Lumos Pharma (LUMO) 10-K 7 Mar 23 2022 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Mar. 03, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-35342
Entity Registrant Name	LUMOS PHARMA, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	42-1491350
Entity Address, Address Line One	4200 Marathon Blvd #200
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78756
City Area Code	512
Local Phone Number	215-2630
Title of 12(b) Security	Common Stock
Trading Symbol	LUMO
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
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 Public Float			$ 46.4
Entity Common Stock, Shares Outstanding (in shares)		8,219,292
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for its 2023 Annual Meeting of Shareholders, to be held on May 10, 2023, which will be filed within 120 days of December 31, 2022, are incorporated by reference into Part III of this Annual Report on Form 10-K .
Entity Central Index Key	0001126234
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Audit Information [Abstract]
Auditor Name	KPMG LLP
Auditor Location	Austin, TX
Auditor Firm ID	185

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 56,007,000	$ 94,809,000
Short-term investments	11,352,000	0
Prepaid expenses and other current assets	4,427,000	4,740,000
Other receivables	223,000	128,000
Total current assets	72,009,000	99,677,000
Non-current assets:
Property and equipment, net	53,000	79,000
Right-of-use asset	230,000	556,000
Total non-current assets	283,000	635,000
Total assets	72,292,000	100,312,000
Current liabilities:
Accounts payable	275,000	612,000
Accrued expenses	6,200,000	4,166,000
Current portion of lease liability	233,000	352,000
Total current liabilities	6,708,000	5,130,000
Long-term liabilities:
Royalty obligation payable to Iowa Economic Development Authority	6,000,000	6,000,000
Lease liability	0	205,000
Total long-term liabilities	6,000,000	6,205,000
Total liabilities	12,708,000	11,335,000
Commitments and contingencies
Stockholders' equity:
Undesignated preferred stock, $0.01 par value: Authorized shares - 5,000,000 at December 31, 2022 and 2021; issued and outstanding shares - 0 at December 31, 2022 and 2021	0	0
Common stock, $0.01 par value: Authorized shares - 75,000,000 at December 31, 2022 and 2021; issued shares - 8,283,708 and 8,366,819 at December 31, 2022 and 2021, respectively, and outstanding shares - 8,267,968 and 8,357,391 at December 31, 2022 and 2021, respectively	82,000	83,000
Treasury stock, at cost, 15,740 and 9,428 shares held as of December 31, 2022 and 2021, respectively	(170,000)	(114,000)
Additional paid-in capital	187,164,000	185,429,000
Accumulated deficit	(127,483,000)	(96,421,000)
Accumulated other comprehensive loss	(9,000)	0
Total stockholders’ equity	59,584,000	88,977,000
Total liabilities and stockholders’ equity	$ 72,292,000	$ 100,312,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Blank check preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Blank check preferred stock, authorized shares (in shares)	5,000,000	5,000,000
Blank check preferred stock, issued shares (in shares)	0	0
Blank check preferred stock, outstanding shares (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	75,000,000	75,000,000
Common stock, issued shares (in shares)	8,283,708	8,366,819
Common stock, outstanding shares (in shares)	8,267,968	8,357,391
Treasury stock, shares (in shares)	15,740	9,428

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Total revenues	$ 1,523	$ 230
Operating expenses:
Research and development	17,857	16,246
General and administrative	15,706	15,331
Total operating expenses	33,563	31,577
Loss from operations	(32,040)	(31,347)
Other income and expense:
Other income, net	91	269
Interest income	874	12
Other income, net	965	281
Net loss before taxes	(31,075)	(31,066)
Income tax benefit	13	636
Net loss	$ (31,062)	$ (30,430)
Net loss per share:
Basic (in dollars per share)	$ (3.71)	$ (3.65)
Diluted (in dollars per share)	$ (3.71)	$ (3.65)
Weighted average number of common shares outstanding
Basic (in shares)	8,373,821	8,334,516
Diluted (in shares)	8,373,821	8,334,516
Other comprehensive loss:
Unrealized loss on short-term investments	$ (9)	$ 0
Total comprehensive loss	(31,071)	(30,430)
Licensing and collaboration revenue
Revenues	0	10
Royalty revenue
Revenues	$ 1,523	$ 220

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Common Stock, balance at beginning of period (shares) at Dec. 31, 2020		8,305,269
Treasury Stock, balance at beginning of period (in shares) at Dec. 31, 2020			0
Balance at beginning of period at Dec. 31, 2020	$ 116,572	$ 83	$ 0	$ 182,480	$ (65,991)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	2,879			2,879
Exercise of stock options (in shares)		26,922
Exercise of stock options	64			64
Stock issued upon vesting of restricted stock units (in shares)		33,933
Stock issued upon vesting of restricted stock units	0
Shares surrendered for tax withholding on vested awards (in shares)		(9,428)	(9,428)
Shares surrendered for tax withholding on vested awards	(114)		$ (114)
Sales of shares under stock purchase plan (in shares)		695
Sales of shares under stock purchase plan	6			6
Net loss	$ (30,430)				(30,430)
Common Stock, balance at end of period (shares) at Dec. 31, 2021	8,357,391	8,357,391
Treasury Stock, balance at end of period (in shares) at Dec. 31, 2021	9,428		9,428
Balance at end of period at Dec. 31, 2021	$ 88,977	$ 83	$ (114)	185,429	(96,421)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	2,320			2,320
Exercise of stock options (in shares)		17,288
Exercise of stock options	40			40
Stock issued upon vesting of restricted stock units (in shares)		25,771
Stock issued upon vesting of restricted stock units	0
Shares surrendered for tax withholding on vested awards (in shares)		(6,312)	(6,312)
Shares surrendered for tax withholding on vested awards	(56)		$ (56)
Sales of shares under stock purchase plan (in shares)		11,356
Sales of shares under stock purchase plan	49			49
Repurchases of common stock (in shares)		(137,526)
Repurchases of common stock	(675)	$ (1)		(674)
Other comprehensive loss	(9)					(9)
Net loss	$ (31,062)				(31,062)
Common Stock, balance at end of period (shares) at Dec. 31, 2022	8,267,968	8,267,968
Treasury Stock, balance at end of period (in shares) at Dec. 31, 2022	15,740		15,740
Balance at end of period at Dec. 31, 2022	$ 59,584	$ 82	$ (170)	$ 187,164	$ (127,483)	$ (9)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash Flows From Operating Activities
Net loss	$ (31,062)	$ (30,430)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	2,320	2,879
Depreciation and amortization	49	217
Other income, net	(26)	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	492	(1,086)
Other receivables	(92)	136
Accounts payable and accrued expenses	1,696	(1,364)
Net cash used in operating activities	(26,623)	(29,648)
Cash Flows From Investing Activities
Final installment from sale of priority review voucher	0	26,000
Purchases of marketable securities	(11,337)	0
Purchase of equipment	(21)	(30)
Net cash provided by (used in) investing activities	(11,358)	25,970
Cash Flows From Financing Activities
Exercise of stock options	40	64
Sale of shares under stock purchase plans	49	6
Payment for tax withholding on vested awards	(56)	(114)
Repurchases of common stock	(675)	0
Costs of common stock offering under Controlled Equity OfferingSM	(179)	(148)
Net cash used in financing activities	(821)	(192)
Net decrease in cash and cash equivalents	(38,802)	(3,870)
Cash and cash equivalents at beginning of year	94,809	98,679
Cash and cash equivalents at end of year	$ 56,007	$ 94,809

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Organization and Nature of operations Lumos Pharma, Inc. is a clinical-stage biopharmaceutical company. References in this Annual Report to “us,” “we,” “our,” the “Company,” or “Lumos” are to Lumos Pharma, Inc. and its wholly-owned subsidiaries. With our principal executive offices located in Austin, Texas and additional executive and administrative offices located in Ames, Iowa, we are engaged in advancing our clinical program and focused on identifying, acquiring, developing, and commercializing novel products and new therapies for people with rare diseases on a global level , for which there is currently a significant unmet need for safe and effective therapies . Our common stock is listed on the Nasdaq Global Market (“Nasdaq”) and trades under the ticker symbol “LUMO.” The Company entered into a business combination (the “Merger”) between the Company, formerly known as NewLink Genetics Corporation (“NewLink”), Cyclone Merger Sub, Inc. (“Merger Sub”), a wholly owned subsidiary of NewLink, and Lumos Pharma, Inc., which has since been renamed “Lumos Pharma Sub, Inc.” (“Private Lumos”). The Merger closed on March 18, 2020, and Merger Sub merged with and into Private Lumos, with Private Lumos surviving as a wholly-owned subsidiary of the Company. Immediately prior to the closing of the Merger, the shares of NewLink common stock were adjusted with a reverse split ratio of 1‑for‑9. Under the terms of the Merger, Private Lumos stockholders received an aggregate of 4,146,398 shares of NewLink common stock (after giving effect to the reverse split) for each share of outstanding common stock, Series A Preferred Stock and Series B Preferred Stock of Private Lumos converted at an exchange ratio of 0.1308319305, 0.0873621142 and 0.1996348626 , respectively . Immediately following the reverse stock split and the completion of the Merger, there were 8,292,803 shares of the Company’s common stock outstanding , of which approximately 50% was held by each of Private Lumos and NewLink security holders. The Merger was accounted for as a reverse asset acquisition. After the consummation of the Merger, the combined company has focused its efforts on the development of Private Lumos’ sole product candidate, secretagogue ibutamoren (“LUM-201”), a potential oral therapy for idiopathic pediatric growth hormone deficiency (“PGHD”) and other rare endocrine disorders. Liquidity and Risks The Company has historically devoted substantially all of its efforts toward research and development and has never earned revenue from commercial sales of its products. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of the Company’s research and development activities. However, the Company believes that its existing cash, cash equivalents and short-term investments of approximately $67.4 million as of December 31, 2022 will be sufficient to allow the Company to fund its operations into the third quarter of 2024, which is inclusive of the primary read out of its Phase 2 clinical trial of LUM-201 in PGHD (“OraGrowtH210 Trial”) and OraGrowtH212 Trial, each of which is expected to occur in the fourth quarter of 2023. If available liquidity becomes insufficient to meet the Company’s obligations as they come due, our future operations will be reliant on additional equity or financing arrangements. There can be no assurances that, in the event that the Company requires additional financing, such financing will be available on terms which are favorable to the Company, or at all. If the Company is unable to raise additional funding to meet its working capital needs in the future, it will be forced to delay or reduce the scope of its research programs and/or limit or cease its operations. The pandemic caused by an outbreak of a novel strain of coronavirus, SARS-CoV-2, which causes COVID-19 (“COVID-19”), has resulted, and is likely to continue to result, in significant national and global economic disruption and may continue to adversely affect the Company’s operations. COVID-19 restrictions resulted in a slower pace of site initiation and patient enrollment in our clinical trials that led to a delay in the six-month primary outcome data read out of our OraGrowtH210 Trial. While we have experienced delays to our clinical trials, we have not incurred impairment of any assets as a result of COVID-19. The extent to which these events may further impact the Company’s business, clinical development, regulatory efforts, and the value of its common stock, will depend on future developments, which are highly uncertain and cannot be predicted at this time. The duration and intensity of these impacts and resulting disruption to the Company’s operations is uncertain, and the Company will continue to evaluate the impact that these events could have on the operations, financial position, and the results of operations and cash flows.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Consolidation The accompanying consolidated financial statements include the accounts of Lumos and its wholly-owned subsidiaries and have been prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”). All significant intercompany accounts and transactions are eliminated in consolidatio n. In the opinion of management, all adjustments of a normal and recurring nature considered necessary for a fair presentation have been included in the accompanying consolidated financial statements. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. Significant management estimates that affect the reported amounts of assets and liabilities include stock-based compensation, accruals for clinical trials and deferred tax assets. While we believe that the estimates and assumptions used in preparation of our consolidated financial statements based on our knowledge of current events and actions that we may underta ke in the future are appropriate, actual results could differ from those estimates, and any such differences may be material. Fair Value of Financial Instruments and Credit Risk The fair values of the Company’s financial instruments are recorded using a hierarchical disclosure framework based upon the level of subjectivity of the inputs used in measuring assets and liabilities. The three levels are described below: • Level 1: Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date . • Level 2: Inputs other than Level 1 that are directly or indirectly observable, such as quoted prices for similar assets or liabilities and quoted prices in less active markets. • Level 3: Inputs are unobservable for the asset or liability and are developed based on the best information available in the circumstances, which might include the Company’s own data. Cash and Cash Equivalents Cash and cash equivalents consist of cash deposits, certificates of deposit, money market funds and investments in debt securities with original maturities of ninety days or less when purchased. Investments Management determines the appropriate classification of its available-for-sale investments in debt securities at the time of purchase. Generally, investments with original maturities greater than ninety days at the date of purchase are classified as short-term because it is management’s intent to use the investments to fund current operations or to make them available for current operations. Investments in available-for-sale securities are reported at fair value, with unrealized gains and losses, net of tax, recorded as a component of accumulated other comprehensive loss in the Consolidated Balance Sheet. The Company reviews its available-for-sale investments as of the end of each reporting period for declines in fair value based on the specific identification method. The Company records an allowance for credit loss when a decline in fair value is due to credit-related factors. The Company considers various factors in determining whether an investment is impaired, including the severity of the impairment, changes in underlying credit ratings, forecasted recovery, its intent to sell or the likelihood that it would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. When the Company concludes that a credit-related impairment has occurred, the Company assesses whether it intends to sell the security or if it is more likely than not that it will be required to sell the security before recovery. If either of these two conditions is met, the Company recognizes a charge in net loss equal to the entire difference between the security’s amortized cost basis and its fair value. If the Company does not intend to sell a security and it is not more likely than not that it will be required to sell the security before recovery, the unrealized loss is separated into an amount representing the credit loss, which is recognized in net loss, and the amount related to all other factors, which is recorded in accumulated other comprehensive income loss. Property and Equipment Leasehold improvements and equipment are capitalized as the Company believes they have alternative future uses and are stated at cost. Depreciation on all leasehold improvements and equipment is calculated on the straight-line method over the shorter of the lease term or estimated useful life of the asset. Computer equipment has useful lives of three Long-lived assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset group to future net undiscounted cash flows expected to be generated by the asset group, primarily relating to proceeds for selling the assets. If such assets are considered to be impaired, the impairment to be recognized is measured at the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. Leases The Company determines if an arrangement is a lease at inception. Operating lease right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company ’ s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expenses for lease payments are recognized on a straight-line basis over the lease term. (See Note 6.) Expenses Accrued Under Contractual Arrangements with Third Parties; Accrued Clinical Expenses The Company estimates its accrued expenses through a process of reviewing open contracts and purchase orders, communicating with personnel to identify services that have been performed and estimating the level of service performed and the associated cost incurred for the service that may not be invoiced from the provider. The estimates of accrued expenses as of each balance sheet date are based on facts and circumstances known at that time. Such estimates are periodically confirmed with the service providers to verify accuracy. The Company bases its expenses related to clinical trials on estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and contract research organizations that conduct and manage clinical trials on behalf of the Company. Invoicing from third-party contractors for services performed can lag several months. The Company accrues the costs of services rendered in connection with third-party contractor activities based on its estimate of management fees, site management and monitoring costs and data management costs as contracted. Differences between actual clinical trial costs and estimated clinical trial costs are adjusted for in the period in which they become known through operations. Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operating results in the period that includes the enactment date. Management assesses the realizability of deferred tax assets and records a valuation allowance if it is more likely than not that all or a portion of the deferred tax assets will not be realized. The Company accounts for the effect of any uncertain tax positions based on a more likely than not threshold to the recognition of the tax positions being sustained based on the technical merits of the position under scrutiny by the applicable taxing authority. If a tax position or positions are deemed to result in uncertainties of those positions, the unrecognized tax position is estimated based on a cumulative probability assessment that aggregates the estimated tax liability for all uncertain tax positions. Interest and penalties assessed, if any, are recorded in its consolidated statement of operations in interest expense and other expenses. Share-Based Compensation Stock options and performance stock options The Company recognizes compensation costs related to stock options granted to employees and non-employees based on the estimated fair value of the awards on the date of grant. The Company estimates the grant date fair value, and the resulting stock-based compensation expense, using the Black-Scholes option-pricing model. The Company records forfeitures as they are incurred. The grant date fair value of the stock options is expensed on a straight-line basis over the applicable vesting period, which generally is four years. The fair value of performance-based stock options is recognized as compensation expense beginning at the time in which the performance conditions are deemed probable of achievement, over the remaining requisite service period. The assumptions used in Black-Scholes option-pricing model are as follows: • Exercise price . If Incentive Stock Options are granted to a 10% stockholder in the Company, the exercise price shall not be less than 110% of the common stock’s fair market value on the date of grant. • Fair Market Value of Common Stoc k. Subsequent to the Merger, the grant date fair market value is the quoted market price of the Company's common stock. • Expected term . The expected term of stock options represents the period that the stock options are expected to remain outstanding and is based on vesting terms, exercise term and contractual lives of the options. The expected term is based on the simplified method and is estimated as the average of the weighted average vesting term and the time to expiration as of the grant date. • Expected volatility . Given the low trading volume in the Company's common stock, the Company uses a blended volatility based both on its own historical data and the trading history from the common stock of a set of comparable publicly-listed biopharmaceutical companies. Volatility for employee stock purchase plan (“ESPP”) shares is equal to the Company’s historical volatility over the six-month offering period. • Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury yield with a maturity equal to the expected term of the stock options in effect at the time of grant. • Dividend yield . The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plan to pay any dividends on its common stock. Restricted stock units Service-based restricted stock units are valued using the market price of our common stock on the grant date. The grant date fair value of the restricted stock units is expensed on a straight-line basis over the applicable vesting period, which generally is four years. Employee stock purchase plan Our ESPP allows employees to purchase common stock at a 15% discount from the lower of the common stock closing price on the first or last day of the offering period. The current offering period is from January 1, 2023 to December 31, 2024. We use the Black-Scholes Model to determine fair value, which incorporates assumptions as described above. The grant date fair value of the ESPP is expensed on a straight-line basis over the applicable vesting period, which generally is six months. Net Loss Per Share Basic net loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share reflects the potential dilution, using the treasury stock method. Revenue Recognition For arrangements that may include sales-based royalties, including milestone payments based on the level of sales, we recognize revenue at the later of (i) when the related sale has occurred or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied. Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses consist primarily of employee-related expenses, which include salaries, bonuses, benefits and share-based compensation; manufacturing-related costs; clinical trial expenses which include expenses incurred under agreements with contract research organizations, investigative sites and consultants that conduct our clinical trials; facilities, depreciation of fixed assets and other allocated expenses, which include direct and allocated expenses for rent and maintenance of research facilities and equipment; license fees for and milestone payments related to in-licensed products and technology; and costs associated with non-clinical activities and regulatory approvals. Advance payments for goods or services to be rendered in the future for use in research and development activities are deferred and recorded as a prepaid asset. The deferred amounts are expensed as the related goods are delivered or the services are performed. Patents The Company generally applies for patent protection on processes and products. Patent application costs are expensed as incurred as a component of general and administrative expense, as recoverability of such expenditures is uncertain.

License and Asset Purchase Agre

License and Asset Purchase Agreements	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License and Asset Purchase Agreements	License and Asset Purchase Agreements License and LUM-201 Asset Purchase Agreements In July 2018, the Company entered into an asset purchase agreement (the “APA”) with Ammonett and acquired substantially all of the assets related to LUM-201, which Ammonett licensed from Merck in October 2013 (the “Lumos Merck Agreement”). The Lumos Merck Agreement, which grants Lumos (as successor in interest to Ammonett) worldwide, exclusive, sublicensable (subject to Merck’s consent in the United States, major European countries and Japan, such consent not to be unreasonably withheld) rights under specified patents and know-how to develop, manufacture and commercialize LUM-201 for any and all indications, excluding Autism Spectrum Disorders as defined in the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders. On August 12, 2020, we entered into Amendment No. 1 to the Lumos Merck Agreement with Merck (the “Lumos Merck Agreement Amendment”). Pursuant to the Lumos Merck Agreement Amendment, we obtained from Merck a worldwide, non-exclusive, sublicensable (subject to Merck’s consent in the United States, specified major European countries and Japan, such consent not to be unreasonably withheld) license under the specified patents and know-how that are the subject of our exclusive license to develop, manufacture and commercialize LUM-201 for diagnostic purposes, excluding Autism Spectrum Disorders. Under the APA, the Company paid Ammonett an upfront fee of $3.5 million which was recorded as research and development expense in 2018. The Company may also incur development milestone payments totaling up to $17.0 million for achievement of specified milestones on the first indication that Lumos pursues and up to $14.0 million for achievements of specified milestones on the second indication that Lumos pursues, sales milestone payments totaling up to $55.0 million on worldwide product sales, and royalty payments based on worldwide product sales, as discussed below. Under the Lumos Merck Agreement, Lumos will be required to pay Merck substantial development milestone payments for achievement of specified milestones relating to each of the first and second indications. Total potential development milestone payments are required of up to $14 million for the first indication that Lumos pursues and up to $8.5 million for the second indication that Lumos pursues. Tiered sales milestone payments totaling up to $80.0 million are required on worldwide net product sales up to $1.0 billion, and substantial royalty payments based on product sales are required if product sales are achieved. If product sales are ever achieved, Lumos is required to make royalty payments under both the APA and the Lumos Merck Agreement collectively of 10% to 12% of total annual product net sales, subject to standard reductions for generic erosion. The royalty obligations under the Lumos Merck Agreement are on a product-by-product and country-by-country basis and will last until the later of expiration of the last licensed patent covering the product in such country and expiration of regulatory exclusivity for such product in such country. The royalty obligations under the APA are on a product-by-product and country-by-country basis for the duration of the royalty obligations under the Merck License and thereafter until the expiration of the last patent assigned to Lumos under the APA covering such product in such country. The Lumos Merck Agreement shall continue in force until the expiration of royalty obligations on a country-by-country and product-by-product basis, or unless terminated by Lumos at will by submitting 180 days’ advance written notice to Merck or by either party for the other party’s uncured material breach or specified bankruptcy events. Upon expiry of the royalty obligations the Lumos Merck Agreement converts to a fully paid-up, perpetual non-exclusive license. If the Lumos Merck Agreement is terminated, and upon Merck’s written request, Lumos is obligated to use reasonable and diligent efforts to assign to Merck any sublicenses previously granted by Lumos. License and PRV Asset Purchase Agreements In November 2014, NewLink entered into a worldwide license and collaboration agreement (the “NewLink Merck Agreement”), with Merck, to develop and potentially commercialize its Ebola vaccine rVSV∆G-ZEBOV that it licensed from the Public Health Agency of Canada (“ PHAC ”). rVSV∆G-ZEBOV was also eligible to receive a PRV if approval was granted by the U.S. Food and Drug Administration (the “FDA”), with the Company entitled to 60% and Merck entitled to the remaining 40% of the PRV value obtained through sale, transfer or other disposition of the PRV. On December 20, 2019, Merck announced that the FDA approved its application for ERVEBO® (Ebola Zaire Vaccine, Live) for the prevention of disease caused by Zaire Ebola virus in individuals 18 years of age and older and grant of the PRV. On July 27, 2020, Lumos and Merck entered into the asset purchase agreement (the “PRV Asset Purchase Agreement”), whereby Lumos and Merck each agreed that Merck would purchase the PRV from the Company. Merck agreed to pay the Company an aggregate of $60 million in two installments. The $35.7 million liability, representing the portion of the PRV value to which Merck was entitled, was also extinguished through the PRV Asset Purchase Agreement. The first installment of $34.0 million was received by the Company at the closing during the three months ended September 30, 2020 and the second installment of $26.0 million was received on January 11, 2021. Under the NewLink Merck Agreement, as amended, the Company has earned and has the potential to continue to earn royalties on sales of the vaccine in certain countries. However, we believe that the market for the vaccine will be limited primarily to areas in the developing world that are excluded from royalty payment or where the vaccine is donated or sold at low or no margin and, therefore, we do not expect to receive material royalty payments from Merck in the foreseeable future. For the years ended December 31, 2022 and 2021, the Company recognized revenues of $0 and $10,000 respectively, for work the Company performed in relation to ERVEBO®, as a subcontractor of Merck, and $1.5 million and $220,000, respectively, for royalties related to royalty-bearing commercial sales of the vaccine.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Financial Instruments	Financial Instruments Fair Value The following summarizes the valuation of the Company’s financial instruments (in thousands). The tables do not include either cash on hand or assets and liabilities that are measured at historical cost or any basis other than fair value. As of December 31, 2021, the Company's cash equivalents consisted entirely of money market funds (Level 1) and were recorded at cost, which approximated fair value. The Company had no short-term investments as of December 31, 2021. As of December 31, 2022 Level 1 Level 2 Total Cash equivalents: Money market funds $ 52,045 $ — $ 52,045 Corporate debt securities — 2,497 2,497 Non-U.S. debt securities — 800 800 Total cash equivalents $ 52,045 $ 3,297 $ 55,342 Short-term investments: Commercial paper $ — $ 2,909 $ 2,909 U.S. government and agency securities 2,451 5,992 8,443 Total short-term investments $ 2,451 $ 8,901 $ 11,352 Total $ 54,496 $ 12,198 $ 66,694 As of December 31, 2022 and 2021, the Company had no Level 3 assets or liabilities. There were no transfers between Level 1, Level 2, or Level 3 measurements for the years ending December 31, 2022 and 2021. The Company’s other financial instruments, including cash, receivables and accounts payable, are recorded at amounts that approximate their fair values due to their short maturities. The Company is unable to estimate the fair value of the royalty obligation to Iowa Economic Development Authority based on future product sales, as the timing of payments, if any, is uncertain. Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist primarily of cash and cash equivalents and short-term investments. Cash and cash equivalents and investments in marketable securities are invested in accordance with the Company’s cash investment policy with the primary objective being the preservation of capital and maintenance of liquidity. The cash investment policy includes guidelines on the quality of financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company limits its exposure to credit loss by placing its cash and cash equivalents and short-term investments with high credit quality financial institutions. Contractual Maturities of Investments As of December 31, 2022, all of the Company's available-for-sale investments were due within one year or less. Available-for-sale Investments The following table summarizes the Company's available-for-sale securities by security type: As of December 31, 2022 Amortized Cost Unrealized Losses Fair Value Cash equivalents: Money market funds $ 52,045 $ — $ 52,045 Corporate debt securities 2,498 (1) 2,497 Non-U.S. debt securities 800 — 800 Total cash equivalents $ 55,343 $ (1) $ 55,342 Short-term investments: Commercial paper $ 2,909 $ — $ 2,909 U.S. government and agency securities 8,451 (8) 8,443 Total short-term investments $ 11,360 $ (8) $ 11,352 Total $ 66,703 $ (9) $ 66,694 The gross unrealized losses as of December 31, 2022 were due primarily to changes in market interest rates. The Company records an allowance for credit loss when a decline in investment market value is due to credit-related factors. When evaluating an investment for impairment, the Company reviews factors such as the severity of the impairment, changes in underlying credit ratings, forecasted recovery, the Company’s intent to sell or the likelihood that it would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. As of December 31, 2022, there were no material declines in the market value of available-for-sale investments due to credit-related factors. As of December 31, 2022, there were no material unrealized gains associated with the Company’s available-for-sale investments.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses are comprised of the following (in thousands): December 31, 2022 December 31, 2021 Compensation and related benefits $ 3,729 $ 2,812 Clinical and contract manufacturing expenses 1,800 508 Other 671 846 Total accrued expenses $ 6,200 $ 4,166

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	Leases The Company has certain facility leases with non-cancellable terms ranging between one The Company records lease liabilities based on the present value of lease payments over the lease term using an incremental borrowing rate to discount its lease liabilities, as the rate implicit in the lease is typically not readily determinable. To compute the present value of the lease liability, the Company used a weighted-average discount rate of 3%. Certain lease agreements include renewal options that are under the Company’s control. The Company includes optional renewal periods in the lease term only when it is reasonably certain that the Company will exercise its option. The weighted-average remaining lease term as of December 31, 2022 is 0.7 years. The Company does not separate lease components from non-lease components. Variable lease payments include payments to lessors for taxes, maintenance, insurance and other operating costs as well as payments that are adjusted based on an index or rate. The Company’s lease agreements do not contain any residual value guarantees or restrictive covenants. Future maturities of operating leases (with initial or remaining lease terms in excess of one year) as of December 31, 2022 are as follows (in thousands), excluding option renewals: As of December 31, 2022: 2023 $ 236 Thereafter — Total lease payments 236 Less: Imputed interest (3) Total $ 233 Lease costs for operating leases were $0.3 million and for each of the years ended December 31, 2022 and 2021.

Stock-Based Compensation and Em

Stock-Based Compensation and Employee Benefit Plans	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation and Employee Benefit Plans	Stock-Based Compensation and Employee Benefit Plans Stock Options and Performance Stock Options In 2012, Private Lumos adopted the 2012 Equity Incentive Plan (“2012 Plan”), and in 2016 it adopted the 2016 Stock Plan (“2016 Plan” and together with the 2012 Plan, the “Plans”). In connection with the Merger, all outstanding options under the Plans were assumed and such assumed options may be exercised to purchase common stock of the Company after the Merger. Subsequent to the Merger, the Plans were terminated as to future awards . In connection with the Merger, the Company assumed NewLink’s 2009 Equity Incentive Plan which was effective since July 2009 and was subsequently amended on May 9 , 2019 (the “2019 Plan”) . The 2019 Plan has a 10 year term from the Board adoption date of March 22, 2019 and on January 1 of each year through January 1, 2029, in accordance with an “evergreen provision”, a number of shares of common stock in an amount equal to 3% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year or such lesser amount of shares (or no shares) approved by the Board, will be added to the shares reserved under the 2019 Plan. The 2019 Plan provides for the grant of incentive stock options, nonstatutory stock options, restricted stock awards and stock appreciation rights to officers, employees, members of the Board, advisors, and consultants to the Company . As of December 31, 2022, we had 426,437 shares available for grant under the 2019 Plan. The table below summarizes the stock option activity, including options with market and performance conditions, for the year ended December 31, 2022 : Number of options Weighted average exercise price Weighted average remaining contractual term (years) Outstanding at beginning of period 1,201,209 $ 10.77 6.1 Options granted 306,986 9.41 Options exercised (17,288) 2.31 Options forfeited (25,960) 13.36 Options expired (15,760) 20.09 Outstanding at end of period 1,449,187 $ 10.43 6.9 Options exercisable at end of period 842,557 $ 10.19 5.9 The weighted-average assumptions used to value the stock options using the Black-Scholes option-pricing were as follows : Year Ended December 31, 2022 2021 Risk-free interest rate 1.32% to 3.01% 0.56% to 1.05% Expected dividend yield —% —% Expected volatility 83.7% to 96.1% 77.2% to 90.3% Expected term (in years) 5.5 to 6.1 5.4 to 7.7 Weighted-average grant-date fair value per share $6.75 $10.65 Restricted Stock Units The table below summarizes the restricted stock units activity for the year ended December 31, 2022 : Number of restricted shares Weighted average grant date fair value Unvested at beginning of period 81,015 $ 8.91 Granted 14,550 9.18 Vested (25,771) 8.87 Unvested at end of period 69,794 $ 8.98 The following summarizes the weighted average fair value at the date of grant: Year Ended December 31, 2022 2021 Per grant of restricted stock unit $ 9.18 $ 10.32 2010 Non-Employee Directors’ Stock Award Plan In connection with the Merger , the Company assumed NewLink’s 2010 Non-Employee Directors’ Stock Award Plan (the “Directors’ Plan”) which was effective on November 10, 2011. As of December 31, 2022, 5,624 shares remain available for grant under the Directors ’ Plan. 2010 Employee Stock Purchase Plan In connection with the Merger, the Company assumed NewLink’s 2010 Employee Stock Purchase Plan, as amended (the "2010 Purchase Plan"), which was effective on November 10, 2011. As of December 31, 2022, 48,644 shares remain available for issuance under the 2010 Purchase Plan. On July 22, 2021, the Board approved an amendment and restatement of the 2010 Purchase Plan (the “A&R ESPP”), and established a special offering period under the A&R ESPP beginning September 1, 2021 and lasting until June 30, 2023, subject to restart provisions as described within the A&R ESPP. The special offering period under the A&R ESPP was fully contingent upon stockholder approval of the A&R ESPP at the 2022 Annual Meeting of Stockholders. The A&R ESPP provided for an increase in the number of shares reserved for issuance under the A&R ESPP by 60,000 shares. On May 4, 2022, at the 2022 Annual Meeting of Stockholders, the A&R ESPP was approved. On June 30, 2022, the restart provision was triggered, resulting in a new offering period beginning July 1, 2022 through June 30, 2024. On December 30, 2022, the restart provision was triggered, resulting in a new offering period beginning January 1, 2023 through December 31, 2024. Share-Based Compensation Expense Stock-based compensation expenses included in the Company’s consolidated statements of operations for the year ended December 31, 2022 and 2021 were (in thousands): Year Ended December 31, 2022 2021 Research and development $ 661 $ 809 General and administrative 1,659 2,070 Total $ 2,320 $ 2,879 As of December 31, 2022, we had unrecognized compensation cost of $4.3 million and the weighted-average period over which it is expected to be recognized is 2.4 years. Employee Benefit Plans

Long-Term Debt and Conversion t

Long-Term Debt and Conversion to Royalty Obligation	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Long-Term Debt and Conversion to Royalty Obligation	Long-Term Debt and Conversion to Royalty ObligationIn March 2005, NewLink entered into a $6.0 million forgivable loan agreement with the Iowa Department of Economic Development (the “IDED”). Under the agreement, in the absence of default, there were no principal or interest payments due until the completion date for the project. This loan was converted into a royalty obligation under the terms of a settlement agreement entered into on March 26, 2012, with the Iowa Economic Development Authority, as successor in interest to the IDED. As no payments are expected in the next 12 months, the entire royalty obligation of $6.0 million, which the Company assumed in connection with the Merger, is classified as a long-term liability as of December 31, 2022.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the years ended December 31, 2022 and 2021, the Company recorded an income tax benefit of $13,000 and $0.6 million, respectively. The income tax benefit is as follows (in thousands): Year Ended December 31, 2022 2021 Current tax benefit - state and local $ 13 $ 636 Total income tax benefit $ 13 $ 636 The Company had no deferred tax liabilities for each of the years ended December 31, 2022 and 2021. The tax effects of temporary differences that give rise to significant portions of deferred tax assets at December 31, 2022 and 2021 are presented below (in thousands): As of December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 35,236 $ 32,281 Federal research and development tax credits 39,190 37,953 Capitalized research and development 4,018 — Share-based compensation 678 627 Capital loss carryforwards 41,144 41,144 Accrued compensation 221 192 Leasehold improvements and equipment 1,205 1,292 Other 2 26 Gross deferred tax assets 121,694 113,515 Less: valuation allowance (121,694) (113,515) Total deferred tax assets $ — $ — In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Due to the uncertainty of the Company’s ability to realize the benefit of the deferred tax assets, the net deferred tax assets are fully offset by a valuation allowance at December 31, 2022 and 2021. The valuation allowance increased by $8.2 million and $8.2 million during the years ended December 31, 2022 and 2021, respectively. Based on Section 382 ownership change analyses through March 18, 2020, as a result of the Merger, both historical NewLink and Private Lumos experienced Section 382 ownership changes on March 18, 2020. These ownership changes limit our ability to utilize federal net operating loss carryforwards and certain other tax attributes that accrued prior to the respective ownership changes of us and our subsidiaries and may continue to limit our ability to utilize such attributes in the future. Based on subsequent analyses, we did not experience a Section 382 ownership change from March 19, 2020 through December 31, 2021. As of December 31, 2022, the Company had federal operating loss carryforwards of approximately $141.5 million, federal capital loss carryforwards of approximately $164.6 million, and federal research credit carryforwards of approximately $39.2 million. Certain of the carryforwards expire in years 2023 through 2042, and certain of the carryforwards have an indefinite life. A reconciliation of income taxes at the statutory federal income tax rate to net income tax benefit included in the accompanying consolidated statements of operations is set forth in the following table: Year Ended December 31, 2022 2021 U.S. federal income tax benefit at the statutory rate (21.0) % (21.0) % State income taxes, net of federal taxes (2.1) (1.4) Federal tax credits (6.3) (8.9) Change in valuation allowance 26.3 26.5 Other 3.1 2.7 Effective income tax rate 0.0 % (2.1) % The Company accounts for the effect of any uncertain tax positions based on a more likely than not threshold to the recognition of the tax positions being sustained based on the technical merits of the position under scrutiny by the applicable taxing authority. If a tax position or positions are deemed to result in uncertainties of those positions, the unrecognized tax position is estimated based on a cumulative probability assessment that aggregates the estimated tax liability for all uncertain tax positions. Interest and penalties assessed, if any, are accrued and recorded in either interest expense or miscellaneous expense, respectively in the consolidated statement of operations.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Common Stock The Company's common stock trades on the Nasdaq under the symbol “LUMO.” Our shareholders are entitled to one vote for each share of common stock held on all matters to be voted on by shareholders. We have 75,000,000 authorized common shares, par value of $0.01 per share. The holders of common stock are entitled to one vote per share on all matters to be voted upon by the Company stockholders. On August 16, 2022, the Company announced that its board of directors had authorized a share repurchase program, under which the Company may purchase up to $3.0 million shares of its outstanding common stock. The Company repurchased 137,526 shares for approximately $675,000 during the year ended December 31, 2022. All such purchases were made through open-market transactions with shares effectively retired upon repurchase. On December 30, 2020, the Company entered into a Controlled Equity Offering SM Sales Agreement (the “Sales Agreement”) with Cantor Fitzgerald & Co., as agent (the “Agent”), pursuant to which the Company may offer and sell from time to time through the Agent up to $50.0 million of shares of the Company’s common stock, $0.01 par value (the “Shares”). The offering and sale of the Shares has been registered under the Securities Act of 1933, as amended (the “Securities Act”). Under the Sales Agreement, the Agent may sell the Shares by any method permitted by law and deemed to be an “at-the-market” offering as defined in Rule 415(a)(4) promulgated under the Securities Act, including sales made directly on or through the Nasdaq, on any other existing trading market for the Shares, in negotiated transactions at market prices prevailing at the time of sale or at prices related to such prevailing market prices and/or any other method permitted by law. The Company will notify the Agent of the number of Shares to be issued, the time period during which sales are requested to be made, any limitation on the number of Shares that may be sold in any one day and any minimum price below which sales may not be made. The Company will pay the Agent a commission of up to 3.0% of the gross sales price of the Shares sold through it under the Sales Agreement. In addition, the Company has agreed to reimburse certain expenses incurred by the Agent in connection with the offering. The Sales Agreement may be terminated by the Agent or the Company at any time upon notice to the other party, as set forth in the Sales Agreement, or by the Agent at any time in certain circumstances, including the occurrence of a material and adverse change in the Company’s business or financial condition that makes it impractical or inadvisable to market the shares or to enforce contracts for the sale of the Shares. As of December 31, 2022, no shares have been issued under the Sales Agreement. Preferred Stock The Company's amended and restated certificate of incorporation authorizes the issuance of 5,000,000 shares of preferred stock, par value $0.01 per share. Our Board is empowered, without shareholder approval, to issue preferred stock with dividend, liquidation, conversion, voting or other rights that could adversely affect the voting power or other rights of the holders of common stock. As of December 31, 2022, the Company had no outstanding preferred stock.

Net Loss per Share of Common St

Net Loss per Share of Common Stock	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Loss per Share of Common Stock	Net Loss per Share of Common Stock Basic loss per share is based upon the weighted-average number of shares of common stock outstanding during the period, without consideration of common stock equivalents. Diluted loss per share is based upon the weighted-average number of common shares outstanding during the period plus additional weighted-average potentially dilutive common stock equivalents during the period when the effect is dilutive. The following table presents the computation of basic and diluted loss per share of common stock (in thousands, except share and per share data) and the number of unexercised stock options and restricted stock units, which are common stock equivalents, that have been excluded from the diluted net loss calculation as their effect would have been anti-dilutive for all periods presented: Year Ended December 31, 2022 2021 Net loss $ (31,062) (30,430) Weighted-average shares outstanding - Basic and diluted 8,373,821 8,334,516 Net loss per share - Basic and diluted $ (3.71) $ (3.65) Anti-dilutive stock options 1,449,187 1,201,209 Anti-dilutive restricted stock units 69,794 81,015 Total anti-dilutive common stock equivalents excluded 1,518,981 1,282,224

Restructuring and Severance Cha

Restructuring and Severance Charges	12 Months Ended
	Dec. 31, 2022
Restructuring and Related Activities [Abstract]
Restructuring and Severance Charges	Restructuring and Severance ChargesOn February 4, 2021, Eugene P. Kennedy, M.D., notified the Company that he would be resigning from his position as the Company's Chief Medical Officer effective March 6, 2021. As per the terms of Dr. Kennedy's employment agreement relating to change in control benefits, the Company paid approximately $0.7 million in severance expenses recognized during the three months ended March 31, 2021 and accelerated vesting of all non-vested equity awards. For the three months ended March 31, 2021, the Company recognized additional stock compensation expense of approximately $0.7 million due to accelerated vesting of all non-vested equity awards held by Dr. Kennedy.On April 16, 2021, Carl W. Langren notified the Company that he would be retiring from his position as the Company's Chief Financial Officer effective June 30, 2021. Mr. Langren's resignation in connection with his retirement was effective June 30, 2021. As per the terms of Mr. Langren's employment agreement relating to change in control benefits, the Company paid approximately $0.9 million as severance, accelerated vesting of all non-vested equity awards and extended the exercise period on any vested equity awards to twenty-four months from the separation date. For the three months ended June 30, 2021, we recognized additional stock compensation expense of approximately $0.4 million due to accelerated vesting of all non-vested equity awards held by Mr. Langren. Final payment of accrued severance compensation of $0.9 million was paid in the fourth quarter of 2021. No severance-related expense was recognized during the year ended December 31, 2022.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying consolidated financial statements include the accounts of Lumos and its wholly-owned subsidiaries and have been prepared in accordance with accounting principles generally accepted in the U.S. (“U.S. GAAP”). All significant intercompany accounts and transactions are eliminated in consolidatio n.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. Significant management estimates that affect the reported amounts of assets and liabilities include stock-based compensation, accruals for clinical trials and deferred tax assets. While we believe that the estimates and assumptions used in preparation of our consolidated financial statements based on our knowledge of current events and actions that we may underta ke in the future are appropriate, actual results could differ from those estimates, and any such differences may be material.
Fair Value of Financial Instruments	Fair Value of Financial Instruments and Credit Risk The fair values of the Company’s financial instruments are recorded using a hierarchical disclosure framework based upon the level of subjectivity of the inputs used in measuring assets and liabilities. The three levels are described below: • Level 1: Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date . • Level 2: Inputs other than Level 1 that are directly or indirectly observable, such as quoted prices for similar assets or liabilities and quoted prices in less active markets. • Level 3: Inputs are unobservable for the asset or liability and are developed based on the best information available in the circumstances, which might include the Company’s own data.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash deposits, certificates of deposit, money market funds and investments in debt securities with original maturities of ninety days or less when purchased. Investments Management determines the appropriate classification of its available-for-sale investments in debt securities at the time of purchase. Generally, investments with original maturities greater than ninety days at the date of purchase are classified as short-term because it is management’s intent to use the investments to fund current operations or to make them available for current operations. Investments in available-for-sale securities are reported at fair value, with unrealized gains and losses, net of tax, recorded as a component of accumulated other comprehensive loss in the Consolidated Balance Sheet. The Company reviews its available-for-sale investments as of the end of each reporting period for declines in fair value based on the specific identification method. The Company records an allowance for credit loss when a decline in fair value is due to credit-related factors. The Company considers various factors in determining whether an investment is impaired, including the severity of the impairment, changes in underlying credit ratings, forecasted recovery, its intent to sell or the likelihood that it would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. When the Company concludes that a credit-related impairment has occurred, the Company assesses whether it intends to sell the security or if it is more likely than not that it will be required to sell the security before recovery. If either of these two conditions is met, the Company recognizes a charge in net loss equal to the entire difference between the security’s amortized cost basis and its fair value. If the Company does not intend to sell a security and it is not more likely than not that it will be required to sell the security before recovery, the unrealized loss is
Property and Equipment	Property and Equipment Leasehold improvements and equipment are capitalized as the Company believes they have alternative future uses and are stated at cost. Depreciation on all leasehold improvements and equipment is calculated on the straight-line method over the shorter of the lease term or estimated useful life of the asset. Computer equipment has useful lives of three Long-lived assets are reviewed for impairment whenever changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset group to future net undiscounted cash flows expected to be generated by the asset group, primarily relating to proceeds for selling the assets. If such assets are considered to be impaired, the impairment to be recognized is measured at the amount by which the carrying amount of the assets exceeds the fair value of the assets. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating lease right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The Company ’
Expenses Accrued Under Contractual Arrangements with Third Parties; Accrued Clinical Expenses	Expenses Accrued Under Contractual Arrangements with Third Parties; Accrued Clinical Expenses The Company estimates its accrued expenses through a process of reviewing open contracts and purchase orders, communicating with personnel to identify services that have been performed and estimating the level of service performed and the associated cost incurred for the service that may not be invoiced from the provider. The estimates of accrued expenses as of each balance sheet date are based on facts and circumstances known at that time. Such estimates are periodically confirmed with the service providers to verify accuracy.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operating results in the period that includes the enactment date. Management assesses the realizability of deferred tax assets and records a valuation allowance if it is more likely than not that all or a portion of the deferred tax assets will not be realized. The Company accounts for the effect of any uncertain tax positions based on a more likely than not threshold to the recognition of the tax positions being sustained based on the technical merits of the position under scrutiny by the applicable taxing authority. If a tax position or positions are deemed to result in uncertainties of those positions, the unrecognized tax position is estimated based on a cumulative probability assessment that aggregates the estimated tax liability for all uncertain
Share-based Compensation	Share-Based Compensation Stock options and performance stock options The Company recognizes compensation costs related to stock options granted to employees and non-employees based on the estimated fair value of the awards on the date of grant. The Company estimates the grant date fair value, and the resulting stock-based compensation expense, using the Black-Scholes option-pricing model. The Company records forfeitures as they are incurred. The grant date fair value of the stock options is expensed on a straight-line basis over the applicable vesting period, which generally is four years. The fair value of performance-based stock options is recognized as compensation expense beginning at the time in which the performance conditions are deemed probable of achievement, over the remaining requisite service period. The assumptions used in Black-Scholes option-pricing model are as follows: • Exercise price . If Incentive Stock Options are granted to a 10% stockholder in the Company, the exercise price shall not be less than 110% of the common stock’s fair market value on the date of grant. • Fair Market Value of Common Stoc k. Subsequent to the Merger, the grant date fair market value is the quoted market price of the Company's common stock. • Expected term . The expected term of stock options represents the period that the stock options are expected to remain outstanding and is based on vesting terms, exercise term and contractual lives of the options. The expected term is based on the simplified method and is estimated as the average of the weighted average vesting term and the time to expiration as of the grant date. • Expected volatility . Given the low trading volume in the Company's common stock, the Company uses a blended volatility based both on its own historical data and the trading history from the common stock of a set of comparable publicly-listed biopharmaceutical companies. Volatility for employee stock purchase plan (“ESPP”) shares is equal to the Company’s historical volatility over the six-month offering period. • Risk-free interest rate . The risk-free interest rate is based on the U.S. Treasury yield with a maturity equal to the expected term of the stock options in effect at the time of grant. • Dividend yield . The expected dividend is assumed to be zero as the Company has never paid dividends and has no current plan to pay any dividends on its common stock. Restricted stock units Service-based restricted stock units are valued using the market price of our common stock on the grant date. The grant date fair value of the restricted stock units is expensed on a straight-line basis over the applicable vesting period, which generally is four years. Employee stock purchase plan
Net Loss Per Share	Net Loss Per ShareBasic net loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of common shares outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share reflects the potential dilution, using the treasury stock method.
Revenue Recognition	Revenue RecognitionFor arrangements that may include sales-based royalties, including milestone payments based on the level of sales, we recognize revenue at the later of (i) when the related sale has occurred or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses consist primarily of employee-related expenses, which include salaries, bonuses, benefits and share-based compensation; manufacturing-related costs; clinical trial expenses which include expenses incurred under agreements with contract research organizations, investigative sites and consultants that conduct our clinical trials; facilities, depreciation of fixed assets and other allocated expenses, which include direct and allocated expenses for rent and maintenance of research facilities and equipment; license fees for and milestone payments related to in-licensed products and technology; and costs associated with non-clinical activities and regulatory approvals. Advance payments for goods or services to be rendered in the future for use in research and development activities are deferred and recorded as a prepaid asset. The deferred amounts are expensed as the related goods are delivered or the services are performed.
Patents	Patents The Company generally applies for patent protection on processes and products. Patent application costs are expensed as incurred as a component of general and administrative expense, as recoverability of such expenditures is uncertain.

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Summarizes the Valuation of the Company’s Financial Instruments	The following summarizes the valuation of the Company’s financial instruments (in thousands). The tables do not include either cash on hand or assets and liabilities that are measured at historical cost or any basis other than fair value. As of December 31, 2021, the Company's cash equivalents consisted entirely of money market funds (Level 1) and were recorded at cost, which approximated fair value. The Company had no short-term investments as of December 31, 2021. As of December 31, 2022 Level 1 Level 2 Total Cash equivalents: Money market funds $ 52,045 $ — $ 52,045 Corporate debt securities — 2,497 2,497 Non-U.S. debt securities — 800 800 Total cash equivalents $ 52,045 $ 3,297 $ 55,342 Short-term investments: Commercial paper $ — $ 2,909 $ 2,909 U.S. government and agency securities 2,451 5,992 8,443 Total short-term investments $ 2,451 $ 8,901 $ 11,352 Total $ 54,496 $ 12,198 $ 66,694 The following table summarizes the Company's available-for-sale securities by security type: As of December 31, 2022 Amortized Cost Unrealized Losses Fair Value Cash equivalents: Money market funds $ 52,045 $ — $ 52,045 Corporate debt securities 2,498 (1) 2,497 Non-U.S. debt securities 800 — 800 Total cash equivalents $ 55,343 $ (1) $ 55,342 Short-term investments: Commercial paper $ 2,909 $ — $ 2,909 U.S. government and agency securities 8,451 (8) 8,443 Total short-term investments $ 11,360 $ (8) $ 11,352 Total $ 66,703 $ (9) $ 66,694

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses are comprised of the following (in thousands): December 31, 2022 December 31, 2021 Compensation and related benefits $ 3,729 $ 2,812 Clinical and contract manufacturing expenses 1,800 508 Other 671 846 Total accrued expenses $ 6,200 $ 4,166

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Maturity of Operating Lease Liabilities	Future maturities of operating leases (with initial or remaining lease terms in excess of one year) as of December 31, 2022 are as follows (in thousands), excluding option renewals: As of December 31, 2022: 2023 $ 236 Thereafter — Total lease payments 236 Less: Imputed interest (3) Total $ 233

Stock-Based Compensation and _2

Stock-Based Compensation and Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock Option Activity	The table below summarizes the stock option activity, including options with market and performance conditions, for the year ended December 31, 2022 : Number of options Weighted average exercise price Weighted average remaining contractual term (years) Outstanding at beginning of period 1,201,209 $ 10.77 6.1 Options granted 306,986 9.41 Options exercised (17,288) 2.31 Options forfeited (25,960) 13.36 Options expired (15,760) 20.09 Outstanding at end of period 1,449,187 $ 10.43 6.9 Options exercisable at end of period 842,557 $ 10.19 5.9
Assumptions Used in Black-Scholes Pricing Model for New Grants	The weighted-average assumptions used to value the stock options using the Black-Scholes option-pricing were as follows : Year Ended December 31, 2022 2021 Risk-free interest rate 1.32% to 3.01% 0.56% to 1.05% Expected dividend yield —% —% Expected volatility 83.7% to 96.1% 77.2% to 90.3% Expected term (in years) 5.5 to 6.1 5.4 to 7.7 Weighted-average grant-date fair value per share $6.75 $10.65
Restricted Stock Activity	The table below summarizes the restricted stock units activity for the year ended December 31, 2022 : Number of restricted shares Weighted average grant date fair value Unvested at beginning of period 81,015 $ 8.91 Granted 14,550 9.18 Vested (25,771) 8.87 Unvested at end of period 69,794 $ 8.98 The following summarizes the weighted average fair value at the date of grant: Year Ended December 31, 2022 2021 Per grant of restricted stock unit $ 9.18 $ 10.32
Share-based Compensation Expense	Stock-based compensation expenses included in the Company’s consolidated statements of operations for the year ended December 31, 2022 and 2021 were (in thousands): Year Ended December 31, 2022 2021 Research and development $ 661 $ 809 General and administrative 1,659 2,070 Total $ 2,320 $ 2,879

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Benefit	The income tax benefit is as follows (in thousands): Year Ended December 31, 2022 2021 Current tax benefit - state and local $ 13 $ 636 Total income tax benefit $ 13 $ 636
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of deferred tax assets at December 31, 2022 and 2021 are presented below (in thousands): As of December 31, 2022 2021 Deferred tax assets: Net operating loss carryforwards $ 35,236 $ 32,281 Federal research and development tax credits 39,190 37,953 Capitalized research and development 4,018 — Share-based compensation 678 627 Capital loss carryforwards 41,144 41,144 Accrued compensation 221 192 Leasehold improvements and equipment 1,205 1,292 Other 2 26 Gross deferred tax assets 121,694 113,515 Less: valuation allowance (121,694) (113,515) Total deferred tax assets $ — $ —
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of income taxes at the statutory federal income tax rate to net income tax benefit included in the accompanying consolidated statements of operations is set forth in the following table: Year Ended December 31, 2022 2021 U.S. federal income tax benefit at the statutory rate (21.0) % (21.0) % State income taxes, net of federal taxes (2.1) (1.4) Federal tax credits (6.3) (8.9) Change in valuation allowance 26.3 26.5 Other 3.1 2.7 Effective income tax rate 0.0 % (2.1) %

Net Loss per Share of Common _2

Net Loss per Share of Common Stock (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Losses Per Share, Basic and Diluted	The following table presents the computation of basic and diluted loss per share of common stock (in thousands, except share and per share data) and the number of unexercised stock options and restricted stock units, which are common stock equivalents, that have been excluded from the diluted net loss calculation as their effect would have been anti-dilutive for all periods presented: Year Ended December 31, 2022 2021 Net loss $ (31,062) (30,430) Weighted-average shares outstanding - Basic and diluted 8,373,821 8,334,516 Net loss per share - Basic and diluted $ (3.71) $ (3.65) Anti-dilutive stock options 1,449,187 1,201,209 Anti-dilutive restricted stock units 69,794 81,015 Total anti-dilutive common stock equivalents excluded 1,518,981 1,282,224

Description of Business (Detail

Description of Business (Details) $ in Millions	Mar. 19, 2020	Mar. 18, 2020 shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 shares	Dec. 31, 2020 shares
Conversion of Stock [Line Items]
Stock conversion ratio		0.1111
Common stock, outstanding shares (in shares)		8,292,803	8,267,968	8,357,391
Cash, cash equivalents, and short-term investments | $			$ 67.4
Series A redeemable convertible preferred stock
Conversion of Stock [Line Items]
Stock conversion ratio		0.0873621142
Series B redeemable convertible preferred stock
Conversion of Stock [Line Items]
Stock conversion ratio		0.1996348626
Private Lumos Stockholders | NewLink Genetics
Conversion of Stock [Line Items]
Ownership percentage after transaction	0.50
Former Stockholders
Conversion of Stock [Line Items]
Ownership percentage after transaction	0.50
Common Stock
Conversion of Stock [Line Items]
Stock conversion ratio		0.1308319305
Common stock, outstanding shares (in shares)			8,267,968	8,357,391	8,305,269
Common Stock | Private Lumos Stockholders
Conversion of Stock [Line Items]
Aggregate shares received (in shares)		4,146,398

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Summary of Significant Accounting Policies and Recent Accounting Pronouncements [Line Items]
ESPP offering period	6 months
Expected dividend yield	0%
Stock Option
Summary of Significant Accounting Policies and Recent Accounting Pronouncements [Line Items]
Award vesting period	4 years
Stockholder ownership (percent)	10%
Incentive stock option exercise price for 10% shareholders (percent)	110%
Expected dividend yield	0%	0%
Restricted stock units
Summary of Significant Accounting Policies and Recent Accounting Pronouncements [Line Items]
Award vesting period	4 years
ESPP
Summary of Significant Accounting Policies and Recent Accounting Pronouncements [Line Items]
Award vesting period	6 months
ESPP stock discount rate	15%
Computer Equipment | Minimum
Summary of Significant Accounting Policies and Recent Accounting Pronouncements [Line Items]
Useful life	3 years
Computer Equipment | Maximum
Summary of Significant Accounting Policies and Recent Accounting Pronouncements [Line Items]
Useful life	5 years

License and Asset Purchase Ag_2

License and Asset Purchase Agreements (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2018 USD ($)	Jan. 11, 2021 USD ($)	Jul. 27, 2020 USD ($) installment	Mar. 18, 2020	Nov. 30, 2014
Deferred Revenue Arrangement [Line Items]
Payments for royalties		$ 1,000	$ 146
Merck | Licensing and collaboration revenue
Deferred Revenue Arrangement [Line Items]
Grant revenue		0	10
Merck | Royalty revenue
Deferred Revenue Arrangement [Line Items]
Grant revenue		1,500	$ 220
License and Collaborative Arrangement | Merck
Deferred Revenue Arrangement [Line Items]
Collaborative arrangement development milestone payments		14,000
Collaborative arrangement second indication development milestone payments		8,500
Collaborative arrangement tiered sales milestone payments		80,000
Net product sales milestone		$ 1,000,000
Value of PRV company is entitled to								60%
Value of PRV liability							40%
Value of PRV						$ 35,700
License and Collaborative Arrangement | Merck | Held-for-sale or Disposed of by Sale | PRV Transfer Agreement
Deferred Revenue Arrangement [Line Items]
Gross proceeds from sale						$ 60,000
Number of installments | installment						2
Cash from sale	$ 34,000
Consideration receivable					$ 26,000
License and Collaborative Arrangement | Merck | Minimum
Deferred Revenue Arrangement [Line Items]
Royalty obligation percent of annual product net sales		10%
License and Collaborative Arrangement | Merck | Maximum
Deferred Revenue Arrangement [Line Items]
Royalty obligation percent of annual product net sales		12%
Ammonett
Deferred Revenue Arrangement [Line Items]
Upfront payments				$ 3,500
Acquisition development milestone payments				17,000
Acquisition specific milestone payments				14,000
Acquisition sales milestone payments				$ 55,000

Financial Instruments - Summary

Financial Instruments - Summary of the Valuation of the Company’s Financial Instruments (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$ 55,342,000
Total short-term investments	11,352,000
Total assets	66,694,000
Short-term investments	11,352,000	$ 0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	2,909,000
U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	8,443,000
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	52,045,000
Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	2,497,000
Non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	800,000
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	52,045,000
Total short-term investments	2,451,000
Total assets	54,496,000
Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	0
Level 1 | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	2,451,000
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	52,045,000
Level 1 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0
Level 1 | Non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	3,297,000
Total short-term investments	8,901,000
Total assets	12,198,000
Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	2,909,000
Level 2 | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments	5,992,000
Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	0
Level 2 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	2,497,000
Level 2 | Non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	$ 800,000

Financial Instruments - Schedul

Financial Instruments - Schedule of Available for Sale by Security Type (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 66,703
Unrealized Losses	(9)
Fair Value	66,694
Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	55,343
Unrealized Losses	(1)
Fair Value	55,342
Cash Equivalents | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	52,045
Unrealized Losses	0
Fair Value	52,045
Cash Equivalents | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	2,498
Unrealized Losses	(1)
Fair Value	2,497
Cash Equivalents | Non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	800
Unrealized Losses	0
Fair Value	800
Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	11,360
Unrealized Losses	(8)
Fair Value	11,352
Short-Term Investments | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	2,909
Unrealized Losses	0
Fair Value	2,909
Short-Term Investments | U.S. government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	8,451
Unrealized Losses	(8)
Fair Value	$ 8,443

Accrued Expenses - Summary (Det

Accrued Expenses - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued expenses
Compensation and related benefits	$ 3,729	$ 2,812
Clinical and contract manufacturing expenses	1,800	508
Other	671	846
Total accrued expenses	$ 6,200	$ 4,166

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Operating lease weighted average discount rate	3%
Operating lease weighted average remaining lease term	8 months 12 days
Operating Lease Liabilities Payments Due
2023	$ 236
Thereafter	0
Total lease payments	236
Less: Imputed interest	(3)
Total	233
Costs for operating leases	$ 300	$ 300
Minimum
Lessee, Lease, Description [Line Items]
Term of operating lease contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of operating lease contract	2 years

Stock-Based Compensation and _3

Stock-Based Compensation and Employee Benefit Plans - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	May 09, 2019	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award
Unrecognized compensation cost		$ 4.3
Weighted average vesting period for non-vested option awards, in years		2 years 4 months 24 days
Defined contribution		$ 0.3	$ 0.3
Discretionary contribution amount			$ 0.1
2009 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Plan term		10 years
Evergreen increase	3%
Number of shares remained available for issuance (in shares)		426,437
2010 Non-Employee Directors' Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares remained available for issuance (in shares)		5,624
2010 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares remained available for issuance (in shares)		48,644
2010 Employee Stock Purchase Plan | ESPP
Share-based Compensation Arrangement by Share-based Payment Award
Increase in shares reserved for future issuance (in shares)		60,000

Stock-Based Compensation and _4

Stock-Based Compensation and Employee Benefit Plans - Stock Option Activity (Details) - Stock Option - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Numberof options
Outstanding at beginning of period (in shares)	1,201,209
Options granted (in shares)	306,986
Options exercised (in shares)	(17,288)
Options forfeited (in shares)	(25,960)
Options expired (in shares)	(15,760)
Outstanding at end of period (in shares)	1,449,187	1,201,209
Options exercisable at end of period (in shares)	842,557
Weighted average exercise price
Outstanding, weighted average exercise price at beginning of period (in dollars per share)	$ 10.77
Granted, weighted average exercise price (in dollars per share)	9.41
Exercised, weighted average exercise price (in dollars per share)	2.31
Forfeited, weighted average exercise price (in dollars per share)	13.36
Expired, weighted average exercise price (in dollars per share)	20.09
Outstanding, weighted average exercise price at end of period (in dollars per share)	10.43	$ 10.77
Exercisable, weighted average exercise price (in dollars per share)	$ 10.19
Outstanding, weighted average remaining contractual term, in years	6 years 10 months 24 days	6 years 1 month 6 days
Exercisable, weighted average remaining contractual term, in years	5 years 10 months 24 days

Stock-Based Compensation and _5

Stock-Based Compensation and Employee Benefit Plans - Range of Assumptions Used (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award
Expected dividend yield	0%
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award
Expected dividend yield	0%	0%
Weighted-average grant-date fair value per share (in dollars per share)	$ 6.75	$ 10.65
Stock Option | Minimum
Share-based Compensation Arrangement by Share-based Payment Award
Risk-free interest rate	1.32%	0.56%
Expected volatility	83.70%	77.20%
Expected term (in years)	5 years 6 months	5 years 4 months 24 days
Stock Option | Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Risk-free interest rate	3.01%	1.05%
Expected volatility	96.10%	90.30%
Expected term (in years)	6 years 1 month 6 days	7 years 8 months 12 days

Stock-Based Compensation and _6

Stock-Based Compensation and Employee Benefit Plans - Restricted Stock Activity (Details) - Restricted Stock - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Number of restricted shares
Unvested at beginning of period (in shares)	81,015
Granted (in shares)	14,550
Vested (in shares)	(25,771)
Unvested at end of period (in shares)	69,794	81,015
Weighted average grant date fair value
Weighted average grant date fair value at beginning of period (in dollars per share)	$ 8.91
Granted, weighted average grant date fair value (in dollars per share)	9.18	$ 10.32
Vested, weighted average grant date fair value (in dollars per share)	8.87
Weighted average grant date fair value at end of period (in dollars per share)	$ 8.98	$ 8.91

Stock-Based Compensation and _7

Stock-Based Compensation and Employee Benefit Plans - Allocated Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 2,320	$ 2,879
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	661	809
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 1,659	$ 2,070

Long-Term Debt and Conversion_2

Long-Term Debt and Conversion to Royalty Obligation (Details) - IDED - Loans payable - USD ($) $ in Millions	Dec. 31, 2022	Mar. 31, 2005
Debt Instrument [Line Items]
Loan available balance		$ 6
Outstanding balance	$ 6

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Income Tax Examination [Line Items]
Income tax benefit		$ 13,000	$ 636,000
Net deferred tax liability		0	0
Increase in amount of valuation allowance		8,200,000	$ 8,200,000
Operating loss carryforwards		141,500,000
Reserve for uncertain tax positions		0
Change in reserve for uncertain tax positions	$ 1,200,000
Income Tax Benefit
Income Tax Examination [Line Items]
Change in reserve for uncertain tax positions	600,000
Other Income
Income Tax Examination [Line Items]
Change in reserve for uncertain tax positions	300,000
General and administrative
Income Tax Examination [Line Items]
Change in reserve for uncertain tax positions	$ 300,000
Research Tax Credit Carryforward
Income Tax Examination [Line Items]
Tax credit carryforward		39,200,000
Domestic Tax Authority | Capital Loss Carryforward
Income Tax Examination [Line Items]
Tax credit carryforward		$ 164,600,000

Income Taxes - Income Tax Benef

Income Taxes - Income Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Current tax benefit - state and local	$ 13	$ 636
Total income tax benefit	$ 13	$ 636

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 35,236	$ 32,281
Federal research and development tax credits	39,190	37,953
Capitalized research and development	4,018	0
Share-based compensation	678	627
Capital loss carryforwards	41,144	41,144
Accrued compensation	221	192
Leasehold improvements and equipment	1,205	1,292
Other	2	26
Gross deferred tax assets	121,694	113,515
Less: valuation allowance	(121,694)	(113,515)
Total deferred tax assets	$ 0	$ 0

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Taxes (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
U.S. federal income tax benefit at the statutory rate	(21.00%)	(21.00%)
State income taxes, net of federal taxes	(2.10%)	(1.40%)
Federal tax credits	(6.30%)	(8.90%)
Change in valuation allowance	26.30%	26.50%
Other	3.10%	2.70%
Effective income tax rate	0%	(2.10%)

Stockholders' Equity (Details)

Stockholders' Equity (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Dec. 30, 2020 USD ($) $ / shares	Dec. 31, 2022 USD ($) vote $ / shares shares	Aug. 16, 2022 shares	Dec. 31, 2021 $ / shares shares
Subsidiary, Sale of Stock [Line Items]
Number of votes each share is entitled to | vote		1
Common stock, authorized shares (in shares)		75,000,000		75,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01		$ 0.01
Number of shares authorized to be repurchased (in shares)			3,000,000
Stock repurchased and retired at cost (in shares)		137,526
Stock repurchased and retired during period, value | $		$ 675
Amount of stock repurchased during period | $		$ 675
Blank check preferred stock, authorized shares (in shares)		5,000,000		5,000,000
Blank check preferred stock, par value (in dollars per share) | $ / shares		$ 0.01		$ 0.01
Blank check preferred stock, outstanding shares (in shares)		0		0
Controlled Equity Offering
Subsidiary, Sale of Stock [Line Items]
Value of shares issued | $	$ 50,000
Commission fee	3%
Number of shares of common stock sold (in shares)		0

Net Loss per Share of Common _3

Net Loss per Share of Common Stock - Net Loss Per Share Computation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net loss	$ (31,062)	$ (30,430)
Weighted-average shares outstanding - Basic (in shares)	8,373,821	8,334,516
Weighted-average shares outstanding - Diluted (in shares)	8,373,821	8,334,516
Net loss per share - Basic (in dollars per share)	$ (3.71)	$ (3.65)
Net loss per share - Diluted (in dollars per share)	$ (3.71)	$ (3.65)
Antidilutive securities (in shares)	1,518,981	1,282,224
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	1,449,187	1,201,209
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	69,794	81,015

Restructuring and Severance C_2

Restructuring and Severance Charges - Narrative (Details) - USD ($)			3 Months Ended		12 Months Ended
	Apr. 16, 2021	Feb. 04, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Restructuring Charges
Accelerated vesting expense				$ 700,000	$ 0
Chief Medical Officer
Restructuring Charges
Accelerated vesting expense		$ 700,000
Chief Financial Officer
Restructuring Charges
Accelerated vesting expense	$ 900,000
Extension of exercise period	24 months
Accelerated cost			$ 400,000
Accrued severance compensation						$ 900,000