5,007 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | (5) | (10) |
Fair Value | 3,998 | 4,997 |
U.S. Government Agency Bonds [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 2,700 | 7,700 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | (2) | (6) |
Fair Value | $ 2,698 | $ 7,694 |
Fair Value of Financial Asset34
Fair Value of Financial Assets and Liabilities - Schedule of Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | $ 28,989 | $ 36,887 |
Money Market Funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 22,293 | 24,196 |
U.S. Treasury Notes [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 3,998 | 4,997 |
U.S. Government Agency Bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 2,698 | 7,694 |
Level 1 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 3,998 | 4,997 |
Level 1 [Member] | U.S. Treasury Notes [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 3,998 | 4,997 |
Level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 24,991 | 31,890 |
Level 2 [Member] | Money Market Funds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | 22,293 | 24,196 |
Level 2 [Member] | U.S. Government Agency Bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Assets Measured at Fair Value on Recurring Basis | $ 2,698 | $ 7,694 |
Fair Value of Financial Asset35
Fair Value of Financial Assets and Liabilities - Additional Information (Detail) - USD ($) | Mar. 31, 2018 | Mar. 31, 2017 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] | ||
Fair value asset, transfers between Level 1, Level 2 and Level 3, amount | $ 0 | $ 0 |
Accrued Expenses and Other Cu36
Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
Payables and Accruals [Abstract] | ||
Accrued employee compensation and benefits | $ 357 | $ 1,315 |
Accrued professional fees | 964 | 980 |
Accrued external research and development expense | 806 | 478 |
Accrued other | 231 | 180 |
Total | $ 2,358 | $ 2,953 |
Collaboration Agreement - Addit
Collaboration Agreement - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | |||
Mar. 31, 2018 | Mar. 31, 2017 | Jan. 01, 2018 | Dec. 31, 2017 | |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
Revenue related to research and clinical development activities | $ 2,220 | $ 1,827 | ||
Remaining performance obligation related to two product candidates | 76,000 | |||
ASU 2014-09 [Member] | ||||
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
Revenue related to research and clinical development activities | 2,220 | |||
ASU 2014-09 [Member] | Cumulative Effect of Changes in Accounting Principle [Member] | ||||
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
Deferred revenue | $ 6,200 | |||
Seattle Genetics [Member] | ||||
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | ||||
Revenue related to research and clinical development activities | 2,200 | $ 1,800 | ||
Deferred revenue | $ 21,200 | $ 15,600 |
Loan and Security Agreement - A
Loan and Security Agreement - Additional Information (Detail) - Loan And Security Agreement [Member] - Pacific Western Bank [Member] | 3 Months Ended |
Mar. 31, 2018USD ($) | |
Debt Instrument [Line Items] | |
Warrant to be issued to purchase number of shares capital stock equal to the amount of each term loan borrowing percentage | 1.00% |
Term Loan [Member] | |
Debt Instrument [Line Items] | |
Maximum term loan borrowings | $ 15,000,000 |
Interest rate during period | 3.75% |
Term loan payment terms | In January 2017, the Company entered into a loan and security agreement (the “Loan Agreement”) with Pacific Western Bank (“PWB”), which provides for term loan borrowings of up to $15.0 million through January 19, 2019. Borrowings under the Loan Agreement bear interest at a variable annual rate equal to the greater of (i) the prime rate plus 0.25% or (ii) 3.75%, and are payable over an interest-only period until January 19, 2019, followed by a 24-month period of equal monthly payments of principal and interest. All amounts outstanding as of the maturity date of January 19, 2021 become immediately due and payable. |
Outstanding amount maturity date | Jan. 19, 2021 |
Term loans borrowed | $ 0 |
Term Loan [Member] | Prime Rate [Member] | |
Debt Instrument [Line Items] | |
Annual variable interest rate | 0.25% |
Redeemable Convertible Prefer39
Redeemable Convertible Preferred Stock - Additional Information (Detail) | Mar. 16, 2018 | Mar. 31, 2018USD ($)$ / shares |
Temporary Equity [Line Items] | ||
Reverse stock split description | One-for-1.5701314513884 reverse stock split | |
Reverse stock split ratio | 0.636889 | |
Voting, description | The holders of Preferred Stock are entitled to vote, together with the holders of common stock, on matters submitted to stockholders for a vote. The holders of Preferred Stock are entitled to the number of votes equal to the number of common shares into which each such share of Preferred Stock could convert. In addition, the holders of Series A preferred stock, voting exclusively and as a separate class, are entitled to elect two directors of the Company. The holders of Series B preferred stock, voting exclusively and as a separate class, are entitled to elect one director of the Company. | |
Conversion, description | Each share of Preferred Stock is convertible at the option of the holder at any time after the date of issuance. Each share of Preferred Stock will be automatically converted into shares of common stock at the applicable conversion ratio then in effect upon the closing of a firm commitment public offering with at least $50.0 million of gross proceeds to the Company. Shares of Series A preferred stock will be automatically converted into shares of common stock at the applicable conversion ratio then in effect upon written consent of the holders of at least 65% of the then-outstanding shares of Series A preferred stock. Shares of Series B preferred stock will be automatically converted into shares of common stock at the applicable conversion ratio then in effect upon written consent of the holders of at least a majority of the then-outstanding shares of Series B preferred stock. | |
Minimum gross proceeds from Initial Public Offering for automatic conversion | $ | $ 50,000,000 | |
Percentage eligibility of conversion, upon outstanding shares held | 65.00% | |
Preferred dividend description | The Company may not declare, pay or set aside any dividends on shares of any other series of capital stock of the Company, other than dividends on common stock payable in common stock, unless the holders of the Series A and Series B preferred stock first receive, or simultaneously receive, a dividend on each outstanding share of Series A and Series B preferred stock in an amount at least equal to the greater of (i) $0.08 per share in the case of Series A preferred stock and $0.61 per share in the case of Series B preferred stock, each subject to appropriate adjustment in the event of any stock split, stock dividend, combination or other similar recapitalization with respect to such shares, and (ii) (A) in the case of a dividend on common stock or any class or series of stock that is convertible into common stock, that dividend per share of Preferred Stock as would equal the product of (1) the dividend payable on each share of such class or series determined, if applicable, as if all shares of such class or series had been converted into common stock and (2) the number of shares of common stock issuable upon conversion of each share of Preferred Stock, or (B) in the case of a dividend on any class or series that is not convertible into common stock, at a rate per share of Preferred Stock determined by (1) dividing the amount of the dividend payable on each share of such class or series of capital stock by the Original Issue Price of such class or series of capital stock (subject to appropriate adjustment in the event of any stock dividend, stock split, combination of or other similar recapitalization affecting such shares) and (2) multiplying such fraction by an amount equal to the Original Issue Price of each series of Preferred Stock. If the Company declares, pays or sets aside, on the same date, a dividend on shares of more than one class or series of capital stock of the Company, the dividend payable to the holders of the Preferred Stock shall be calculated based upon the dividend on the class or series of capital stock that would result in the highest Preferred Stock dividend. Stockholders are not entitled to any accruing dividends. | |
Dividend payable | $ | $ 0 | |
Redemption, description | At any time on or after June 10, 2020, shares of each of the Series A and Series B preferred stock are subject to mandatory redemption by the Company in three equal annual installments beginning 60 days after receipt of a notice of redemption from the holders of at least two-thirds of the combined voting power of the holders of outstanding shares of Series A and Series B preferred stock, voting together as a single class, in an amount equal to the Original Issue Price per share of each series of Preferred Stock plus any dividends declared but unpaid thereon. | |
Preferred Stock [Member] | ||
Temporary Equity [Line Items] | ||
Reverse stock split description | 1:1.5701314513884 basis upon the closing of the IPO | |
Reverse stock split ratio | 0.63688935 | |
Series A preferred stock [Member] | ||
Temporary Equity [Line Items] | ||
Original Issue Price, per share | $ 1 | |
Conversion Price at issuance | 1.570131 | |
Series A preferred stock [Member] | Minimum [Member] | ||
Temporary Equity [Line Items] | ||
Dividend Rate | 0.08 | |
Series B preferred stock [Member] | ||
Temporary Equity [Line Items] | ||
Original Issue Price, per share | 7.67 | |
Conversion Price at issuance | 12.042908 | |
Series B preferred stock [Member] | Minimum [Member] | ||
Temporary Equity [Line Items] | ||
Dividend Rate | $ 0.61 |
Redeemable Convertible Prefer40
Redeemable Convertible Preferred Stock - Summary of Preferred Stock (Detail) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 |
Temporary Equity [Line Items] | ||
Preferred Stock Authorized | 20,791,407 | 20,791,407 |
Preferred Stock Issued | 20,771,850 | 20,771,850 |
Preferred Stock Outstanding | 20,771,850 | 20,771,850 |
Carrying Value | $ 77,167 | $ 77,151 |
Liquidation Preference | $ 77,297 | $ 77,297 |
Common Stock Issuable Upon Conversion | 13,229,362 | 13,229,362 |
Series A preferred stock [Member] | ||
Temporary Equity [Line Items] | ||
Preferred Stock Authorized | 12,297,276 | 12,297,276 |
Preferred Stock Issued | 12,297,276 | 12,297,276 |
Preferred Stock Outstanding | 12,297,276 | 12,297,276 |
Carrying Value | $ 12,271 | $ 12,267 |
Liquidation Preference | $ 12,297 | $ 12,297 |
Common Stock Issuable Upon Conversion | 7,832,001 | 7,832,001 |
Series B preferred stock [Member] | ||
Temporary Equity [Line Items] | ||
Preferred Stock Authorized | 8,494,131 | 8,494,131 |
Preferred Stock Issued | 8,474,574 | 8,474,574 |
Preferred Stock Outstanding | 8,474,574 | 8,474,574 |
Carrying Value | $ 64,896 | $ 64,884 |
Liquidation Preference | $ 65,000 | $ 65,000 |
Common Stock Issuable Upon Conversion | 5,397,361 | 5,397,361 |
Common Stock - Additional Infor
Common Stock - Additional Information (Detail) | 3 Months Ended |
Mar. 31, 2018 | |
Equity [Abstract] | |
Common stock voting right | Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company's stockholders. |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions | Mar. 16, 2018 | Mar. 31, 2018 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Option grants | 777,071 | |
Exercise price | $ 12 | |
Weighted average grant date fair value | $ 6.28 | |
Total unrecognized stock-based compensation expense | $ 9.8 | |
Period for recognition of unrecognized expense | 3 years | |
Two Thousand Fifteen Stock Incentive Plan [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Vesting period of stock option | 4 years | |
Expiration period of stock option | 10 years | |
Number of shares initially reserved for issuance | 4,144,876 | |
Shares available for future issuance | 1,041,700 | |
Two Thousand Eighteen Stock Option and Incentive Plan [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Number of shares initially reserved for issuance | 2,800,721 | |
Shares available for future issuance | 3,065,350 | |
Percentage applied to the outstanding shares as annual increase in the number of shares authorized for issuance | 4.00% | |
Two Thousand Eighteen Employee Stock Purchase Plan [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Shares reserved for future issuance | 314,000 | |
Two Thousand Eighteen Employee Stock Purchase Plan [Member] | Maximum [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Option grants | 500,000 | |
Percentage of shares of common stock available for issuance | 1.00% |
Stock-Based Compensation - Sche
Stock-Based Compensation - Schedule of Stock Based Compensation Expense (Detail) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||
Share Based Compensation Expense | $ 479 | $ 300 |
Research and Development Expense [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||
Share Based Compensation Expense | 401 | 260 |
General and Administrative Expense [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||
Share Based Compensation Expense | $ 78 | $ 40 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) | 3 Months Ended | 12 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | |
Income Tax Disclosure [Abstract] | |||
Federal corporate income tax rate | 21.00% | 34.00% | |
Percentage of net operating loss carry forward deductible from current year taxable income | 80.00% | ||
Income tax expense or benefit recognized | $ 0 | ||
Income tax benefits | 0 | $ 0 | |
Unrecognized tax benefits | $ 0 | $ 0 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) $ in Millions | 1 Months Ended | 3 Months Ended | |||
Dec. 31, 2017ft² | Jan. 31, 2017ft² | Mar. 31, 2018USD ($) | Mar. 31, 2017USD ($) | Mar. 31, 2018SGD ($) | |
Commitments And Contingencies Disclosure [Line Items] | |||||
Lease expiration date | Apr. 30, 2023 | ||||
Rent expense | $ 400,000 | $ 400,000 | |||
Sublease term | 12 months | 12 months | |||
Area of subleased property | ft² | 5,000 | ||||
Sublease rent recognized | 200,000 | ||||
Non-cancelable minimum purchase commitments | 900,000 | ||||
License Agreement [Member] | |||||
Commitments And Contingencies Disclosure [Line Items] | |||||
License maintenance fees on eighth anniversary and each year thereafter | 100,000 | ||||
Aggregate milestone payments | $ 4,200,000 | ||||
License agreement expiration terms | The license agreement will expire on a country-by-country basis until the last to expire of the patents and patent applications covering such licensed product or service. The Licensors may terminate the license agreement within 60 days after written notice in the event of a breach of contract. The Licensors may also terminate the agreement upon written notice in the event of the Company’s bankruptcy, liquidation, or insolvency. In addition, the Company has the right to terminate this agreement in its entirety at will upon 90 days’ advance written notice to the Licensors. However, if the Company has commenced the commercialization of licensed products, the Company can only terminate at will if it ceases all development and commercialization of licensed products. | ||||
Maximum [Member] | |||||
Commitments And Contingencies Disclosure [Line Items] | |||||
Area of subleased property | ft² | 2,500 | ||||
Sublease rent recognized | $ 100,000 | ||||
Maximum [Member] | License Agreement [Member] | |||||
Commitments And Contingencies Disclosure [Line Items] | |||||
License maintenance fees for each of first seven years | $ 100,000 | ||||
Aggregate milestone payments | $ 5.5 | ||||
Non-current restricted cash [Member] | Letter of Credit [Member] | |||||
Commitments And Contingencies Disclosure [Line Items] | |||||
Lease security | $ 1,300,000 |
Commitments and Contingencies46
Commitments and Contingencies - Summary of Future Minimum Payments Due under Operating Leases (Detail) $ in Thousands | Mar. 31, 2018USD ($) |
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] | |
2018 (nine months ending December 31) | $ 1,378 |
2,019 | 1,878 |
2,020 | 1,933 |
2,021 | 1,989 |
2,022 | 2,046 |
Thereafter | 689 |
Operating Leases, Future Minimum Payments Due, Total | $ 9,913 |
Net Loss Per Share - Schedule o
Net Loss Per Share - Schedule of Earnings Per Share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | Dec. 31, 2017 | |
Earnings Per Share [Abstract] | |||
Net loss | $ (6,735) | $ (5,939) | $ 25,500 |
Accretion of redeemable convertible preferred stock to redemption value | (16) | (16) | |
Net loss attributable to common stockholders | $ (6,751) | $ (5,955) | |
Weighted average common shares outstanding, basic and diluted | 10,204,591 | 10,190,228 | |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.66) | $ (0.58) |
Net Loss Per Share - Summary of
Net Loss Per Share - Summary of Potential Dilutive Securities (Detail) - shares | 3 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Potential dilutive securities excluded from computation of diluted net loss per common share | 17,103,241 | 15,779,170 |
Convertible Preferred Stock [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Potential dilutive securities excluded from computation of diluted net loss per common share | 13,229,362 | 13,229,362 |
Employee Stock Option [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Potential dilutive securities excluded from computation of diluted net loss per common share | 3,873,879 | 2,549,808 |
Retirement Plan - Additional In
Retirement Plan - Additional Information (Detail) - USD ($) | 3 Months Ended | |
Mar. 31, 2018 | Mar. 31, 2017 | |
Retirement Benefits [Abstract] | ||
Defined contribution plan, matching amount | $ 0 | $ 0 |
Subsequent Events - Additional
Subsequent Events - Additional information (Detail) - Subsequent Event [Member] - Common Stock [Member] - USD ($) $ / shares in Units, $ in Millions | Apr. 25, 2018 | Apr. 03, 2018 |
IPO [Member] | ||
Subsequent Event [Line Items] | ||
Shares of common stock issued and sold | 215,000 | 5,770,000 |
Public offering price, per share | $ 12 | $ 12 |
Net proceeds from initial public offering | $ 2.4 | $ 64.4 |
Private Placement [Member] | ||
Subsequent Event [Line Items] | ||
Public offering price, per share | $ 12 | |
Sale of stock, consideration received on transaction | $ 5 | |
Sale of stock, number of shares issued in transaction | 416,666 | |
Period of lock-up agreement | 180 days |