Cover
Cover - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Feb. 23, 2021 | Jun. 30, 2020 | |
Cover [Abstract] | |||
Document Type | 10-K | ||
Document Annual Report | true | ||
Document Period End Date | Dec. 31, 2020 | ||
Current Fiscal Year End Date | --12-31 | ||
Document Transition Report | false | ||
Entity File Number | 001-38129 | ||
Entity Registrant Name | Mersana Therapeutics, Inc. | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Tax Identification Number | 04-3562403 | ||
Entity Address, Address Line One | 840 Memorial Drive | ||
Entity Address, City or Town | Cambridge | ||
Entity Address, State or Province | MA | ||
Entity Address, Postal Zip Code | 02139 | ||
City Area Code | 617 | ||
Local Phone Number | 498-0020 | ||
Title of 12(b) Security | Common Stock, $0.0001 par value | ||
Trading Symbol | MRSN | ||
Security Exchange Name | NASDAQ | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | true | ||
Entity Shell Company | false | ||
Entity Public Float | $ 1,147,647,431 | ||
Entity Common Stock, Shares Outstanding | 69,042,942 | ||
Documents Incorporated by Reference | Portions of the registrant’s definitive proxy statement that will be filed for the 2021 Annual Meeting of Stockholders are incorporated by reference in Part III. | ||
Entity Central Index Key | 0001442836 | ||
Document Fiscal Year Focus | 2020 | ||
Document Fiscal Period Focus | FY | ||
Amendment Flag | false |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Current assets: | ||
Cash and cash equivalents | $ 255,094 | $ 62,351 |
Short-term marketable securities | 0 | 37,439 |
Prepaid expenses and other current assets | 3,486 | 1,536 |
Total current assets | 258,580 | 101,326 |
Property and equipment, net | 1,730 | 2,164 |
Operating lease right-of-use assets | 10,936 | 2,598 |
Other assets | 2,153 | 1,453 |
Total assets | 273,399 | 107,541 |
Current liabilities: | ||
Accounts payable | 8,340 | 7,296 |
Accrued expenses | 16,146 | 8,986 |
Deferred revenue | 3,987 | 4,815 |
Operating lease liabilities | 1,437 | 2,219 |
Short-term debt | 0 | 667 |
Other liabilities | 93 | 87 |
Total current liabilities | 30,003 | 24,070 |
Operating lease liabilities | 10,158 | 677 |
Long-term debt, net | 4,977 | 4,201 |
Other liabilities | 174 | 275 |
Total liabilities | 45,312 | 29,223 |
Commitments (Note 14) | ||
Stockholders' equity | ||
Preferred stock, $0.0001 par value; 25,000,000 shares authorized; 0 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively | 0 | 0 |
Common stock, $0.0001 par value; 175,000,000 shares authorized; 68,841,288 and 45,388,023 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively | 7 | 5 |
Additional paid-in capital | 508,499 | 270,662 |
Accumulated other comprehensive income | 0 | 25 |
Accumulated deficit | (280,419) | (192,374) |
Total stockholders’ equity | 228,087 | 78,318 |
Total liabilities and stockholders’ equity | $ 273,399 | $ 107,541 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2020 | Dec. 31, 2019 |
Stockholders' equity | ||
Preferred stock, par value (in dollars per share) | $ 0.0001 | $ 0.0001 |
Preferred stock, shares authorized (in shares) | 25,000,000 | 25,000,000 |
Preferred stock, shares issued (in shares) | 0 | 0 |
Preferred stock, shares outstanding (in shares) | 0 | 0 |
Common stock, par value (in dollars per share) | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized (in shares) | 175,000,000 | 175,000,000 |
Common stock, shares issued (in shares) | 68,841,288 | 45,388,023 |
Common stock, shares outstanding (in shares) | 68,841,288 | 45,388,023 |
Consolidated Statements of Oper
Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Income Statement [Abstract] | |||
Collaboration revenue | $ 828 | $ 42,123 | $ 10,594 |
Type of revenue | mrsn:CollaborationMember | mrsn:CollaborationMember | mrsn:CollaborationMember |
Operating expenses: | |||
Research and development | $ 67,036 | $ 55,040 | $ 59,915 |
General and administrative | 21,902 | 17,283 | 16,334 |
Total operating expenses | 88,938 | 72,323 | 76,249 |
Other income (expense): | |||
Interest income | 424 | 2,226 | 1,398 |
Interest expense | (359) | (234) | 0 |
Total other income (expense), net | 65 | 1,992 | 1,398 |
Net loss | (88,045) | (28,208) | (64,257) |
Other comprehensive loss: | |||
Unrealized gain (loss) on marketable securities | (25) | 33 | 141 |
Comprehensive loss | (88,070) | (28,175) | (64,116) |
Net loss attributable to common stockholders - basic | (88,045) | (28,208) | (64,257) |
Net loss attributable to common stockholders - diluted | $ (88,045) | $ (28,208) | $ (64,257) |
Net loss per share attributable to common stockholders — basic and diluted (in dollars per share) | $ (1.43) | $ (0.65) | $ (2.79) |
Weighted-average number of common shares used in net loss per share attributable to common stockholders — basic and diluted (in shares) | 61,485,205 | 43,492,113 | 23,032,250 |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands | Total | Cumulative effect adjustment for adoption of ASC 606 | At market equity offering program (2018 ATM) | Public Stock Offering | Common Stock | Common StockAt market equity offering program (2018 ATM) | Common StockPublic Stock Offering | Additional Paid-in Capital | Additional Paid-in CapitalAt market equity offering program (2018 ATM) | Additional Paid-in CapitalPublic Stock Offering | Accumulated Other Comprehensive Loss | Accumulated Deficit | Accumulated DeficitCumulative effect adjustment for adoption of ASC 606 |
Balance at beginning of period (in shares) at Dec. 31, 2017 | 22,765,017 | ||||||||||||
Balance at beginning of period at Dec. 31, 2017 | $ 69,994 | $ (2,031) | $ 3 | $ 168,018 | $ (149) | $ (97,878) | $ (2,031) | ||||||
Increase (Decrease) in Stockholders' Equity | |||||||||||||
Exercise of stock options (in shares) | 427,269 | ||||||||||||
Exercise of stock options | 918 | 918 | |||||||||||
Purchase of common stock under ESPP (in shares) | 42,186 | ||||||||||||
Purchase of common stock under ESPP | 146 | 146 | |||||||||||
Stock-based compensation expense | 3,884 | 3,884 | |||||||||||
Other comprehensive income (loss) | 141 | 141 | |||||||||||
Net loss | (64,257) | (64,257) | |||||||||||
Balance at end of period (in shares) at Dec. 31, 2018 | 23,234,472 | ||||||||||||
Balance at end of period at Dec. 31, 2018 | $ 8,795 | $ 3 | 172,966 | (8) | (164,166) | ||||||||
Increase (Decrease) in Stockholders' Equity | |||||||||||||
Accounting Standards Update [Extensible List] | us-gaap:AccountingStandardsUpdate201409Member | ||||||||||||
Purchase of common stock under ESPP (in shares) | 140,073 | ||||||||||||
Purchase of common stock under ESPP | $ 489 | 489 | |||||||||||
Stock-based compensation expense | 4,872 | 4,872 | |||||||||||
Issuance of stock (in shares) | 24,437,500 | ||||||||||||
Issuance of stock | 92,162 | $ 2 | 92,160 | ||||||||||
Exercise of stock options and warrants (in shares) | 150,978 | ||||||||||||
Exercise of stock options and warrants | 175 | 175 | |||||||||||
Retirement of common stock in exchange for common stock warrant (in shares) | (2,575,000) | ||||||||||||
Retirement of common stock in exchange for common stock warrant | (8,986) | (8,986) | |||||||||||
Issuance of common stock warrant in exchange for retirement of common stock | 8,986 | 8,986 | |||||||||||
Other comprehensive income (loss) | 33 | 33 | |||||||||||
Net loss | (28,208) | (28,208) | |||||||||||
Balance at end of period (in shares) at Dec. 31, 2019 | 45,388,023 | ||||||||||||
Balance at end of period at Dec. 31, 2019 | 78,318 | $ 5 | 270,662 | 25 | (192,374) | ||||||||
Increase (Decrease) in Stockholders' Equity | |||||||||||||
Stock issuance, Discounts And Commissions On Transaction | $ 5,587 | ||||||||||||
Exercise of stock options (in shares) | 697,428 | 697,428 | |||||||||||
Exercise of stock options | $ 3,138 | 3,138 | |||||||||||
Purchase of common stock under ESPP (in shares) | 80,267 | ||||||||||||
Purchase of common stock under ESPP | 561 | 561 | |||||||||||
Stock-based compensation expense | 7,172 | 7,172 | |||||||||||
Issuance of stock (in shares) | 10,900,599 | 9,200,000 | |||||||||||
Issuance of stock | $ 62,977 | $ 163,991 | $ 1 | $ 1 | $ 62,976 | $ 163,990 | |||||||
Exercise of common stock warrant in exchange for common stock (in shares) | 2,574,971 | ||||||||||||
Other comprehensive income (loss) | (25) | (25) | |||||||||||
Net loss | (88,045) | (88,045) | |||||||||||
Balance at end of period (in shares) at Dec. 31, 2020 | 68,841,288 | ||||||||||||
Balance at end of period at Dec. 31, 2020 | $ 228,087 | $ 7 | $ 508,499 | $ 0 | $ (280,419) | ||||||||
Increase (Decrease) in Stockholders' Equity | |||||||||||||
Stock issuance, Discounts And Commissions On Transaction | $ 2,176 | $ 10,809 |
Consolidated Statements of St_2
Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Issuance costs | $ 5,587 | |
At market equity offering program (2018 ATM) | ||
Issuance costs | $ 2,176 | |
Public Stock Offering | ||
Issuance costs | $ 10,809 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Cash flows from operating activities | |||
Net loss | $ (88,045) | $ (28,208) | $ (64,257) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation | 1,010 | 1,245 | 1,257 |
Loss on disposal of fixed assets | 0 | 0 | 20 |
Net amortization of premiums and discounts on investments | (86) | (222) | (296) |
Stock-based compensation | 7,172 | 4,872 | 3,884 |
Change in deferred rent | 0 | 0 | 110 |
Other non-cash items | 148 | 103 | 0 |
Changes in operating assets and liabilities: | |||
Accounts receivable | 0 | 459 | 325 |
Prepaid expenses and other current assets | (1,950) | 2,179 | (1,690) |
Other assets | (700) | 0 | (1,132) |
Accounts payable | 942 | (3,110) | 7,375 |
Accrued expenses | 7,280 | (3,569) | 5,431 |
Operating lease assets | 1,642 | 1,771 | 0 |
Operating lease liabilities | (1,281) | (1,883) | 0 |
Deferred revenue | (828) | (41,381) | (6,243) |
Net cash used in operating activities | (74,696) | (67,744) | (55,216) |
Cash flows from investing activities | |||
Maturities of marketable securities | 37,500 | 27,000 | 88,565 |
Purchase of marketable securities | 0 | (53,688) | 0 |
Purchase of property and equipment | (473) | (605) | (1,370) |
Net cash provided by (used in) investing activities | 37,027 | (27,293) | 87,195 |
Cash flows from financing activities | |||
Proceeds from exercise of stock options | 3,138 | 175 | 918 |
Proceeds from purchases of common stock under ESPP | 561 | 489 | 146 |
Proceeds from issuance of debt, net of issuance costs | (197) | 4,965 | 0 |
Payments under capital lease obligations | (116) | (87) | 0 |
Net cash provided by financing activities | 230,412 | 97,704 | 1,064 |
Increase in cash, cash equivalents and restricted cash | 192,743 | 2,667 | 33,043 |
Cash, cash equivalents and restricted cash, beginning of period | 62,672 | 60,005 | 26,962 |
Cash, cash equivalents and restricted cash, end of period | 255,415 | 62,672 | 60,005 |
Supplemental disclosures of non-cash activities: | |||
Fair value of common stock retired in exchange for issuance of common stock warrant | 0 | 8,986 | 0 |
Purchases of property and equipment in accounts payable and accrued expenses | 102 | 0 | 317 |
Debt financing costs in accrued expenses | 0 | 180 | 0 |
Cash paid for interest | 234 | 132 | 0 |
Right-of-use assets obtained in exchange for operating lease liabilities | 9,980 | 4,369 | 0 |
Right-of-use assets obtained in exchange for financing lease liabilities | 0 | 429 | 0 |
Adjustment to accumulated deficit and deferred revenue upon adoption of Topic 606 | 0 | 0 | 2,031 |
Public Stock Offering | |||
Cash flows from financing activities | |||
Net proceeds from public offering of common stock | 163,990 | 92,162 | 0 |
At market equity offering program (2018 ATM) | |||
Cash flows from financing activities | |||
Net proceeds from public offering of common stock | $ 63,036 | $ 0 | $ 0 |
Nature of Business and Basis of
Nature of Business and Basis of Presentation | 12 Months Ended |
Dec. 31, 2020 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Nature of Business and Basis of Presentation | Nature of Business and Basis of Presentation Mersana Therapeutics, Inc. is a clinical stage biopharmaceutical company focused on developing antibody drug conjugates (ADCs) that offer a clinically meaningful benefit for cancer patients with significant unmet need. The Company has leveraged 20 years of industry learning in the ADC field to develop proprietary and differentiated technology platforms that enable it to design ADCs to have improved efficacy, safety and tolerability relative to existing ADC therapies. The Company’s innovative platforms, which include Dolaflexin and Dolasynthen, each delivering its DolaLock payload, as well as Immunosynthen, delivering a novel stimulator of interferon genes (STING) agonist, provide an efficient product engine that has enabled a robust discovery pipeline for the Company and its partners. The Company’s product candidates include upifitamab rilsodotin (UpRi, XMT-1536) and XMT-1592. The Company's early stage programs include a potentially first-in-class B7-H4-targeted DolaLock ADC, XMT-1660, as well as candidates leveraging the Immunosynthen platform, the most advanced of which is XMT-2056. UpRi, an ADC utilizing the Company’s Dolaflexin platform and targeting NaPi2b, an antigen broadly expressed in ovarian cancer and non-small cell lung cancer (NSCLC) adenocarcinoma, is currently in the expansion portion of a Phase 1 study in patients with ovarian cancer and NSCLC adenocarcinoma. XMT-1592 uses one of the Company’s new platforms, Dolasynthen, and also targets NaPi2b. In the first half of 2020, the Company initiated the Phase 1 dose escalation study of XMT-1592 . The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, the need for additional capital, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval and reimbursement for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development of technological innovations by competitors, reliance on third party manufacturers and the ability to transition from pilot-scale production to large-scale manufacturing of products. The Company has incurred net losses since inception. The Company’s net loss was $88,045, $28,208 and $64,257 for the years ended December 31, 2020, 2019 and 2018, respectively. The Company expects to continue to incur operating losses for at least the next several years. As of December 31, 2020, the Company had an accumulated deficit of $280,419. The future success of the Company is dependent on, among other factors, its ability to identify and develop its product candidates and ultimately upon its ability to attain profitable operations. The Company has devoted substantially all of its financial resources and efforts to research and development and general and administrative expense to support such research and development. Net losses and negative operating cash flows have had, and will continue to have, an adverse effect on the Company’s stockholders’ equity and working capital. In April 2020, the Company sold 10,900,599 shares of common stock and received net proceeds of $62,976. In addition, in June 2020, the Company sold 9,200,000 shares of common stock and received net proceeds of $163,990. The Company believes that its currently available funds will be sufficient to fund the Company’s operations through at least the next twelve months from the issuance of this Annual Report on Form 10-K. Management’s belief with respect to its ability to fund operations is based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, the Company may need to seek additional funding. The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (U.S. GAAP) and the rules and regulations of the Securities and Exchange Commission (SEC). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Updates (ASU) of the Financial Accounting Standards Board (FASB). All dollar amounts, except per share data in the text and tables herein, are stated in thousands unless otherwise indicated. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | Summary of Significant Accounting Policies Principles of Consolidation The accompanying consolidated financial statements include those of the Company and its wholly owned subsidiary, Mersana Securities Corp. All intercompany balances and transactions have been eliminated. Use of Estimates The preparation of the Company's consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and related disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. On an ongoing basis, the Company's management evaluates its estimates which include, but are not limited to, management's judgments with respect to the identification of performance obligations and standalone selling prices of those performance obligations within its revenue arrangements, accrued preclinical, manufacturing and clinical expenses, valuation of stock-based awards and income taxes. Actual results could differ from those estimates. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision-maker, or decision making group, in deciding how to allocate resources and assess performance. The Company views its operations and manages its business as a single operating segment, which is the business of discovering and developing ADCs. Research and Development Research and development costs are expensed as incurred and include: • employee-related expenses, including salaries, bonuses, benefits, travel and stock-based compensation expense; • fees and expenses incurred under agreements with contract research organizations, investigative sites and other entities in connection with the conduct of preclinical and clinical studies and related services; • the cost of acquiring, developing and manufacturing ADC product candidates, clinical study materials and other research and development materials; • fees and costs related to regulatory filings and activities; • costs associated with collaboration agreements and license fees and milestone payments related to license agreements; • costs associated with creating and obtaining approval for the NaPi2b companion or complementary diagnostic biomarker; • facilities, depreciation and other expenses, which include direct and allocated expenses for rent, utilities, maintenance of facilities, insurance and other supplies; and • other costs associated with clinical, preclinical, discovery and other research activities. Costs for certain development activities, such as clinical studies and manufacturing development activities, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, and information provided to the Company by its vendors on their actual costs incurred or level of effort expended. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected on the consolidated balance sheets as prepaid or accrued preclinical, manufacturing and clinical expenses. Revenue Recognition The Company enters into collaboration agreements which are within the scope of Accounting Standards Update (ASU) No. 2014-9, Revenue from Contracts with Customers (Topic 606), under which the Company licenses rights to its technology and certain of the Company’s product candidates and performs research and development services for third parties. The terms of these arrangements typically include payment of one or more of the following: non-refundable, up-front fees; reimbursement of research and development costs; development, regulatory and commercial milestone payments; and royalties on net sales of licensed products. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine the appropriate amount of revenue to be recognized for arrangements determined to be within the scope of Topic 606, the Company performs the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect consideration it is entitled to in exchange for the goods or services it transfers to the customer. The promised good or services in the Company’s arrangement typically consist of license rights to the Company’s intellectual property and research and development services. The Company also has optional additional items in contracts, which are considered marketing offers and are accounted for as separate contracts with the customer if such option is elected by the customer, unless the option provides a material right which would not be provided without entering into the contract. Performance obligations are promised goods or services in a contract to transfer a distinct good or service to the customer. Promised goods or services are considered distinct when (i) the customer can benefit from the good or service on its own or together with other readily available resources or (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, the Company considers factors such as the stage of development of the underlying intellectual property, the capabilities of the customer to develop the intellectual property on their own or whether the required expertise is readily available. The Company estimates the transaction price based on the amount expected to be received for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. At the inception of each arrangement that includes variable consideration and at each reporting period, the Company evaluates the amount of potential payment and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected amount method to estimate the amount expected to be received based on which method better predicts the amount expected to be received. If it is probable that a significant revenue reversal would not occur, the variable consideration is included in the transaction price. We assessed each of our revenue generating arrangements in order to determine whether a significant financing component exists and concluded that a significant financing component does not exist in any of our arrangements because: (a) the promised consideration approximates the cash selling price of the promised goods and services; and (b) timing of payment approximates the transfer of goods and services and performance is over a relatively short period of time within the context of the entire term of the contract. The Company’s contracts often include development and regulatory milestone payments. At contract inception and at each reporting period, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are not included in the transaction price. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license, collaboration and other revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of the Company’s collaboration arrangements. The Company allocates the transaction price based on the estimated standalone selling price of the underlying performance obligations or in the case of certain variable consideration to one or more performance obligations. The Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the stand-alone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction and the estimated costs to complete the respective performance obligation. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. For performance obligations consisting of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. The Company receives payments from its customers based on billing schedules established in each contract. Such billings generally have 30-day terms. Up-front payments and fees are recorded as deferred revenue upon receipt or when due until the Company performs its obligations under these arrangements. Amounts are recorded as accounts receivable when the right to consideration is unconditional. Effective January 1, 2018, the Company adopted the provisions of Topic 606, using the modified retrospective transition method. Under this method, the Company recorded the cumulative effect of initially applying the new standard to all contracts in process as of the date of adoption. This standard applied to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. The adoption of the new revenue recognition guidance resulted in increases of $2,031 in deferred revenue and accumulated deficit as of January 1, 2018. For the years ended December 31, 2019 and 2018, revenue was not materially impacted as compared to the Company’s prior revenue recognition methodology under ASC 605 Revenue Recognition. Collaborative Arrangements The Company records the elements of its collaboration agreements that represent joint operating activities in accordance with ASC Topic 808, Collaborative Arrangements (ASC 808). Accordingly, the elements of the collaboration agreements that represent activities in which both parties are active participants and to which both parties are exposed to the significant risks and rewards that are dependent on the commercial success of the activities, are recorded as collaborative arrangements. The Company considers the guidance in ASC Topic 606 in determining the appropriate treatment for the transactions between the Company and its collaborative partners and the transactions between the Company and third parties. Generally, the classification of transactions under the collaborative arrangements is determined based on the nature and contractual terms of the arrangement along with the nature of the operations of the participants. To the extent revenue is generated from a collaboration, the Company will recognize its share of the net sales on a gross basis if it is deemed to be the principal in the transactions with customers, or on a net basis if it is instead deemed to be the agent in the transactions with customers, consistent with the guidance in Topic 606. Fair Value Measurements Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability between market participants at measurement dates. ASC Topic 820 Fair Value Measurement (ASC 820) establishes a three-level valuation hierarchy for instruments measured at fair value. The hierarchy is based on the transparency of inputs to the valuation of an asset or liability as of the measurement date. The three levels are defined as follows: Level 1—Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2—Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level 3—Inputs to the valuation methodology are unobservable and significant to the fair value measurement. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity, or a remaining maturity at the time of purchase, of three months or less to be cash equivalents. The Company invests excess cash primarily in money market funds, commercial paper and government agency securities, which are highly liquid and have strong credit ratings. These investments are subject to minimal credit and market risks. Cash and cash equivalents are stated at cost, which approximates market value. Year ended December 31, 2020 Year ended December 31, 2019 Beginning of period End of period Beginning of period End of period Cash and cash equivalents $ 62,351 $ 255,094 $ 59,634 $ 62,351 Restricted cash included in other assets, noncurrent 321 321 371 321 Total cash, cash equivalents and restricted cash per statement of cash flows $ 62,672 $ 255,415 $ 60,005 $ 62,672 Marketable Securities Short-term marketable securities consist of investments in debt securities with maturities greater than three months and less than one year from the balance sheet date. The Company classifies all of its marketable securities as available-for-sale. Accordingly, these investments are recorded at fair value. Amortization and accretion of discounts and premiums are recorded as interest income within other income. Prior to the adoption of ASU 2016-13, Financial Instruments - Credit Losses , unrealized gains and losses on available-for-sale securities were included in other accumulated comprehensive loss as a component of stockholders’ equity until realized. Realized gains and losses and declines in value judged to be other than temporary are included as a component of other income (expense), net, based on the specific identification method. When determining whether a decline in value is other than temporary, the Company considers various factors, including whether the Company has the intent to sell the security, and whether it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis. Fair value is determined based on quoted market prices. In accordance with the adoption of ASU 2016-13, the Company is required to determine whether any portion of the unrealized loss for any available-for-sale debt security is due to a credit loss, and if so, to measure the amount of the credit loss. The Company reviews each of its available-for-sale marketable securities for unrealized losses (declines in fair value below its amortized cost basis) at each balance sheet date presented in its financial statements and whenever events or changes in circumstances indicate that the amortized cost basis of an asset may not be recoverable. Other Assets The Company recorded other assets of $2,153 and $1,453 as of December 31, 2020 and 2019, respectively, comprised of $1,832 and $1,132, respectively, held by a service provider, and restricted cash of $321 and $321 at the end of each period held as a security deposit for a standby letter of credit related to a facility lease. Accounting for Stock-based Compensation The Company accounts for its stock-based compensation in accordance with ASC Topic 718 Compensation— Stock Compensation (ASC 718). ASC 718 requires all stock-based payments to employees, directors and non-employees to be recognized as expense in the statements of operations based on their grant date fair values. The Company estimates the fair value of options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (a) the expected stock price volatility, (b) the calculation of expected term of the award, (c) the risk-free interest rate and (d) expected dividends. Due to the lack of a public market for the Company's common stock prior to completion of the initial public offering and a lack of company-specific historical and implied volatility data, the Company has based its estimate of expected volatility on the historical volatility of a group of similar companies that are publicly traded. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The computation of expected volatility is based on the historical volatility of a representative group of companies with similar characteristics to the Company, including stage of product development and life science industry focus. The Company uses the simplified method as prescribed by the SEC Staff Accounting Bulletin No. 107, Share-Based Payment , to calculate the expected term for options granted to employees as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. For options granted to non-employees, the Company utilizes the contractual term of the arrangement as the basis for the expected term assumption. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected term of the stock options. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to do so. The Company determines the fair value of each restricted stock unit, or RSU, at its grant date based on the closing market price of the Company’s common stock on that date. For stock-based compensation subject to service-based vesting conditions, the Company recognizes stock-based compensation expense equal to the grant date fair value of stock-based compensation on a straight-line basis over the requisite service period. The Company records forfeitures as a cumulative adjustment in the period in which they occur. Net Loss per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding and 2,575,000 Exchange Warrants (as defined in footnote 9) outstanding during the period, without further consideration for potentially dilutive securities. In accordance with Accounting Standards Codification Topic 260, Earnings Per Share , the Exchange Warrants are included in the computation of basic net loss per share because the exercise price is negligible and they are fully vested and exercisable at any time after the original issuance date. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury stock method. For purposes of the diluted net loss per share calculation, stock options, unvested restricted stock units (RSUs) and warrants to purchase common stock are considered to be potentially dilutive securities, but are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore, basic and diluted net loss per share were the same for all periods presented. The following table sets forth the outstanding potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive (in common stock equivalent shares): Year ended December 31, 2020 2019 2018 Stock options 6,112,948 4,720,772 3,746,567 Unvested restricted stock units 716,767 447,336 — Warrants 39,474 39,474 110,365 6,869,189 5,207,582 3,856,932 Property and Equipment Property and equipment is stated at cost, less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful life of each asset as follows: Computer equipment, office equipment and software 3 years Laboratory equipment 5 years Leasehold improvements Shorter of useful life or life of lease Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheet and related gains or losses are reflected in the statement of operations. There were no material sales of assets during the years ended December 31, 2020, 2019 and 2018. The Company reviews its long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. If an impairment review is performed to evaluate an asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the asset to its carrying value. If the carrying amount of the asset exceeds its estimated undiscounted future net cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. The Company did not recognize impairment charges during the years ended December 31, 2020, 2019 and 2018. Leases Consistent with ASC 842, the Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use lease assets (ROU assets), current portion of lease obligations and long-term lease obligations on the Company’s consolidated balance sheets. Assets subject to finance leases are included in property and equipment, and the related lease obligation is included in other current liabilities and other long-term liabilities on the Company’s consolidated balance sheets. Lease assets are tested for impairment in the same manner as long-lived assets used in operations. Lease expense for operating leases is recognized on a straight-line basis over the lease term as an operating expense while expense for financing leases is recognized as depreciation expense and interest expense using the effective interest method. The Company has elected the short-term lease recognition exemption for short-term leases, which allows the Company not to recognize lease liabilities and ROU assets on the consolidated balance sheets for leases with an original term of twelve months or less. ROU assets represent the Company’s right to use an underlying asset for the lease term, and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating lease liabilities and their corresponding ROU assets are initially recorded based on the present value of lease payments over the expected remaining lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the option will be exercised. Certain adjustments to the ROU asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments. The incremental borrowing rate reflects the fixed rate at which the Company could borrow, on a collateralized basis, the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the ROU assets for straight-line rent expense, or any incentives received and remeasure the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company has lease agreements with lease and non-lease components, which are generally accounted for separately. Patent Costs The Company expenses patent application and related legal costs as incurred and classifies such costs as general and administrative expenses in the accompanying consolidated statements of operations. Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Accounting for Income Taxes , which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. The Company determines its deferred tax assets and liabilities based on differences between financial reporting and tax bases of assets and liabilities, which are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company recognizes the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is more likely than not to be realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. Comprehensive Income (Loss) Comprehensive income (loss) comprises net loss and other comprehensive loss. For the years ended December 31, 2020, 2019 and 2018, other comprehensive income (loss) consisted of changes in unrealized income and loss on marketable securities. Concentration of Credit Risk and Off-balance Sheet Risk The Company has no financial instruments with off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash equivalents and marketable securities. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company has not experienced any credit losses and does not believe this it is subject to any significant concentrations of credit risk from these financial instruments. Recently Issued Accounting Pronouncements In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 . The main provisions of ASU 2018-18 include: (i) clarifying that certain transactions between collaborative arrangement participants should be accounted for as revenue when the collaborative arrangement participant is a customer in the context of a unit of account and (ii) precluding the presentation of transactions with collaborative arrangement participants that are not directly related to sales to third parties together with revenue. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods, and early adoption is permitted. The guidance per ASU 2018-18 is to be adopted retrospectively to the date of initial application of Topic 606. The Company adopted the new standard effective January 1, 2020. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. Historically, U.S. GAAP delayed recognition of the full amount of credit losses until the loss was probable of occurring. Under this ASU, the income statement will reflect an entity’s current estimate of all expected credit losses. The measurement of expected credit losses will be based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down of the security. This ASU is effective for annual periods beginning after December 15, 2019, including interim periods within those annual reporting periods, and early adoption is permitted. The Company adopted the new standard effective January 1, 2020 using the modified retrospective method. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , as part of its initiative to reduce complexity in the accounting standards. The amendments in ASU 2019-12 eliminate certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also clarifies and simplifies other aspects of the accounting for income taxes. The amendments in ASU 2019-12 are effective for the fiscal years beginning after December 15, 2020. Early adoption is permitted, including adoption in any interim period. The Company is currently evaluating the potential impact ASU 2019-12 may have on its financial position and results of operations upon adoption. |
Collaboration Agreements
Collaboration Agreements | 12 Months Ended |
Dec. 31, 2020 | |
Collaboration agreements | |
Collaboration Agreements | Collaboration Agreements Merck KGaA In June 2014, the Company entered into a Collaboration and Commercial License Agreement with Merck KGaA (the Merck KGaA Agreement). Upon the execution of the Merck KGaA Agreement, Merck KGaA paid the Company a nonrefundable technology access fee of $12,000 for the right to develop ADCs directed to six exclusive targets over a specified period of time. No additional fees are due when a target is designated and the commercial license to the target is granted. Merck KGaA will be responsible for the product development and marketing of any products resulting from this collaboration. All six targets were designated prior to 2018. Under the terms of the Merck KGaA Agreement, the Company and Merck KGaA develop research plans to evaluate Merck KGaA's antibodies as ADCs incorporating the Company's technology. The Company receives reimbursement for its efforts under the research plans. The goal of the research plans is to provide Merck KGaA with sufficient information to formally nominate a development candidate and begin IND-enabling studies or cease development on the designated target. In addition to the payments received for research and development activities performed on behalf of Merck KGaA, the Company could be eligible to receive up to a total of $780,000 in future milestones related to all targets under the Merck KGaA Agreement, plus low to mid single digit royalties on the commercial sales of any resulting products during the applicable royalty term. The total milestones are categorized as follows: development milestones $84,000; regulatory milestones $264,000; and sales milestones $432,000. There are six individual development milestones per target, payable upon the completion of various activities from the delivery of ADCs meeting defined specifications, through the dosing in a Phase 3 clinical trial. There are five regulatory milestones, which are payable upon regulatory approvals for a first indication in each of the U.S., European Union and Japanese markets and regulatory approvals for both a second and a third indication in the United States. There are three individual commercial milestones, which are payable upon the attainment of certain defined thresholds for annual net sales. Prior to 2018, the Company had received $3,000 related to development milestones under the Merck KGaA Agreement. There have been no additional milestone payments in the years ended December 31, 2019 or 2020. The next potential milestone payment the Company will be eligible to receive will be a development milestone of $500 on Merck KGaA's designation of a preclinical development candidate for any target. Revenue will be recognized when achievement of the milestone is considered probable. Unless earlier terminated, the Merck KGaA Agreement will expire upon the expiration of the last royalty term for a product under the Merck KGaA Agreement, after which time, Merck KGaA will have a perpetual, royalty-free license, or if Merck KGaA does not designate any ADC product candidates produced by the Company under the Merck KGaA Agreement as preclinical development candidates, upon the expiration of the last to expire research program. Merck KGaA may terminate the Merck KGaA Agreement in its entirety or with respect to any target for convenience upon 60 days' prior written notice. Each party may terminate the Merck KGaA Agreement in its entirety upon bankruptcy or similar proceedings of the other party or upon an uncured material breach of the Merck KGaA Agreement by the other party. However, if such breach only relates to one target, the agreement may only be terminated with respect to such target. In May 2018, the Company entered into a Supply Agreement with Merck KGaA (the Merck KGaA Supply Agreement). Under the terms of the Merck KGaA Supply Agreement, the Company will provide Merck KGaA preclinical non-GMP ADC Drug Substance and clinical GMP Drug Substance for use in clinical trials associated with one of the antibodies designated under the Merck KGaA Agreement. The Company receives fees for its efforts under the Merck KGaA Supply Agreement and reimbursement equal to the supply cost. The Company may also enter into future supply agreements to provide clinical supply material should Merck KGaA pursue clinical development of any other candidates nominated under the Merck KGaA Agreement. Accounting Analysis The Company identified the following performance obligations under the Merck KGaA Agreement: (i) exclusive license and research services for six designated targets, (ii) rights to future technological improvements and (iii) participation of project team leaders and providing joint research committee services. The Company has concluded that each license for a designated target is not distinct from the research services performed related to the designated target as Merck KGaA cannot obtain the benefit of the license without the related research services. Each license for a designated target and the related services performance obligation is considered distinct from every other license for a designated target and related services performance obligation as each research plan is pursued independent of every other research plans for other designated targets. The Company utilizes the expected value approach to estimate the amount of consideration related to the payment of fees associated with development and research services. The Company utilizes the most likely amount approach to estimate any development and regulatory milestone payments to be received. As of the date of initial application of Topic 606, there were no milestones payments that had not already been received, included in the estimated transaction price. The Company considered the stage of development and the remaining risks associated with the remaining development required to achieve the milestone, as well as whether the achievement of the milestone is outside the control of the Company or Merck KGaA. The milestone payment amounts were fully constrained, as a result of the uncertainty whether any of the associated milestones would be achieved. The Company has determined that any commercial milestones and sales based royalties will be recognized when the related sales occur as they were determined to relate predominantly to the license granted and therefore have also been excluded from the transaction price. The transaction price was allocated to the performance obligations based on the relative estimated standalone selling prices of each performance obligation or in the case of certain variable consideration to one or more performance obligations. The estimated standalone selling prices for performance obligations, that include a license and research services, were developed using the estimated selling price of the license and an estimate of the overall effort to perform the research service and an estimated market rate for research services. The estimated standalone selling price of the licenses was established based on comparable transactions. The estimated standalone selling price for the rights to future technological improvements was developed based on the estimated selling prices of a license or rights received, as well as considering the probability that additional technology would be made available or the probability the counterpart would utilize the technology. The estimated standalone selling price for the joint research committee services was developed using an estimate of the time and costs incurred to participate in the committees. The Company re-evaluates the transaction price in each reporting period and as uncertain events are resolved or other changes in circumstances occur. As of December 31, 2019, the total transaction price for the Merck KGaA Agreement was $21,500. During 2020, the Company revised its estimate for fees associated with research and development activities under the Merck KGaA Agreement to $6,325, a decrease of $175. The revised total transaction price for the Merck KGaA Agreement is $21,325. The transaction price of $21,325 was allocated to the performance obligations as follows: approximately $3,941 for each of the license and corresponding research and development services units of account for the first and second designated targets; $3,439 for each of the license and corresponding research and development services units of account for the third and sixth designated target; $3,152 for the license and corresponding research and development services unit of account for the fourth designated target; $2,746 for the license and corresponding research and development services unit of account for the fifth designated target; $425 for rights to future technological improvements; and $242 for joint research committee services. The Company is recognizing revenue related to the exclusive license and research and development services performance obligation over the estimated period of the research and development services using a proportional performance model. The Company measures proportional performance based on the costs incurred relative to the total costs expected to be incurred. To the extent that the Company receives fees for the research services as they are preformed, these amounts are recorded as deferred revenue. Revenue related to future technological improvements and joint research committee services will be recognized ratably over the performance period (which in the case of the joint research committee services approximate the time and cost incurred each period), which are 10 and 5 years, respectively. The Company is continuing to reassess the estimated remaining term at each subsequent reporting period. As of December 31, 2020, the Company has completed its research service obligations associated with four of the six designated targets. During the years ended December 31, 2020, 2019 and 2018, the Company recorded collaboration revenue of $828, $853 and $2,444, respectively, related to its efforts under the Merck KGaA Agreement. During the year ended December 31, 2019, the Company recognized collaboration revenue and corresponding research and development expense of $1,280 related to the Merck KGaA Supply Agreement. There were no amounts recognized during the years ended December 31, 2020 and 2018 related to the Merck KGaA Supply Agreement. There was no balance in accounts receivable related to the Merck KGaA Agreement and Merck KGaA Supply Agreement as of either December 31, 2020 or December 31, 2019. As of December 31, 2020 and 2019, the Company had recorded $3,987 and $4,815, respectively, in deferred revenue related to the Merck KGaA Agreement and Merck KGaA Supply Agreement that will be recognized over the remaining performance period. Takeda XMT-1522 Strategic Partnership In January 2016, the Company entered into a Development Collaboration and Commercial License Agreement with Takeda’s wholly owned subsidiary, Millennium Pharmaceuticals, Inc. for the development and commercialization of XMT-1522 (the XMT-1522 Agreement). Under the XMT-1522 Agreement, Takeda was granted the exclusive right to commercialize XMT-1522 outside of the United States and Canada. Under the XMT-1522 Agreement, the Company was responsible for conducting certain Phase 1 development activities for XMT-1522, including the ongoing Phase 1 clinical trial, at its own expense. The parties agreed to collaborate on the further development of XMT-1522 in accordance with a global development plan (Post-Phase 1 Development). On January 2, 2019, the Company received notice from Takeda stating that Takeda was exercising its right to terminate the XMT-1522 Agreement upon 30 days’ prior written notice. The XMT-1522 Agreement terminated in accordance with its provisions, and the Company and Takeda wound down activities related to the XMT-1522 Agreement as of March 31, 2019. Under the XMT-1522 Agreement, the Company and Takeda shared equally all agreed Post-Phase 1 Development costs through the date of termination and for a period of 30 days after the effective termination date. Takeda Strategic Research and Development Partnership In March 2014, the Company entered into a Research Collaboration and Commercial License Agreement with Takeda’s wholly owned subsidiary, Millennium Pharmaceuticals, Inc. (the 2014 Agreement). The 2014 Agreement was amended in January 2015 and amended and restated in January 2016 (the 2016 Restated Agreement). The agreements provided Takeda with the right to develop ADCs directed to a total of seven exclusive targets, designated by Takeda, over a specified period of time. On January 2, 2019, the Company received notice from Takeda stating that Takeda was exercising its right to terminate the 2016 Restated Agreement upon 45 days’ prior written notice. The 2016 Restated Agreement terminated in accordance with its provisions, and the Company and Takeda wound down activities related to the 2016 Restated Agreement as of March 31, 2019. Accounting Analysis The Company’s collaboration agreements with Takeda were terminated following receipt of written notices during the first quarter of 2019. As there are no further performance obligation, the Company recognized the remaining deferred revenue of $39,965 related to the termination of the Takeda agreements in the first quarter of 2019. Prior to the termination of the agreements, the Company had identified 14 performance obligations in the agreements. The Company concluded that the license related to each of the designated targets was not distinct from the research services performed related to each of the designated targets as Takeda could not have obtain the benefit of the license without the related research services. Each license to a designated target and the related service performance obligation was considered distinct from every other license to a designated target and related services performance obligation as each research plan was pursued independent of the any other research plans for other designated targets. Further, the material rights provided were determined to be distinct from the other performance obligations in the arrangement as they were options in the contract Takeda agreements and not required for Takeda to obtain the benefit of the other promised goods or services in the arrangement. Similarly, the Company concluded that the XMT-1522 license and the related research and development services, including the Phase 1 development and the transfer of certain materials and know-how related to the Company's manufacturing processes, were one performance obligation. The license to the Company's intellectual property was not determined to be distinct from the research and related development services that the Company was obligated to perform. For the years ended December 31, 2019 and 2018, the Company recorded total revenue of $39,965 and $5,868, respectively, related to its efforts under the 2016 Restated Agreement and the XMT-1522 Agreement. The Company concluded that the Post-Phase 1 Development activities under the XMT-1522 Agreement represented joint operating activities in which both parties were active participants and of which both parties were exposed to significant risks and rewards that are dependent on the commercial success of the activities. Accordingly, the Company accounted for the Post-Phase 1 Development activities in accordance with ASC 808. For the years ended December 31, 2019 and 2018, the Company was billed approximately $200 and $8,046, respectively, from Takeda representing Post-Phase 1 Development costs incurred by Takeda. These amounts have been reflected as research and development costs in the consolidated statement of operations. The Company did not perform any Post-Phase 1 Development activities or incur any associated costs prior to January 1, 2018. During the years ended December 31, 2019 and 2018, the Company billed Takeda $195 and $3,746, respectively, related to ASC 808 costs. Summary of Contract Assets and Liabilities The following table presents changes in the balances of our contract assets and liabilities during the years ended December 31, 2020 and December 31, 2019: Balance at Beginning of Period Additions Deductions Balance at End of Period Year ended December 31, 2020 Contract assets $ — $ — $ — $ — Contract liabilities: Deferred revenue $ 4,815 $ — $ 828 $ 3,987 Balance at Beginning of Period Additions Deductions Balance at End of Period Year ended December 31, 2019 Contract assets $ — $ — $ — $ — Contract liabilities: Deferred revenue $ 46,196 $ 210 $ 41,591 $ 4,815 During the year ended December 31, 2020, the Company recognized the following revenues as a result of changes in the contract asset and the contract liability balances in the respective periods. Year ended December 31, 2020 2019 Revenue recognized in the period from: Amounts included in the contract liability at the beginning of the period $ 828 $ 41,591 Performance obligations satisfied in previous periods $ — $ — Other Revenue The Company has provided limited services for a collaboration partner, Asana BioSciences. For the years ended December 31, 2020, 2019 and 2018, the Company recorded revenue of $0, $25 and $782, respectively, related to these services. In addition, during the year ended December 31, 2018, the Company recognized revenue of $1,500 related to a milestone achieved upon the completion of a GLP toxicology study by Asana BioSciences. The next potential milestone the Company is eligible to receive is $2,500 upon dosing the fifth patient in a Phase 1 clinical study by Asana BioSciences. As of December 31, 2020, the Company considered this next milestone to be fully constrained as there is considerable judgment involved in determining whether it is probable that a significant revenue reversal would occur. As part of its evaluation of the constraint, the Company considered numerous factors, including the fact that achievement of the milestone is outside the control of the Company and there is a high level of uncertainty in achieving this milestone, as this would require initiation of clinical trials by the collaboration partner. The Company reevaluates the probability of achievement of a milestone subject to constraint at each reporting period and as uncertain events are resolved or other changes in circumstances occur. |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | Fair Value Measurements The following table presents information about the Company's assets and liabilities regularly measured and carried at a fair value and indicates the level within fair value hierarchy of the valuation techniques utilized to determine such value as of December 31, 2019. The Company had no marketable securities as of December 31, 2020: Fair Quoted Prices Significant Significant December 31, 2019 Marketable securities: Commercial paper $ 11,940 $ — $ 11,940 $ — Corporate bonds 12,010 — 12,010 — U.S. Treasuries 13,489 13,489 — — $ 37,439 $ 13,489 $ 23,950 $ — There were no changes in valuation techniques or transfers between fair value measurement levels during the years ended December 31, 2020 and 2019. The carrying amounts reflected in the consolidated balance sheets for prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values due to their short-term nature. As of December 31, 2020, the carrying value of the Company’s outstanding borrowing under the Credit Facility (as defined below) approximated fair value (a Level 2 fair value measurement), reflecting interest rates currently available to the Company. The Credit Facility is discussed more detail in Note 8, “Debt”. |
Marketable Securities
Marketable Securities | 12 Months Ended |
Dec. 31, 2020 | |
Marketable Securities [Abstract] | |
Marketable Securities | Marketable Securities The following table summarizes marketable securities held at December 31, 2019. The Company had no marketable securities as of December 31, 2020: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value December 31, 2019 Commercial paper $ 11,940 $ — $ — $ 11,940 Corporate bonds 11,990 20 — 12,010 U.S. Treasuries 13,484 5 — 13,489 $ 37,414 $ 25 $ — $ 37,439 |
Property and Equipment
Property and Equipment | 12 Months Ended |
Dec. 31, 2020 | |
Property, Plant and Equipment [Abstract] | |
Property and Equipment | Property and Equipment Property and equipment consists of the following as of December 31, 2020 and 2019: December 31, December 31, Laboratory equipment $ 6,520 $ 6,419 Leasehold improvements 1,886 1,886 Computer equipment and office equipment 959 1,068 Total property and equipment at cost 9,365 9,373 Less: Accumulated depreciation (7,635) (7,209) $ 1,730 $ 2,164 |
Accrued Expenses
Accrued Expenses | 12 Months Ended |
Dec. 31, 2020 | |
Accrued Liabilities, Current [Abstract] | |
Accrued Expenses | Accrued Expenses Accrued expenses consist of the following as of December 31, 2020 and 2019: December 31, December 31, Accrued preclinical, manufacturing and clinical expenses $ 9,902 $ 4,230 Accrued payroll and related expenses 5,412 4,037 Accrued professional fees 757 675 Accrued other 75 44 $ 16,146 $ 8,986 |
Debt
Debt | 12 Months Ended |
Dec. 31, 2020 | |
Debt Disclosure [Abstract] | |
Debt | Debt On May 8, 2019, the Company entered into a loan and security agreement (the Original Agreement) with Silicon Valley Bank (SVB) pursuant to which the Company borrowed $5,000. The Original Agreement accrued interest at a floating per annum rate equal to the greater of (i) 4.0% and (ii) 1.50% below the Prime Rate. The Original Agreement had an interest-only period through August 31, 2020. On August 28, 2020 (the Effective Date), the Company entered into a second amendment (the Amendment) to its existing loan and security agreement (as amended prior to the Amendment, the Existing Credit Facility) with SVB. Pursuant to the Amendment, the Company can borrow term loans in an aggregate amount of $30,000 (the Amended Credit Facility), at its option, (i) up to $25,000 in up to five principal advances through April 30, 2022, and (ii) an additional $5,000 in one principal advance, if the Company reaches certain development milestone events, as described in the Amendment, through April 30, 2022. The Company drew $5,200 upon execution of the Amendment, the proceeds of which were used to repay the Company’s existing balance and satisfy its obligations to SVB, including the final payment obligation under the Existing Credit Facility. The Amended Credit Facility bears interest at a floating per annum rate equal to the greater of (i) 4.25% and (ii) 1.00% above the Prime Rate, as defined. The Company is obligated to make monthly interest-only payments on each outstanding term loan commencing on the first calendar day of the month following the funding date of such term loan, and continuing on the first calendar day of each month thereafter through May 31, 2022. The interest only period may be extended through January 31, 2023 upon the achievement of a regulatory milestone, as described in the Amendment. Following the interest-only period, the Company will be required to repay the outstanding principal balance under the term loans in equal monthly payments plus interest in arrears to SVB through November 1, 2024 (the Maturity Date). The Company is also required to make a final payment to SVB equal to 5.5% of the principal amount of the Term Loans then extended to the Company. This final payment is accreted under the effective interest method over the life of each term loan. The term loans are secured by substantially all of the Company’s assets, except for its intellectual property which is subject to a negative pledge, and certain other customary exclusions. At the Company’s option, it may prepay the outstanding principal balance of any term loans in whole but not in part, subject to a prepayment fee of: (a) 3.0% of the term loans then extended to the Company if the prepayment occurs on or prior to August 28, 2021, (b) 2.0% of the term loans then extended to the Company if the prepayment occurs after August 28, 2021 but on or prior to August 28, 2022, or (c) 1.0% of the term loans then extended to the Company if the prepayment occurs after August 28, 2022 but before November 1, 2024. The Amended Credit Facility includes customary affirmative and restrictive covenants applicable to the Company. Affirmative covenants include, among others, covenants requiring the Company to maintain its corporate existence and governmental approvals, deliver certain financial reports, maintain insurance coverage and satisfy certain requirements regarding deposit accounts. The Amendment removed the requirement for the Company to maintain a minimum liquidity ratio. The restrictive covenants include, among others, requirements relating to the Company’s ability to transfer collateral, incur additional indebtedness, engage in mergers or acquisitions, pay dividends or make other distributions, make investments, create liens, sell assets and agree to a change in control, in each case subject to certain customary exceptions. The Company’s payment obligations under the Amended Credit Facility are subject to acceleration upon the occurrence of specified events of default, which include, but are not limited to, the occurrence of a material adverse change in the Company’s business, operations, or financial or other condition. Amounts outstanding upon the occurrence of an event of default are payable upon SVB’s demand and shall accrue interest at an additional rate of 5.0% per annum of the past due amount outstanding. As of December 31, 2020, the Company was in compliance with all covenants under the Credit Facility. As such, as of December 31, 2020, the classification of the loan balance as stated on the balance sheet was based on the timing of defined future payment obligations. The unamortized issuance costs under the Existing Credit Facility were $139 as of the date of the Amendment. The Company incurred debt issuance costs paid to the lender in connection with the Amended Credit Facility of $17. The Company recorded such costs, including the settlement of the final payment obligation under the Existing Credit Facility as a discount from the carrying value of the term loans which are amortized as interest expense using the effective-interest method over the term of the Amended Credit Facility. As of December 31, 2020, there was $5,200 outstanding under the Amended Credit Facility and the debt consisted of the following: December 31, Total debt $ 5,200 Less: Current portion of long-term-debt — Total debt, net of current portion 5,200 Debt financing costs, net of accretion (246) Accretion related to final payment 23 Long-term debt, net $ 4,977 As of December 31, 2020, the estimated future principal payments due are as follows: 2021 $ — 2022 1,213 2023 2,080 2024 1,907 Total debt $ 5,200 During the year ended December 31, 2020 and 2019, the Company recognized $340 and $214, respectively, of interest expense related to the Existing Credit Facility and Amended Credit Facility, as applicable. |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2020 | |
Stockholders' Equity Note [Abstract] | |
Stockholders' Equity | Stockholders’ Equity Preferred stock As of December 31, 2020, the Company has 25,000,000 shares of authorized preferred stock. No shares of preferred stock have been issued. At-the-market equity offering program In July 2018, the Company established an at-the-market (ATM) equity offering program (the 2018 ATM) pursuant to which it could offer and sell up to $75,000 of its common stock from time to time at prevailing market prices. In April 2020, the Company sold 8,938,599 and 1,962,000 shares of common stock at $5.59 per share and $7.74 per share, respectively, to raise aggregate gross proceeds of $65,153 through the 2018 ATM facility. Net proceeds to the Company after deducting fees, commissions and other expenses related to the offering were approximately $62,976. In May 2020, the Company terminated the 2018 ATM and established a new ATM equity offering program (the 2020 ATM) pursuant to which it is able to sell up to $100,000 of its common stock from time to time at prevailing market prices. As of December 31, 2020, the Company had not sold any shares under the 2020 ATM. Follow-on offering In June 2020, the Company sold 9,200,000 shares of common stock, in an underwritten public offering price to the public of $19.00 per share. Net proceeds to the Company after deducting fees, commissions and other expenses related to the offering were $163,990. Warrants In connection with a 2013 Series A-1 Preferred Stock issuance, the Company granted to certain investors warrants to purchase 129,491 shares of common stock. The warrants have a $0.05 per share exercise price and a contractual life of 10 years. The fair value of these warrants was recorded as a component of equity at the time of issuance. As of December 31, 2020 and 2019 there were warrants to purchase 39,474 shares of common stock. During the year ended December 31, 2020, there were no exercises of warrants in exchange for shares of common stock. Exchange warrants On November 26, 2019, the Company entered into an exchange agreement with entities affiliated with Biotechnology Value Fund, L.P. (the Exchanging Stockholders), pursuant to which the Exchanging Stockholders exchanged an aggregate of 2,575,000 shares of common stock for warrants (the Exchange Warrants) to purchase an aggregate of 2,575,000 shares of common stock (subject to adjustment in the event of any stock dividends and splits, reverse stock split, merger or consolidation, change of control, reorganization or similar transaction, as described in the Exchange Warrants), with an exercise price of $0.0001 per share. In accordance with Accounting Standards Codification Topic 505, Equity , the Company recorded the retirement of the common stock exchanged as a reduction of common shares outstanding and a corresponding debit to additional paid-in-capital at the fair value of the Exchange Warrants on the issuance date. While outstanding, the Exchange Warrants were classified as equity in accordance with Accounting Standards Codification Topic 480, Distinguishing Liabilities from Equity , and the fair value of the Exchange Warrants was recorded as a credit to additional paid-in capital and is not subject to remeasurement. The Company determined that the fair value of the Exchange Warrants is substantially similar to the fair value of the retired shares on the issuance date due to the negligible exercise price for the Exchange Warrants. On March 2, 2020, the Exchanging Stockholders exercised the Exchange Warrants in full on a net cashless exercise basis, resulting in the issuance of 2,574,971 shares of common stock. Common Stock The holders of the common stock are entitled to one vote for each share held. Common stockholders are not entitled to receive dividends, unless declared by the Board of Directors (the Board). As of December 31, 2020 and 2019 there were 6,869,189 and 7,782,582, respectively, shares of common stock reserved for the exercise of outstanding stock options and warrants. December 31, December 31, Stock options 6,112,948 4,720,772 Restricted stock units 716,767 447,336 Warrants 39,474 39,474 Exchange warrants — 2,575,000 6,869,189 7,782,582 |
Stock Options
Stock Options | 12 Months Ended |
Dec. 31, 2020 | |
Share-based Payment Arrangement [Abstract] | |
Stock Options | Stock Options Stock option plans As of June 30, 2017, there were 3,141,625 options outstanding under the Company’s 2007 Stock Incentive Plan. The 2007 Plan expired in June 2017. Any cancellations under the 2007 Stock Incentive Plan will increase the options available under the 2017 Stock Incentive Plan as described below. In June 2017 the Company’s shareholders approved the 2017 Stock Incentive Plan (the 2017 Plan or the Plan). Under the 2017 Plan initially, up to 2,255,000 shares of common stock may be granted to the Company's employees, officers, directors, consultants and advisors in the form of options, restricted stock units (RSUs) or other stock-based awards. The number of shares of common stock issuable under the Plan will be cumulatively increased annually by 4% of the outstanding shares or such lesser amount specified by the Board. The terms of the awards are determined by the Board, subject to the provisions of the Plan. As of December 31, 2020 there were 1,288,072 shares available for future issuance under the Plan, including 1,815,520 shares automatically added to the Plan on January 1, 2020. Inducement awards The Company granted its senior vice president of regulatory affairs an option to purchase up to 120,000 and its senior vice president and chief medical officer an option to purchase 200,000 shares of common stock on September 2, 2020 and November 30, 2020, respectively, as an inducement to employment in accordance with Nasdaq Listing Rule 5635(c)(4). No underwriters were involved in this issuance of securities. The securities were issued pursuant to Section 4(a)(2) under the Securities Act of 1933, as amended, relating to transactions by an issuer not involving any public offering. These options are subject to terms substantially the same as the 2017 Plan. With respect to incentive stock options, the exercise price per share will equal the fair market value of the common stock on the date of grant, as determined by the Board, and the vesting period is generally four years. Nonqualified stock options will be granted at an exercise price established by the Board at its sole discretion (which has not been less than fair market value on the date of grant) and the vesting periods may vary. Options granted under the Plan expire no later than 10 years from the date of grant. The Board may accelerate vesting or extend the expiration of granted options in the case of a merger, consolidation, dissolution, or liquidation of the Company. Stock option activity A summary of the activity under the Plan is as follows: Number of Shares Weighted- Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2020 4,720,772 $ 5.24 7.3 $ 9,836 Granted 2,359,074 11.96 Exercised (697,428) 4.50 Cancelled (269,470) 7.05 Outstanding at December 31, 2020 6,112,948 $ 7.84 7.3 $ 114,729 Exercisable at December 31, 2020 3,147,379 $ 5.14 6.1 $ 67,562 The weighted-average grant date fair value of options granted during the years ended December 31, 2020, 2019 and 2018, was $7.99, $2.47 and $8.78 per share, respectively. Cash received from the exercise of stock options was $3,138, $175 and $918 for the years ended December 31, 2020, 2019 and 2018, respectively. Restricted stock units In July 2019, the Company issued RSUs with service conditions to employees. The awards cliff-vest two years after the grant date. In January 2020, the Company issued 324,932 RSUs with a service condition to employees for which the vesting term is annually over four years. Vesting of these awards is contingent on the fulfillment of the service conditions during the vesting term. A summary of the RSU activity under the 2017 Plan is as follow: Number Weighted-Average Aggregate Weighted-Average Unvested at January 1, 2020 447,336 1.5 $ 2,564 $ 4.00 Granted 361,932 — 8.14 Vested — — — Forfeited (92,501) — 4.68 Unvested at December 31, 2020 716,767 1.0 $ 19,073 $ 6.00 Stock-based compensation expense The Company uses the provisions of ASC 718, Stock Compensation , to account for all stock-based awards to employees and non-employees. The measurement date for employee awards is generally the date of grant. Stock-based compensation expense is recognized over the requisite service period, which is generally the vesting period, using the straight-line method. The following table presents stock-based compensation expense by award type included within the Company’s consolidated statement of operations and comprehensive loss: Year ended December 31, 2020 2019 2018 Stock options $ 5,725 $ 4,230 $ 3,754 Restricted stock units 1,187 410 — Employee stock purchase plan 260 232 130 Stock-based compensation expense included in Total operating expenses $ 7,172 $ 4,872 $ 3,884 The following table presents stock-based compensation expense as reflected in the Company’s consolidated statements of operations and comprehensive loss: Year ended December 31, 2020 2019 2018 Research and development $ 3,841 $ 2,245 $ 1,788 General and administrative 3,331 2,627 2,096 Stock-based compensation expense included in Total operating expenses $ 7,172 $ 4,872 $ 3,884 As of December 31, 2020, there was $19,487 and $2,699 of unrecognized compensation expense related to unvested stock options and unvested RSUs, respectively, that is expected to be recognized over a weighted average period of 2.8 years and 2.3 years, respectively. The fair value of each option award is estimated on the date of grant using the Black–Scholes option pricing model with the following weighted average assumptions: December 31, 2020 2019 2018 Risk-free interest rate 1.2 % 2.3 % 2.7 % Expected dividend yield — % — % — % Expected term (years) 6.05 5.99 6.07 Expected stock price volatility 74 % 74 % 73 % Expected volatility for the Company’s common stock is determined based on the historical volatility of comparable publicly traded companies. The risk-free interest rate is based on the yield of U.S. Treasury securities consistent with the expected term of the option. No dividend yield was assumed as the Company has not historically and does not expect to pay dividends on its common stock. The expected term of the options granted is based on the use of the simplified method, in which the expected term is presumed to be the mid-point between the vesting date and the end of the contractual term. The fair value of RSUs is determined based on the closing price of the Company’s common stock on the date of grant. Employee Stock Purchase Plan During the year ended December 31, 2017, the Board adopted and the Company's stockholders approved the 2017 employee stock purchase plan (the 2017 ESPP). The Company initially reserved 225,000 shares of common stock for issuance under the 2017 ESPP. During the years ended December 31, 2020 and 2019 the Company issued 80,267 and 140,073 shares, respectively, under the 2017 ESPP. As of December 31, 2020, there were 644,818 shares available for issuance, including 450,000 shares automatically added to the 2017 ESPP on January 1, 2020. |
Leases
Leases | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Leases | Leases The Company has an operating lease for its office space in Cambridge, MA and operating and finance leases for certain equipment. In March 2020, the Company entered into the Seventh Amendment to the office space lease to extend the term of the lease through March 2026 and to provide the Company with a tenant improvement allowance of $172. The current rate per square foot that is in place through March 2021 (the original expiration date of the lease) did not change. After March 2021, there are predetermined fixed escalations of the rate as outlined in the amendment. The Company has an option to extend the lease term for an additional five years. The Company’s exercise of this option was not considered reasonably certain as of December 31, 2020. The extension is accounted for as a lease modification. The Company assessed the lease classification of the amended office space lease at the modification date and determined that the amended office space lease should be accounted for as an operating lease. The right-of-use asset and corresponding operating lease liability have been remeasured based on the present value of remaining lease payments over the remaining extended lease term, using the incremental borrowing rate applicable as of the lease modification date. The Company determined the appropriate incremental borrowing rate by using a synthetic credit rating which was estimated based on an analysis of outstanding debt of companies with similar credit and financial profiles. Since the operating lease is a net lease, as the non-lease components (i.e., common area maintenance) are paid separately from rent based on actual costs incurred, such non-lease components were not included in the right-of-use asset and liability and are reflected as an expense in the period incurred. As a result of the modification in March 2020, the Company recorded an increase of $9,980 to its right-of-use (ROU) asset and lease liabilities in the first quarter of 2020. In connection with the office lease, the Company had a letter of credit agreement for the benefit of its landlord in the amount of $321 as of each December 31, 2020 and 2019, collateralized by a money market account. During the first quarter of 2019, the Company entered into finance leases for certain equipment. The Company recorded assets under finance leases of $429 as property and equipment. The components of lease expense were as follows: Year ended December 31, 2020 2019 Operating lease cost $ 2,755 $ 2,160 Finance lease cost: Amortization of right-of-use assets $ 176 $ 75 Interest on lease liabilities 21 20 $ 197 $ 95 Supplemental balance sheet information related to leases was as follows: Year ended December 31, 2020 2019 Operating leases: Operating lease right-of-use assets $ 10,936 $ 2,598 Operating lease liabilities, current 1,437 2,219 Operating lease liabilities 10,158 677 Finance leases: Property and equipment, gross $ 429 $ 429 Property and equipment, accumulated depreciation (176) (75) Other liabilities, current 93 87 Other liabilities 174 275 Weighted-average remaining lease term: Operating leases 5.2 years 1.3 years Finance leases 2.9 years 3.7 years Weighted-average discount rate: Operating leases 10.8 % 10.3 % Finance leases 6.9 % 6.9 % Supplemental cash flow information related to leases was as follows: Year ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,394 $ 2,271 Operating cash flows from finance leases 21 20 Financing cash flows from finance leases 116 87 Rent expense was $2,644, $2,160 and $1,994 for the years ended December 31, 2020, 2019 and 2018, respectively. Future minimum lease payments under non-cancellable leases as of December 31, 2020 were as follows: Operating leases Finance leases 2021 $ 2,772 $ 116 2022 2,843 84 2023 2,928 74 2024 3,016 18 2025 and thereafter 3,888 — Total lease payments 15,447 292 Present value adjustment (3,854) (25) Present value of lease liabilities $ 11,593 $ 267 |
Leases | Leases The Company has an operating lease for its office space in Cambridge, MA and operating and finance leases for certain equipment. In March 2020, the Company entered into the Seventh Amendment to the office space lease to extend the term of the lease through March 2026 and to provide the Company with a tenant improvement allowance of $172. The current rate per square foot that is in place through March 2021 (the original expiration date of the lease) did not change. After March 2021, there are predetermined fixed escalations of the rate as outlined in the amendment. The Company has an option to extend the lease term for an additional five years. The Company’s exercise of this option was not considered reasonably certain as of December 31, 2020. The extension is accounted for as a lease modification. The Company assessed the lease classification of the amended office space lease at the modification date and determined that the amended office space lease should be accounted for as an operating lease. The right-of-use asset and corresponding operating lease liability have been remeasured based on the present value of remaining lease payments over the remaining extended lease term, using the incremental borrowing rate applicable as of the lease modification date. The Company determined the appropriate incremental borrowing rate by using a synthetic credit rating which was estimated based on an analysis of outstanding debt of companies with similar credit and financial profiles. Since the operating lease is a net lease, as the non-lease components (i.e., common area maintenance) are paid separately from rent based on actual costs incurred, such non-lease components were not included in the right-of-use asset and liability and are reflected as an expense in the period incurred. As a result of the modification in March 2020, the Company recorded an increase of $9,980 to its right-of-use (ROU) asset and lease liabilities in the first quarter of 2020. In connection with the office lease, the Company had a letter of credit agreement for the benefit of its landlord in the amount of $321 as of each December 31, 2020 and 2019, collateralized by a money market account. During the first quarter of 2019, the Company entered into finance leases for certain equipment. The Company recorded assets under finance leases of $429 as property and equipment. The components of lease expense were as follows: Year ended December 31, 2020 2019 Operating lease cost $ 2,755 $ 2,160 Finance lease cost: Amortization of right-of-use assets $ 176 $ 75 Interest on lease liabilities 21 20 $ 197 $ 95 Supplemental balance sheet information related to leases was as follows: Year ended December 31, 2020 2019 Operating leases: Operating lease right-of-use assets $ 10,936 $ 2,598 Operating lease liabilities, current 1,437 2,219 Operating lease liabilities 10,158 677 Finance leases: Property and equipment, gross $ 429 $ 429 Property and equipment, accumulated depreciation (176) (75) Other liabilities, current 93 87 Other liabilities 174 275 Weighted-average remaining lease term: Operating leases 5.2 years 1.3 years Finance leases 2.9 years 3.7 years Weighted-average discount rate: Operating leases 10.8 % 10.3 % Finance leases 6.9 % 6.9 % Supplemental cash flow information related to leases was as follows: Year ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,394 $ 2,271 Operating cash flows from finance leases 21 20 Financing cash flows from finance leases 116 87 Rent expense was $2,644, $2,160 and $1,994 for the years ended December 31, 2020, 2019 and 2018, respectively. Future minimum lease payments under non-cancellable leases as of December 31, 2020 were as follows: Operating leases Finance leases 2021 $ 2,772 $ 116 2022 2,843 84 2023 2,928 74 2024 3,016 18 2025 and thereafter 3,888 — Total lease payments 15,447 292 Present value adjustment (3,854) (25) Present value of lease liabilities $ 11,593 $ 267 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | Income Taxes For the years ended December 31, 2020, 2019 and 2018, the Company recorded no income tax benefit for the net operating losses incurred in each year, due to its uncertainty of realizing a benefit from those items. A reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations as of December 31, 2020, 2019 and 2018 are as follows: 2020 2019 2018 Income tax computed at federal statutory tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.7 % 6.1 % 6.5 % Permanent differences 1.2 % (2.0) % 0.6 % General business credits 3.4 % 10.3 % 4.2 % Impact of ownership shift — % (53.3) % — % Change in valuation allowance (32.3) % 17.9 % (32.3) % — % — % — % Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s net deferred tax assets as of December 31, 2020 and 2019 are as follows: 2020 2019 Deferred tax assets: Net operating losses $ 64,259 $ 40,554 Tax credit carryforwards 5,670 2,448 Accrued expenses 4,058 2,520 Lease liabilities 3,166 791 Licensed technology 1,534 1,402 Deferred revenue 1,088 1,315 Depreciation 502 492 Other 84 77 Total gross deferred tax assets 80,361 49,599 Valuation allowance (77,375) (48,889) Net deferred tax assets less valuation allowance 2,986 710 Deferred tax liabilities Right-of-use assets (2,986) (710) Total gross deferred tax liabilities (2,986) (710) Net deferred taxes $ — $ — The Company has incurred net operating losses (NOL) since inception. At December 31, 2020, the Company had Federal and State net operating loss carryforwards of approximately $250,367 and $184,781, respectively. Of the $250,367 of Federal net operating loss carryforwards, $34,149 expire at various dates through 2037. The remaining $216,218 of Federal net operating loss carryforwards do not expire. The State net operating loss carryforwards expire at various dates through 2040. At December 31, 2020, the Company had Federal and State research and development tax credit carryforwards of approximately $4,582 and $1,482, respectively, which expire at various dates through 2040. As required by ASC 740, management of the Company has evaluated the evidence bearing upon the reliability of its deferred tax assets. Based on the weight of available evidence, both positive and negative, management has determined that it is more likely than not that the Company will not realize the benefits of all of these assets. Accordingly, the Company recorded a valuation allowance of $77,375 and $48,889 at December 31, 2020 and December 31, 2019, respectively. The valuation allowance increased by $28,468 and decreased by $5,051 during the years ended December 31, 2020 and 2019, respectively, primarily as a result of the Company’s 382 limitation and net operating losses generated during the periods, respectively. Utilization of the NOLs and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 due to ownership change limitations that have occurred previously or that could occur in the future in accordance with Section 382, as well as similar state provisions. These ownership changes may limit the amount of NOLs and research and development tax credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. If a change in control as defined by Section 382 has occurred at any time since the Company’s formation, utilization of its NOLs or research and development tax credit carryforwards would be subject to an annual limitation under Section 382, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term tax-exempt rate, which could then be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the NOLs or research and development tax carryforwards before their utilization. The Company has determined that ownership changes have occurred through November 4, 2019 and that certain NOLs and research and development tax credit carryforwards will be subject to limitation. The amounts presented do not include NOLs or research and development tax credit carryforwards that will expire unused due to ownership changes. The Company applies the accounting guidance in ASC 740 related to accounting for uncertainty in income taxes. The Company’s reserves related to taxes are based on a determination of whether, and how much of, a tax benefit taken by the Company in its tax filings or positions is more likely than not to be realized following resolution of any potential contingencies present related to the tax benefit. As of December 31, 2020 and 2019, the Company had no unrecognized tax benefits. The Company has not conducted a study of its research and development credit carryforwards. This study may result in an adjustment to research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the valuation allowance. Thus, there would be no impact to the balance sheets or statements of operations if an adjustment were required. Interest and penalties related to uncertain tax positions would be classified as income tax expense in the accompanying statements of operations. As of December 31, 2020 and 2019, the Company had no accrued interest or penalties related to uncertain tax positions. The Company files income tax returns in the United States federal tax jurisdiction and two state jurisdiction. The Company did not have any foreign operations during the years ended December 31, 2020, 2019 and 2018. The statute of limitations for assessment by the Internal Revenue Service and state tax authorities is closed for tax years prior to 2016, although carryforward attributes that were generated prior to tax year 2015 may still be adjusted upon examination to the extent utilized in a future period. There are no federal or state audits currently in progress. |
Employee Benefit Plan
Employee Benefit Plan | 12 Months Ended |
Dec. 31, 2020 | |
Retirement Benefits [Abstract] | |
Employee Benefit Plan | Employee Benefit PlanThe Company has a defined contribution plan established under Section 401(k) of the Internal Revenue Code (401(k) Plan), which covers substantially all employees. Employees who have attained the age of 21 are eligible to participate in the 401(k) Plan with no service requirement. Employees may contribute up to 75% of eligible pay on a pre–tax basis up to the federal annual limits. For the year ended December 31, 2018 and the period from January 1, 2019 to July 31, 2019, the Company matched the employees’ contributions at 50% on the first 6% up to $6. For the period from August 1, 2019 to December 31, 2019 and for the year ended December 31, 2020, the Company matched the employees’ contributions at 100% on the first 4% up to $7. For the years ended December 31, 2020, 2019 and 2018, the Company recorded expense of $486, $404 and $332, respectively, related to its contribution to its 401(k) Plan. |
Commitments
Commitments | 12 Months Ended |
Dec. 31, 2020 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments | Commitments License Agreements During the years ended December 31, 2020, 2019 and 2018, the Company recorded research and development expense related to non-refundable upfront payments of $250, $750, and $0, respectively. Further milestone payments of $750, $600 and $0, respectively, were also recorded as research and development expense during the years ended December 31, 2020, 2019 and 2018. See Note 11 for the Company’s future obligations related to leases as of December 31, 2020. |
Selected Quarterly Financial Da
Selected Quarterly Financial Data (Unaudited) | 12 Months Ended |
Dec. 31, 2020 | |
Quarterly Financial Information Disclosure [Abstract] | |
Selected Quarterly Financial Data (Unaudited) | Selected Quarterly Financial Data (unaudited)The following table contains selected quarterly financial information for 2020 and 2019. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Three months ended March 31, 2020 June 30, 2020 September 30, 2020 December 31, 2020 Collaboration revenue $ 11 $ 796 $ 11 $ 10 Operating expenses: Research and development 12,219 15,413 16,546 22,858 General and administrative 4,936 5,171 5,881 5,914 Total operating expenses 17,155 20,584 22,427 28,772 Other income: Interest income 306 89 19 10 Interest expense (88) (87) (92) (92) Total other income (expense), net 218 2 (73) (82) Net loss $ (16,926) $ (19,786) $ (22,489) $ (28,844) Net loss per share attributable to common stockholders — basic and diluted $ (0.35) $ (0.33) $ (0.33) $ (0.42) Weighted-average number of common shares used in net loss per share attributable to common stockholders — basic and diluted 47,988,630 60,748,225 68,419,192 68,630,078 Three months ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Collaboration revenue $ 41,035 $ 202 $ 844 $ 42 Operating expenses: Research and development 15,143 13,766 13,701 12,430 General and administrative 4,443 4,192 4,436 4,212 Total operating expenses 19,586 17,958 18,137 16,642 Other income: Interest income 452 725 608 441 Interest expense — (40) (107) (87) Total other income (expense), net 452 685 501 354 Net income (loss) $ 21,901 $ (17,071) $ (16,792) $ (16,246) Net income (loss) per share attributable to common stockholders — basic $ 0.72 $ (0.36) $ (0.35) $ (0.34) Net income (loss) per share attributable to common stockholders — diluted $ 0.70 $ (0.36) $ (0.35) $ (0.34) Weighted-average number of common shares used in net income (loss) per share attributable to common stockholders — basic 30,299,650 47,708,085 47,833,607 47,886,144 Weighted-average number of common shares used in net income (loss) per share attributable to common stockholders — diluted 31,461,696 47,708,085 47,833,607 47,886,144 |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Principles of Consolidation | Principles of Consolidation The accompanying consolidated financial statements include those of the Company and its wholly owned subsidiary, Mersana Securities Corp. All intercompany balances and transactions have been eliminated. |
Use of Estimates | Use of Estimates The preparation of the Company's consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, revenue, expenses and related disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. On an ongoing basis, the Company's management evaluates its estimates which include, but are not limited to, management's judgments with respect to the identification of performance obligations and standalone selling prices of those performance obligations within its revenue arrangements, accrued preclinical, manufacturing and clinical expenses, valuation of stock-based awards and income taxes. Actual results could differ from those estimates. |
Segment Information | Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision-maker, or decision making group, in deciding how to allocate resources and assess performance. The Company views its operations and manages its business as a single operating segment, which is the business of discovering and developing ADCs. |
Research and Development | Research and Development Research and development costs are expensed as incurred and include: • employee-related expenses, including salaries, bonuses, benefits, travel and stock-based compensation expense; • fees and expenses incurred under agreements with contract research organizations, investigative sites and other entities in connection with the conduct of preclinical and clinical studies and related services; • the cost of acquiring, developing and manufacturing ADC product candidates, clinical study materials and other research and development materials; • fees and costs related to regulatory filings and activities; • costs associated with collaboration agreements and license fees and milestone payments related to license agreements; • costs associated with creating and obtaining approval for the NaPi2b companion or complementary diagnostic biomarker; • facilities, depreciation and other expenses, which include direct and allocated expenses for rent, utilities, maintenance of facilities, insurance and other supplies; and • other costs associated with clinical, preclinical, discovery and other research activities. Costs for certain development activities, such as clinical studies and manufacturing development activities, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, and information provided to the Company by its vendors on their actual costs incurred or level of effort expended. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected on the consolidated balance sheets as prepaid or accrued preclinical, manufacturing and clinical expenses. |
Revenue Recognition | Revenue Recognition The Company enters into collaboration agreements which are within the scope of Accounting Standards Update (ASU) No. 2014-9, Revenue from Contracts with Customers (Topic 606), under which the Company licenses rights to its technology and certain of the Company’s product candidates and performs research and development services for third parties. The terms of these arrangements typically include payment of one or more of the following: non-refundable, up-front fees; reimbursement of research and development costs; development, regulatory and commercial milestone payments; and royalties on net sales of licensed products. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine the appropriate amount of revenue to be recognized for arrangements determined to be within the scope of Topic 606, the Company performs the following five steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect consideration it is entitled to in exchange for the goods or services it transfers to the customer. The promised good or services in the Company’s arrangement typically consist of license rights to the Company’s intellectual property and research and development services. The Company also has optional additional items in contracts, which are considered marketing offers and are accounted for as separate contracts with the customer if such option is elected by the customer, unless the option provides a material right which would not be provided without entering into the contract. Performance obligations are promised goods or services in a contract to transfer a distinct good or service to the customer. Promised goods or services are considered distinct when (i) the customer can benefit from the good or service on its own or together with other readily available resources or (ii) the promised good or service is separately identifiable from other promises in the contract. In assessing whether promised goods or services are distinct, the Company considers factors such as the stage of development of the underlying intellectual property, the capabilities of the customer to develop the intellectual property on their own or whether the required expertise is readily available. The Company estimates the transaction price based on the amount expected to be received for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. At the inception of each arrangement that includes variable consideration and at each reporting period, the Company evaluates the amount of potential payment and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected amount method to estimate the amount expected to be received based on which method better predicts the amount expected to be received. If it is probable that a significant revenue reversal would not occur, the variable consideration is included in the transaction price. We assessed each of our revenue generating arrangements in order to determine whether a significant financing component exists and concluded that a significant financing component does not exist in any of our arrangements because: (a) the promised consideration approximates the cash selling price of the promised goods and services; and (b) timing of payment approximates the transfer of goods and services and performance is over a relatively short period of time within the context of the entire term of the contract. The Company’s contracts often include development and regulatory milestone payments. At contract inception and at each reporting period, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are not included in the transaction price. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license, collaboration and other revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any royalty revenue resulting from any of the Company’s collaboration arrangements. The Company allocates the transaction price based on the estimated standalone selling price of the underlying performance obligations or in the case of certain variable consideration to one or more performance obligations. The Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the stand-alone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction and the estimated costs to complete the respective performance obligation. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. For performance obligations consisting of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. The Company receives payments from its customers based on billing schedules established in each contract. Such billings generally have 30-day terms. Up-front payments and fees are recorded as deferred revenue upon receipt or when due until the Company performs its obligations under these arrangements. Amounts are recorded as accounts receivable when the right to consideration is unconditional. Effective January 1, 2018, the Company adopted the provisions of Topic 606, using the modified retrospective transition method. Under this method, the Company recorded the cumulative effect of initially applying the new standard to all contracts in process as of the date of adoption. This standard applied to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. The adoption of the new revenue recognition guidance resulted in increases of $2,031 in deferred revenue and accumulated deficit as of January 1, 2018. For the years ended December 31, 2019 and 2018, revenue was not materially impacted as compared to the Company’s prior revenue recognition methodology under ASC 605 Revenue Recognition. |
Collaborative Arrangements | Collaborative Arrangements The Company records the elements of its collaboration agreements that represent joint operating activities in accordance with ASC Topic 808, Collaborative Arrangements (ASC 808). Accordingly, the elements of the collaboration agreements that represent activities in which both parties are active participants and to which both parties are exposed to the significant risks and rewards that are dependent on the commercial success of the activities, are recorded as collaborative arrangements. The Company considers the guidance in ASC Topic 606 in determining the appropriate treatment for the transactions between the Company and its collaborative partners and the transactions between the Company and third parties. Generally, the classification of transactions under the collaborative arrangements is determined based on the nature and contractual terms of the arrangement along with the nature of the operations of the participants. To the extent revenue is generated from a collaboration, the Company will recognize its share of the net sales on a gross basis if it is deemed to be the principal in the transactions with customers, or on a net basis if it is instead deemed to be the agent in the transactions with customers, consistent with the guidance in Topic 606. |
Fair Value Measurements | Fair Value Measurements Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability between market participants at measurement dates. ASC Topic 820 Fair Value Measurement (ASC 820) establishes a three-level valuation hierarchy for instruments measured at fair value. The hierarchy is based on the transparency of inputs to the valuation of an asset or liability as of the measurement date. The three levels are defined as follows: Level 1—Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2—Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. |
Cash and Cash Equivalents | Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity, or a remaining maturity at the time of purchase, of three months or less to be cash equivalents. The Company invests excess cash primarily in money market funds, commercial paper and government agency securities, which are highly liquid and have strong credit ratings. These investments are subject to minimal credit and market risks. Cash and cash equivalents are stated at cost, which approximates market value. |
Marketable Securities | Marketable Securities Short-term marketable securities consist of investments in debt securities with maturities greater than three months and less than one year from the balance sheet date. The Company classifies all of its marketable securities as available-for-sale. Accordingly, these investments are recorded at fair value. Amortization and accretion of discounts and premiums are recorded as interest income within other income. Prior to the adoption of ASU 2016-13, Financial Instruments - Credit Losses , unrealized gains and losses on available-for-sale securities were included in other accumulated comprehensive loss as a component of stockholders’ equity until realized. Realized gains and losses and declines in value judged to be other than temporary are included as a component of other income (expense), net, based on the specific identification method. When determining whether a decline in value is other than temporary, the Company considers various factors, including whether the Company has the intent to sell the security, and whether it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis. Fair value is determined based on quoted market prices. |
Other Assets | Other Assets The Company recorded other assets of $2,153 and $1,453 as of December 31, 2020 and 2019, respectively, comprised of $1,832 and $1,132, respectively, held by a service provider, and restricted cash of $321 and $321 at the end of each period held as a security deposit for a standby letter of credit related to a facility lease. |
Accounting for Stock-based Compensation | Accounting for Stock-based Compensation The Company accounts for its stock-based compensation in accordance with ASC Topic 718 Compensation— Stock Compensation (ASC 718). ASC 718 requires all stock-based payments to employees, directors and non-employees to be recognized as expense in the statements of operations based on their grant date fair values. The Company estimates the fair value of options granted using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (a) the expected stock price volatility, (b) the calculation of expected term of the award, (c) the risk-free interest rate and (d) expected dividends. Due to the lack of a public market for the Company's common stock prior to completion of the initial public offering and a lack of company-specific historical and implied volatility data, the Company has based its estimate of expected volatility on the historical volatility of a group of similar companies that are publicly traded. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The historical volatility is calculated based on a period of time commensurate with the expected term assumption. The computation of expected volatility is based on the historical volatility of a representative group of companies with similar characteristics to the Company, including stage of product development and life science industry focus. The Company uses the simplified method as prescribed by the SEC Staff Accounting Bulletin No. 107, Share-Based Payment , to calculate the expected term for options granted to employees as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. For options granted to non-employees, the Company utilizes the contractual term of the arrangement as the basis for the expected term assumption. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected term of the stock options. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to do so. The Company determines the fair value of each restricted stock unit, or RSU, at its grant date based on the closing market price of the Company’s common stock on that date. For stock-based compensation subject to service-based vesting conditions, the Company recognizes stock-based compensation expense equal to the grant date fair value of stock-based compensation on a straight-line basis over the requisite service period. The Company records forfeitures as a cumulative adjustment in the period in which they occur. |
Net Loss per Share | Net Loss per Share Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding and 2,575,000 Exchange Warrants (as defined in footnote 9) outstanding during the period, without further consideration for potentially dilutive securities. In accordance with Accounting Standards Codification Topic 260, Earnings Per Share , the Exchange Warrants are included in the computation of basic net loss per share because the exercise price is negligible and they are fully vested and exercisable at any time after the original issuance date. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares and potentially dilutive securities outstanding for the period determined using the treasury stock method. For purposes of the diluted net loss per share calculation, stock options, unvested restricted stock units (RSUs) and warrants to purchase common stock are considered to be potentially dilutive securities, but are excluded from the calculation of diluted net loss per share because their effect would be anti-dilutive and therefore, basic and diluted net loss per share were the same for all periods presented. |
Property and Equipment | Property and Equipment Property and equipment is stated at cost, less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful life of each asset as follows: Computer equipment, office equipment and software 3 years Laboratory equipment 5 years Leasehold improvements Shorter of useful life or life of lease Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are eliminated from the balance sheet and related gains or losses are reflected in the statement of operations. There were no material sales of assets during the years ended December 31, 2020, 2019 and 2018. |
Leases | Leases Consistent with ASC 842, the Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use lease assets (ROU assets), current portion of lease obligations and long-term lease obligations on the Company’s consolidated balance sheets. Assets subject to finance leases are included in property and equipment, and the related lease obligation is included in other current liabilities and other long-term liabilities on the Company’s consolidated balance sheets. Lease assets are tested for impairment in the same manner as long-lived assets used in operations. Lease expense for operating leases is recognized on a straight-line basis over the lease term as an operating expense while expense for financing leases is recognized as depreciation expense and interest expense using the effective interest method. The Company has elected the short-term lease recognition exemption for short-term leases, which allows the Company not to recognize lease liabilities and ROU assets on the consolidated balance sheets for leases with an original term of twelve months or less. ROU assets represent the Company’s right to use an underlying asset for the lease term, and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating lease liabilities and their corresponding ROU assets are initially recorded based on the present value of lease payments over the expected remaining lease term. When determining the lease term, the Company includes options to extend or terminate the lease when it is reasonably certain that the option will be exercised. Certain adjustments to the ROU asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate to discount lease payments. The incremental borrowing rate reflects the fixed rate at which the Company could borrow, on a collateralized basis, the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. Prospectively, the Company will adjust the ROU assets for straight-line rent expense, or any incentives received and remeasure the lease liability at the net present value using the same incremental borrowing rate that was in effect as of the lease commencement or transition date. The Company has lease agreements with lease and non-lease components, which are generally accounted for separately. |
Patent Costs | Patent Costs The Company expenses patent application and related legal costs as incurred and classifies such costs as general and administrative expenses in the accompanying consolidated statements of operations. |
Income Taxes | Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Accounting for Income Taxes , which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. The Company determines its deferred tax assets and liabilities based on differences between financial reporting and tax bases of assets and liabilities, which are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company recognizes the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is more likely than not to be realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. |
Comprehensive Income (Loss) | Comprehensive Income (Loss) Comprehensive income (loss) comprises net loss and other comprehensive loss. For the years ended December 31, 2020, 2019 and 2018, other comprehensive income (loss) consisted of changes in unrealized income and loss on marketable securities. |
Concentration of Credit Risk and Off-balance Sheet Risk | Concentration of Credit Risk and Off-balance Sheet Risk The Company has no financial instruments with off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash equivalents and marketable securities. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company has not experienced any credit losses and does not believe this it is subject to any significant concentrations of credit risk from these financial instruments. |
Recently Issued Accounting Pronouncements | Recently Issued Accounting Pronouncements In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 . The main provisions of ASU 2018-18 include: (i) clarifying that certain transactions between collaborative arrangement participants should be accounted for as revenue when the collaborative arrangement participant is a customer in the context of a unit of account and (ii) precluding the presentation of transactions with collaborative arrangement participants that are not directly related to sales to third parties together with revenue. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods, and early adoption is permitted. The guidance per ASU 2018-18 is to be adopted retrospectively to the date of initial application of Topic 606. The Company adopted the new standard effective January 1, 2020. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. Historically, U.S. GAAP delayed recognition of the full amount of credit losses until the loss was probable of occurring. Under this ASU, the income statement will reflect an entity’s current estimate of all expected credit losses. The measurement of expected credit losses will be based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down of the security. This ASU is effective for annual periods beginning after December 15, 2019, including interim periods within those annual reporting periods, and early adoption is permitted. The Company adopted the new standard effective January 1, 2020 using the modified retrospective method. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and related disclosures. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , as part of its initiative to reduce complexity in the accounting standards. The amendments in ASU 2019-12 eliminate certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. ASU 2019-12 also clarifies and simplifies other aspects of the accounting for income taxes. The amendments in ASU 2019-12 are effective for the fiscal years beginning after December 15, 2020. Early adoption is permitted, including adoption in any interim period. The Company is currently evaluating the potential impact ASU 2019-12 may have on its financial position and results of operations upon adoption. |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Schedule of cash and cash equivalents | Year ended December 31, 2020 Year ended December 31, 2019 Beginning of period End of period Beginning of period End of period Cash and cash equivalents $ 62,351 $ 255,094 $ 59,634 $ 62,351 Restricted cash included in other assets, noncurrent 321 321 371 321 Total cash, cash equivalents and restricted cash per statement of cash flows $ 62,672 $ 255,415 $ 60,005 $ 62,672 |
Schedule of restricted cash | Year ended December 31, 2020 Year ended December 31, 2019 Beginning of period End of period Beginning of period End of period Cash and cash equivalents $ 62,351 $ 255,094 $ 59,634 $ 62,351 Restricted cash included in other assets, noncurrent 321 321 371 321 Total cash, cash equivalents and restricted cash per statement of cash flows $ 62,672 $ 255,415 $ 60,005 $ 62,672 |
Schedule of outstanding potentially dilutive securities excluded from calculation of diluted net loss per share | The following table sets forth the outstanding potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive (in common stock equivalent shares): Year ended December 31, 2020 2019 2018 Stock options 6,112,948 4,720,772 3,746,567 Unvested restricted stock units 716,767 447,336 — Warrants 39,474 39,474 110,365 6,869,189 5,207,582 3,856,932 |
Schedule of estimated useful life of property and equipment | Depreciation is computed using the straight-line method over the estimated useful life of each asset as follows: Computer equipment, office equipment and software 3 years Laboratory equipment 5 years Leasehold improvements Shorter of useful life or life of lease |
Collaboration Agreements (Table
Collaboration Agreements (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Collaboration agreements | |
Schedule of changes in the balances of our contract assets and liabilities and recognized revenue | The following table presents changes in the balances of our contract assets and liabilities during the years ended December 31, 2020 and December 31, 2019: Balance at Beginning of Period Additions Deductions Balance at End of Period Year ended December 31, 2020 Contract assets $ — $ — $ — $ — Contract liabilities: Deferred revenue $ 4,815 $ — $ 828 $ 3,987 Balance at Beginning of Period Additions Deductions Balance at End of Period Year ended December 31, 2019 Contract assets $ — $ — $ — $ — Contract liabilities: Deferred revenue $ 46,196 $ 210 $ 41,591 $ 4,815 During the year ended December 31, 2020, the Company recognized the following revenues as a result of changes in the contract asset and the contract liability balances in the respective periods. Year ended December 31, 2020 2019 Revenue recognized in the period from: Amounts included in the contract liability at the beginning of the period $ 828 $ 41,591 Performance obligations satisfied in previous periods $ — $ — |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Schedule of assets and liabilities measured and carried at fair value | The following table presents information about the Company's assets and liabilities regularly measured and carried at a fair value and indicates the level within fair value hierarchy of the valuation techniques utilized to determine such value as of December 31, 2019. The Company had no marketable securities as of December 31, 2020: Fair Quoted Prices Significant Significant December 31, 2019 Marketable securities: Commercial paper $ 11,940 $ — $ 11,940 $ — Corporate bonds 12,010 — 12,010 — U.S. Treasuries 13,489 13,489 — — $ 37,439 $ 13,489 $ 23,950 $ — |
Marketable Securities (Tables)
Marketable Securities (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Marketable Securities [Abstract] | |
Schedule of reconciliation of marketable securities from cost basis to fair value | The following table summarizes marketable securities held at December 31, 2019. The Company had no marketable securities as of December 31, 2020: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value December 31, 2019 Commercial paper $ 11,940 $ — $ — $ 11,940 Corporate bonds 11,990 20 — 12,010 U.S. Treasuries 13,484 5 — 13,489 $ 37,414 $ 25 $ — $ 37,439 |
Property and Equipment (Tables)
Property and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Property, Plant and Equipment [Abstract] | |
Schedule of property and equipment | Property and equipment consists of the following as of December 31, 2020 and 2019: December 31, December 31, Laboratory equipment $ 6,520 $ 6,419 Leasehold improvements 1,886 1,886 Computer equipment and office equipment 959 1,068 Total property and equipment at cost 9,365 9,373 Less: Accumulated depreciation (7,635) (7,209) $ 1,730 $ 2,164 |
Accrued expenses (Tables)
Accrued expenses (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Accrued Liabilities, Current [Abstract] | |
Schedule of accrued expenses | Accrued expenses consist of the following as of December 31, 2020 and 2019: December 31, December 31, Accrued preclinical, manufacturing and clinical expenses $ 9,902 $ 4,230 Accrued payroll and related expenses 5,412 4,037 Accrued professional fees 757 675 Accrued other 75 44 $ 16,146 $ 8,986 |
Debt (Tables)
Debt (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Debt Disclosure [Abstract] | |
Schedule of debt | As of December 31, 2020, there was $5,200 outstanding under the Amended Credit Facility and the debt consisted of the following: December 31, Total debt $ 5,200 Less: Current portion of long-term-debt — Total debt, net of current portion 5,200 Debt financing costs, net of accretion (246) Accretion related to final payment 23 Long-term debt, net $ 4,977 |
Schedule of estimated future payments | As of December 31, 2020, the estimated future principal payments due are as follows: 2021 $ — 2022 1,213 2023 2,080 2024 1,907 Total debt $ 5,200 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Stockholders' Equity Note [Abstract] | |
Schedule for number of common stock reserved for exercise of outstanding stock options and warrants | December 31, December 31, Stock options 6,112,948 4,720,772 Restricted stock units 716,767 447,336 Warrants 39,474 39,474 Exchange warrants — 2,575,000 6,869,189 7,782,582 |
Stock Options (Tables)
Stock Options (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Share-based Payment Arrangement [Abstract] | |
Schedule of stock option activity | A summary of the activity under the Plan is as follows: Number of Shares Weighted- Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at January 1, 2020 4,720,772 $ 5.24 7.3 $ 9,836 Granted 2,359,074 11.96 Exercised (697,428) 4.50 Cancelled (269,470) 7.05 Outstanding at December 31, 2020 6,112,948 $ 7.84 7.3 $ 114,729 Exercisable at December 31, 2020 3,147,379 $ 5.14 6.1 $ 67,562 |
Schedule of restricted stock unit activity | A summary of the RSU activity under the 2017 Plan is as follow: Number Weighted-Average Aggregate Weighted-Average Unvested at January 1, 2020 447,336 1.5 $ 2,564 $ 4.00 Granted 361,932 — 8.14 Vested — — — Forfeited (92,501) — 4.68 Unvested at December 31, 2020 716,767 1.0 $ 19,073 $ 6.00 |
Schedule of stock-based compensation expense by award type | The following table presents stock-based compensation expense by award type included within the Company’s consolidated statement of operations and comprehensive loss: Year ended December 31, 2020 2019 2018 Stock options $ 5,725 $ 4,230 $ 3,754 Restricted stock units 1,187 410 — Employee stock purchase plan 260 232 130 Stock-based compensation expense included in Total operating expenses $ 7,172 $ 4,872 $ 3,884 |
Schedule of stock-based compensation expense as reflected in the Company’s condensed consolidated statements of operations and comprehensive loss | The following table presents stock-based compensation expense as reflected in the Company’s consolidated statements of operations and comprehensive loss: Year ended December 31, 2020 2019 2018 Research and development $ 3,841 $ 2,245 $ 1,788 General and administrative 3,331 2,627 2,096 Stock-based compensation expense included in Total operating expenses $ 7,172 $ 4,872 $ 3,884 |
Schedule of weighted average assumptions for estimating fair value of option awards | The fair value of each option award is estimated on the date of grant using the Black–Scholes option pricing model with the following weighted average assumptions: December 31, 2020 2019 2018 Risk-free interest rate 1.2 % 2.3 % 2.7 % Expected dividend yield — % — % — % Expected term (years) 6.05 5.99 6.07 Expected stock price volatility 74 % 74 % 73 % |
Leases (Tables)
Leases (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Schedule of components of lease expense | The components of lease expense were as follows: Year ended December 31, 2020 2019 Operating lease cost $ 2,755 $ 2,160 Finance lease cost: Amortization of right-of-use assets $ 176 $ 75 Interest on lease liabilities 21 20 $ 197 $ 95 |
Schedule of supplemental balance sheet information related to leases | Supplemental balance sheet information related to leases was as follows: Year ended December 31, 2020 2019 Operating leases: Operating lease right-of-use assets $ 10,936 $ 2,598 Operating lease liabilities, current 1,437 2,219 Operating lease liabilities 10,158 677 Finance leases: Property and equipment, gross $ 429 $ 429 Property and equipment, accumulated depreciation (176) (75) Other liabilities, current 93 87 Other liabilities 174 275 Weighted-average remaining lease term: Operating leases 5.2 years 1.3 years Finance leases 2.9 years 3.7 years Weighted-average discount rate: Operating leases 10.8 % 10.3 % Finance leases 6.9 % 6.9 % |
Schedule of supplemental cash flow information related to leases | Supplemental cash flow information related to leases was as follows: Year ended December 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,394 $ 2,271 Operating cash flows from finance leases 21 20 Financing cash flows from finance leases 116 87 |
Schedule of future minimum payments under operating leases | Future minimum lease payments under non-cancellable leases as of December 31, 2020 were as follows: Operating leases Finance leases 2021 $ 2,772 $ 116 2022 2,843 84 2023 2,928 74 2024 3,016 18 2025 and thereafter 3,888 — Total lease payments 15,447 292 Present value adjustment (3,854) (25) Present value of lease liabilities $ 11,593 $ 267 |
Schedule of future minimum payments on finance leases | Future minimum lease payments under non-cancellable leases as of December 31, 2020 were as follows: Operating leases Finance leases 2021 $ 2,772 $ 116 2022 2,843 84 2023 2,928 74 2024 3,016 18 2025 and thereafter 3,888 — Total lease payments 15,447 292 Present value adjustment (3,854) (25) Present value of lease liabilities $ 11,593 $ 267 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Schedule of reconciliation of income tax rates | A reconciliation of income taxes computed using the U.S. federal statutory rate to that reflected in operations as of December 31, 2020, 2019 and 2018 are as follows: 2020 2019 2018 Income tax computed at federal statutory tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.7 % 6.1 % 6.5 % Permanent differences 1.2 % (2.0) % 0.6 % General business credits 3.4 % 10.3 % 4.2 % Impact of ownership shift — % (53.3) % — % Change in valuation allowance (32.3) % 17.9 % (32.3) % — % — % — % |
Schedule of significant components of net deferred tax assets | Significant components of the Company’s net deferred tax assets as of December 31, 2020 and 2019 are as follows: 2020 2019 Deferred tax assets: Net operating losses $ 64,259 $ 40,554 Tax credit carryforwards 5,670 2,448 Accrued expenses 4,058 2,520 Lease liabilities 3,166 791 Licensed technology 1,534 1,402 Deferred revenue 1,088 1,315 Depreciation 502 492 Other 84 77 Total gross deferred tax assets 80,361 49,599 Valuation allowance (77,375) (48,889) Net deferred tax assets less valuation allowance 2,986 710 Deferred tax liabilities Right-of-use assets (2,986) (710) Total gross deferred tax liabilities (2,986) (710) Net deferred taxes $ — $ — |
Selected Quarterly Financial _2
Selected Quarterly Financial Data (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Quarterly Financial Information Disclosure [Abstract] | |
Selected quarterly financial data (unaudited) | The following table contains selected quarterly financial information for 2020 and 2019. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Three months ended March 31, 2020 June 30, 2020 September 30, 2020 December 31, 2020 Collaboration revenue $ 11 $ 796 $ 11 $ 10 Operating expenses: Research and development 12,219 15,413 16,546 22,858 General and administrative 4,936 5,171 5,881 5,914 Total operating expenses 17,155 20,584 22,427 28,772 Other income: Interest income 306 89 19 10 Interest expense (88) (87) (92) (92) Total other income (expense), net 218 2 (73) (82) Net loss $ (16,926) $ (19,786) $ (22,489) $ (28,844) Net loss per share attributable to common stockholders — basic and diluted $ (0.35) $ (0.33) $ (0.33) $ (0.42) Weighted-average number of common shares used in net loss per share attributable to common stockholders — basic and diluted 47,988,630 60,748,225 68,419,192 68,630,078 Three months ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 Collaboration revenue $ 41,035 $ 202 $ 844 $ 42 Operating expenses: Research and development 15,143 13,766 13,701 12,430 General and administrative 4,443 4,192 4,436 4,212 Total operating expenses 19,586 17,958 18,137 16,642 Other income: Interest income 452 725 608 441 Interest expense — (40) (107) (87) Total other income (expense), net 452 685 501 354 Net income (loss) $ 21,901 $ (17,071) $ (16,792) $ (16,246) Net income (loss) per share attributable to common stockholders — basic $ 0.72 $ (0.36) $ (0.35) $ (0.34) Net income (loss) per share attributable to common stockholders — diluted $ 0.70 $ (0.36) $ (0.35) $ (0.34) Weighted-average number of common shares used in net income (loss) per share attributable to common stockholders — basic 30,299,650 47,708,085 47,833,607 47,886,144 Weighted-average number of common shares used in net income (loss) per share attributable to common stockholders — diluted 31,461,696 47,708,085 47,833,607 47,886,144 |
Nature of Business and Basis _2
Nature of Business and Basis of Presentation (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||||||||
Jun. 30, 2020 | Apr. 30, 2020 | Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Subsidiary or Equity Method Investee [Line Items] | |||||||||||||
Net loss | $ 28,844 | $ 22,489 | $ 19,786 | $ 16,926 | $ 16,246 | $ 16,792 | $ 17,071 | $ (21,901) | $ 88,045 | $ 28,208 | $ 64,257 | ||
Accumulated deficit | $ 280,419 | $ 192,374 | $ 280,419 | $ 192,374 | |||||||||
At market equity offering program (2018 ATM) | |||||||||||||
Subsidiary or Equity Method Investee [Line Items] | |||||||||||||
Number of shares sold (in shares) | 10,900,599 | ||||||||||||
Proceeds from stock issuance, net of issuance costs | $ 62,976 | ||||||||||||
Public Stock Offering | |||||||||||||
Subsidiary or Equity Method Investee [Line Items] | |||||||||||||
Number of shares sold (in shares) | 9,200,000 | ||||||||||||
Proceeds from stock issuance, net of issuance costs | $ 163,990 |
Summary of significant accoun_4
Summary of significant accounting policies - Revenue Recognition (Details) - USD ($) $ in Thousands | 12 Months Ended | |||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jan. 01, 2018 | |
New Accounting pronouncements | ||||
Billing term | 30 days | |||
Deferred revenue | $ 3,987 | $ 4,815 | $ 46,196 | |
Accumulated deficit | $ 280,419 | $ 192,374 | ||
Cumulative effect adjustment for adoption of ASC 606 | ||||
New Accounting pronouncements | ||||
Deferred revenue | $ 2,031 | |||
Accumulated deficit | $ 2,031 |
Summary of significant accoun_5
Summary of significant accounting policies - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 |
Cash, cash equivalents and restricted cash | ||||
Cash and cash equivalents | $ 255,094 | $ 62,351 | $ 59,634 | |
Restricted cash included in other assets, noncurrent | 321 | 321 | 371 | |
Total cash, cash equivalents and restricted cash per statement of cash flows | $ 255,415 | $ 62,672 | $ 60,005 | $ 26,962 |
Summary of significant accoun_6
Summary of significant accounting policies - Other Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Other Assets | ||
Other assets | $ 2,153 | $ 1,453 |
Held by service provider | 1,832 | 1,132 |
Letter of credit for security deposit | $ 321 | $ 321 |
Summary of Significant Accoun_7
Summary of Significant Accounting Policies - Stock Based Compensation (Details) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Accounting Policies [Abstract] | |||
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Summary of significant accoun_8
Summary of significant accounting policies - Net loss per share (Details) - shares | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Net Loss per Share | |||
Warrants outstanding (in shares) | 39,474 | 39,474 | |
Anti-dilutive securities | 6,869,189 | 5,207,582 | 3,856,932 |
Stock options | |||
Net Loss per Share | |||
Anti-dilutive securities | 6,112,948 | 4,720,772 | 3,746,567 |
Unvested restricted stock units | |||
Net Loss per Share | |||
Anti-dilutive securities | 716,767 | 447,336 | 0 |
Warrants | |||
Net Loss per Share | |||
Anti-dilutive securities | 39,474 | 39,474 | 110,365 |
Exchange warrants | |||
Net Loss per Share | |||
Warrants outstanding (in shares) | 2,575,000 |
Summary of Significant Accoun_9
Summary of Significant Accounting Policies - Property and Equipment (Details) | 12 Months Ended |
Dec. 31, 2020 | |
Computer equipment, office equipment and software | |
Property, equipment and software, net | |
Estimated useful life | 3 years |
Laboratory equipment | |
Property, equipment and software, net | |
Estimated useful life | 5 years |
Leasehold improvements | |
Property, equipment and software, net | |
Leasehold improvements, estimated useful lives | Shorter of useful life or life of lease |
Summary of significant accou_10
Summary of significant accounting policies - Risks (Details) | 12 Months Ended |
Dec. 31, 2020USD ($) | |
Concentration of Credit Risk and Off-balance Sheet Risk | |
Financial instruments with off-balance sheet risk | $ 0 |
Summary of significant accou_11
Summary of significant accounting policies - Recently Issued Accounting Pronouncement (Details) | Jan. 01, 2020 |
Accounting Standards Update 2018-18 | |
New Accounting pronouncements | |
Change in Accounting Principle, Accounting Standards Update, Adopted | true |
Accounting Standards Update 2016-13 | |
New Accounting pronouncements | |
Change in Accounting Principle, Accounting Standards Update, Adopted | true |
Collaboration Agreements - Merc
Collaboration Agreements - Merck KGaA (Detail) - Merck KGaA $ in Thousands | 1 Months Ended | 12 Months Ended | 36 Months Ended | ||
Jun. 30, 2014USD ($)milestonetarget | Dec. 31, 2020USD ($)target | Dec. 31, 2019USD ($) | Dec. 31, 2017USD ($)target | Dec. 31, 2018target | |
Collaboration agreements | |||||
Upfront payment received | $ 12,000 | ||||
Amount of additional fees receivable when target is designated and commercial license to target is granted | $ 0 | ||||
Number of targets | target | 6 | ||||
Number of targets designated | target | 6 | 6 | 6 | ||
Aggregate milestones | $ 780,000 | ||||
Development milestones | 84,000 | ||||
Regulatory milestones | 264,000 | ||||
Sales milestones | $ 432,000 | ||||
Number of individual development milestones per target | milestone | 6 | ||||
Number of individual regulatory milestones per target | milestone | 5 | ||||
Number of individual commercial milestones | milestone | 3 | ||||
Amount of development milestone payment received | $ 0 | $ 0 | $ 3,000 | ||
Next potential development milestone payment eligible to receive | $ 500 | ||||
Prior written notice for termination period | 60 days |
Collaboration Agreements - Me_2
Collaboration Agreements - Merck KGaA - Accounting Analysis (Details) | 3 Months Ended | 12 Months Ended | |||||||||||
Dec. 31, 2020USD ($)target | Sep. 30, 2020USD ($) | Jun. 30, 2020USD ($) | Mar. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Sep. 30, 2019USD ($) | Jun. 30, 2019USD ($) | Mar. 31, 2019USD ($) | Dec. 31, 2020USD ($)target | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($)target | Jan. 01, 2018USD ($) | Dec. 31, 2017target | |
Collaboration agreements | |||||||||||||
Collaboration revenue | $ 10,000 | $ 11,000 | $ 796,000 | $ 11,000 | $ 42,000 | $ 844,000 | $ 202,000 | $ 41,035,000 | $ 828,000 | $ 42,123,000 | $ 10,594,000 | ||
Deferred revenue | 3,987,000 | 4,815,000 | 3,987,000 | 4,815,000 | $ 46,196,000 | ||||||||
Merck KGaA Agreement and Merck KGaA supply agreement | |||||||||||||
Collaboration agreements | |||||||||||||
Accounts receivable | 0 | 0 | 0 | 0 | |||||||||
Deferred revenue | $ 3,987,000 | 4,815,000 | $ 3,987,000 | 4,815,000 | |||||||||
Merck KGaA | |||||||||||||
Collaboration agreements | |||||||||||||
Number of targets designated | target | 6 | 6 | 6 | 6 | |||||||||
Amount of milestone payments, which had not been received, included in the estimated transaction price | $ 0 | ||||||||||||
Transaction price | $ 21,325,000 | $ 21,500,000 | $ 21,325,000 | 21,500,000 | |||||||||
Number of service obligations completed of designated targets | target | 4 | 4 | |||||||||||
Amount of research and development fees expected to be received | $ 6,325,000 | $ 6,325,000 | |||||||||||
Decrease in fees expected to be received for research and development activities | 175,000 | ||||||||||||
Collaboration revenue | 828,000 | 853,000 | $ 2,444,000 | ||||||||||
Merck KGaA | License and corresponding research and development services, first and second targets | |||||||||||||
Collaboration agreements | |||||||||||||
Transaction price | 3,941,000 | 3,941,000 | |||||||||||
Merck KGaA | License and corresponding research and development services, third and sixth target | |||||||||||||
Collaboration agreements | |||||||||||||
Transaction price | 3,439,000 | 3,439,000 | |||||||||||
Merck KGaA | License and corresponding research and development services, fourth target | |||||||||||||
Collaboration agreements | |||||||||||||
Transaction price | 3,152,000 | 3,152,000 | |||||||||||
Merck KGaA | License and corresponding research and development services, fifth target | |||||||||||||
Collaboration agreements | |||||||||||||
Transaction price | 2,746,000 | 2,746,000 | |||||||||||
Merck KGaA | Rights to future technological improvements | |||||||||||||
Collaboration agreements | |||||||||||||
Transaction price | 425,000 | 425,000 | |||||||||||
Merck KGaA | Joint research committee services | |||||||||||||
Collaboration agreements | |||||||||||||
Transaction price | $ 242,000 | 242,000 | |||||||||||
Merck KGaA supply agreement | |||||||||||||
Collaboration agreements | |||||||||||||
Collaboration revenue | $ 0 | $ 1,280,000 | $ 0 | ||||||||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Merck KGaA | Rights to future technological improvements | |||||||||||||
Collaboration agreements | |||||||||||||
Expected recognition period | 10 years | 10 years | |||||||||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Merck KGaA | Joint research committee services | |||||||||||||
Collaboration agreements | |||||||||||||
Expected recognition period | 5 years | 5 years |
Collaboration Agreements - Take
Collaboration Agreements - Takeda XMT-1522 Strategic Partnership (Details) - XMT-1522 agreement | Jan. 02, 2019 |
Collaboration agreements | |
Period of time until agreement terminated | 30 days |
Period of shared development costs following effective termination date | 30 days |
Collaboration Agreements - Ta_2
Collaboration Agreements - Takeda strategic R & D partnership (Details) - 2016 Restated Tokeda agreement - target | Jan. 02, 2019 | Jan. 31, 2016 |
Collaboration agreements | ||
Number of targets | 7 | |
Period of time until agreement terminated | 45 days |
Collaboration Agreements - Ta_3
Collaboration Agreements - Takeda - Accounting Analysis (Details) $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2020USD ($) | Sep. 30, 2020USD ($) | Jun. 30, 2020USD ($) | Mar. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Sep. 30, 2019USD ($) | Jun. 30, 2019USD ($) | Mar. 31, 2019USD ($) | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($)agreement | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction | |||||||||||
Revenue recognized | $ 828 | $ 41,591 | |||||||||
Collaboration revenue | $ 10 | $ 11 | $ 796 | $ 11 | $ 42 | $ 844 | $ 202 | $ 41,035 | 828 | 42,123 | $ 10,594 |
Research and development | $ 22,858 | $ 16,546 | $ 15,413 | $ 12,219 | $ 12,430 | $ 13,701 | $ 13,766 | 15,143 | $ 67,036 | 55,040 | $ 59,915 |
2016 Restated Tokeda agreement and XMT-1522 agreement | |||||||||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction | |||||||||||
Revenue recognized | $ 39,965 | ||||||||||
Number of performance obligations | agreement | 14 | ||||||||||
Collaboration revenue | 39,965 | $ 5,868 | |||||||||
2016 Restated Tokeda agreement and XMT-1522 agreement | License and related research and development services, including phase 1 development and transfer certain materials and know how | |||||||||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction | |||||||||||
Number of performance obligations | agreement | 1 | ||||||||||
XMT-1522 agreement | |||||||||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction | |||||||||||
Research and development | 200 | $ 8,046 | |||||||||
ASC 808 costs billed to Takeda | $ 195 | $ 3,746 |
Collaboration Agreements - Cont
Collaboration Agreements - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Collaboration agreements | |||
Contract assets | $ 0 | $ 0 | $ 0 |
Contract liabilities | |||
Deferred revenue, balance at beginning of period | 4,815 | 46,196 | |
Deferred revenue, additions | 0 | 210 | |
Deferred revenue, deductions | 828 | 41,591 | |
Deferred revenue, balance at end of period | 3,987 | 4,815 | |
Revenue recognized in the period from: | |||
Amounts included in the contract liability at the beginning of the period | 828 | 41,591 | |
Performance obligations satisfied in previous periods | $ 0 | $ 0 |
Collaboration Agreements - Othe
Collaboration Agreements - Other Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Collaboration agreements | |||||||||||
Collaboration revenue | $ 10 | $ 11 | $ 796 | $ 11 | $ 42 | $ 844 | $ 202 | $ 41,035 | $ 828 | $ 42,123 | $ 10,594 |
Asana BioSciences | |||||||||||
Collaboration agreements | |||||||||||
Next potential milestone payment eligible to receive | $ 2,500 | 2,500 | |||||||||
Asana BioSciences | Limited services | |||||||||||
Collaboration agreements | |||||||||||
Collaboration revenue | $ 0 | $ 25 | 782 | ||||||||
Asana BioSciences | Milestone | |||||||||||
Collaboration agreements | |||||||||||
Collaboration revenue | $ 1,500 |
Fair Value Measurements (Detail
Fair Value Measurements (Details) $ in Thousands | Dec. 31, 2019USD ($) |
Fair value measurements | |
Marketable securities | $ 37,439 |
Recurring basis | |
Fair value measurements | |
Total assets regularly measured and carried at fair value | 37,439 |
Recurring basis | Commercial paper | |
Fair value measurements | |
Marketable securities | 11,940 |
Recurring basis | Corporate bonds | |
Fair value measurements | |
Marketable securities | 12,010 |
Recurring basis | U.S. Treasuries | |
Fair value measurements | |
Marketable securities | 13,489 |
Recurring basis | Quoted Prices in Active Markets (Level 1) | |
Fair value measurements | |
Total assets regularly measured and carried at fair value | 13,489 |
Recurring basis | Quoted Prices in Active Markets (Level 1) | Commercial paper | |
Fair value measurements | |
Marketable securities | 0 |
Recurring basis | Quoted Prices in Active Markets (Level 1) | Corporate bonds | |
Fair value measurements | |
Marketable securities | 0 |
Recurring basis | Quoted Prices in Active Markets (Level 1) | U.S. Treasuries | |
Fair value measurements | |
Marketable securities | 13,489 |
Recurring basis | Significant Other Observable Inputs (Level 2) | |
Fair value measurements | |
Total assets regularly measured and carried at fair value | 23,950 |
Recurring basis | Significant Other Observable Inputs (Level 2) | Commercial paper | |
Fair value measurements | |
Marketable securities | 11,940 |
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate bonds | |
Fair value measurements | |
Marketable securities | 12,010 |
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. Treasuries | |
Fair value measurements | |
Marketable securities | 0 |
Recurring basis | Significant Unobservable Inputs (Level 3) | |
Fair value measurements | |
Total assets regularly measured and carried at fair value | 0 |
Recurring basis | Significant Unobservable Inputs (Level 3) | Commercial paper | |
Fair value measurements | |
Marketable securities | 0 |
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate bonds | |
Fair value measurements | |
Marketable securities | 0 |
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. Treasuries | |
Fair value measurements | |
Marketable securities | $ 0 |
Marketable Securities (Details)
Marketable Securities (Details) $ in Thousands | Dec. 31, 2020security | Dec. 31, 2019USD ($) |
Debt Securities, Available-for-sale [Line Items] | ||
Number of securities in an unrealized loss position | security | 0 | |
Marketable securities | ||
Amortized Cost | $ 37,414 | |
Gross Unrealized Gains | 25 | |
Gross Unrealized Losses | 0 | |
Fair Value | 37,439 | |
Commercial paper | ||
Marketable securities | ||
Amortized Cost | 11,940 | |
Gross Unrealized Gains | 0 | |
Gross Unrealized Losses | 0 | |
Fair Value | 11,940 | |
Corporate bonds | ||
Marketable securities | ||
Amortized Cost | 11,990 | |
Gross Unrealized Gains | 20 | |
Gross Unrealized Losses | 0 | |
Fair Value | 12,010 | |
U.S. Treasuries | ||
Marketable securities | ||
Amortized Cost | 13,484 | |
Gross Unrealized Gains | 5 | |
Gross Unrealized Losses | 0 | |
Fair Value | $ 13,489 |
Property and Equipment (Details
Property and Equipment (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Property, equipment and software, net | |||
Total property and equipment at cost | $ 9,365 | $ 9,373 | |
Less: Accumulated depreciation | (7,635) | (7,209) | |
Property and equipment | 1,730 | 2,164 | |
Depreciation expense | 1,010 | 1,245 | $ 1,257 |
Laboratory equipment | |||
Property, equipment and software, net | |||
Total property and equipment at cost | 6,520 | 6,419 | |
Leasehold improvements | |||
Property, equipment and software, net | |||
Total property and equipment at cost | 1,886 | 1,886 | |
Computer equipment, office equipment and software | |||
Property, equipment and software, net | |||
Total property and equipment at cost | $ 959 | 1,068 | |
Laboratory equipment , under finance lease | |||
Property, equipment and software, net | |||
Total property and equipment at cost | $ 429 |
Accrued Expenses (Details)
Accrued Expenses (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Accrued Liabilities, Current [Abstract] | ||
Accrued preclinical, manufacturing and clinical expenses | $ 9,902 | $ 4,230 |
Accrued payroll and related expenses | 5,412 | 4,037 |
Accrued professional fees | 757 | 675 |
Accrued other | 75 | 44 |
Total | $ 16,146 | $ 8,986 |
Debt - Narrative (Details)
Debt - Narrative (Details) - USD ($) | Aug. 28, 2020 | May 08, 2019 | Dec. 31, 2020 |
Debt | |||
Unamortized issuance costs | $ 246,000 | ||
Debt outstanding | $ 5,200,000 | ||
Existing Credit Facility | Line of Credit | |||
Debt | |||
Proceeds from line of credit | $ 5,000,000 | ||
Unamortized issuance costs | $ 139,000 | ||
Existing Credit Facility | Minimum | Line of Credit | |||
Debt | |||
Debt interest rate percentage | 4.00% | ||
Existing Credit Facility | Prime rate | Minimum | Line of Credit | |||
Debt | |||
Spread (as a percent) | (1.50%) | ||
Amended Credit Facility | Line of Credit | |||
Debt | |||
Maximum borrowing capacity | $ 30,000,000 | ||
Final payment as percentage of original principal amount | 5.50% | ||
Additional rate in event of default | 5.00% | ||
Incurred debt issuance costs | $ 17,000 | ||
Debt outstanding | $ 5,200,000 | ||
Amended Credit Facility | Line of Credit | Prepayment occurs prior to August 28, 2020 | |||
Debt | |||
Prepayment fee percentage | 3.00% | ||
Amended Credit Facility | Line of Credit | Prepayment occurs between August 28, 2021 and August 28, 2022 | |||
Debt | |||
Prepayment fee percentage | 2.00% | ||
Amended Credit Facility | Line of Credit | Prepayment occurs after August 28, 2022 but on or prior to August 28, 2022 | |||
Debt | |||
Prepayment fee percentage | 1.00% | ||
Amended Credit Facility | Minimum | Line of Credit | |||
Debt | |||
Debt interest rate percentage | 4.25% | ||
Amended Credit Facility | Prime rate | Minimum | Line of Credit | |||
Debt | |||
Spread (as a percent) | 1.00% | ||
Amended Credit Facility, Tranche One | Line of Credit | |||
Debt | |||
Maximum borrowing capacity | $ 25,000,000 | ||
Amended Credit Facility, Tranche Two | Line of Credit | |||
Debt | |||
Maximum borrowing capacity | 25,000,000 | ||
Amended Credit Facility, Tranche Three | Line of Credit | |||
Debt | |||
Maximum borrowing capacity | 25,000,000 | ||
Amended Credit Facility, Tranche Four | Line of Credit | |||
Debt | |||
Maximum borrowing capacity | 25,000,000 | ||
Amended Credit Facility, Tranche Five | Line of Credit | |||
Debt | |||
Maximum borrowing capacity | 25,000,000 | ||
Amended Credit Facility, Tranche Six | Line of Credit | |||
Debt | |||
Line of credit, increase limit | $ 5,000,000 |
Debt - Components (Details)
Debt - Components (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Debt Disclosure [Abstract] | ||
Total debt | $ 5,200 | |
Less: Current portion of long-term-debt | 0 | $ (667) |
Total debt, net of current portion | 5,200 | |
Debt financing costs, net of accretion | (246) | |
Accretion related to final payment | 23 | |
Long-term debt, net | $ 4,977 | $ 4,201 |
Debt - Future payments (Details
Debt - Future payments (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Estimated future principal payments | ||
2021 | $ 0 | |
2022 | 1,213 | |
2023 | 2,080 | |
2024 | 1,907 | |
Total debt | 5,200 | |
Interest expense | $ 340 | $ 214 |
Stockholders' Equity Preferred
Stockholders' Equity Preferred Stock (Details) - shares | Dec. 31, 2020 | Dec. 31, 2019 |
Equity [Abstract] | ||
Preferred stock, shares authorized (in shares) | 25,000,000 | 25,000,000 |
Preferred stock, shares issued (in shares) | 0 | 0 |
Stockholders' Equity At-the-mar
Stockholders' Equity At-the-market Equity and Follow On Offering Programs (Details) - USD ($) | 1 Months Ended | ||||
Jun. 30, 2020 | Apr. 30, 2020 | Dec. 31, 2020 | May 31, 2020 | Jul. 31, 2018 | |
At market equity offering program (2018 ATM) | |||||
Class of Stock [Line Items] | |||||
Amount of shares authorized to be offered and sold | $ 75,000,000 | ||||
Number of shares sold (in shares) | 10,900,599 | ||||
Proceeds from issuance of common stock, gross | $ 65,153,000 | ||||
Proceeds from stock issuance, net of issuance costs | $ 62,976,000 | ||||
At Market Equity Offering Program, 5.59 per Share | |||||
Class of Stock [Line Items] | |||||
Number of shares sold (in shares) | 8,938,599 | ||||
Shares sold, price per share (in dollars per share) | $ 5.59 | ||||
At Market Equity Offering Program, 7.74 per Share | |||||
Class of Stock [Line Items] | |||||
Number of shares sold (in shares) | 1,962,000 | ||||
Shares sold, price per share (in dollars per share) | $ 7.74 | ||||
At Market Equity Offering Program (2020 ATM) | |||||
Class of Stock [Line Items] | |||||
Amount of shares authorized to be offered and sold | $ 100,000,000 | ||||
Shares sold to date (in shares) | 0 | ||||
Public Stock Offering | |||||
Class of Stock [Line Items] | |||||
Number of shares sold (in shares) | 9,200,000 | ||||
Shares sold, price per share (in dollars per share) | $ 19 | ||||
Proceeds from stock issuance, net of issuance costs | $ 163,990,000 |
Stockholders' Equity - Warrants
Stockholders' Equity - Warrants (Details) - $ / shares | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2013 | Dec. 31, 2019 | |
Stockholders' Equity Note [Abstract] | |||
Number of shares into which warrant issued during period may be converted | 129,491 | ||
Warrant exercise price per share (in dollars per share) | $ 0.05 | ||
Contractual life of warrants | 10 years | ||
Warrants outstanding (in shares) | 39,474 | 39,474 | |
Common stock issued upon exercise of warrant (in shares) | 0 |
Stockholders' Equity - Exchange
Stockholders' Equity - Exchange Warrants (Details) - $ / shares | Mar. 02, 2020 | Nov. 26, 2019 | Dec. 31, 2013 |
Class of Stock [Line Items] | |||
Warrant exercise price per share (in dollars per share) | $ 0.05 | ||
Exchange warrants | |||
Class of Stock [Line Items] | |||
Number of common shares exchanged for warrants (in shares) | 2,575,000 | ||
Number of shares of common stock into which warrants may be converted (in shares) | 2,575,000 | ||
Warrant exercise price per share (in dollars per share) | $ 0.0001 | ||
Common Stock | |||
Class of Stock [Line Items] | |||
Issuance of common upon exercise of warrant (in shares) | 2,574,971 |
Stockholders' Equity - Common s
Stockholders' Equity - Common stock (Details) | 12 Months Ended | |
Dec. 31, 2020voteshares | Dec. 31, 2019shares | |
Class of Stock [Line Items] | ||
Number of shares reserved for future issuance (in shares) | 6,869,189 | 7,782,582 |
Common Stock | ||
Class of Stock [Line Items] | ||
Number of votes per common share | vote | 1 | |
Warrants and share-based payment awards | ||
Class of Stock [Line Items] | ||
Number of shares reserved for future issuance (in shares) | 6,869,189 | 7,782,582 |
Share-based payments | Stock options | ||
Class of Stock [Line Items] | ||
Number of shares reserved for future issuance (in shares) | 6,112,948 | 4,720,772 |
Share-based payments | Restricted stock units | ||
Class of Stock [Line Items] | ||
Number of shares reserved for future issuance (in shares) | 716,767 | 447,336 |
Warrants | ||
Class of Stock [Line Items] | ||
Number of shares reserved for future issuance (in shares) | 39,474 | 39,474 |
Exchange warrants | ||
Class of Stock [Line Items] | ||
Number of shares reserved for future issuance (in shares) | 0 | 2,575,000 |
Stock Options - Plans Narrative
Stock Options - Plans Narrative (Details) - shares | Jan. 01, 2020 | Jun. 30, 2017 | Dec. 31, 2020 | Dec. 31, 2019 |
Share-based awards | ||||
Number of shares outstanding (in shares) | 6,112,948 | 4,720,772 | ||
Employee stock purchase plan | ||||
Share-based awards | ||||
Number of shares available for future issuance (in shares) | 644,818 | |||
Additional shares authorized (in shares) | 450,000 | |||
2007 Plan | ||||
Share-based awards | ||||
Number of shares outstanding (in shares) | 3,141,625 | |||
2017 Plan | ||||
Share-based awards | ||||
Number of shares authorized (in shares) | 2,255,000 | |||
Cumulative annual increase in number of shares issuable, percentage | 4.00% | |||
Number of shares available for future issuance (in shares) | 1,288,072 | |||
Additional shares authorized (in shares) | 1,815,520 |
Stock Options - Inducement Narr
Stock Options - Inducement Narrative (Details) - shares | Nov. 30, 2020 | Sep. 02, 2020 | Dec. 31, 2020 |
Share-based awards | |||
Granted (in shares) | 2,359,074 | ||
Inducement Award Program | |||
Share-based awards | |||
Granted (in shares) | 200,000 | 120,000 | |
Inducement Award Program | Stock options | |||
Share-based awards | |||
Vesting period | 4 years | ||
Inducement Award Program | Maximum | |||
Share-based awards | |||
Expiration period | 10 years |
Stock Options - Activity Under
Stock Options - Activity Under Stock Option Plan (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Number of Shares | |||
Outstanding at beginning of period (in shares) | 4,720,772 | ||
Granted (in shares) | 2,359,074 | ||
Exercised (in shares) | (697,428) | ||
Cancelled (in shares) | (269,470) | ||
Outstanding at end of period (in shares) | 6,112,948 | 4,720,772 | |
Options exercisable, at end of period (in shares) | 3,147,379 | ||
Weighted- Average Exercise Price | |||
Outstanding at beginning of period (in dollars per share) | $ 5.24 | ||
Granted (in dollars per share) | 11.96 | ||
Exercised (in dollars per share) | 4.50 | ||
Cancelled (in dollars per share) | 7.05 | ||
Outstanding at end of period (in dollars per share) | 7.84 | $ 5.24 | |
Options exercisable, at end of period (in dollars per share) | $ 5.14 | ||
Additional Disclosures | |||
Weighted Average Remaining Contractual Term, Options outstanding | 7 years 3 months 18 days | 7 years 3 months 18 days | |
Weighted Average Remaining Contractual Term, Options exercisable | 6 years 1 month 6 days | ||
Aggregate Intrinsic Value, Options outstanding | $ 114,729 | $ 9,836 | |
Aggregate Intrinsic Value, Options exercisable | $ 67,562 | ||
Weighted-average grant date fair value of options granted (in dollars per share) | $ 7.99 | $ 2.47 | $ 8.78 |
Cash received from the exercise of stock options (in dollars) | $ 3,138 | $ 175 | $ 918 |
Stock Options - Restricted Stoc
Stock Options - Restricted Stock Units (Details) - Unvested restricted stock units - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended | ||
Jan. 31, 2020 | Jul. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | |
Share-based awards | ||||
Vesting period | 4 years | 2 years | ||
Number of Shares | ||||
Unvested at beginning of period (in shares) | 447,336 | 447,336 | ||
Granted (in shares) | 324,932 | 361,932 | ||
Vested (in shares) | 0 | |||
Forfeited (in shares) | (92,501) | |||
Unvested at end of period (in shares) | 716,767 | 447,336 | ||
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value | ||||
Weighted-average remaining contractual term | 1 year | 1 year 6 months | ||
Aggregate intrinsic value (in dollars) | $ 19,073 | $ 2,564 | ||
Weighted-Average Grant Date Fair Value | ||||
Unvested at beginning of period (in dollars per share) | $ 4 | $ 4 | ||
Granted (in dollars per share) | 8.14 | |||
Vested (in dollars per share) | 0 | |||
Forfeited (in dollars per share) | 4.68 | |||
Unvested at end of period (in dollars per share) | $ 6 | $ 4 |
Stock Options - Stock Based Com
Stock Options - Stock Based Compensation Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Stock options | |||
Stock-based compensation expense included in Total operating expenses | $ 7,172 | $ 4,872 | $ 3,884 |
Stock options | |||
Stock options | |||
Stock-based compensation expense included in Total operating expenses | 5,725 | 4,230 | 3,754 |
Unrecognized stock compensation cost | $ 19,487 | ||
Weighted-average amortization period of unrecognized stock compensation cost | 2 years 9 months 18 days | ||
Unvested restricted stock units | |||
Stock options | |||
Stock-based compensation expense included in Total operating expenses | $ 1,187 | 410 | 0 |
Unrecognized stock compensation cost | $ 2,699 | ||
Weighted-average amortization period of unrecognized stock compensation cost | 2 years 3 months 18 days | ||
Employee stock purchase plan | |||
Stock options | |||
Stock-based compensation expense included in Total operating expenses | $ 260 | 232 | 130 |
Research and development | |||
Stock options | |||
Stock-based compensation expense included in Total operating expenses | 3,841 | 2,245 | 1,788 |
General and administrative | |||
Stock options | |||
Stock-based compensation expense included in Total operating expenses | $ 3,331 | $ 2,627 | $ 2,096 |
Stock Options - Fair Value Assu
Stock Options - Fair Value Assumptions (Details) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share-based Payment Arrangement [Abstract] | |||
Risk-free interest rate | 1.20% | 2.30% | 2.70% |
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Expected term (years) | 6 years 18 days | 5 years 11 months 26 days | 6 years 25 days |
Expected stock price volatility | 74.00% | 74.00% | 73.00% |
Stock Options - Employee Stock
Stock Options - Employee Stock Purchase Plan (Details) - shares | Jan. 01, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2017 |
Share-based awards | ||||
Number of shares reserved for future issuance (in shares) | 6,869,189 | 7,782,582 | ||
Employee stock purchase plan | ||||
Share-based awards | ||||
Number of shares reserved for future issuance (in shares) | 225,000 | |||
Purchase of common stock under ESPP (in shares) | 80,267 | 140,073 | ||
Number of shares available for future issuance (in shares) | 644,818 | |||
Additional shares authorized (in shares) | 450,000 |
Leases - Description (Details)
Leases - Description (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||
Mar. 31, 2020 | Mar. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Mar. 31, 2019 | |
Leases | |||||
Tenant improvement allowance | $ 172 | ||||
Increase in lease liabilities | $ 9,980 | ||||
Increase in right-of-use asset | $ 9,980 | ||||
Letter of credit for security deposit | $ 321 | $ 321 | |||
Assets under finance leases | $ 429 | $ 429 | $ 429 | ||
Office space, Cambridge, MA, Leased | |||||
Leases | |||||
Renewal term | 5 years | ||||
Lessee, operating lease, existence of option to extend | true |
Leases - Components of Lease Ex
Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Leases [Abstract] | ||
Operating lease cost | $ 2,755 | $ 2,160 |
Finance lease cost: | ||
Amortization of right-of-use assets | 176 | 75 |
Interest on lease liabilities | 21 | 20 |
Finance lease cost | $ 197 | $ 95 |
Leases - Supplemental balance s
Leases - Supplemental balance sheet information (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Mar. 31, 2019 |
Operating leases: | |||
Operating lease right-of-use assets | $ 10,936 | $ 2,598 | |
Operating lease liabilities, current | 1,437 | 2,219 | |
Operating lease liabilities | 10,158 | 677 | |
Finance leases: | |||
Property and equipment, gross | 429 | 429 | $ 429 |
Less: Accumulated depreciation | (176) | (75) | |
Other liabilities, current | 93 | 87 | |
Other liabilities | $ 174 | $ 275 | |
Weighted-average remaining lease term: | |||
Operating leases | 5 years 2 months 12 days | 1 year 3 months 18 days | |
Finance leases | 2 years 10 months 24 days | 3 years 8 months 12 days | |
Weighted-average discount rate: | |||
Operating leases | 10.80% | 10.30% | |
Finance leases | 6.90% | 6.90% | |
Finance lease, liability, current, statement of financial position | us-gaap:OtherLiabilitiesCurrent | ||
Finance lease, liability, noncurrent, statement of financial position | us-gaap:OtherLiabilitiesNoncurrent |
Leases - Supplemental cash flow
Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Cash paid for amounts included in the measurement of lease liabilities: | |||
Operating cash flows from operating leases | $ 2,394 | $ 2,271 | |
Operating cash flows from finance leases | 21 | 20 | |
Financing cash flows from finance leases | $ 116 | $ 87 | $ 0 |
Leases - Future minimum lease p
Leases - Future minimum lease payments (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Leases [Abstract] | |||
Rent expense | $ 2,644 | $ 2,160 | $ 1,994 |
Operating leases | |||
2021 | 2,772 | ||
2022 | 2,843 | ||
2023 | 2,928 | ||
2024 | 3,016 | ||
2025 and thereafter | 3,888 | ||
Total lease payments | 15,447 | ||
Present value adjustment | (3,854) | ||
Present value of lease liabilities | 11,593 | ||
Finance leases | |||
2021 | 116 | ||
2022 | 84 | ||
2023 | 74 | ||
2024 | 18 | ||
2025 and thereafter | 0 | ||
Total lease payments | 292 | ||
Present value adjustment | (25) | ||
Present value of lease liabilities | $ 267 |
Income Taxes - Reconciliation (
Income Taxes - Reconciliation (Details) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Effective Income Tax Rate Reconciliation, Percent [Abstract] | |||
Income tax computed at federal statutory tax rate | 21.00% | 21.00% | 21.00% |
State taxes, net of federal benefit | 6.70% | 6.10% | 6.50% |
Permanent differences | 1.20% | (2.00%) | 0.60% |
General business credits | 3.40% | 10.30% | 4.20% |
Impact of ownership shift | 0.00% | (53.30%) | 0.00% |
Change in valuation allowance | (32.30%) | 17.90% | (32.30%) |
Income tax benefit | 0.00% | 0.00% | 0.00% |
Income Taxes - Components of de
Income Taxes - Components of deferred tax assets (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Deferred tax assets: | ||
Net operating losses | $ 64,259 | $ 40,554 |
Tax credit carryforwards | 5,670 | 2,448 |
Accrued expenses | 4,058 | 2,520 |
Lease liabilities | 3,166 | 791 |
Licensed technology | 1,534 | 1,402 |
Deferred revenue | 1,088 | 1,315 |
Depreciation | 502 | 492 |
Other | 84 | 77 |
Total gross deferred tax assets | 80,361 | 49,599 |
Valuation allowance | (77,375) | (48,889) |
Net deferred tax assets less valuation allowance | 2,986 | 710 |
Deferred tax liabilities | ||
Right-of-use assets | (2,986) | (710) |
Total gross deferred tax liabilities | (2,986) | (710) |
Net deferred taxes | $ 0 | $ 0 |
Income Taxes - Net operating lo
Income Taxes - Net operating loss carryforwards (Details) $ in Thousands | Dec. 31, 2020USD ($) |
Federal | |
Operating loss carry-forwards | |
Net operating loss carry forwards | $ 250,367 |
Net operating loss carryforwards subject to expiration | 34,149 |
Net operating loss carryforwards not subject to expiration | 216,218 |
State | |
Operating loss carry-forwards | |
Net operating loss carry forwards | $ 184,781 |
Income Taxes - Tax credit carry
Income Taxes - Tax credit carryforward (Details) - Research and Development $ in Thousands | Dec. 31, 2020USD ($) |
Federal | |
Tax credit carryforwards | |
Tax credit carryforwards | $ 4,582 |
State | |
Tax credit carryforwards | |
Tax credit carryforwards | $ 1,482 |
Income Taxes - Valuation allowa
Income Taxes - Valuation allowance (Details) | 12 Months Ended | |
Dec. 31, 2020USD ($)auditjurisdiction | Dec. 31, 2019USD ($) | |
Valuation allowance | ||
Valuation allowance | $ 77,375,000 | $ 48,889,000 |
Increase (decrease) in valuation allowance | 28,468,000 | (5,051,000) |
Unrecognized tax benefits | 0 | 0 |
Accrued interest or penalties related to uncertain tax position | $ 0 | $ 0 |
Number of state jurisdictions in which entity files income tax returns | jurisdiction | 2 | |
Number of federal or state audits in progress | audit | 0 |
Employee Benefit Plan (Details)
Employee Benefit Plan (Details) - USD ($) $ in Thousands | 7 Months Ended | 12 Months Ended | 17 Months Ended | ||
Jul. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2020 | |
Retirement Benefits [Abstract] | |||||
Eligible age to participate | 21 years | ||||
Maximum contribution by employee (as a percent) | 75.00% | ||||
Percentage employer matches of the employee's percentage contribution matched | 50.00% | 50.00% | 100.00% | ||
Employer matching contribution (as a percent) | 6.00% | 6.00% | 4.00% | ||
Maximum annual amount employer contributes per employee | $ 6 | $ 6 | $ 7 | ||
Employee benefit expenses | $ 486 | $ 404 | $ 332 |
Commitments - License agreement
Commitments - License agreements (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
License Agreement, Upfront Payments | |||
Research and Development Arrangement, Contract to Perform for Others [Line Items] | |||
Research and development expense | $ 250 | $ 750 | $ 0 |
License Agreement, Milestone Payments | |||
Research and Development Arrangement, Contract to Perform for Others [Line Items] | |||
Research and development expense | $ 750 | $ 600 | $ 0 |
Selected Quarterly Financial _3
Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Quarterly Financial Data | |||||||||||
Collaboration revenue | $ 10 | $ 11 | $ 796 | $ 11 | $ 42 | $ 844 | $ 202 | $ 41,035 | $ 828 | $ 42,123 | $ 10,594 |
Operating expenses: | |||||||||||
Research and development | 22,858 | 16,546 | 15,413 | 12,219 | 12,430 | 13,701 | 13,766 | 15,143 | 67,036 | 55,040 | 59,915 |
General and administrative | 5,914 | 5,881 | 5,171 | 4,936 | 4,212 | 4,436 | 4,192 | 4,443 | 21,902 | 17,283 | 16,334 |
Total operating expenses | 28,772 | 22,427 | 20,584 | 17,155 | 16,642 | 18,137 | 17,958 | 19,586 | 88,938 | 72,323 | 76,249 |
Other income: | |||||||||||
Interest income | 10 | 19 | 89 | 306 | 441 | 608 | 725 | 452 | 424 | 2,226 | 1,398 |
Interest expense | (92) | (92) | (87) | (88) | (87) | (107) | (40) | 0 | (359) | (234) | 0 |
Total other income (expense), net | (82) | (73) | 2 | 218 | 354 | 501 | 685 | 452 | 65 | 1,992 | 1,398 |
Net loss | $ (28,844) | $ (22,489) | $ (19,786) | $ (16,926) | $ (16,246) | $ (16,792) | $ (17,071) | $ 21,901 | $ (88,045) | $ (28,208) | $ (64,257) |
Net income (loss) per share - basic (in dollars per share) | $ (0.42) | $ (0.33) | $ (0.33) | $ (0.35) | $ (0.34) | $ (0.35) | $ (0.36) | $ 0.72 | |||
Net income (loss) per share - diluted (in dollars per share) | $ (0.42) | $ (0.33) | $ (0.33) | $ (0.35) | $ (0.34) | $ (0.35) | $ (0.36) | $ 0.70 | |||
Weighted-average number of shares of common stock used in net income (loss) per share attributable to common stockholders — basic (in shares) | 47,886,144 | 47,833,607 | 47,708,085 | 30,299,650 | |||||||
Weighted-average number of shares of common stock used in net income (loss) per share attributable to common stockholders — diluted (in shares) | 47,886,144 | 47,833,607 | 47,708,085 | 31,461,696 | |||||||
Weighted-average number of common shares used in net loss per share attributable to common stockholders — basic and diluted (in shares) | 68,630,078 | 68,419,192 | 60,748,225 | 47,988,630 | 61,485,205 | 43,492,113 | 23,032,250 |