Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2022 | Mar. 21, 2023 | Jun. 30, 2022 | |
Cover [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2022 | ||
Document Fiscal Year Focus | 2022 | ||
Document Fiscal Period Focus | FY | ||
Trading Symbol | SCPH | ||
Entity Registrant Name | SCPHARMACEUTICALS INC. | ||
Entity Central Index Key | 0001604950 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | true | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | false | ||
Entity Shell Company | false | ||
Entity Interactive Data Current | Yes | ||
Title of 12(b) Security | Common stock, par value $0.0001 | ||
Security Exchange Name | NASDAQ | ||
Entity File Number | 001-38293 | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Tax Identification Number | 46-5184075 | ||
Entity Address, Address Line One | 2400 District Avenue | ||
Entity Address, Address Line Two | Suite 310 | ||
Entity Address, City or Town | Burlington | ||
Entity Address, State or Province | MA | ||
Entity Address, Postal Zip Code | 01803 | ||
City Area Code | 617 | ||
Local Phone Number | 517-0730 | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
Auditor Name | RSM US LLP | ||
Auditor Location | Boston, Massachusetts | ||
Auditor Firm ID | 49 | ||
Entity Common Stock, Shares Outstanding | 35,769,073 | ||
Entity Public Float | $ 75,626,427 | ||
Documents Incorporated by Reference | DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant’s definitive proxy statement relating to its 2023 annual meeting of stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The registrant’s definitive proxy statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year ended December 31, 2022. |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Current assets | ||
Cash and cash equivalents | $ 71,061 | $ 74,268 |
Short-term investments | 47,125 | 1,010 |
Restricted cash | 182 | 182 |
Inventory | 1,230 | |
Prepaid expenses | 2,282 | 2,791 |
Deposits and other current assets | 1,428 | 24 |
Total current assets | 123,308 | 78,275 |
Property and equipment, net | 54 | 69 |
Right-of-use lease assets - operating, net | 566 | 410 |
Deposits and other assets | 267 | 283 |
Total assets | 124,195 | 79,037 |
Current liabilities | ||
Accounts payable | 1,518 | 544 |
Accrued expenses | 5,289 | 3,995 |
Term loan, short-term | 9,805 | |
Lease obligation - operating, short-term | 567 | 476 |
Other current liabilities | 42 | 26 |
Total current liabilities | 7,416 | 14,846 |
Term loan, long-term | 36,794 | 7,354 |
Derivative liability | 7,517 | |
Lease obligation - operating, long-term | 7 | |
Other liabilities | 28 | 367 |
Total liabilities | 51,762 | 22,567 |
Commitments and contingencies (Note 13) | ||
Stockholders’ Equity | ||
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued and outstanding | ||
Common stock; $0.0001 par value; 150,000,000 shares authorized at December 31, 2022; 27,325,959 and 27,366,707 and 34,257,916 shares issued and outstanding at December 31, 2021 and December 31, 2022, respectively | 3 | 3 |
Additional paid-in capital | 298,934 | 246,166 |
Accumulated deficit | (226,536) | (189,698) |
Accumulated other comprehensive (loss) income | 32 | (1) |
Total stockholders’ equity | 72,433 | 56,470 |
Total liabilities and stockholders’ equity | $ 124,195 | $ 79,037 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2022 | Dec. 31, 2021 |
Statement of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.0001 | $ 0.0001 |
Preferred stock, shares authorized | 10,000,000 | 10,000,000 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized | 150,000,000 | 150,000,000 |
Common stock, shares issued | 34,257,916 | 27,366,707 |
Common stock, shares outstanding | 34,257,916 | 27,366,707 |
Consolidated Statements of Oper
Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Operating expenses: | ||
Research and development | $ 15,533 | $ 16,039 |
General and administrative | 20,624 | 9,784 |
Total operating expenses | 36,157 | 25,823 |
Loss from operations | (36,157) | (25,823) |
Other income | 1,418 | 315 |
Interest income | 1,203 | 49 |
Interest expense | (3,302) | (2,575) |
Net loss | $ (36,838) | $ (28,034) |
Net loss per share, basic | $ (1.30) | $ (1.02) |
Net loss per share, diluted | $ (1.30) | $ (1.02) |
Weighted --average common shares outstanding, basic | 28,358,502 | 27,351,730 |
Weighted--average common shares outstanding, diluted | 28,358,502 | 27,351,730 |
Other comprehensive loss: | ||
Unrealized (loss) gain on short-term investments | $ 33 | $ (2) |
Comprehensive loss | $ (36,805) | $ (28,036) |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands | Total | At The Market Offering | Common Stock | Common Stock At The Market Offering | Additional Paid-in Capital | Additional Paid-in Capital At The Market Offering | Accumulated Deficit | Other Comprehensive Income (Loss) |
Beginning Balance at Dec. 31, 2020 | $ 82,170 | $ 3 | $ 243,830 | $ (161,664) | $ 1 | |||
Beginning Balance, Shares at Dec. 31, 2020 | 27,325,959 | |||||||
Net loss | (28,034) | (28,034) | ||||||
Issuance of common stock upon exercise of stock options | $ 9 | 9 | ||||||
Issuance of common stock upon exercise of stock options, Shares | 2,501 | 2,501 | ||||||
Issuance of common stock purchased through employee stock purchase plan | $ 42 | 42 | ||||||
Issuance of common stock purchased through employee stock purchase plan, Shares | 11,253 | |||||||
Vesting of restricted stock | (81) | (81) | ||||||
Vesting of restricted stock, Shares | 26,994 | |||||||
Stock-based compensation | 2,366 | 2,366 | ||||||
Unrealized gain (loss) on short term investments | (2) | (2) | ||||||
Ending Balance at Dec. 31, 2021 | 56,470 | $ 3 | 246,166 | (189,698) | (1) | |||
Ending Balance, Shares at Dec. 31, 2021 | 27,366,707 | |||||||
Net loss | (36,838) | (36,838) | ||||||
Issuance of common stock, net of issuance costs | $ 1,114 | $ 1,114 | ||||||
Issuance of common stock net of issuance costs, Shares | 181,553 | |||||||
Issuance of common stock and pre-funded warrants in common stock offering, net of issuance costs | 46,645 | 46,645 | ||||||
Issuance of common stock and pre-funded warrants in common stock offering, net of issuance costs, Shares | 6,620,000 | |||||||
Issuance of common stock upon exercise of stock options | $ 44 | 44 | ||||||
Issuance of common stock upon exercise of stock options, Shares | 11,756 | 11,756 | ||||||
Issuance of common stock purchased through employee stock purchase plan | $ 173 | 173 | ||||||
Issuance of common stock purchased through employee stock purchase plan, Shares | 45,938 | |||||||
Vesting of restricted stock | (54) | (54) | ||||||
Vesting of restricted stock, Shares | 31,962 | |||||||
Issuance of warrants | 2,008 | 2,008 | ||||||
Stock-based compensation | 2,838 | 2,838 | ||||||
Unrealized gain (loss) on short term investments | 33 | 33 | ||||||
Ending Balance at Dec. 31, 2022 | $ 72,433 | $ 3 | $ 298,934 | $ (226,536) | $ 32 | |||
Ending Balance, Shares at Dec. 31, 2022 | 34,257,916 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Cash flows from operating activities | ||
Net loss | $ (36,838,000) | $ (28,034,000) |
Adjustments to reconcile net loss to net cash used in operating activities | ||
Depreciation expense | 37,000 | 34,000 |
Amortization expense - right-of-use leased assets - operating | 431,000 | 404,000 |
Accretion on short-term investments | (244,000) | 124,000 |
Stock-based compensation | 2,838,000 | 2,366,000 |
Non-cash interest expense | 884,000 | 554,000 |
Fair value adjustment to derivative liability | (1,335,000) | |
Changes in operating assets and liabilities | ||
Inventory | (1,230,000) | |
Prepaid expenses and other assets | (887,000) | (234,000) |
Accounts payable, accrued expenses and other liabilities | 1,767,000 | (2,365,000) |
Net cash flows used in operating activities | (34,577,000) | (27,151,000) |
Cash flows from investing activities | ||
Purchases of property and equipment | (21,000) | (9,000) |
Maturities of short-term investments | 21,700,000 | 41,150,000 |
Purchases of short-term investments | (67,538,000) | (9,011,000) |
Net cash flows provided by (used in) investing activities | (45,859,000) | 32,130,000 |
Cash flows from financing activities | ||
Proceeds from common stock offering, net of underwriter discounts and offering costs | 46,645,000 | |
Proceeds from at-the-market offering, net | 1,120,000 | |
Proceeds from the exercise of stock options | 44,000 | 9,000 |
Proceeds from employee stock purchase plan | 173,000 | 42,000 |
Proceeds from term loan | 47,301,000 | |
Principal payments on term loan | (17,500,000) | (2,500,000) |
Payment Of Term Loan Final Fee | (500,000) | |
Settlement of restricted stock units for tax withholding obligations | (54,000) | (81,000) |
Net cash flows (used in) provided by financing activities | 77,229,000 | (2,530,000) |
Net increase (decrease) in cash | (3,207,000) | 2,449,000 |
Cash, cash equivalents and restricted cash, beginning of year | 74,450,000 | 72,001,000 |
Cash, cash equivalents and restricted cash, end of year | 71,243,000 | 74,450,000 |
Supplemental cash flow information | ||
Interest paid | 2,555,000 | 2,043,000 |
Taxes paid | 190,000 | $ 206,000 |
Supplemental disclosure of non-cash activities | ||
Transfer of issuance costs from other noncurrent assets to equity | $ 6,000 |
Description of Business and Bas
Description of Business and Basis of Presentation | 12 Months Ended |
Dec. 31, 2022 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Description of Business and Basis of Presentation | 1. Description of Business and Basis of Presentation Description of Business scPharmaceuticals LLC was formed as a Limited Liability Company under the laws of the State of Delaware on February 19, 2013. On March 24, 2014, scPharmaceuticals LLC was converted to a Delaware Corporation and changed its name to scPharmaceuticals Inc. (“the Company”). The Company is a pharmaceutical company focused on developing and commercializing products that have the potential to optimize the delivery of infused therapies, advance patient care and reduce healthcare costs. The Company’s strategy is designed to enable the subcutaneous administration of therapies that have previously been limited to intravenous (“IV”) delivery. The Company’s headquarters and primary place of business is Burlington, Massachusetts. Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”) and have been prepared on a basis which assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiary, scPharmaceuticals Securities Corporation. All significant intercompany balances and transactions have been eliminated in consolidation. Liquidity At December 31, 2022 , the Company had cash, cash equivalents, restricted cash and investments of $ 118.4 million and working capital of $ 115.9 million. During the year ended December 31, 2022 , the Company incurred a net loss totaling $ 36.8 million and used cash in operating activities totaling $ 34.6 million. The Company expects to continue to incur losses and use cash in operating activities in 2023. In October 2022, the Company entered into a Credit Agreement and Guaranty (the "Oaktree Agreement") with, among others, the lenders from time to time party thereto (the "Lenders") and Oaktree Fund Administration, LLC, in its capacity as administrative agent for the Lenders (Note 10). In November 2022, the Company completed an underwritten public offering with net proceeds of $ 46.6 million (Note 11). In addition, the Company currently has an at-the-market offering program with Cowen and Company, LLC that has $ 48.9 million in capacity remaining at December 31, 2022 (Note 11). The Company believes that, based on its current development plans and activities, its resources will be sufficient to satisfy its liquidity requirements for more than one year from the issuance date of these consolidated financial statements. |
Significant Accounting Policies
Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2022 | |
Accounting Policies [Abstract] | |
Significant Accounting Policies | 2. Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant items subject to such estimates and assumptions include the determination of fair value of financial instruments, accruals related to development costs and clinical activities, and the establishment of the tax valuation allowance. Actual results could differ from those estimates. Foreign Currency Transactions The functional currency of the Company is the U.S. dollar. Accordingly, gains and losses resulting from translating transactions denominated in currencies and balances of assets and liabilities outstanding at the balance sheet date, other than U.S. dollars, are included in net loss in the Statements of Operations and Comprehensive Loss. Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company places its cash and cash equivalents with institutions with high credit quality. However, at certain times such cash and cash equivalents may be in excess of Federal Deposit Insurance Corporation and Securities Investor Protection Corporation insurance limits. The Company has not experienced any losses with respect to these accounts. As of December 31, 2021 and 2022 , the Company classified $ 182,000 as restricted cash related to a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate office facilities (Note 13). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, December 31, Cash and cash equivalents $ 74,268 $ 71,061 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 74,450 $ 71,243 Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and short-term investments. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s short-term investments consist of commercial paper, United States Treasury securities and United States Government Agency securities. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to hold a minimum rating, thereby reducing credit risk exposure. Investments The Company invests excess cash balances in available-for-sale debt securities. The Company determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company reports available-for-sale investments at fair value at each balance sheet date and includes any unrealized gains and losses in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense). If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the intention to sell and, if so, marks the investment to market through a charge to the Company’s consolidated statements of operations and comprehensive loss. Inventory Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-process and finished goods. The Company began capitalizing inventory costs following U.S. Food and Drug Administration ("FDA") approval of FUROSCIX on October 7, 2022. Inventory is sold on a first in, first out ("FIFO") basis. The Company periodically reviews inventory for expiry and obsolescence and writes it down accordingly, if necessary. Prior to FDA approval of FUROSCIX, the Company expensed all inventory-related costs, including that used for clinical development, to research and development ("R&D") costs in the period incurred. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) lease assets, current portion of lease obligations, and long term lease obligations on the Company’s balance sheets. ROU lease 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 ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset excludes lease incentives. The Company’s lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Debt Issuance Costs Debt issuance costs are amortized to interest expense using the effective interest rate method over the term of the debt. Debt issuance costs paid to the lender and third parties are reflected as a discount to the debt in the consolidated balance sheets. Research and Development Costs Research and development costs are expensed as incurred. Nonrefundable advance payments, if any, for goods or services used in research and development are initially recorded as an asset and then recognized as an expense as the related goods are delivered or services are performed. Research and development expenses include contract services, consulting, salaries, materials and supplies and overhead. Income Taxes The Company accounts for income taxes in accordance with Accounting Standard Codification (“ASC”) 740 Income Taxes (“ASC 740”) . Deferred tax assets and liabilities are recorded to reflect the impact of temporary differences between amounts of assets and liabilities for financial reporting purposes and such amounts as measured under enacted tax laws. A valuation allowance is required to offset any net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax asset will not be realized. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions. The tax benefits recorded 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 uncertainty related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Potential interest and penalties associated with such uncertain tax positions are recorded as a component of income tax expense. At December 31, 2021 and 2022 , the Company had no such accruals. Stock-Based Compensation Stock-based compensation expense for stock options is recognized based on the grant-date fair value using the Black-Scholes valuation model. Restricted stock units are valued at the fair market value per share of the Company’s common stock on the date of grant. The Company recognizes compensation expense only for those stock-based awards expected to vest after considering expected forfeitures. Cumulative compensation expense is at least equal to the compensation expense for vested awards. Stock-based compensation is recognized on a straight-line basis over the service period of each award. Segments Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (“CODM”) in making decisions regarding resource allocation and assessing performance. The Company’s chief executive officer is the CODM, and he uses consolidated financial information in determining how to allocate resources and assess performance. The Company has determined that it operates in one segment. Recently Issued Accounting Standards In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2016-13, Financial Instruments-Credit Losses : Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss methodology, which will result in more timely recognition of credit losses. The ASU will be effective for the Company's fiscal year beginning January 1, 2023. The Company is currently evaluating the impact of the adoption of ASU 2016-13 and does not expect adoption to have a material effect on the Company’s consolidated financial statements or disclosures. |
Net Loss per Share
Net Loss per Share | 12 Months Ended |
Dec. 31, 2022 | |
Earnings Per Share [Abstract] | |
Net Loss per Share | 3. Net Loss per Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period without consideration of dilutive common stock equivalents. Diluted net loss per share is the same as basic net loss per common share, since the effects of potentially dilutive securities are anti-dilutive. Basic and diluted weighted average shares of common stock outstanding for the year ended December 31, 2022 include the weighted average effect of outstanding pre-funded warrants for the purchase of shares of common stock for which the remaining unfunded exercise price is $ 0.001 per share. Dilutive common stock equivalents are comprised of unexercised stock options outstanding under the Company’s equity plan, unexercised warrants and unvested restricted stock. The following table sets forth the computation of basic and diluted net loss per share of common stock (in thousands, except shares and per share data): For the year ended December 31, December 31, Net loss $ ( 28,034 ) $ ( 36,838 ) Weighted—average common shares 27,351,730 28,358,502 Net loss per share, basic and diluted $ ( 1.02 ) $ ( 1.30 ) The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive (in common stock equivalent shares): For the year ended December 31, December 31, Stock options to purchase common stock 2,662,752 4,008,177 Warrants to purchase common stock — 516,345 Unvested restricted stock 42,250 — 2,705,002 4,524,522 |
Investments
Investments | 12 Months Ended |
Dec. 31, 2022 | |
Investments, Debt and Equity Securities [Abstract] | |
Investments | 4. Investments Cash in excess of the Company’s immediate requirements is invested in accordance with the Company’s investment policy that primarily seeks to maintain adequate liquidity and preserve capital. A summary of the Company’s available-for-sale classified investments as of December 31, 2021 and 2022 consisted of the following (in thousands): At December 31, 2021 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Corporate debt securities $ 1,011 $ - $ ( 1 ) $ 1,010 Total $ 1,011 $ - $ ( 1 ) $ 1,010 At December 31, 2022 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Commercial paper $ 16,741 $ - $ - $ 16,741 United States Treasury securities 15,768 7 - 15,775 United States Government Agency securities 14,584 25 - 14,609 Total $ 47,093 $ 32 $ - $ 47,125 The amortized cost and fair value of the Company’s available-for-sale investments, by contract maturity, as of December 31, 2022 consisted of the following (in thousands): Amortized Cost Fair Value Due in one year or less $ 47,093 $ 47,125 Total $ 47,093 $ 47,125 |
Inventory
Inventory | 12 Months Ended |
Dec. 31, 2022 | |
Inventory Disclosure [Abstract] | |
Inventory | 5. Inventory The Company's inventory balance consists of the following (in thousands): As of December 31, 2021 2022 Raw materials $ — $ 1,201 Work-in-process — 29 Finished goods — — $ — $ 1,230 Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-process and |
Property and Equipment
Property and Equipment | 12 Months Ended |
Dec. 31, 2022 | |
Property, Plant and Equipment [Abstract] | |
Property and Equipment | 6. Property and Equipment Purchased property and equipment consist of the following as of December 31, 2021 and 2022 (in thousands): ESTIMATED 2021 2022 Office equipment 5 years $ 10 $ 6 Office furniture 7 years 126 126 Computer equipment 3 years 8 15 Leasehold improvements Life of lease 95 95 239 242 Less: Accumulated depreciation ( 170 ) ( 188 ) Property and equipment, net $ 69 $ 54 Depreciation expense for the years ended December 31, 2021 and 2022 was $ 34,000 and $ 37,000 , respectively. |
Accrued Expenses
Accrued Expenses | 12 Months Ended |
Dec. 31, 2022 | |
Accrued Liabilities, Current [Abstract] | |
Accrued Expenses | 7. Accrued Expenses Accrued expenses at December 31, 2021 and 2022 consist of (in thousands): 2021 2022 Employee compensation and related costs $ 1,152 $ 2,754 Contract research and development 2,350 1,827 Consulting and professional service fees 265 603 State taxes 5 49 Financing related costs 60 29 Interest 154 16 Other 9 11 Total accrued expenses $ 3,995 $ 5,289 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2022 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 8. Income Taxes The Company accounts for income taxes in accordance with ASC 740, which requires an asset and liability approach for measuring deferred taxes based on temporary differences between the financial statement and tax bases of assets and liabilities existing at each balance sheet date using enacted tax rates for the years in which taxes are expected to be paid or recovered. The tax benefit arising from the Company’s net loss has been offset by an increase in the valuation allowance. Accordingly, the Company had no net income tax provision or benefit during the years ended December 31, 2021 and 2022 . Components of the net deferred tax assets at December 31, 2021 and 2022 are as follows (in thousands): 2021 2022 Deferred tax assets: Federal net operating loss carryforwards $ 12,813 $ 17,252 State net operating loss carryforwards 3,630 4,585 Research and development tax credits 3,719 4,214 Accrued liabilities 327 677 Stock-based compensation 1,087 1,329 Depreciation and amortization 247 324 Capitalized research and development costs 29,529 30,976 Lease liabilities 129 146 Other 29 — Total deferred tax assets 51,510 59,503 Deferred tax liabilities: Right-of-use lease assets ( 111 ) ( 144 ) Other — ( 273 ) Total deferred tax liabilities $ ( 111 ) $ ( 417 ) Valuation allowance $ ( 51,399 ) $ ( 59,086 ) Net deferred tax assets $ — $ — At December 31, 2022 , the Company had available federal net operating loss carryforwards of $ 17.5 million, which expire at various dates through 2037 , and $ 64.6 million, which may be carried forward indefinitely. At December 31, 2022, the Company had available state net operating loss carryforwards of $ 72.6 million, which expire at various dates through 2042 , and $ 300,000 , which may be carried forward indefinitely. In assessing the realizability of net deferred tax assets, management considers whether it is more likely than not that the net deferred tax assets will be realized. The ultimate realization of net deferred tax assets is dependent upon the generation of future taxable income during the periods in which temporary differences representing future deductible amounts become deductible. Management has established a full valuation allowance against the net deferred tax assets at December 31, 2021 and 2022 since it is more likely than not that these future tax benefits will not be realized. During 2022 , the valuation allowance increased by $ 7.7 million. At December 31, 2022 , the Company had federal and state research and development credit carryforwards of $ 4.3 million and $ 1.0 million, respectively. The net credit carryforwards may be used to offset future income taxes and expire at various dates through 2042 . Changes in the Company’s ownership, as defined in the U.S. Internal Revenue Code, may limit the Company’s ability to utilize the tax credit and net operating loss carryforwards. A reconciliation of income tax (expense) benefit at the statutory federal income tax rate and income taxes as reflected in the consolidated financial statements at December 31, 2021 and 2022 are as follows: 2021 2022 Federal income tax at statutory rate 21.00 % 21.00 % State income tax, net of federal benefit 5.97 % 4.28 % Research and development credits 3.16 % 1.39 % Book compensation related to stock options 0.03 % ( 0.80 )% Change in income tax rate 0.45 % ( 4.93 )% Other ( 0.93 )% ( 0.09 )% Increase in valuation allowance ( 29.68 )% ( 20.87 )% Effective tax rate — % ( 0.02 )% The Company files tax returns in the United States, Massachusetts and other states. The tax years 2018 through 2022 remain open to examination by major taxing jurisdictions to which the Company is subject, which are primarily the United States federal and Massachusetts. Carryforward attributes generated in years past may still be adjusted upon examination by the Internal Revenue Service or state tax authorities if they have or will be used in a future period. The Company is currently not under examination by the Internal Revenue Service or any other jurisdictions for any tax years. The Company recognizes both accrued interest and penalties related to unrecognized benefits in income tax expense. The Company has not recorded any interest or penalties on any unrecognized tax benefits since its inception. A reconciliation of the beginning and ending amount of uncertain tax benefits is as follows (in thousands): 2021 2022 Beginning uncertain tax benefits $ 774 $ 977 Prior year - increases — — Current year - decreases — — Current year - increases 203 129 Ending uncertain tax benefits $ 977 $ 1,106 |
Fair Value of Financial Instrum
Fair Value of Financial Instruments | 12 Months Ended |
Dec. 31, 2022 | |
Fair Value Disclosures [Abstract] | |
Fair Value of Financial Instruments | 9. Fair Value of Financial Instruments The FASB ASC Topic, Fair Value Measurements and Disclosures ( “ASC 820” ), provides a fair value hierarchy, which classifies fair value measurements based on the inputs used in measuring fair value. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below: Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and observable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying values of the Company’s cash and restricted cash, prepaid expenses and deposits approximate their fair values due to their short-term nature. The carrying value of the Company’s term loan payable was considered a reasonable estimate of fair value because the Company’s interest rate is near current market rates for instruments with similar characteristics. The following tables summarize the Company’s assets and liabilities that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of December 31, 2021 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 72,449 $ 72,449 $ — $ — Total cash equivalents 72,449 72,449 — — Corporate debt securities 1,010 — 1,010 — Investments 1,010 — 1,010 — Total $ 73,459 $ 72,449 $ 1,010 $ — As of December 31, 2022 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 65,875 $ 65,875 $ — $ — Total cash equivalents 65,875 65,875 — — Commercial Paper 16,741 — 16,741 — United States Treasury securities 15,775 15,775 — — United States Government Agency securities 14,609 — 14,609 — Investments 47,125 15,775 31,350 — Total $ 113,000 $ 81,650 $ 31,350 $ — Liabilities: Derivative liability $ 7,517 $ — $ — $ 7,517 Total $ 7,517 $ — $ — $ 7,517 Changes in the fair value of the Company’s Level 3 derivative liability for the year ended December 31, 2022 are as follows: At December 31, 2021 $ — Initial fair value of derivative liability 8,852 Change in fair value of derivative liability ( 1,335 ) At December 31, 2022 $ 7,517 The Oaktree Agreement contains embedded derivatives requiring bifurcation as a derivative instrument. The derivative liability related to the term loan is recorded and accounted for separately in the consolidated financial statements as one compound derivative liability, see Note 10 for additional details. The fair value of the embedded derivative liabilities associated with the term loan was estimated using a hybrid between the discounted cash flow and Monte Carlo simulation methods. This involves significant Level 3 inputs and assumptions including (i) the estimated probability and timing of a change in control and (2) the probability-weighted net sales of FUROSCIX. A summary of quantitative information about significant unobservable inputs (Level 3 inputs) used in measuring the Company's derivative liability that are categorized within Level 3 of the fair value hierarchy is as follows: October 13, December 31, Net sales discount rate 23.3 % 22.3 % Net sales volatility 80.0 % 80.0 % Risk-free rate 4.2 % 4.0 % Recovery rate 80.0 % 80.0 % |
Debt
Debt | 12 Months Ended |
Dec. 31, 2022 | |
Debt Disclosure [Abstract] | |
Debt | 10. Debt The following table presents the carrying value of the Company's debt balance as of December 31, 2021 and 2022 (in thousands): DECEMBER 31, DECEMBER 31, Face value of term loans $ 17,500 $ 50,000 Unamortized debt discount ( 341 ) ( 13,206 ) Total debt, net $ 17,159 $ 36,794 Less: short-term debt ( 9,805 ) — Long-term debt $ 7,354 $ 36,794 Oaktree Agreement On October 13, 2022 (“Closing Date”), the Company entered into a Credit Agreement and Guaranty (the “Oaktree Agreement”) with Oaktree Fund Administration, LLC as administrative agent, and the lenders party thereto (collectively “Oaktree”) to borrow up to $ 100.0 million in three tranches with a maturity date of October 13, 2027 . The first tranche of $ 50.0 million was drawn immediately, with $ 9.8 million of the proceeds used to repay in full the outstanding loan and fees under the 2019 Loan Agreement with SLR Investment Corp. and Silicon Valley Bank and $ 2.7 million in fees and expenses incurred in connection with the financing, leaving $ 37.5 million in available proceeds from the first tranche. The ability to draw the remaining $ 50.0 million is contingent upon reaching certain net sales revenue milestone targets prior to September 30, 2024 and December 31, 2024, respectively. The term loan initially bears interest at the three-month term Secured Overnight Financing Rate (“SOFR”) plus an applicable margin of 8.75 % (with a SOFR floor of 1.00 % and a 3.00 % cap). Once FUROSCIX achieves at least $ 100.0 million in trailing 12-month net sales, the applicable margin will step down to 8.25 %. The Company is required to make quarterly interest-only payments until the third anniversary of the Closing Date, after which the Company is required to make quarterly amortizing payments, with the remaining balance of the principal plus accrued and unpaid interest due at maturity. In connection with entering into the Oaktree Agreement, the Company granted warrants to Oaktree to purchase up to an aggregate of 516,345 shares of the Company’s common stock at an exercise price of $ 5.40 per share. Upon inception, the Company evaluated the warrants and determined that they met all the requirements for equity classification under ASC 815. This transaction was accounted for as a detachable warrant at its fair value, using the relative fair value method, which is based on a number of unobservable inputs and is recorded as an increase to additional paid-in-capital on the consolidated statement of stockholder’s equity. The relative fair value of the warrants, $ 2.0 million, was reflected as a discount to the term loan and will be amortized over the life of the term loan using the effective interest method. The Company used the Black-Scholes option pricing model to determine the fair value of the warrants. Assumptions included the fair market value per share of common stock on the valuation date of $ 5.50 , the exercise price per warrant equal to $ 5.40 , the expected volatility of 77 %, the risk-free interest rate of 4.11 %, the expected term of 7 years and the absence of a dividend. The warrants are immediately exercisable and the exercise period expires on October 13, 2029. The Company identified a number of embedded derivatives that require bifurcation from the term loan and that were separately accounted for in the consolidated financial statements as one compound derivative liability. Certain of these embedded features include contingent interest rate reset upon event of default, contingent put options, including change in control and going concern provisions, and additional costs as a result of changes in law. These embedded features met the criteria requiring these to be bifurcated because they were not clearly and closely related to the host instrument in accordance with ASC 815-15 and the derivative liability is presented separately in the condensed consolidated balance sheet as of December 31, 2022. The fair value of the embedded derivative liabilities associated with the term loan was estimated using a hybrid between the discounted cash flow and Monte Carlo simulation methods. This involves significant Level 3 inputs and assumptions including an estimated probability and timing of a change in control. The Company re-evaluates this assessment each reporting period and any changes in estimated fair value is recorded as other income (expense). The initial recognition of the embedded derivative liability upon issuance of the Term Loan was $ 8.9 million. At December 31, 2022, the fair value of the embedded derivative liability was $ 7.5 million. In connection with the issuance of the term loan, the Company recorded a debt discount of $ 13.6 million, inclusive of debt issuance costs, the derivative liability and the relative fair value of the warrants. The discount will be amortized over the life of the term loan using the effective interest method. For the year ended December 31, 2022, the Company recorded $ 383,000 related to the amortization of the debt discount associated with the Oaktree Agreement. Prepayments of the term loan, in whole or in part, will be subject to a prepayment fee which declines each year until the fourth anniversary date of the Closing Date, after which no prepayment fee is required. The Company is also required to pay an exit fee upon any payment or prepayment equal to 2.0 % of the aggregate principal amount of the loans funded under the Oaktree Agreement. The Company recorded an additional debt discount of $ 1.0 million related to the exit fee. For the year ended December 31, 2022, the Company recorded $ 28,000 related to the amortization of the exit fee associated with the Oaktree Agreement. The Oaktree Agreement contains customary representations, warranties and affirmative and negative covenants, including financial covenants requiring the Company to (i) maintain unrestricted cash of at least $ 15.0 million at all times, increasing to $ 20.0 million upon accessing the second tranche of the term loan and (ii) meet minimum quarterly net sales revenue targets. In addition, the Oaktree Agreement contains customary events of default that could cause the Company’s indebtedness to become immediately due and payable. The lenders could declare the Company in default under its debt obligation upon the occurrence of any event that the lenders interpret as having a material adverse effect as defined under the Oaktree Agreement. Upon the occurrence and for the duration of an event of default, an additional interest rate equal to 2.0 % per annum could apply to all obligations owed under the Oaktree Agreement. Among other loan covenant requirements, the Oaktree Agreement also requires the Company to provide an audit opinion of its annual financial statements not subject to any "going concern" or like qualification or exception. SLR Investment Corp. and Silicon Valley Bank Term Loan In May 2017, the Company entered into a loan and security agreement (the “2017 Loan Agreement”), with SLR Investment Corp. (f/k/a Solar Capital Ltd.) and Silicon Valley Bank, (together, the “Lenders”) for $ 10.0 million. The 2017 Loan Agreement had a maturity date of May 1, 2021 . Debt issuance costs for the 2017 Loan Agreement were to be amortized to interest expense over the remaining term of the 2017 Loan Agreement using the effective-interest method. In September 2019, the Company replaced the 2017 Loan Agreement with a new $ 20.0 million term loan with the Lenders (the "2019 Loan Agreement"). The restructured four-year term loan facility allowed for an expansion of the 2017 Loan Agreement. Some of the proceeds from the 2019 Loan Agreement were used to pay off the 2017 Loan Agreement including the final fee of $ 325,000 . The 2019 Loan Agreement extended the term of the credit facility until September 17, 2023 . The payoff of the 2017 Loan Agreement was treated as a modification of the debt. Debt issuance costs for the 2019 Loan Agreement, including unamortized issuance costs for the 2017 Loan Agreement, would be amortized to interest expense over the remaining term of the 2019 Loan Agreement using the effective-interest method. The interest rate under the 2019 Loan Agreement was the higher of (i) LIBOR plus 7.95 % or (ii) 10.18 % and there was an interest-only period until September 30, 2021. The rate at December 31, 2022 was 10.18 %. Pursuant to the 2019 Loan Agreement, the Company provided a first priority security interest in substantially all of the Company’s assets, including intellectual property, subject to certain exceptions. The Company entered into the Exit Agreement in connection with the 2019 Loan Agreement which provided for an aggregate payment of 4 % of the loan commitment, or $ 800,000 , to the Lenders upon the occurrence of an exit event (the "Exit Fee"). The Company concluded that the exit payment obligation met the definition of a derivative that was required to be accounted for as a separate unit of accounting. The Company recorded the issuance-date fair value of the derivative liability of $ 763,000 as a debt discount and as a derivative liability in the Company’s balance sheet. The derivative liability was re-measured at each balance sheet date and any changes in estimated fair value was recorded as other income (expense). The Company paid the Exit Fee during the year ended December 31, 2020 in conjunction with the Company’s public offering, which was deemed to be an exit event pursuant to the Exit Agreement. Prior to its public offering in 2020, the Company recorded $ 30,000 in non-cash expense as a fair value adjustment to the derivative liability. The 2019 Loan Agreement allowed the Company to voluntarily prepay all (but not less than all) of the outstanding principal at any time. A prepayment premium of 3 % or 1 % through the one-year anniversary and the two-year anniversary, respectively, would be assessed on the outstanding principal. After the two-year anniversary, a 0.5 % prepayment premium would be assessed on the outstanding principal. A final payment fee of $ 500,000 was due upon the earlier to occur of the maturity date or prepayment of such borrowings. In connection with the Oaktree Agreement, the Company paid off all unpaid borrowings under the 2019 Loan Agreement on October 13, 2022, including the $ 500,000 final fee and a prepayment premium of $ 46,000 . For the years ended December 31, 2021, and 2022, the Company recorded $ 392,000 and $ 341,000 , respectively, related to the amortization of the debt discount associated with the 2019 Loan Agreement. For the years ended December 31, 2021, and 2022, the Company recorded $ 162,000 and $ 132,000 related to the amortization of the final payment fee associated with the 2019 Loan Agreement. As of December 31, 2022, future principal payments due under the Oaktree Agreement are as follows (in thousands): Year ended: December 31, 2023 $ - December 31, 2024 - December 31, 2025 2,500 December 31, 2026 10,000 December 31, 2027 37,500 Total minimum principal payments $ 50,000 |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2022 | |
Equity [Abstract] | |
Stockholders' Equity | 11. Stockholders’ Equity Common Stock At December 31, 2021 and 2022 , the Company had 150,000,000 shares of common stock authorized with a par value of $ 0.0001 . There were 27,366,707 and 34,257,916 shares issued and outstanding at December 31, 2021 and 2022, respectively. Voting, dividend and liquidation rights of the holders of the common stock are subject to the Company’s articles of incorporation, corporate bylaws and underlying shareholder agreements. Reserved Shares The Company has reserved 4,008,177 shares of common stock for the exercise of outstanding options to purchase common stock. 2021 At-the-Market Issuance Sales Agreement On March 23, 2021, the Company entered into an Open Market Sale Agreement SM (the “2021 ATM Agreement”) with Cowen and Company, LLC (“Cowen”) with respect to an at-the-market offering program (the “2021 ATM Program”) under which the Company could offer and sell shares of its common stock (the “2021 ATM Shares”), having an aggregate offering price of up to $ 50.0 million through Cowen as its sales agent. The offering and sale of 2021 ATM Shares are made pursuant to the Company’s shelf registration statement on Form S-3, which was declared effective by the SEC on April 29, 2021 (the “2021 Registration Statement”). The Company agreed to pay Cowen a commission up to 3.0 % of the gross sales proceeds of such 2021 ATM Shares. The Company incurred $ 273,000 of legal, accounting, and other costs to establish and activate the 2021 ATM Program. During the year ended December 31, 2022, the Company sold a total of 181,553 2021 ATM Shares under the 2021 ATM Agreement, in the open market, at a weighted average gross selling price of $ 6.33 per share for net proceeds of $ 1.1 million. The Company charged $ 6,000 in costs related to establishing and activating the program against additional paid in capital upon issuance of shares in 2022. Sale of Common Stock In November 2022, the Company completed an underwritten public offering of 6,620,000 shares of its common stock (the “2022 Offering Shares”), pursuant to the 2021 Registration Statement. The 2022 Offering Shares were sold at an offering price of $ 5.25 per share. In addition, a prefunded warrant to purchase up to 2,905,000 shares of common stock at a purchase price of $ 5.249 per underlying share was issued as part of the transaction. The pre-funded warrants were accounted for as equity instruments. Net proceeds of the offering were $ 46.6 million, after deducting underwriting discounts, commissions and offering expenses. Preferred Stock At December 31, 2021 and 2022 , the Company had 10,000,000 shares of preferred stock authorized with a par value of $ 0.0001 and no shares of preferred stock were issued or outstanding. |
Stock-Based Compensation
Stock-Based Compensation | 12 Months Ended |
Dec. 31, 2022 | |
Share-Based Payment Arrangement [Abstract] | |
Stock-Based Compensation | 12. Stock-Based Compensation Stock Options In October 2017, the board of directors approved the 2017 Stock Option and Incentive Plan (the “2017 Stock Plan”) which became effective in November 2017 , upon the closing of the Company’s IPO. The 2017 Stock Plan will expire in October 2027 . Under the 2017 Stock Plan, the Company may grant incentive stock options, non-statutory stock options, restricted stock awards, RSUs and other stock-based awards. The Company’s 2014 Stock Incentive Plan (the “2014 Stock Plan”) terminated in November 2017 effective upon the completion of the Company’s IPO. No additional options will be granted under the 2014 Stock Plan. At December 31, 2022 , there were 598,411 options outstanding under the 2014 Stock Plan. At December 31, 2022 , there were 6,105,147 shares of the Company’s common stock authorized for issuance under the 2017 Stock Plan, including 359,860 options that have been forfeited from the 2014 Stock Plan. At December 31, 2022 , there were 2,655,289 options available for issuance and 3,409,766 options outstanding under the 2017 Stock Plan. Awards granted under the 2017 Stock Plan have a term of ten years . Vesting of awards under the 2017 Stock Plan is determined by the compensation committee of the board of directors but is generally over one to four-year terms. The fair value of options at date of grant was estimated using the Black-Scholes option-pricing model with the following assumptions: 2021 2022 Risk-free interest rate 0.50 %— 1.25 % 1.67 %— 4.18 % Expected dividend yield 0 % 0 % Expected life 5.5 — 6.7 years 5.5 — 6.7 years Expected volatility 72 %— 74 % 70 %— 84 % Weighted-average grant date $ 4.18 $ 3.18 Due to the lack of a public market for the trading of the Company’s common stock prior to its initial public offering and the lack of company-specific historical volatility, volatility was estimated using historical volatilities of similar companies. The expected life of the awards is estimated based on the simplified method, which calculates the expected life based upon the midpoint of the term of the award and the vesting period. The Company uses the simplified method because it does not have sufficient option exercise data to provide a reasonable basis upon which to estimate the expected term. The Company has no history of paying dividends nor does management expect to pay dividends over the contractual terms of these options. The risk-free interest rates are based on the United States Treasury yield curve in effect at the time of grant, with maturities approximating the expected life of the stock options. The following table summarizes information about stock option activity during 2021 and 2022 (in thousands, except share and per share data): NUMBER OF WEIGHTED- WEIGHTED- AGGREGATE Outstanding, December 31, 2020 2,224,913 $ 6.26 Granted 953,506 6.57 Exercised ( 2,501 ) 3.81 Forfeited ( 513,166 ) 6.72 Outstanding, December 31, 2021 2,662,752 $ 6.28 Granted 1,455,594 4.86 Exercised ( 11,756 ) 3.71 Forfeited ( 98,413 ) 6.73 Outstanding, December 31, 2022 4,008,177 $ 5.76 7.47 $ 7,147 Vested and exercisable, December 31, 2022 1,982,329 $ 6.15 6.01 $ 3,436 Vested and expected to vest, December 31, 2022 3,489,134 $ 5.81 7.25 $ 6,226 The following table summarizes information about RSU activity during 2021 and 2022: RSUs AVERAGE GRANT DATE FAIR VALUE (IN DOLLARS PER SHARE) RSUs outstanding, December 31, 2020 80,450 $ 3.25 Granted — — Vested ( 38,200 ) 3.25 Forfeited — — RSUs outstanding, December 31, 2021 42,250 3.25 Granted — — Vested ( 42,250 ) 3.25 Forfeited — — RSUs outstanding, December 31, 2022 — $ — The number of RSUs vested includes shares of common stock withheld on behalf of employees to satisfy the minimum statutory tax withholding requirements. During 2021 and 2022 , the Company received $ 9,000 and $ 44,000 , respectively, upon exercise of stock options. The intrinsic value of the options exercised in 2021 and 2022 was $ 7,000 and $ 18,000 , respectively. Unrecognized compensation expense related to unvested options as of December 31, 2022 was $ 4.2 million and will be recognized over the remaining vesting periods of the underlying awards. The weighted-average period over which such compensation is expected to be recognized is 2.5 years. Employee Stock Purchase Plan In October 2017, the board of directors approved the 2017 Employee Stock Purchase Plan (“the ESPP”) which became effective in November 2017, upon the closing of the Company’s IPO. As part of the ESPP, eligible employees may acquire an ownership interest in the Company by purchasing common stock, at a discount, through payroll deductions. Eligible employees who elected to participate were able to participate in the ESPP beginning September 1, 2021. During 2021 and 2022 , 11,253 and 45,938 shares of common stock were issued under the ESPP, respectively. As of December 31, 2022 , there were 1,142,691 shares of common stock available for issuance under the ESPP. The Company recorded stock-based compensation expense in the following expense categories of its accompanying condensed consolidated statements of operations and comprehensive loss for employees, directors and non-employees during the years ended December 31, 2021 and 2022 as follows (in thousands): 2021 2022 Research and development $ 947 $ 1,050 General and administrative 1,419 1,788 Total $ 2,366 $ 2,838 |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2022 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 13. Commitments and Contingencies Operating Leases The Company entered into noncancelable operating leases for office facilities located in Lexington, Massachusetts and Burlington, Massachusetts through December 31, 2022 and November 30, 2023 , respectively. Rent expense under the operating leases totaled $ 0.5 million and $ 0.5 million for the years ended December 31, 2021 and 2022, respectively. Certain leases provide for increases in future minimum annual rental payments as defined in the lease agreements. The leases generally also include real estate taxes and common area maintenance charges in the annual rental payments. Pursuant to the terms of its lease agreement for the Company’s headquarters in Burlington, Massachusetts, the Company obtained a letter of credit in the amount of approximately $ 182,000 as security on the lease obligation. The letter of credit is listed as restricted cash on the Company’s consolidated balance sheets. Short-term leases are leases having a term of twelve months or less. The Company recognizes short-term leases on a straight-line basis and does no t record a related lease asset or liability for such leases. The following is a maturity analysis of the annual undiscounted cash flows reconciled to the carrying value of the operating lease liabilities as of December 31, 2022 (in thousands): Year ended: December 31, 2023 $ 596 December 31, 2024 9 December 31, 2025 1 Total minimum lease payments 606 Less imputed interest ( 32 ) Total $ 574 2021 2022 Lease cost: Operating lease cost $ 482 $ 505 Short-term lease cost 20 37 Sublease income ( 51 ) ( 47 ) Total lease cost $ 451 $ 495 Other information Cash paid for amounts included in the $ 530 $ 551 Operating cash flows from operating leases $ ( 60 ) $ ( 57 ) Weighted-average remaining lease term - 0.9 years 0.9 years Weighted-average discount rate - 10.1 % 10.1 % In July 2021, the Company signed a lease agreement for a new office facility located in Salem, New Hampshire. The lease commenced on September 1, 2021 and had an initial term of 12 months with an optional extension term through August 2023. In June 2022, the Company exercised the lease option. The lease is considered short-term and is being recognized on a straight-line basis. Research and Development Agreements As part of the Company’s research and development efforts, the Company enters into research and development agreements with unrelated companies. These agreements contain varying terms and provisions which include fees and milestones to be paid by the Company. Some of these agreements also contain provisions which require the Company to make payments for exclusivity in the development of products in the area of loop diuretics. Contingencies The Company follows subtopic 450-20 of the FASB ASC to report accounting for contingencies. Certain conditions may exist as of the date the financial statements are issued, which may result in a loss to the Company but which will only be resolved when one or more future events occur or fail to occur. The Company assesses such contingent liabilities, and such assessment inherently involves an exercise of judgment. If the assessment of a contingency indicates that it is probable that a material loss has been incurred and the amount of the liability can be estimated, then the estimated liability would be accrued in the Company’s financial statements. If the assessment indicates that a potential material loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, then the nature of the contingent liability, and an estimate of the range of possible losses, if determinable and material, would be disclosed. Loss contingencies considered remote are generally not disclosed unless they involve guarantees, in which case the guarantees would be disclosed. Due to the discontinuation of use of the first generation device in 2019, the Company has received notice of termination costs related to the program. Certain of the Company’s vendors have claimed or billed for additional costs for which the Company believes it is not obligated. The Company has evaluated this contingent liability in accordance with ASC 450, Contingencies, and determined that the possibility of additional costs is remote and no longer probable. |
401(k) Savings Plan
401(k) Savings Plan | 12 Months Ended |
Dec. 31, 2022 | |
Retirement Benefits [Abstract] | |
401(k) Savings Plan | 14. 401(k) Savings Plan In July 2014, the Company established a defined contribution savings plan under Section 401(k) of the Internal Revenue Code covering all of its employees. Employees may make contributions by withholding a percentage of their salary. The plan includes an employer match equal to 100 % on the first 3 % of deferred compensation and an additional 50 % on the next 2 % of deferred compensation. During the years ended December 31, 2021 and 2022 , the Company has recognized compensation expense of $ 198,000 and $ 340,000 , respectively, for the employer match contribution. |
Subsequent Events
Subsequent Events | 12 Months Ended |
Dec. 31, 2022 | |
Subsequent Events [Abstract] | |
Subsequent Events | 15. Subsequent Events The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. In the period beginning January 1, 2023 through the date of this Annual Report on Form 10-K, the Company issued and sold an additional 1,511,157 shares of its common stock under the 2021 ATM Agreement at a weighted average gross selling price of $ 9.30 per share for net proceeds of $ 13.7 million. On February 1, 2023, the Board of Directors of the Company adopted the 2023 Employment Inducement Award Plan (the "Inducement Plan") and, subject to the adjustment provisions of the Inducement Plan, reserved 500,000 shares of the Company’s Common Stock for issuance pursuant to equity awards granted under the Inducement Plan. |
Significant Accounting Polici_2
Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2022 | |
Accounting Policies [Abstract] | |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant items subject to such estimates and assumptions include the determination of fair value of financial instruments, accruals related to development costs and clinical activities, and the establishment of the tax valuation allowance. Actual results could differ from those estimates. |
Foreign Currency Transactions | Foreign Currency Transactions The functional currency of the Company is the U.S. dollar. Accordingly, gains and losses resulting from translating transactions denominated in currencies and balances of assets and liabilities outstanding at the balance sheet date, other than U.S. dollars, are included in net loss in the Statements of Operations and Comprehensive Loss. |
Cash Cash Equivalents and Restricted Cash | Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits, certificates of deposit and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company places its cash and cash equivalents with institutions with high credit quality. However, at certain times such cash and cash equivalents may be in excess of Federal Deposit Insurance Corporation and Securities Investor Protection Corporation insurance limits. The Company has not experienced any losses with respect to these accounts. As of December 31, 2021 and 2022 , the Company classified $ 182,000 as restricted cash related to a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate office facilities (Note 13). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, December 31, Cash and cash equivalents $ 74,268 $ 71,061 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 74,450 $ 71,243 |
Concentration of Credit Risk | Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and short-term investments. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s short-term investments consist of commercial paper, United States Treasury securities and United States Government Agency securities. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to hold a minimum rating, thereby reducing credit risk exposure. |
Investments | Investments The Company invests excess cash balances in available-for-sale debt securities. The Company determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company reports available-for-sale investments at fair value at each balance sheet date and includes any unrealized gains and losses in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense). If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the intention to sell and, if so, marks the investment to market through a charge to the Company’s consolidated statements of operations and comprehensive loss. |
Inventory | Inventory Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-process and finished goods. The Company began capitalizing inventory costs following U.S. Food and Drug Administration ("FDA") approval of FUROSCIX on October 7, 2022. Inventory is sold on a first in, first out ("FIFO") basis. The Company periodically reviews inventory for expiry and obsolescence and writes it down accordingly, if necessary. Prior to FDA approval of FUROSCIX, the Company expensed all inventory-related costs, including that used for clinical development, to research and development ("R&D") costs in the period incurred. |
Leases | Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) lease assets, current portion of lease obligations, and long term lease obligations on the Company’s balance sheets. ROU lease 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 ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset excludes lease incentives. The Company’s lease terms include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. |
Debt Issuance Costs | Debt Issuance Costs Debt issuance costs are amortized to interest expense using the effective interest rate method over the term of the debt. Debt issuance costs paid to the lender and third parties are reflected as a discount to the debt in the consolidated balance sheets. |
Research and Development Costs | Research and Development Costs Research and development costs are expensed as incurred. Nonrefundable advance payments, if any, for goods or services used in research and development are initially recorded as an asset and then recognized as an expense as the related goods are delivered or services are performed. Research and development expenses include contract services, consulting, salaries, materials and supplies and overhead. |
Income Taxes | Income Taxes The Company accounts for income taxes in accordance with Accounting Standard Codification (“ASC”) 740 Income Taxes (“ASC 740”) . Deferred tax assets and liabilities are recorded to reflect the impact of temporary differences between amounts of assets and liabilities for financial reporting purposes and such amounts as measured under enacted tax laws. A valuation allowance is required to offset any net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax asset will not be realized. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions. The tax benefits recorded 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 uncertainty related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Potential interest and penalties associated with such uncertain tax positions are recorded as a component of income tax expense. At December 31, 2021 and 2022 , the Company had no such accruals. |
Stock-Based Compensation | Stock-Based Compensation Stock-based compensation expense for stock options is recognized based on the grant-date fair value using the Black-Scholes valuation model. Restricted stock units are valued at the fair market value per share of the Company’s common stock on the date of grant. The Company recognizes compensation expense only for those stock-based awards expected to vest after considering expected forfeitures. Cumulative compensation expense is at least equal to the compensation expense for vested awards. Stock-based compensation is recognized on a straight-line basis over the service period of each award. |
Segments | Segments Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (“CODM”) in making decisions regarding resource allocation and assessing performance. The Company’s chief executive officer is the CODM, and he uses consolidated financial information in determining how to allocate resources and assess performance. The Company has determined that it operates in one segment. |
Recently Issued Accounting Standards | Recently Issued Accounting Standards In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2016-13, Financial Instruments-Credit Losses : Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"), which requires the measurement and recognition of expected credit losses for financial assets held at amortized cost. ASU 2016-13 replaces the existing incurred loss impairment model with an expected loss methodology, which will result in more timely recognition of credit losses. The ASU will be effective for the Company's fiscal year beginning January 1, 2023. The Company is currently evaluating the impact of the adoption of ASU 2016-13 and does not expect adoption to have a material effect on the Company’s consolidated financial statements or disclosures. |
Significant Accounting Polici_3
Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Accounting Policies [Abstract] | |
Schedule of Cash, Cash Equivalents and Restricted Cash | As of December 31, 2021 and 2022 , the Company classified $ 182,000 as restricted cash related to a letter of credit issued as a security deposit in connection with the Company’s lease of its corporate office facilities (Note 13). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, December 31, Cash and cash equivalents $ 74,268 $ 71,061 Restricted cash 182 182 Cash, cash equivalents and restricted cash $ 74,450 $ 71,243 |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Earnings Per Share [Abstract] | |
Computation of Basic and Diluted Net Loss Per Share of Common Stock | The following table sets forth the computation of basic and diluted net loss per share of common stock (in thousands, except shares and per share data): For the year ended December 31, December 31, Net loss $ ( 28,034 ) $ ( 36,838 ) Weighted—average common shares 27,351,730 28,358,502 Net loss per share, basic and diluted $ ( 1.02 ) $ ( 1.30 ) |
Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share | The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive (in common stock equivalent shares): For the year ended December 31, December 31, Stock options to purchase common stock 2,662,752 4,008,177 Warrants to purchase common stock — 516,345 Unvested restricted stock 42,250 — 2,705,002 4,524,522 |
Investments (Tables)
Investments (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Investments, Debt and Equity Securities [Abstract] | |
Summary of Available-for-Sale Classified Investments | A summary of the Company’s available-for-sale classified investments as of December 31, 2021 and 2022 consisted of the following (in thousands): At December 31, 2021 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Corporate debt securities $ 1,011 $ - $ ( 1 ) $ 1,010 Total $ 1,011 $ - $ ( 1 ) $ 1,010 At December 31, 2022 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Commercial paper $ 16,741 $ - $ - $ 16,741 United States Treasury securities 15,768 7 - 15,775 United States Government Agency securities 14,584 25 - 14,609 Total $ 47,093 $ 32 $ - $ 47,125 |
Summary of Amortized Cost and Fair Value of Available-for-Sale Investments by Contract Maturity | The amortized cost and fair value of the Company’s available-for-sale investments, by contract maturity, as of December 31, 2022 consisted of the following (in thousands): Amortized Cost Fair Value Due in one year or less $ 47,093 $ 47,125 Total $ 47,093 $ 47,125 |
Inventory (Tables)
Inventory (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Inventory Disclosure [Abstract] | |
Schedule of Inventory | The Company's inventory balance consists of the following (in thousands): As of December 31, 2021 2022 Raw materials $ — $ 1,201 Work-in-process — 29 Finished goods — — $ — $ 1,230 |
Property and Equipment (Tables)
Property and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Property, Plant and Equipment [Abstract] | |
Schedule of Purchased Property and Equipment | Purchased property and equipment consist of the following as of December 31, 2021 and 2022 (in thousands): ESTIMATED 2021 2022 Office equipment 5 years $ 10 $ 6 Office furniture 7 years 126 126 Computer equipment 3 years 8 15 Leasehold improvements Life of lease 95 95 239 242 Less: Accumulated depreciation ( 170 ) ( 188 ) Property and equipment, net $ 69 $ 54 |
Accrued Expenses (Tables)
Accrued Expenses (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Accrued Liabilities, Current [Abstract] | |
Schedule of Accrued Expenses | Accrued expenses at December 31, 2021 and 2022 consist of (in thousands): 2021 2022 Employee compensation and related costs $ 1,152 $ 2,754 Contract research and development 2,350 1,827 Consulting and professional service fees 265 603 State taxes 5 49 Financing related costs 60 29 Interest 154 16 Other 9 11 Total accrued expenses $ 3,995 $ 5,289 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Income Tax Disclosure [Abstract] | |
Schedule of Components of Net Deferred Tax Assets | Components of the net deferred tax assets at December 31, 2021 and 2022 are as follows (in thousands): 2021 2022 Deferred tax assets: Federal net operating loss carryforwards $ 12,813 $ 17,252 State net operating loss carryforwards 3,630 4,585 Research and development tax credits 3,719 4,214 Accrued liabilities 327 677 Stock-based compensation 1,087 1,329 Depreciation and amortization 247 324 Capitalized research and development costs 29,529 30,976 Lease liabilities 129 146 Other 29 — Total deferred tax assets 51,510 59,503 Deferred tax liabilities: Right-of-use lease assets ( 111 ) ( 144 ) Other — ( 273 ) Total deferred tax liabilities $ ( 111 ) $ ( 417 ) Valuation allowance $ ( 51,399 ) $ ( 59,086 ) Net deferred tax assets $ — $ — |
Schedule of Reconciliation of Income Tax (Expense) Benefit | A reconciliation of income tax (expense) benefit at the statutory federal income tax rate and income taxes as reflected in the consolidated financial statements at December 31, 2021 and 2022 are as follows: 2021 2022 Federal income tax at statutory rate 21.00 % 21.00 % State income tax, net of federal benefit 5.97 % 4.28 % Research and development credits 3.16 % 1.39 % Book compensation related to stock options 0.03 % ( 0.80 )% Change in income tax rate 0.45 % ( 4.93 )% Other ( 0.93 )% ( 0.09 )% Increase in valuation allowance ( 29.68 )% ( 20.87 )% Effective tax rate — % ( 0.02 )% |
Schedule of Reconciliation of Uncertain Tax Benefits | A reconciliation of the beginning and ending amount of uncertain tax benefits is as follows (in thousands): 2021 2022 Beginning uncertain tax benefits $ 774 $ 977 Prior year - increases — — Current year - decreases — — Current year - increases 203 129 Ending uncertain tax benefits $ 977 $ 1,106 |
Fair Value of Financial Instr_2
Fair Value of Financial Instruments (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Fair Value Disclosures [Abstract] | |
Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis | The following tables summarize the Company’s assets and liabilities that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of December 31, 2021 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 72,449 $ 72,449 $ — $ — Total cash equivalents 72,449 72,449 — — Corporate debt securities 1,010 — 1,010 — Investments 1,010 — 1,010 — Total $ 73,459 $ 72,449 $ 1,010 $ — As of December 31, 2022 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 65,875 $ 65,875 $ — $ — Total cash equivalents 65,875 65,875 — — Commercial Paper 16,741 — 16,741 — United States Treasury securities 15,775 15,775 — — United States Government Agency securities 14,609 — 14,609 — Investments 47,125 15,775 31,350 — Total $ 113,000 $ 81,650 $ 31,350 $ — Liabilities: Derivative liability $ 7,517 $ — $ — $ 7,517 Total $ 7,517 $ — $ — $ 7,517 |
Schedule of Changes in Fair Value of Level 3 Derivative Liability | Changes in the fair value of the Company’s Level 3 derivative liability for the year ended December 31, 2022 are as follows: At December 31, 2021 $ — Initial fair value of derivative liability 8,852 Change in fair value of derivative liability ( 1,335 ) At December 31, 2022 $ 7,517 |
Schedule of Quantitative Information about Significant Unobservable Inputs | A summary of quantitative information about significant unobservable inputs (Level 3 inputs) used in measuring the Company's derivative liability that are categorized within Level 3 of the fair value hierarchy is as follows: October 13, December 31, Net sales discount rate 23.3 % 22.3 % Net sales volatility 80.0 % 80.0 % Risk-free rate 4.2 % 4.0 % Recovery rate 80.0 % 80.0 % |
Debt (Tables)
Debt (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Debt Disclosure [Abstract] | |
Schedule of Carrying Value of Debt Balnce | The following table presents the carrying value of the Company's debt balance as of December 31, 2021 and 2022 (in thousands): DECEMBER 31, DECEMBER 31, Face value of term loans $ 17,500 $ 50,000 Unamortized debt discount ( 341 ) ( 13,206 ) Total debt, net $ 17,159 $ 36,794 Less: short-term debt ( 9,805 ) — Long-term debt $ 7,354 $ 36,794 |
Schedule of Future Principal Payments Due | As of December 31, 2022, future principal payments due under the Oaktree Agreement are as follows (in thousands): Year ended: December 31, 2023 $ - December 31, 2024 - December 31, 2025 2,500 December 31, 2026 10,000 December 31, 2027 37,500 Total minimum principal payments $ 50,000 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Share-Based Payment Arrangement [Abstract] | |
Schedule of Estimated Fair Value of Options Valuation Assumptions | The fair value of options at date of grant was estimated using the Black-Scholes option-pricing model with the following assumptions: 2021 2022 Risk-free interest rate 0.50 %— 1.25 % 1.67 %— 4.18 % Expected dividend yield 0 % 0 % Expected life 5.5 — 6.7 years 5.5 — 6.7 years Expected volatility 72 %— 74 % 70 %— 84 % Weighted-average grant date $ 4.18 $ 3.18 |
Summary of Information about Stock Option Activity | The following table summarizes information about stock option activity during 2021 and 2022 (in thousands, except share and per share data): NUMBER OF WEIGHTED- WEIGHTED- AGGREGATE Outstanding, December 31, 2020 2,224,913 $ 6.26 Granted 953,506 6.57 Exercised ( 2,501 ) 3.81 Forfeited ( 513,166 ) 6.72 Outstanding, December 31, 2021 2,662,752 $ 6.28 Granted 1,455,594 4.86 Exercised ( 11,756 ) 3.71 Forfeited ( 98,413 ) 6.73 Outstanding, December 31, 2022 4,008,177 $ 5.76 7.47 $ 7,147 Vested and exercisable, December 31, 2022 1,982,329 $ 6.15 6.01 $ 3,436 Vested and expected to vest, December 31, 2022 3,489,134 $ 5.81 7.25 $ 6,226 |
Schedule of RSU Activity | The following table summarizes information about RSU activity during 2021 and 2022: RSUs AVERAGE GRANT DATE FAIR VALUE (IN DOLLARS PER SHARE) RSUs outstanding, December 31, 2020 80,450 $ 3.25 Granted — — Vested ( 38,200 ) 3.25 Forfeited — — RSUs outstanding, December 31, 2021 42,250 3.25 Granted — — Vested ( 42,250 ) 3.25 Forfeited — — RSUs outstanding, December 31, 2022 — $ — |
Summary of Stock-Based Compensation Expense | The Company recorded stock-based compensation expense in the following expense categories of its accompanying condensed consolidated statements of operations and comprehensive loss for employees, directors and non-employees during the years ended December 31, 2021 and 2022 as follows (in thousands): 2021 2022 Research and development $ 947 $ 1,050 General and administrative 1,419 1,788 Total $ 2,366 $ 2,838 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2022 | |
Commitments and Contingencies Disclosure [Abstract] | |
Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating Lease Liabilities | The following is a maturity analysis of the annual undiscounted cash flows reconciled to the carrying value of the operating lease liabilities as of December 31, 2022 (in thousands): Year ended: December 31, 2023 $ 596 December 31, 2024 9 December 31, 2025 1 Total minimum lease payments 606 Less imputed interest ( 32 ) Total $ 574 |
Schedule of Lease Cost and Other Information of Operating Lease Liabilities | 2021 2022 Lease cost: Operating lease cost $ 482 $ 505 Short-term lease cost 20 37 Sublease income ( 51 ) ( 47 ) Total lease cost $ 451 $ 495 Other information Cash paid for amounts included in the $ 530 $ 551 Operating cash flows from operating leases $ ( 60 ) $ ( 57 ) Weighted-average remaining lease term - 0.9 years 0.9 years Weighted-average discount rate - 10.1 % 10.1 % |
Description of Business and B_2
Description of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands | 1 Months Ended | 12 Months Ended | |
Nov. 30, 2022 | Dec. 31, 2022 | Dec. 31, 2021 | |
Description Of Business And Basis Of Presentation [Line Items] | |||
Cash, cash equivalents, restricted cash and investments | $ 118,400 | ||
Working capital | 115,900 | ||
Net loss | 36,838 | $ 28,034 | |
Net cash flows used in operating activities | 34,577 | $ 27,151 | |
Common Stock | Maximum | Cowen | |||
Description Of Business And Basis Of Presentation [Line Items] | |||
Aggregate offering price | $ 48,900 | ||
Follow On Offering | Common Stock | |||
Description Of Business And Basis Of Presentation [Line Items] | |||
Proceeds from sale of shares, Net | $ 46,600 |
Significant Accounting Polici_4
Significant Accounting Policies - Additional Information (Details) | 12 Months Ended | |
Dec. 31, 2022 USD ($) Segment | Dec. 31, 2021 USD ($) | |
Schedule Of Accounting Policies [Line Items] | ||
Restricted cash, current | $ 182,000 | $ 182,000 |
Potential interest and penalties associated with uncertain tax positions, accruals | $ 0 | 0 |
Number of operating segments | Segment | 1 | |
Letter of Credit | ||
Schedule Of Accounting Policies [Line Items] | ||
Restricted cash, current | $ 182,000 | $ 182,000 |
Significant Accounting Polici_5
Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 |
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract] | |||
Cash and cash equivalents | $ 71,061 | $ 74,268 | |
Restricted cash | 182 | 182 | |
Cash, cash equivalents and restricted cash | $ 71,243 | $ 74,450 | $ 72,001 |
Net Loss per Share - Additional
Net Loss per Share - Additional Information (Details) | Dec. 31, 2022 $ / shares |
Earnings Per Share [Abstract] | |
Exercise price per share | $ 0.001 |
Net Loss per Share - Computatio
Net Loss per Share - Computation of Basic and Diluted Net Loss Per Share of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Earnings Per Share [Abstract] | ||
Net loss | $ (36,838) | $ (28,034) |
Weighted Average Number of Shares Outstanding, Basic | 28,358,502 | 27,351,730 |
Weighted Average Number of Shares Outstanding, Diluted | 28,358,502 | 27,351,730 |
Net loss per share, basic | $ (1.30) | $ (1.02) |
Net loss per share, diluted | $ (1.30) | $ (1.02) |
Net Loss per Share - Schedule o
Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share (Details) - shares | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from calculation of diluted net loss per share | 4,524,522 | 2,705,002 |
Stock Options to Purchase Common Stock | ||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from calculation of diluted net loss per share | 4,008,177 | 2,662,752 |
Warrants to purchase common stock | ||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from calculation of diluted net loss per share | 516,345 | |
Unvested Restricted Stock | ||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from calculation of diluted net loss per share | 42,250 |
Investments - Summary of Availa
Investments - Summary of Available-for-Sale Classified Investments (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Marketable Securities [Line Items] | ||
Cost Basis | $ 47,093 | $ 1,011 |
Accumulated Unrealized Gains | 32 | |
Accumulated Unrealized Losses | (1) | |
Fair Value | 47,125 | 1,010 |
Commercial Paper | ||
Marketable Securities [Line Items] | ||
Cost Basis | 16,741 | |
Fair Value | 16,741 | |
Corporate Debt Securities | ||
Marketable Securities [Line Items] | ||
Cost Basis | 1,011 | |
Accumulated Unrealized Losses | (1) | |
Fair Value | $ 1,010 | |
United States Treasury securities | ||
Marketable Securities [Line Items] | ||
Cost Basis | 15,768 | |
Accumulated Unrealized Gains | 7 | |
Fair Value | 15,775 | |
United States Government Agency securitites | ||
Marketable Securities [Line Items] | ||
Cost Basis | 14,584 | |
Accumulated Unrealized Gains | 25 | |
Fair Value | $ 14,609 |
Investments - Summary of Amorti
Investments - Summary of Amortized Cost and Fair Value of Available-for-Sale Investments by Contract Maturity (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Investments, Debt and Equity Securities [Abstract] | ||
Amortized Cost, Due in one year or less | $ 47,093 | |
Amortized Cost, Total | 47,093 | $ 1,011 |
Fair value, Due in one year or less | 47,125 | |
Fair Value, Total | $ 47,125 | $ 1,010 |
Inventory - Schedule of Invento
Inventory - Schedule of Inventory (Details) $ in Thousands | Dec. 31, 2022 USD ($) |
Inventory Disclosure [Abstract] | |
Raw materials | $ 1,201 |
Work-in-process | 29 |
Inventory, Net, Total | $ 1,230 |
Property and Equipment - Schedu
Property and Equipment - Schedule of Purchased Property and Equipment (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 242 | $ 239 |
Less: Accumulated depreciation | (188) | (170) |
Property and equipment, net | $ 54 | 69 |
Office Equipment | ||
Property Plant And Equipment [Line Items] | ||
ESTIMATED USEFUL LIFE | 5 years | |
Property and equipment, gross | $ 6 | 10 |
Office Furniture | ||
Property Plant And Equipment [Line Items] | ||
ESTIMATED USEFUL LIFE | 7 years | |
Property and equipment, gross | $ 126 | 126 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
ESTIMATED USEFUL LIFE | 3 years | |
Property and equipment, gross | $ 15 | 8 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
ESTIMATED USEFUL LIFE | Life of lease | |
Property and equipment, gross | $ 95 | $ 95 |
Property and Equipment - Additi
Property and Equipment - Additional Information (Details) - USD ($) | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Property, Plant and Equipment [Abstract] | ||
Depreciation expense | $ 37,000 | $ 34,000 |
Accrued Expenses - Schedule of
Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Accrued Liabilities, Current [Abstract] | ||
Employee compensation and related costs | $ 2,754 | $ 1,152 |
Contract research and development | 1,827 | 2,350 |
Consulting and professional service fees | 603 | 265 |
State taxes | 49 | 5 |
Financing related costs | 29 | 60 |
Interest | 16 | 154 |
Other | 11 | 9 |
Total accrued expenses | $ 5,289 | $ 3,995 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Details) - USD ($) | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Income Taxes [Line Items] | ||
Net income tax provision or benefit | $ 0 | $ 0 |
Federal net operating loss carryforwards expiration year | 2037 | |
State net operating loss carryforwards expiration year | 2042 | |
Increase in valuation allowance | $ 7,700,000 | |
Research and development credit carryforwards | $ 4,214,000 | $ 3,719,000 |
Federal and state research and development credit carryforwards expiration year | 2042 | |
Federal | ||
Income Taxes [Line Items] | ||
Net operating loss carryforwards | $ 64,600,000 | |
Research and development credit carryforwards | 4,300,000 | |
Federal | 2037 | ||
Income Taxes [Line Items] | ||
Net operating loss carryforwards | 17,500,000 | |
State | ||
Income Taxes [Line Items] | ||
Net operating loss carryforwards | 300,000 | |
Research and development credit carryforwards | 1,000,000 | |
State | 2041 | ||
Income Taxes [Line Items] | ||
Net operating loss carryforwards | $ 72,600,000 |
Income Taxes - Schedule of Comp
Income Taxes - Schedule of Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Deferred tax assets: | ||
Federal net operating loss carryforwards | $ 17,252 | $ 12,813 |
State net operating loss carryforwards | 4,585 | 3,630 |
Research and development tax credits | 4,214 | 3,719 |
Accrued liabilities | 677 | 327 |
Stock-based compensation | 1,329 | 1,087 |
Depreciation and amortization | 324 | 247 |
Capitalized research and development costs | 30,976 | 29,529 |
Lease liabilities | 146 | 129 |
Other | 29 | |
Total deferred tax assets | 59,503 | 51,510 |
Deferred tax liabilities: | ||
Right-of-use lease assets | (144) | (111) |
Other | (273) | |
Total deferred tax liabilities | (417) | (111) |
Valuation allowance | (59,086) | (51,399) |
Net deferred tax assets | $ 0 | $ 0 |
Income Taxes - Schedule of Reco
Income Taxes - Schedule of Reconciliation of Income Tax (Expense) Benefit (Details) | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | ||
Federal income tax at statutory rate | 21% | 21% |
State income tax, net of federal benefit | 4.28% | 5.97% |
Research and development credits | 1.39% | 3.16% |
Book compensation related to stock options | (0.80%) | 0.03% |
Change in income tax rate | (4.93%) | 0.45% |
Other | (0.09%) | (0.93%) |
Increase in valuation allowance | (20.87%) | (29.68%) |
Effective tax rate | (0.02%) | 0% |
Income Taxes - Schedule of Re_2
Income Taxes - Schedule of Reconciliation of Uncertain Tax Benefits (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | ||
Beginning uncertain tax benefits | $ 977 | $ 774 |
Prior year - increases | 0 | 0 |
Current year - decreases | 0 | 0 |
Current year - increases | 129 | 203 |
Ending uncertain tax benefits | $ 1,106 | $ 977 |
Fair Value of Financial Instr_3
Fair Value of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Liabilities: | ||
Derivative liability | $ 7,517 | |
Fair Value, Measurements, Recurring | ||
Assets: | ||
Cash equivalents | 65,875 | $ 72,449 |
Investments | 47,125 | 1,010 |
Total | 113,000 | 73,459 |
Liabilities: | ||
Derivative liability | 7,517 | |
Total | 7,517 | |
Fair Value, Measurements, Recurring | Corporate Debt Securities | ||
Assets: | ||
Investments | 1,010 | |
Fair Value, Measurements, Recurring | Commercial Paper | ||
Assets: | ||
Investments | 16,741 | |
Fair Value, Measurements, Recurring | United States Treasury securities | ||
Assets: | ||
Investments | 15,775 | |
Fair Value, Measurements, Recurring | United States Government Agency securitites | ||
Assets: | ||
Investments | 14,609 | |
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) [Member] | ||
Assets: | ||
Cash equivalents | 65,875 | 72,449 |
Investments | 15,775 | |
Total | 81,650 | 72,449 |
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) [Member] | United States Treasury securities | ||
Assets: | ||
Investments | 15,775 | |
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member] | ||
Assets: | ||
Investments | 31,350 | 1,010 |
Total | 31,350 | 1,010 |
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt Securities | ||
Assets: | ||
Investments | $ 1,010 | |
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper | ||
Assets: | ||
Investments | 16,741 | |
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member] | United States Government Agency securitites | ||
Assets: | ||
Investments | 14,609 | |
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) [Member] | ||
Liabilities: | ||
Derivative liability | 7,517 | |
Total | $ 7,517 |
Fair Value of Financial Instr_4
Fair Value of Financial Instruments - Schedule of Changes in Fair Value of Level 3 Derivative Liability (Details) - Significant Unobservable Inputs (Level 3) [Member] $ in Thousands | 12 Months Ended |
Dec. 31, 2022 USD ($) | |
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | |
Initial fair value of derivative liability | $ 8,852 |
Change in fair value of derivative liability | $ (1,335) |
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Income (Expense) |
Ending balance | $ 7,517 |
Fair Value of Financial Instr_5
Fair Value of Financial Instruments - Schedule of Quantitative Information about Significant Unobservable Inputs (Details) - Level 3 | Dec. 31, 2022 | Oct. 13, 2022 |
Net Sales Discount Rate | ||
Fair Value Measurement Inputs and Valuation Techniques [Line Items] | ||
Measurement input | 0.223 | 0.233 |
Net Sales Volatility | ||
Fair Value Measurement Inputs and Valuation Techniques [Line Items] | ||
Measurement input | 0.800 | 0.800 |
Risk-free Rate | ||
Fair Value Measurement Inputs and Valuation Techniques [Line Items] | ||
Measurement input | 0.040 | 0.042 |
Recovery Rate | ||
Fair Value Measurement Inputs and Valuation Techniques [Line Items] | ||
Measurement input | 0.800 | 0.800 |
Debt - Schedule of Carrying Val
Debt - Schedule of Carrying Value of Debt Balance (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 |
Debt Disclosure [Abstract] | ||
Face value of term loans | $ 50,000 | $ 17,500 |
Unamortized debt discount | (13,206) | (341) |
Total debt, net | 36,794 | 17,159 |
Less: short-term debt | (9,805) | |
Long-term debt | $ 36,794 | $ 7,354 |
Debt - Additional Information (
Debt - Additional Information (Details) - USD ($) | 1 Months Ended | 12 Months Ended | |||
Oct. 13, 2022 | Sep. 30, 2019 | May 31, 2017 | Dec. 31, 2022 | Dec. 31, 2021 | |
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | $ 50,000,000 | $ 17,500,000 | |||
Proceeds from term loan | $ 47,301,000 | ||||
Exercise price per share | $ 0.001 | ||||
Fair market value per share of common stock | $ 3.18 | $ 4.18 | |||
Unamortized debt discount | $ (13,206,000) | $ (341,000) | |||
Fair value adjustment to derivative liability | $ (1,335,000) | ||||
Minimum | |||||
Debt Instrument [Line Items] | |||||
Expected life | 5 years 6 months | 5 years 6 months | |||
Maximum | |||||
Debt Instrument [Line Items] | |||||
Expected life | 6 years 8 months 12 days | 6 years 8 months 12 days | |||
SLR Investment Corp. and Silicon Valley Bank | 2017 Loan Agreement | |||||
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | $ 10,000,000 | ||||
Loan agreement, maturity date | May 01, 2021 | ||||
Payment of final fee | $ 325,000 | ||||
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | |||||
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | $ 20,000,000 | $ 50,000,000 | |||
Loan agreement, maturity date | Sep. 17, 2023 | ||||
Amortization of debt discount | 341,000 | $ 392,000 | |||
Final payment fee | 500,000 | ||||
Amortization of final payment fee | $ 132,000 | $ 162,000 | |||
Loan agreement, term | 4 years | ||||
Debt instrument, interest rate terms | The interest rate under the 2019 Loan Agreement was the higher of (i) LIBOR plus 7.95% or (ii) 10.18% | ||||
Debt instrument, effective interest rate | 10.18% | ||||
Exit fee, percentage | 4% | ||||
Exit fee | $ 800,000 | ||||
Derivative liability recorded against exit fee obligation | 763,000 | ||||
Fair value adjustment to derivative liability | $ 30,000 | ||||
Prepayment premium percentage after year two | 0.50% | ||||
Long term debt prepayment premium amount | $ 46,000 | ||||
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | Minimum | |||||
Debt Instrument [Line Items] | |||||
Interest rate, minimum | 10.18% | ||||
Prepayment premium percentage two | 0.01 | ||||
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | Maximum | |||||
Debt Instrument [Line Items] | |||||
Prepayment premium percentage one | 0.03 | ||||
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | Libor | |||||
Debt Instrument [Line Items] | |||||
Basis spread on variable base rate | 7.95% | ||||
Oaktree Agreement [Member] | |||||
Debt Instrument [Line Items] | |||||
Loan agreement, maturity date | Oct. 13, 2027 | ||||
Basis spread on variable base rate | 8.25% | ||||
Proceeds from (Repayments of) Debt, Total | $ 9,800,000 | ||||
Payment of financing and stock issuance costs | 2,700 | ||||
Long term additional debt discount exit fee | $ 1,000,000 | ||||
Embedded derivative liability upon issuance of Term Loan | 8,900,000 | ||||
Fair value of embedded derivative liability | 7,500,000 | ||||
Amortization of debt discount | 383,000 | ||||
Unamortized debt discount | $ (13,600,000) | ||||
Exit fee | $ 28,000,000 | ||||
Prepayment premium percentage one | 0.020 | ||||
Increase in interest rate on default | 2% | ||||
Oaktree Agreement [Member] | Minimum | |||||
Debt Instrument [Line Items] | |||||
Trailing of net sales | $ 100,000,000 | ||||
Oaktree Agreement [Member] | Maximum | |||||
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | $ 100,000,000 | ||||
Oaktree Agreement [Member] | Warrants | |||||
Debt Instrument [Line Items] | |||||
Exercise price per share | $ 5.40 | ||||
Relative fair value of detachable warrants | $ 2,000,000 | ||||
Risk-free rate | 4.11% | ||||
Expected life | 7 years | ||||
Fair market value per share of common stock | $ 5.50 | ||||
Exercise price per warrant | $ 5.40 | ||||
Expected volatility | 77% | ||||
Oaktree Agreement [Member] | Warrants | Maximum | |||||
Debt Instrument [Line Items] | |||||
Purchase shares of common stock | 516,345 | ||||
Oaktree Agreement [Member] | SOFR | |||||
Debt Instrument [Line Items] | |||||
Basis spread on variable base rate | 8.75% | ||||
Oaktree Agreement [Member] | SOFR | Interest Rate Floor [Member] | |||||
Debt Instrument [Line Items] | |||||
Basis spread on variable base rate | 1% | ||||
Oaktree Agreement [Member] | SOFR | Interest Rate Cap [Member] | |||||
Debt Instrument [Line Items] | |||||
Basis spread on variable base rate | 3% | ||||
Oaktree Agreement [Member] | Borrowings One [Member] | |||||
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | $ 50,000,000 | ||||
Proceeds from term loan | 37,500,000 | ||||
Unrestricted cash | 15,000,000 | ||||
Oaktree Agreement [Member] | Borrowings Two [Member] | |||||
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | 50,000,000 | ||||
Unrestricted cash | 20,000,000 | ||||
Oaktree Agreement [Member] | Borrowings Three [Member] | |||||
Debt Instrument [Line Items] | |||||
Loan and security agreement, amount | $ 50,000,000 |
Debt - Schedule of Future Princ
Debt - Schedule of Future Principal Payments Due (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 | Sep. 30, 2019 |
Debt Instrument [Line Items] | |||
Total minimum principal payments | $ 50,000 | $ 17,500 | |
2019 Loan Agreement | SLR Investment Corp. and Silicon Valley Bank | |||
Debt Instrument [Line Items] | |||
December 31, 2025 | 2,500 | ||
December 31, 2026 | 10,000 | ||
December 31, 2027 | 37,500 | ||
Total minimum principal payments | $ 50,000 | $ 20,000 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||
Jan. 01, 2023 | Mar. 23, 2021 | Nov. 30, 2022 | Mar. 22, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
Stockholders Equity Note [Line Items] | |||||||
Common stock, shares authorized | 150,000,000 | 150,000,000 | |||||
Common stock, par value | $ 0.0001 | $ 0.0001 | |||||
Common stock, shares issued | 34,257,916 | 27,366,707 | |||||
Common stock, shares outstanding | 34,257,916 | 27,366,707 | |||||
Reserved shares of common stock for exercise of outstanding options to purchase common stock | 4,008,177 | 2,662,752 | 2,224,913 | ||||
Preferred stock, shares authorized | 10,000,000 | 10,000,000 | |||||
Preferred stock, par value | $ 0.0001 | $ 0.0001 | |||||
Preferred stock, shares issued | 0 | 0 | |||||
Preferred stock, shares outstanding | 0 | 0 | |||||
prefunded warrant purchase price | $ 0.001 | ||||||
Cowen | Common Stock | Maximum | |||||||
Stockholders Equity Note [Line Items] | |||||||
Aggregate offering price | $ 48,900,000 | ||||||
2021 ATM Agreement | |||||||
Stockholders Equity Note [Line Items] | |||||||
Number of shares sold | 1,511,157 | ||||||
Selling price per share | $ 9.30 | ||||||
Proceeds from sale of shares, Net | $ 13,700,000 | ||||||
2021 ATM Agreement | Legal Accounting and Other Costs | |||||||
Stockholders Equity Note [Line Items] | |||||||
Stock issuance cost | $ 273,000 | ||||||
2021 ATM Agreement | Additional Paid-in Capital | Legal Accounting and Other Costs | |||||||
Stockholders Equity Note [Line Items] | |||||||
Stock issuance cost | $ 6,000 | ||||||
2021 ATM Agreement | Cowen | Common Stock | |||||||
Stockholders Equity Note [Line Items] | |||||||
Number of shares sold | 181,553 | ||||||
Proceeds from sale of shares, Net | $ 1,100,000 | ||||||
2021 ATM Agreement | Cowen | Common Stock | Weighted Average | |||||||
Stockholders Equity Note [Line Items] | |||||||
Selling price per share | $ 6.33 | ||||||
2021 ATM Agreement | Cowen | Common Stock | Maximum | |||||||
Stockholders Equity Note [Line Items] | |||||||
Aggregate offering price | $ 50,000,000 | ||||||
Percentage of commission on gross sales proceeds | 3% | ||||||
Underwritten Public Offering | Common Stock | |||||||
Stockholders Equity Note [Line Items] | |||||||
Number of shares sold | 6,620,000 | ||||||
Selling price per share | $ 5.25 | ||||||
Proceeds from sale of shares, Net | $ 46,600,000 | ||||||
prefunded warrant purchase price | $ 5.249 | ||||||
Underwritten Public Offering | Common Stock | Maximum | |||||||
Stockholders Equity Note [Line Items] | |||||||
prefunded warrant shares | 2,905,000 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Additional options granted | 1,455,594 | 953,506 | |
Stock option, number of shares outstanding | 4,008,177 | 2,662,752 | 2,224,913 |
Cash received upon exercise of stock options | $ 44,000 | $ 9,000 | |
Intrinsic value of options exercised | 18,000 | $ 7,000 | |
Unrecognized compensation expense | $ 4,200,000 | ||
Recognition period (in years) | 2 years 6 months | ||
2017 Stock Plan | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Stock option and incentive plan effective date | Nov. 30, 2017 | ||
Stock option and incentive plan expiration date | Oct. 31, 2027 | ||
Stock option, number of shares outstanding | 3,409,766 | ||
Number of common stock initially reserved for issuance | 6,105,147 | ||
Stock options, available for issuance | 2,655,289 | ||
Term of option granted | 10 years | ||
2017 Stock Plan | Minimum | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Stock option vesting term | 1 year | ||
2017 Stock Plan | Maximum | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Stock option vesting term | 4 years | ||
2014 Stock Plan | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Stock option and incentive plan expiration date | Nov. 30, 2017 | ||
Additional options granted | 0 | ||
Stock option, number of shares outstanding | 598,411 | ||
Number of options forfeited | 359,860 | ||
2017 Employee Stock Purchase Plan | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Number of common stock shares issued | 45,938 | 11,253 | |
Number of common stock shares available for issuance | 1,142,691 |
Stock-Based Compensation - Sche
Stock-Based Compensation - Schedule of Estimated Fair Value of Options Valuation Assumptions (Details) - $ / shares | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Risk-free interest rate, minimum | 1.67% | 0.50% |
Risk-free interest rate, maximum | 4.18% | 1.25% |
Expected dividend yield | 0% | 0% |
Expected volatility, minimum | 70% | 72% |
Expected volatility, maximum | 84% | 74% |
Weighted-average grant date fair value | $ 3.18 | $ 4.18 |
Minimum | ||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Expected life | 5 years 6 months | 5 years 6 months |
Maximum | ||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Expected life | 6 years 8 months 12 days | 6 years 8 months 12 days |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Information about Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
NUMBER OF SHARES | ||
Number of shares outstanding, beginning balance | 2,662,752 | 2,224,913 |
Number of shares granted | 1,455,594 | 953,506 |
Number of shares exercised | (11,756) | (2,501) |
Number of shares forfeited | (98,413) | (513,166) |
Number of shares outstanding, ending balance | 4,008,177 | 2,662,752 |
Vested and exercisable, ending balance | 1,982,329 | |
Vested and expected to vest, ending balance | 3,489,134 | |
WEIGHTED-AVERAGE EXERCISE PRICE | ||
Weighted average exercise prices, outstanding beginning balance | $ 6.28 | $ 6.26 |
Weighted average exercise prices, granted | 4.86 | 6.57 |
Weighted average exercise prices, exercised | 3.71 | 3.81 |
Weighted average exercise prices, forfeited | 6.73 | 6.72 |
Weighted average exercise prices, outstanding ending balance | 5.76 | $ 6.28 |
Weighted average exercise prices, vested and exercisable ending balance | 6.15 | |
Weighted average exercise prices, vested and expected to vest ending balance | $ 5.81 | |
WEIGHTED-AVERAGE REMAINING CONTRACTUAL TERM | ||
Weighted average remaining contractual term, outstanding | 7 years 5 months 19 days | |
Weighted average remaining contractual term, vested and exercisable | 6 years 3 days | |
Weighted average remaining contractual term, vested and expected to vest | 7 years 3 months | |
AGGREGATE INTRINSIC VALUE | ||
Aggregate intrinsic value, outstanding ending balance | $ 7,147 | |
Aggregate intrinsic value, vested and exercisable ending balance | 3,436 | |
Aggregate intrinsic value, vested and expected to vest ending balance | $ 6,226 |
Stock-Based Compensation - Sc_2
Stock-Based Compensation - Schedule of RSU Activity (Details) - Restricted Stock Units (RSUs) - $ / shares | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
RSUs outstanding | 42,250 | 80,450 |
RSUs Granted | 0 | 0 |
RSUs Vested | (42,250) | (38,200) |
RSUs Forfeited | 0 | 0 |
RSUs outstanding | 0 | 42,250 |
AVERAGE GRANT DATE FAIR VALUE, Outstanding | $ 3.25 | $ 3.25 |
AVERAGE GRANT DATE FAIR VALUE, Granted | 0 | 0 |
AVERAGE GRANT DATE FAIR VALUE, Vested | 3.25 | 3.25 |
AVERAGE GRANT DATE FAIR VALUE, Forfeited | 0 | 0 |
AVERAGE GRANT DATE FAIR VALUE, RSUs outstanding | $ 0 | $ 3.25 |
Stock-Based Compensation - Su_2
Stock-Based Compensation - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||
Total stock-based compensation expense | $ 2,838 | $ 2,366 |
Research and Development | ||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||
Total stock-based compensation expense | 1,050 | 947 |
General and Administrative | ||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | ||
Total stock-based compensation expense | $ 1,788 | $ 1,419 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Details) - USD ($) | 1 Months Ended | 12 Months Ended | |
Jul. 30, 2021 | Dec. 31, 2022 | Dec. 31, 2021 | |
Commitments And Contingencies [Line Items] | |||
Operating leases rent expense | $ 500,000 | $ 500,000 | |
Restricted cash | 182,000 | 182,000 | |
Short-term lease asset | 566,000 | 410,000 | |
Short-term lease liability | 567,000 | 476,000 | |
Operating sublease term | 12 months | ||
Short-term Leases Recognized on Straight-line Basis | |||
Commitments And Contingencies [Line Items] | |||
Short-term lease asset | 0 | ||
Short-term lease liability | 0 | ||
Letter of Credit | |||
Commitments And Contingencies [Line Items] | |||
Restricted cash | $ 182,000 | $ 182,000 | |
Lexington, Massachusetts | |||
Commitments And Contingencies [Line Items] | |||
Operating leases expiration date | Dec. 31, 2022 | ||
Burlington, Massachusetts | |||
Commitments And Contingencies [Line Items] | |||
Operating leases expiration date | Nov. 30, 2023 | ||
Burlington, Massachusetts | Letter of Credit | Lease Agreement Require Standby Letter of Credit | |||
Commitments And Contingencies [Line Items] | |||
Restricted cash | $ 182,000 |
Commitments and Contingencies_2
Commitments and Contingencies - Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating Lease Liabilities (Details) $ in Thousands | Dec. 31, 2022 USD ($) |
Year ended: | |
December 31, 2023 | $ 596 |
December 31, 2024 | 9 |
December 31, 2025 | 1 |
Total minimum lease payments | 606 |
Less imputed interest | (32) |
Total | $ 574 |
Commitments and Contingencies_3
Commitments and Contingencies - Schedule of Lease Cost and Other Information of Operating Lease Liabilities (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2022 | Dec. 31, 2021 | |
Lease cost: | ||
Operating lease cost | $ 505 | $ 482 |
Short-term lease cost | 37 | 20 |
Sublease income | (47) | (51) |
Total lease cost | 495 | 451 |
Other information | ||
Cash paid for amounts included in the measurement of liabilities | 551 | 530 |
Operating cash flows from operating leases | $ (57) | $ (60) |
Weighted-average remaining lease term - operating leases | 10 months 24 days | 10 months 24 days |
Weighted-average discount rate - operating leases | 10.10% | 10.10% |
401(k) Savings Plan - Additiona
401(k) Savings Plan - Additional Information (Details) - USD ($) | 12 Months Ended | |||
Jul. 31, 2014 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
Defined Contribution Plan Disclosure [Line Items] | ||||
Defined Contribution Plan, Tax Status [Extensible List] | us-gaap:QualifiedPlanMember | us-gaap:QualifiedPlanMember | us-gaap:QualifiedPlanMember | |
Compensation expense for employer match contribution | $ 340,000 | $ 198,000 | ||
First 3% of Deferred Compensation | ||||
Defined Contribution Plan Disclosure [Line Items] | ||||
Employer matching contribution percentage | 100% | |||
Employer matching contribution percentage of employees contributions of deferred compensation | 3% | |||
Defined Contribution Plan, Tax Status [Extensible List] | us-gaap:QualifiedPlanMember | |||
Next 2% of Deferred Compensation | ||||
Defined Contribution Plan Disclosure [Line Items] | ||||
Employer matching contribution percentage | 50% | |||
Employer matching contribution percentage of employees contributions of deferred compensation | 2% | |||
Defined Contribution Plan, Tax Status [Extensible List] | us-gaap:QualifiedPlanMember |
Subsequent Events (Additional I
Subsequent Events (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | ||
Feb. 01, 2023 | Jan. 01, 2023 | Mar. 22, 2023 | |
Subsequent Event [Line Items] | |||
Equity awards granted under the inducement , Granted | 500,000 | ||
2021 ATM Agreement | |||
Subsequent Event [Line Items] | |||
Number of shares sold | 1,511,157 | ||
Selling price per share | $ 9.30 | ||
Proceeds from sale of shares, Net | $ 13.7 |