Longeveron (LGVN) 10-Q 14 May 24 2024 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2024	May 10, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Mar. 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Information [Line Items]
Entity Registrant Name	Longeveron Inc.
Entity Central Index Key	0001721484
Entity File Number	001-40060
Entity Tax Identification Number	47-2174146
Entity Incorporation, State or Country Code	DE
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Contact Personnel [Line Items]
Entity Address, Address Line One	1951 NW 7th Avenue
Entity Address, Address Line Two	Suite 520
Entity Address, City or Town	Miami
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33136
Entity Phone Fax Numbers [Line Items]
City Area Code	(305)
Local Phone Number	909-0840
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	LGVN
Security Exchange Name	NASDAQ
Class A Common Stock
Entity Listings [Line Items]
Entity Common Stock, Shares Outstanding		4,864,619
Class B Common Stock
Entity Listings [Line Items]
Entity Common Stock, Shares Outstanding		1,484,005

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets
Cash and cash equivalents	$ 1,940	$ 4,949
Marketable securities	351	412
Prepaid expenses and other current assets	1,288	376
Accounts and grants receivable	178	111
Total current assets	3,757	5,848
Property and equipment, net	2,348	2,529
Intangible assets, net	2,263	2,287
Operating lease asset	1,139	1,221
Other assets	190	193
Total assets	9,697	12,078
Current liabilities:
Accounts payable	1,467	638
Accrued expenses	2,401	2,152
Current portion of lease liability	601	593
Deferred revenue	826	506
Total current liabilities	5,295	3,889
Long-term liabilities:
Lease liability	1,295	1,448
Other liabilities	66
Total long-term liabilities	1,361	1,448
Total liabilities	6,656	5,337
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.001 par value per share, 5,000,000 shares authorized, no shares issued and outstanding at March 31, 2024, and December 31, 2023.
Additional paid-in capital	92,080	91,823
Stock subscription receivable		(100)
Accumulated deficit	(89,042)	(84,984)
Accumulated other comprehensive gain	1
Total stockholders’ equity	3,041	6,741
Total liabilities and stockholders’ equity	9,697	12,078
Class A common stock
Stockholders’ equity:
Common stock value	1	1
Class B common stock
Stockholders’ equity:
Common stock value	$ 1	$ 1

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parentheticals) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Preferred stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Class A common stock
Common stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	84,295,000	84,295,000
Common stock, shares issued	1,034,283	1,025,183
Common stock, shares outstanding	1,034,283	1,025,183
Class B common stock
Common stock, par value (in Dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	15,705,000	15,705,000
Common stock, shares issued	1,484,005	1,485,560
Common stock, shares outstanding	1,484,005	1,485,560

Condensed Statements of Operati

Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Total revenues	$ 548	$ 279
Cost of revenues	219	203
Gross profit	329	76
Operating expenses
General and administrative	2,200	2,012
Research and development	2,219	2,780
Total operating expenses	4,419	4,792
Loss from operations	(4,090)	(4,716)
Other income and (expenses)
Other income, net	32	69
Total other income, net	32	69
Net loss	$ (4,058)	$ (4,647)
Basic and diluted net loss per share (in Dollars per share)	$ (1.61)	$ (2.21)
Basic and diluted weighted average common shares outstanding (in Shares)	2,513,587	2,103,362
Clinical trial revenue
Revenues
Total revenues	$ 515	$ 238
Contract manufacturing revenue
Revenues
Total revenues	33
Grant revenue
Revenues
Total revenues		$ 41

Condensed Statements of Opera_2

Condensed Statements of Operations (Unaudited) (Parentheticals) - $ / shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Diluted net loss per share	$ (1.61)	$ (2.21)
Diluted weighted average common shares outstanding	2,513,587	2,103,362

Condensed Statements of Compreh

Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (4,058)	$ (4,647)
Other comprehensive gains:
Net unrealized gains on available-for-sale securities	1	58
Total comprehensive loss	$ (4,057)	$ (4,589)

Condensed Statements of Stockho

Condensed Statements of Stockholders’ Equity (Unaudited) - USD ($) $ in Thousands	Common Stock Class A	Common Stock Class B	Subscription Receivable	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2022	$ 1	$ 1	$ (100)	$ 83,731	$ (62,773)	$ (357)	$ 20,503
Balance (in Shares) at Dec. 31, 2022	612,732	1,489,109
Conversion of Class B common stock for Class A common stock
Conversion of Class B common stock for Class A common stock (in Shares)	2,000	(2,000)
Class A common stock, issued for RSUs vested
Class A common stock, issued for RSUs vested (in Shares)	2,017
Class A common stock, held for taxes on RSUs vested				(17)			(17)
Class A common stock, held for taxes on RSUs vested (in Shares)	(444)
Equity-based compensation				421			421
Unrealized gain attributable to change in market value of available for sale investments						58	58
Net loss					(4,647)		(4,647)
Balance at Mar. 31, 2023	$ 1	$ 1	(100)	84,135	(67,420)	(299)	16,318
Balance (in Shares) at Mar. 31, 2023	616,305	1,487,109
Balance at Dec. 31, 2023	$ 1	$ 1	(100)	91,823	(84,984)		6,741
Balance (in Shares) at Dec. 31, 2023	1,025,183	1,485,560
Conversion of Class B common stock for Class A common stock
Conversion of Class B common stock for Class A common stock (in Shares)	1,555	(1,555)
Class A common stock, issued for RSUs vested
Class A common stock, issued for RSUs vested (in Shares)	4,556
Class A common stock, held for taxes on RSUs vested				(21)			(21)
Class A common stock, held for taxes on RSUs vested (in Shares)	(1,745)
Class A common stock, issued for PSUs vested
Class A common stock, issued for PSUs vested (in Shares)	8,002
Class A common stock, held for taxes on PSUs vested				(17)			(17)
Class A common stock, held for taxes on PSUs vested (in Shares)	(3,268)
Collection of stock subscription receivable			100				100
Equity-based compensation				295			295
Unrealized gain attributable to change in market value of available for sale investments						1	1
Net loss					(4,058)		(4,058)
Balance at Mar. 31, 2024	$ 1	$ 1		$ 92,080	$ (89,042)	$ 1	$ 3,041
Balance (in Shares) at Mar. 31, 2024	1,034,283	1,484,005

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net loss	$ (4,058)	$ (4,647)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	252	238
Interest earned on marketable securities		72
Equity-based compensation	295	421
Changes in operating assets and liabilities:
Accounts and grants receivable	(67)	122
Prepaid expenses and other current assets	(912)	(694)
Other assets	3	(2)
Accounts payable	829	(1,294)
Deferred revenue	320	50
Accrued expenses	249	(38)
Operating lease asset and lease liability	(63)	(76)
Other liabilities	66
Net cash used in operating activities	(3,086)	(5,848)
Cash flows from investing activities
Proceeds from the sale of marketable securities	61	461
Acquisition of property and equipment	(16)	(42)
Acquisition of intangible assets	(31)	(73)
Net cash provided by investing activities	14	346
Cash flows from financing activities
Payments for taxes on RSUs vested	(37)	(17)
Proceeds from stock subscription receivable	100
Net cash provided by (used in) financing activities	63	(17)
Change in cash and cash equivalents	(3,009)	(5,519)
Cash and cash equivalents at beginning of the period	4,949	10,503
Cash and cash equivalents at end of the period	1,940	4,984
Supplement Disclosure of Non-cash Investing and Financing Activities:
Vesting of RSUs and PSUs into Class A common stock	$ (97)	$ (68)

Nature of Business, Basis of Pr

Nature of Business, Basis of Presentation, and Liquidity	3 Months Ended
	Mar. 31, 2024
Nature of Business, Basis of Presentation, and Liquidity [Abstract]
Nature of Business, Basis of Presentation, and Liquidity	1. Nature of Business, Basis of Presentation, and Liquidity Nature of business: Longeveron was formed as a Delaware limited liability company on October 9, 2014, and was authorized to transact business in Florida on December 15, 2014. On February 12, 2021, Longeveron, LLC converted its corporate form (the “Corporate Conversion”) from a Delaware limited liability company (Longeveron, LLC) to a Delaware corporation, Longeveron Inc. (the “Company,” “Longeveron” or “we,” “us,” or “our”). The Company is a clinical stage biotechnology company developing cellular therapies for specific aging-related and life-threatening conditions. The Company operates out of its leased facilities in Miami, Florida. The Company’s product candidates are currently in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid technological change and substantial competition from, among others, existing pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, partners and consultants. The accompanying interim condensed balance sheet as of March 31, 2024, and the condensed statements of operations, statements of comprehensive loss, stockholders’ equity, and cash flows for the three months ended March 31, 2024 and 2023, are unaudited. The unaudited condensed financial statements have been prepared according to the rules and regulations of the Securities and Exchange Commission (“SEC”) and, therefore, certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) have been omitted. In the opinion of management, the accompanying unaudited condensed financial statements for the periods presented reflect all adjustments which are normal and recurring, and necessary to fairly state the financial position, results of operations, and cash flows of the Company. Liquidity: Since inception, the Company has primarily been engaged in organizational activities, including raising capital, and research and development activities. The Company does not yet have a product that has been approved by the U.S. Food and Drug Administration (“FDA”), and has only generated revenues from grants, clinical trials and contract manufacturing. The Company has not yet achieved profitable operations or generated positive cash flows from operations. The Company intends to continue its efforts to raise additional funds via equity financing, develop its intellectual property, and secure regulatory approvals to commercialize its products. There is no assurance that profitable operations, if achieved, could be sustained on a continuing basis. Further, the Company’s future operations are dependent on the success of the Company’s efforts to raise additional capital, its research and commercialization efforts, regulatory approval, and, ultimately, the market acceptance of the Company’s approved products, if any. These condensed financial statements do not include adjustments that might result from the outcome of these uncertainties. The Company has incurred recurring losses from operations since its inception, including a net loss of $4.1 million and $4.6 million for the three months ended March 31, 2024 and 2023, respectively. In addition, as of March 31, 2024, the Company had an accumulated deficit of $89.0 million. The Company expects to continue to generate operating losses in the foreseeable future. As of March 31, 2024, the Company had cash and cash equivalents of $1.9 million and marketable securities of $0.4 million. The Company has prepared a cash flow forecast which indicates that it does not have sufficient cash to meet its minimum expenditure commitments for one year from the date these condensed financial statements are available to be issued and therefore needs to raise additional funds to continue as a going concern. As a result, there is substantial doubt about the Company’s ability to continue as a going concern. To address the future funding requirements, management has undertaken the following initiatives: ● the Company may seek additional capital in the private and/or public equity markets, to continue its operations, respond to competitive pressures, develop new products and services, and to support new strategic partnerships. The Company is evaluating additional equity/debt financing opportunities on an ongoing basis and may execute them when appropriate. However, there can be no assurances that the Company can consummate such a transaction or consummate a transaction at favorable pricing; ● the Company will attempt to use equity instruments to provide a portion of the compensation due to vendors and collaboration partners; ● the Company plans to pursue potential partnerships for pipeline programs, however, there can be no assurances that it can consummate such transactions; ● the Company will continue to support its Bahamas Registry to generate revenue; and ● since 2016 our clinical programs have received over $16.0 million in competitive extramural grant awards ($11.5 million which has been directly awarded to us and which are recognized as revenue when the performance obligations are met) from the National Institutes of Health (“NIH”), Alzheimer’s Association, and Maryland Stem Cell Research Fund (“MSCRF”), and the Company plans to submit additional contract and grant applications for further support of its programs with various funding agencies. The Company’s condensed financial statements do not include any adjustments to the assets’ carrying amount, to the expenses presented and to the reclassification of the condensed balance sheets items that could be necessary should the Company be unable to continue its operations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of presentation: The condensed financial statements of the Company were prepared in accordance with U.S. GAAP. Certain reclassifications have been made to prior year condensed financial statements to conform to classifications used in the current year. These reclassifications had no impact on net loss, stockholders’ equity or cash flows as previously reported. Reverse Stock Split: On March 26, 2024, the Company effected a reverse stock split of the outstanding shares of its Class A common stock and Class B common stock on a one-for-10 (1:10) basis (the “Reverse Stock Split”). The Reverse Stock Split became effective at 11:59 p.m. Eastern Time on March 26, 2024 via a certificate of amendment to the Company’s Certificate of Incorporation filed with the Secretary of State of the State of Delaware. At the effective time of the Reverse Stock Split, every 10 shares of the Company’s Class A common stock and Class B common stock, whether issued and outstanding or held by the Company as treasury stock, were automatically combined and converted (without any further act) into one fully paid and nonassessable share of Class A common stock or Class B common stock, respectively, subject to rounding up of fractional shares to the nearest whole number of shares resulting from the Reverse Stock Split without any change in the par value per share. All share, per share, option, warrant, equity award, and other derivative security numbers and exercise prices appearing in this Quarterly Report on Form 10-Q and the accompanying condensed financial statements have been adjusted to give effect to the Reverse Stock Split for all prior periods presented. However, the Company’s annual, other periodic, and current reports, and all other information and documents incorporated by reference into this Quarterly Report on Form 10-Q that were filed prior to March 19, 2024, do not give effect to the Reverse Stock Split. Use of estimates: The presentation of condensed financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Accounting Standard Updates: A variety of proposed or otherwise potential accounting standards are currently under consideration by standard-setting organizations and certain regulatory agencies. Because of the tentative and preliminary nature of such proposed standards, management has not yet determined the effect, if any, that the implementation of such proposed standards would have on the Company’s condensed financial statements. In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, “Improvements to Income Tax Disclosures”. The amendments in this ASU change disclosure requirements for various items, including effective tax rate reconciliations and cash taxes paid. This ASU is effective for public companies for the financial reporting periods beginning on January 1, 2025, with early adoption permitted. We have not adopted ASU 2023-09 for our financial reporting period ending December 31, 2023, and will continue to evaluate early adoption for our financial reporting period ending December 31, 2024. Cash and cash equivalents: The Company considers cash to consist of cash on hand and temporary investments having an original maturity of 90 days or less that are readily convertible into cash. Marketable securities: Marketable securities at March 31, 2024 and December 31, 2023 consisted of marketable fixed income securities, primarily corporate bonds which are categorized as available for sale securities and are thus marked to market and stated at fair value in accordance with ASC 820 Fair Value Measurement Accounts and grants receivable: Accounts and grants receivable include amounts due from customers, granting institutions and others. The amounts as of March 31, 2024, and December 31, 2023 are certain to be collected, and no amount has been recognized for doubtful accounts. In addition, for the clinical trial revenue, most participants pay in advance of treatment. Advanced grant funds and prepayments for the clinical trial revenue are recorded to deferred revenue. Advance contract manufacturing payments are recorded to deferred revenue. Accounts and grants receivable by source, as of (in thousands): March 31, December 31, National Institutes of Health – Grant $ 96 $ 96 Accounts receivable from customers 82 15 Total $ 178 $ 111 Deferred offering costs: The Company recorded certain legal, professional and other third-party fees that were directly associated with in-process equity financings as deferred offering costs until the applicable equity financing was consummated. After consummation of an equity financing, these costs are recorded in stockholders’ equity as a reduction of proceeds generated as a result of the offering. Property and equipment: Property and equipment, including improvements that extend the useful lives of related assets, are recorded at cost, while maintenance and repairs are charged to operations as incurred. Depreciation is calculated using the straight-line method based on the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the estimated useful life of the asset or the original term of the lease. Depreciation expense is recorded in the research and development line of the condensed statements of operations as the assets are primarily related to the Company’s clinical programs. Intangible assets: Intangible assets include payments on license agreements with the Company’s co-founder and Chief Scientific Officer (“CSO”) and the University of Miami (“UM”) (see Note 9) and legal costs incurred related to patents and trademarks. License agreements have been recorded at the value of cash consideration, common stock and membership units transferred to the respective parties when acquired. Payments for license agreements are amortized using the straight-line method over the estimated term of the agreements, which range from 5-20 years. Patents are amortized over their estimated useful life, once issued. The Company considers trademarks to have an indefinite useful life and evaluates them for impairment on an annual basis. Amortization expense is recorded in the research and development line of the condensed statements of operations as the assets are primarily related to the Company’s clinical programs. Impairment of Long-Lived Assets: The Company evaluates long-lived assets for impairment, including property and equipment and intangible assets, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value. Any resulting impairment loss is reflected in the condensed statements of operations. Upon evaluation, management determined that there was no impairment of long-lived assets during the three months ended March 31, 2024 and 2023. Deferred revenue: The unearned portion of advanced grant funds and prepayments for clinical trial and contract manufacturing revenues, which will be recognized as revenue when the Company meets the respective performance obligations, has been presented as deferred revenue in the accompanying condensed balance sheets. For both of the three months ended March 31, 2024 and 2023, the Company recognized $0 of funds that were previously classified as deferred revenue due to the MSCRF – Technology Development Corporation (“TEDCO”) – grant Acute Respiratory Distress Syndrome (“ARDS”) program being discontinued. The $0.4 million recorded as deferred revenue will be reversed when the funds are returned to MSCRF – TEDCO. Revenue recognition: The Company recognizes revenue when performance obligations related to respective revenue streams are met. For grant revenue, the Company considers the performance obligation met when the grant related expenses are incurred or supplies and materials are received. The Company is paid in tranches pursuant to terms of the related grant agreements, and then applies payments based on regular expense reimbursement submissions to grantors. There are no remaining performance obligations or variable consideration once grant expense reporting to the grantor is complete. For clinical trial revenue, the Company considers the performance obligation met when the participant has received the treatment. The Company usually receives prepayment for these services or receives payment at the time the treatment is provided, and there are no remaining performance obligations or variable consideration once the participant receives the treatment. For contract manufacturing revenue, the Company considers the performance obligation met when the contractual obligation and/or statement of work has been satisfied. Payment terms may vary depending on specific contract terms. There are no significant judgments affecting the determination of the amount and timing of revenue recognition. Revenue by source (in thousands): Three months ended 2024 2023 NIH - grant $ - $ 41 Clinical trial revenue 515 238 Contract manufacturing 33 - Total $ 548 $ 279 The Company records cost of revenues based on expenses directly related to revenue. For grants, the Company records allocated expenses for research and development costs to a grant as a cost of revenues. For the clinical trial revenue, directly related expenses for that program are expensed as incurred. These expenses are similar to those described under “Research and development expense” below. For the contract manufacturing, the Company records costs incurred under the contract as cost of revenues. Research and development expense: Research and development costs are charged to expense when incurred in accordance with ASC 730 Research and Development Concentrations of credit risk: Financial instruments which potentially subject the Company to credit risk consist principally of cash and cash equivalents, marketable securities and accounts and grants receivable. Cash and cash equivalents are held in U.S. financial institutions. At times, the Company may maintain balances in excess of the federally insured amounts. Income taxes: The Company’s tax provision consists of taxes currently payable or receivable, plus any change during the period in deferred tax assets and liabilities. The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their respective tax basis. 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 income in the period that includes the enactment date. In addition, a valuation allowance is established to reduce any deferred tax asset for which it is determined that it is more likely than not that some portion of the deferred tax asset will not be realized. The Company’s tax provision was $0 for the three months ended March 31, 2024 and 2023 due to net operating losses. The Company has not recorded any tax benefit for the net operating losses incurred due to the offset created by the Company’s valuation allowance. The Company recognizes the tax benefits from uncertain tax positions that the Company has taken or expects to take on a tax return. In the unlikely event an uncertain tax position exists in which the Company could incur income taxes, the Company would evaluate whether there is a probability that the uncertain tax position taken would be sustained upon examination by a taxing authority. Reserves for uncertain tax positions would then be recorded if the Company determined it is probable that either a position would not be sustained upon examination, or a payment would have to be made to a taxing authority and the amount was reasonably estimable. As of March 31, 2024 and December 31, 2023, the Company does not believe it has any uncertain tax positions that would result in the Company having a liability to a taxing authority. It is the Company’s policy to expense any interest and penalties associated with its tax obligations when they are probable and estimable. Equity-based compensation: The Company accounts for equity-based compensation expense by the measurement and recognition of compensation expense for stock-based awards based on estimated fair values on the date of grant. The fair value of the stock options is estimated at the date of the grant using the Black-Scholes option-pricing model. The Black-Scholes option-pricing model requires the input of highly subjective assumptions, the most significant of which are the expected share price volatility, the expected life of the stock option award, the risk-free rate of return, and dividends during the expected term. Because the option-pricing model is sensitive to changes in the input assumptions, different determinations of the required inputs may result in different fair value estimates of the stock options. Neither the Company’s stock options nor its restricted stock units (“RSUs”) trade on an active market. Volatility is a measure of the amount by which a financial variable, such as a stock price, has fluctuated (historical volatility) or is expected to fluctuate (expected volatility) during a period. Given the Company’s limited historical data, the Company utilizes the average historical volatility of similar publicly traded companies that are in the same industry. The risk-free interest rate is the average U.S. treasury rate (having a term that most closely approximates the expected life of the option) for the period in which the stock option was granted. The expected life is the period of time that the stock options granted are expected to remain outstanding. Stock options granted have a maximum term of ten years. The Company has insufficient historical data to utilize in determining its expected life assumptions and, therefore, uses the simplified method for determining expected life.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2024
Marketable Securities [Abstract]
Marketable securities	3. Marketable securities The following is summary of marketable securities that the Company measures at fair value (in thousands): Fair Value at March 31, 2024 Level 1 Level 2 Level 3 Total Corporate bonds $ - $ 351 $ - $ 351 Money market funds (1) 796 - - 796 Accrued income 13 - - 13 Total marketable securities $ 809 $ 351 $ - $ 1,160 (1) Money market funds are included in cash and cash equivalents in the condensed balance sheet. Fair Value at December 31, 2023 Level 1 Level 2 Level 3 Total Corporate bonds $ - $ 412 $ - $ 412 Money market funds (1) 3,948 - - 3,948 Accrued income 16 - - 16 Total marketable securities $ 3,964 $ 412 $ - $ 4,376 (1) Money market funds are included in cash and cash equivalents in the condensed balance sheet. As of March 31, 2024 and December 31, 2023, the Company reported accrued interest receivable related to marketable securities of less than $0.1 million. These amounts are recorded in other assets on the condensed balance sheets and are not included in the carrying value of the marketable securities.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2024
Property and Equipment, Net [Abstract]
Property and equipment, net	4. Property and equipment, net Major components of property and equipment are as follows (in thousands): Useful Lives March 31, December 31, Leasehold improvements 10 years $ 4,328 $ 4,328 Furniture/Lab equipment 7 years 2,499 2,483 Computer equipment 5 years 120 120 Software/Website 3 years 38 38 Total property and equipment 6,985 6,969 Less accumulated depreciation and amortization 4,637 4,440 Property and equipment, net $ 2,348 $ 2,529 Depreciation and amortization expense amounted to approximately $0.2 million for the three-month periods ended March 31, 2024 and 2023.

Intangible Assets, Net

Intangible Assets, Net	3 Months Ended
	Mar. 31, 2024
Intangible Assets, Net [Abstract]
Intangible assets, net	5. Intangible assets, net Major components of intangible assets as of March 31, 2024, are as follows (in thousands): Useful Lives Cost Accumulated Total License agreements 20 years $ 2,043 $ (964 ) $ 1,079 Patent costs 980 - 980 Trademark costs 204 - 204 Total $ 3,227 $ (964 ) $ 2,263 Major components of intangible assets as of December 31, 2023, are as follows: Useful Lives Cost Accumulated Total License agreements 20 years $ 2,043 $ (909 ) $ 1,134 Patent costs 959 - 959 Trademark costs 194 - 194 Total $ 3,196 $ (909 ) $ 2,287 Amortization expense related to intangible assets amounted to approximately $0.1 million for each of the three-month periods ended March 31, 2024 and 2023. Future amortization expense for intangible assets as of March 31, 2024 is as follows (in thousands): Year Ending December 31, Amount 2024 (remaining nine months) $ 168 2025 224 2026 224 2027 224 2028 224 Thereafter 15 Total $ 1,079

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Leases	6. Leases The Company records a right-of-use operating lease asset and a lease liability related to its operating leases (there are no finance leases). The Company’s corporate office lease expires in March 2027. As of March 31, 2024, the operating lease asset and lease liability were approximately $1.1 million and $1.9 million, respectively. As of December 31, 2023, the operating lease asset and lease liability were approximately $1.2 million and $2.0 million, respectively. Future minimum payments under the operating leases as of March 31, 2024, are as follows (in thousands): Year Ending December 31, Amount 2024 (remaining nine months) $ 511 2025 682 2026 682 2027 170 Total 2,046 Less: Interest 149 Present value of operating lease liability $ 1,896 During each of the three months ended March 31, 2024 and 2023, the Company incurred approximately $0.2 million of total lease costs that are included in the general and administrative expenses in the condensed statements of operations.

Stockholders_ Equity

Stockholders’ Equity	3 Months Ended
	Mar. 31, 2024
Stockholders’ Equity [Abstract]
Stockholders’ Equity	7. Stockholders’ Equity Class A Common Stock Restricted Stock Units (“RSUs”) are taxable upon vesting based on the market value on the date of vesting. The Company is required to make mandatory tax withholding for the payment and satisfaction of income tax, social security tax, payroll tax, or payment on account of other tax related to withholding obligations that arise by reason of vesting of an RSU. The taxable income is calculated by multiplying the number of vested RSUs for each individual by the closing share price as of the vesting date and a tax liability is calculated based on each individual’s tax bracket. The shares withheld are available for reissuance pursuant to the Company’s 2021 Incentive Award Plan. During the three months ended March 31, 2024, no stock options were exercised for Class A common stock shares. Class B Common Stock In connection with the Corporate Conversion, 200,000 outstanding Series A and B units were converted into 1,570,284 shares of our unregistered Class B common stock. Holders of Class A common stock generally have rights identical to holders of Class B common stock, except that holders of Class A common stock are entitled to one (1) vote per share and holders of Class B common stock are entitled to five (5) votes per share. The holders of Class B common stock may convert each share of Class B common stock into one share of Class A common stock at any time at the holder’s option. Class B common stock is not publicly tradable. During the three months ended March 31, 2024, stockholders exchanged 1,555 shares of Class B common stock for 1,555 shares of Class A common stock. During the year ended December 31, 2023, stockholders exchanged 3,555 shares of Class B common stock for 3,555 shares of Class A common stock. Warrants As part of the Company’s initial public offering (“IPO”), the underwriter received warrants to purchase 10,640 shares of Class A common stock. The warrants are exercisable at any time and from time to time, in whole or in part, during the four and a half-year period commencing August 12, 2021, at a price of $120.00 per share and the fair value of warrants was approximately $0.5 million. During 2021, the underwriters assigned 9,576 of the warrants to its employees. As of December 31, 2023, 5,107 warrants have been exercised for Class A common stock shares at an exercise price of $120.00 for $612,732. As part of the 2021 PIPE Offering, the Company issued 116,935 warrants to investors to purchase up to a number of shares of Class A common stock equal to the number of shares of Class A common stock purchased by such investor in the offering, at an exercise price of $175.00 per share (the “Purchaser Warrants”) The purchaser warrants were immediately exercisable, expire five years from the date of issuance and have certain downward pricing adjustment mechanisms, subject to a floor, as set forth in greater detail in the purchase warrants. In addition, the Company granted the underwriters warrants, under similar terms, to purchase 4,679 shares of Class A common stock, at an exercise price of $175.00 per share. On August 16, 2023, the Company announced its Stock Rights Offering, which triggered the downward pricing mechanism on the Purchaser Warrants, at which time these warrants were adjusted downward to an exercise price of $52.50 for the period remaining through expiration. This resulted in a deemed dividend to common stockholders of approximately $0.8 million for the change in the fair value of the warrants using a Black-Scholes pricing model. As part of the October 2023 Offering, the Company issued an aggregate of 242,425 Series A warrants and 242,425 Series B warrants to the purchaser to purchase up to a number of shares of Class A common stock. The Series A warrants have an exercise price of $16.50 per share and have a term of five and one-half years from the date of issuance. The Series B warrants have an exercise price of $16.50 per share and have a term of eighteen months from the date of issuance. Both the Series A and Series B warrants became exercisable as of December 26, 2023, following stockholder approval. In addition, the Company granted the underwriters warrants, under similar terms, to purchase 16,971 shares of Class A common stock, at an exercise price of $20.625 per share. As part of the December 2023 Offering, the Company sold unregistered long-term warrants to purchase an aggregate of 135,531 warrants to the purchase shares of Class A common stock. These unregistered warrants have an exercise price of $16.20 per share, became immediately issuable upon issuance, and expire on June 20, 2029. In addition, the Company granted the underwriters warrants, under similar terms, to purchase 9,489 shares of Class A common stock, at an exercise price of $21.813 per share.

Equity Incentive Plan

Equity Incentive Plan	3 Months Ended
	Mar. 31, 2024
Equity Incentive Plan [Abstract]
Equity Incentive Plan	8. Equity Incentive Plan As part of the Company’s IPO, the Company adopted and approved the 2021 Incentive Award Plan (“2021 Incentive Plan”). Under the 2021 Incentive Plan, the Company may grant cash and equity incentive awards to eligible service providers in order to attract, motivate and retain the talent for which the Company competes. RSUs As of March 31, 2024, and December 31, 2023, the Company had 7,933 and 11,239, respectively of RSUs outstanding (unvested). RSU activity for the three months ended March 31, 2024, was as follows: Number of Outstanding (unvested) at December 31, 2023 11,239 RSU granted 3,000 RSUs vested (3,306 ) RSU expired/forfeited (3,000 ) Outstanding (unvested) at March 31, 2024 7,933 Stock Options Stock options may be granted under the 2021 Incentive Plan. The exercise price of stock options is equal to the fair market value of the Company’s Class A common stock as of the grant date. Stock options historically granted have generally become exercisable over four years and expire ten years from the date of grant. The 2021 Incentive Plan provides for equity grants to be granted up to 5% of the outstanding common stock shares. As of March 31, 2024, there have been no stock options granted during 2024. The fair value of the options issued during 2023 were estimated using the Black-Scholes option-pricing model and had the following assumptions: a dividend yield of 0%; an expected life of 10 As of March 31, 2024 and December 31, 2023, the Company has recorded issued and outstanding options to purchase a total of 42,200 and 43,782 shares of Class A common stock, respectively, pursuant to the 2021 Incentive Plan, at a weighted average exercise price of $48.61 and $49.60 per share, respectively. For the three months ended March 31, 2024: Number of Stock options vested (based on ratable vesting) 22,599 Stock options unvested 19,605 Total stock options outstanding at March 31, 2024 42,204 For the year ended December 31, 2023: Number of Stock options vested (based on ratable vesting) 16,091 Stock options unvested 27,695 Total stock options outstanding at December 31, 2023 43,786 Stock option activity for the three months ended March 31, 2024, was as follows: Number of Weighted Outstanding at December 31, 2023 43,786 $ 49.60 Options granted - - Options exercised - - Options expired/forfeited (1,582 ) (77.29 ) Outstanding at March 31, 2024 42,204 $ 48.61 For the three months ended March 31, 2024 and 2023, the equity-based compensation expense amounted to approximately $0.3 million and $0.4 million, respectively, which is included in the research and development and general and administrative expenses in the condensed statements of operations for the three months ended March 31, 2024 and 2023, respectively. As of March 31, 2024, the remaining unrecognized equity-based compensation (which includes RSUs and stock options) of approximately $0.9 million will be recognized over approximately 1.6

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Master Services Agreements: As of March 31, 2024, the Company had two active master services agreements with third parties to conduct its clinical trials and manage clinical research programs and clinical development services. The Company expects these agreements or amended current agreements to have total expenditures of approximately $1.4 million over the next two years. As of December 31, 2023, the Company had three active master services agreements with third parties to conduct its clinical trials and manage clinical research programs and clinical development services on behalf of the Company. The Company expects these agreements or amended current agreements to have total expenditures of approximately $1.5 million over the next two years. Consulting Services Agreement: On November 20, 2014, the Company entered into a ten-year consulting services agreement with Dr. Joshua Hare, its CSO. Under the agreement, the Company has agreed to pay the CSO $265,000 annually. The compensation payments are for scientific knowledge, medical research, technical knowledge, skills, and abilities to be provided by the CSO to further develop the intellectual property rights assigned by the CSO to the Company. This agreement requires the CSO to also assign to the Company the exclusive right, title, and interest in any work product developed from his efforts during the term of this agreement. On November 16, 2022, the Company accounted for but had not issued 4,814 RSUs convertible to unregistered shares of Class A common stock, with an aggregate value of $0.2 million as payment for accrued expenses under the consulting agreement with the CSO. These shares were issued on May 24, 2023. As of March 31, 2024 and December 31, 2023, the Company had accrued balances due to the CSO of approximately $0.1 million and $0.1 million, respectively, which are included in accrued expenses and approximately $0.1 million for both years, which are included in accounts payable in the accompanying condensed balance sheets. Technology Services Agreement: On March 27, 2015, the Company entered into a technology services agreement with Optimal Networks, Inc. (a related company owned by Dr. Joshua Hare’s brother-in-law) for use of information technology services. The technology services agreement was terminated as of April 14, 2023. As of March 31, 2024 and December 31, 2023, the Company owed $0 pursuant to this agreement. Exclusive Licensing Agreements: UM Agreement On November 20, 2014, the Company entered into an Exclusive License Agreement with UM (the “UM License”) for the use of certain Aging-related Frailty Mesenchymal Stem Cell (“MSC”) technology rights developed by our CSO at UM. The UM License is a worldwide, exclusive license, with right to sublicense, with respect to any and all know-how specifically related to the development of the culture-expanded MSCs for Aging-related Frailty used at the Human-induced pluripotent stem cell-derived MSCs (“IMSCs”), all standard operating procedures used to create the IMSCs, and all data supporting isolation, culture, expansion, processing, cryopreservation and management of the IMSCs. The Company is required to pay UM (i) a license issue fee of $5,000, (ii) a running royalty in an amount equal to three percent of annual net sales on products or services developed from the technology, payable on a country-by-country basis beginning on the date of first commercial sale through termination of the UM License Agreement, and which may be reduced to the extent we are required to pay royalties to a third party for the same product or process, (iii) escalating annual cash payments of up to $50,000, subject to offset. The agreement extends for up to 20 years from the last date a product or process is commercialized from the technology and was amended in 2017 to modify certain milestone completion dates as detailed below. In 2021 the license fee was increased by an additional $100,000, to defray patent costs. In addition, the Company issued 11,039 unregistered shares of Class A common stock to UM. The milestone payment amendments shifted the triggering payments to three payments of $500,000, to be paid within six months of: (a) the completion of the first Phase 3 clinical trial of the products (based upon the final data unblinding); (b) the receipt by the Company of approval for the first new drug application (“NDA”), biologics application (“BLA”), or other marketing or licensing application for the product; and (c) the first sale following product approval. “Approval” refers to product approval, licensure, or other marketing authorization by the U.S. Food and Drug Administration, or any successor agency. The amendments also provided for the Company’s license of additional technology, to the extent not previously included in the UM License and granted the Company an exclusive option to obtain an exclusive license for (a) the HLHS investigational new drug application (“IND”) with ckit+ cells; and (b) UMP-438 titled “Method of Determining Responsiveness to Cell Therapy in Dilated Cardiomyopathy.” The Company has the right to terminate the UM License upon 60 days’ prior written notice, and either party has the right to terminate upon a breach of the UM License. To date, the Company has made payments totaling $365,000 to UM, and as of March 31, 2024 and December 31, 2023, we had accrued $77,500 and $50,000 in milestone fees payable to UM, respectively and $15,000 for the year ended December 31, 2023 for patent related reimbursements based on the estimated progress to date. CD271 On December 22, 2016, the Company entered into an exclusive license agreement with an affiliated entity of Dr. Joshua Hare, JMH MD Holdings, LLC (“JMHMD”), for the use of CD271 cellular therapy technology. The Company recorded the value of the cash consideration and membership units issued to obtain this license agreement as an intangible asset. The Company is required to pay as a royalty 1% of the annual net sales of the licensed product(s) used, leased, or sold by or for the licensee or its sub-licensees. If the Company sublicenses the technology, it is also required to pay an amount equal to 10% of the net sales of the sub-licensees. In addition, on December 23, 2016, as required by the license agreement, the Company paid an initial fee of $250,000 to JMHMD, and issued to it 10,000 Series C Units, valued at $250,000. The $0.5 million of value provided to JMHMD for the license agreement, along with professional fees of approximately $27,000, were recorded as an intangible asset that is amortized over the life of the license agreement which was defined as 20 years. Further, expenses related to the furtherance of the CD271+ technology are being capitalized and amortized as incurred over 20 years. There were no license fees due for March 31, 2024 and December 31, 2023 pertaining to this agreement. Other Royalty Under the grant award agreement with the Alzheimer’s Association, the Company may be required to make revenue sharing or distribution of revenue payments for products or inventions generated or resulting from this clinical trial program. The potential payments, although not currently defined, could result in a maximum payment of five times (5x) the award amount of $3.0 million. Contingencies – Legal From time to time, the Company could become involved in disputes and various litigation matters that arise in the normal course of business. These may include disputes and lawsuits related to intellectual property, licensing, contract law and employee relations matters. As of March 31, 2024, the Company is not aware of any legal proceedings or material developments requiring disclosure.

Employee Benefits Plan

Employee Benefits Plan	3 Months Ended
	Mar. 31, 2024
Employee Benefits Plan [Abstract]
Employee Benefits Plan	10. Employee Benefits Plan The Company sponsors a defined contribution employee benefit plan (the “Plan”) under the provisions of Section 401(k) of the Internal Revenue Code. The Plan covers substantially all full-time employees of the Company who are eligible upon date of hire. Contributions to the Plan by the Company are at the discretion of the Board of Directors. The Company contributed approximately $46,000 and $38,000 to the Plan during the three months ended March 31, 2024 and 2023, respectively.

Loss Per Share

Loss Per Share	3 Months Ended
	Mar. 31, 2024
Loss Per Share [Abstract]
Loss Per Share	11. Loss Per Share Basic and diluted net loss per share have been computed using the weighted-average number of shares of common stock outstanding during the period. We have outstanding stock-based awards that are not used in the calculation of diluted net loss per share because to do so would be anti-dilutive. The following instruments (in thousands) were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended 2024 2023 RSUs 8 36 Stock options 42 47 Warrants 774 127 Total 824 210

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2024
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events On April 8, 2024, we commenced a public offering (“the Offering”) of up to 661,149 shares of our Class A common stock and pre-funded warrants to purchase up to an aggregate of 1,572,894 shares of our Class A common stock (the “Pre-funded Warrants”). The Class A common stock and Pre-funded Warrants were sold together with warrants to purchase up to an aggregate of 2,234,043 shares of Class A common stock (the “Common Warrants”). The combined public Offering price was $2.35 per share of Class A common stock and $2.349 per Pre-funded Warrant and related Common Warrant. The Common Warrants are immediately exercisable and expire five years from the date of issuance. In connection with the Offering, the Company also entered into an agreement (the “Warrant Amendment Agreement”) with a holder (the “Holder”) of existing warrants to purchase shares of the Company’s Class A common stock, in consideration for the Holder’s participation in the Offering and purchase of securities in the Offering, and contingent upon the closing of the Offering and the Holder’s participation in the Offering, amend the Holder’s existing warrants to purchase up to (a) 242,425 shares of Class A common stock at an exercise price of $16.50 per share, issued on October 13, 2023 and expiring on April 13, 2029 (the “Series A Warrants”) and (b) 242,425 shares of Class A common stock at an exercise price of $16.50 per share, issued on October 13, 2023 and expiring on April 14, 2025 (the “Series B Warrants” and together with the Series A Warrants, the “Existing Warrants”) to (i) reduce the exercise price of the Existing Warrants to $2.35 per share and (ii) amend the expiration date of the Series A Warrants to five and one-half (5.5) years following the closing of the Offering and the Series B Warrants to eighteen (18) months following the closing of the Offering, in each case for a payment to the Company of $0.125 per amended warrant, for aggregate gross consideration of $60,606.25, prior to deducting placement agent fees (the “Warrant Amendment”). The Offering closed on April 10, 2024 and the gross proceeds from the Offering were $5.25 million, and net proceeds of $4.7 million after placement agent fees but before other offering expenses payable by the Company. The Warrant Amendment was effective upon the closing of the Offering. On April 16, 2024, we entered into an inducement letter agreement (the “Inducement Letter Agreement”) with certain holders (the “Holders”) of our existing (i) Series A Warrants and Series B Warrants (the Series B Warrants together with the Series A Warrants the “October Warrants”), originally issued on October 11, 2023, and thereafter amended on April 10, 2024, with an exercise price of $2.35 per share, and which became exercisable on December 26, 2023, and (ii) common stock warrants to purchase up to an aggregate of 1,914,984 shares of common stock, originally issued to the Holders on April 10, 2024, with an exercise price of $2.35 per share, and which were exercisable immediately following issuance (the “April Warrants” and collectively with the October Warrants, the “Warrants”). Pursuant to the Inducement Letter Agreement, the Holders agreed to exercise for cash the Warrants at an exercise price of $2.35 per share in consideration for payment of $0.125 per new warrant and our issuance of new unregistered Common Stock Warrants (the “New Warrants”) to purchase up to 4,799,488 shares of common stock (the “New Warrant Shares”), at an exercise price of $2.35 per share (the “Inducement Transaction”), and which were immediately exercisable. The new Series C warrants to purchase 2,399,744 shares of Class A common stock have a term of five years from the issuance date, and the new Series D warrants to purchase 2,399,744 shares of Class A common stock have a term of twenty-four months from the issuance date. The Inducement Transaction closed on April 18, 2024, and the gross proceeds to the Company from the exercise of the Warrants, inclusive of the payment consideration for the New Warrants, were approximately $6.2 million, and net proceeds of $5.6 million after deducting placement agent fees but before other offering expenses payable by the Company.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (4,058)	$ (4,647)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Trading Arrangements Rock Soffer, a member of the Company’s Board of Directors, adopted a “Rule 10b5-1 trading arrangement” during the Company’s fiscal quarter ended March 31, 2024. The trading arrangement, adopted January 11, 2024, and effective January 12, 2024, is intended to satisfy the affirmative defense of Rule 10b5-1(c). The trading arrangement will remain in place per its terms until the earlier of (a) April 17, 2025; (b) completion of the sale of 275,000 shares of Longeveron Class A common stock; (d) notice or awareness of the closing of a tender or exchange offer or a merger, acquisition, reorganization, recapitalization, or comparable transaction for Longeveron in which its capital stock is exchanged or converted; (e) the death, incapacity, bankruptcy, or insolvency of Mr. Soffer; or (e) such other termination in accordance with its terms. Other than Mr. Soffer, none of the Company’s other directors or “officers,” as defined in Rule 16a-1(f) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), adopted, modified, or terminated a “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408 of Regulation S-K, during the Company’s fiscal quarter ended March 31, 2024.
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b51 ArrModified Flag	false
Non-Rule 10b51 ArrModified Flag	false

Accounting Policies, by Policy

Accounting Policies, by Policy (Policies)	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies [Abstract]
Basis of presentation	Basis of presentation: The condensed financial statements of the Company were prepared in accordance with U.S. GAAP. Certain reclassifications have been made to prior year condensed financial statements to conform to classifications used in the current year. These reclassifications had no impact on net loss, stockholders’ equity or cash flows as previously reported.
Reverse Stock Split	Reverse Stock Split: On March 26, 2024, the Company effected a reverse stock split of the outstanding shares of its Class A common stock and Class B common stock on a one-for-10 (1:10) basis (the “Reverse Stock Split”). The Reverse Stock Split became effective at 11:59 p.m. Eastern Time on March 26, 2024 via a certificate of amendment to the Company’s Certificate of Incorporation filed with the Secretary of State of the State of Delaware. At the effective time of the Reverse Stock Split, every 10 shares of the Company’s Class A common stock and Class B common stock, whether issued and outstanding or held by the Company as treasury stock, were automatically combined and converted (without any further act) into one fully paid and nonassessable share of Class A common stock or Class B common stock, respectively, subject to rounding up of fractional shares to the nearest whole number of shares resulting from the Reverse Stock Split without any change in the par value per share. All share, per share, option, warrant, equity award, and other derivative security numbers and exercise prices appearing in this Quarterly Report on Form 10-Q and the accompanying condensed financial statements have been adjusted to give effect to the Reverse Stock Split for all prior periods presented. However, the Company’s annual, other periodic, and current reports, and all other information and documents incorporated by reference into this Quarterly Report on Form 10-Q that were filed prior to March 19, 2024, do not give effect to the Reverse Stock Split.
Use of estimates	Use of estimates: The presentation of condensed financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Accounting Standard Updates	Accounting Standard Updates: A variety of proposed or otherwise potential accounting standards are currently under consideration by standard-setting organizations and certain regulatory agencies. Because of the tentative and preliminary nature of such proposed standards, management has not yet determined the effect, if any, that the implementation of such proposed standards would have on the Company’s condensed financial statements. In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, “Improvements to Income Tax Disclosures”. The amendments in this ASU change disclosure requirements for various items, including effective tax rate reconciliations and cash taxes paid. This ASU is effective for public companies for the financial reporting periods beginning on January 1, 2025, with early adoption permitted. We have not adopted ASU 2023-09 for our financial reporting period ending December 31, 2023, and will continue to evaluate early adoption for our financial reporting period ending December 31, 2024.
Cash and cash equivalents	Cash and cash equivalents: The Company considers cash to consist of cash on hand and temporary investments having an original maturity of 90 days or less that are readily convertible into cash.
Marketable securities	Marketable securities: Marketable securities at March 31, 2024 and December 31, 2023 consisted of marketable fixed income securities, primarily corporate bonds which are categorized as available for sale securities and are thus marked to market and stated at fair value in accordance with ASC 820 Fair Value Measurement
Accounts and grants receivable	Accounts and grants receivable: Accounts and grants receivable include amounts due from customers, granting institutions and others. The amounts as of March 31, 2024, and December 31, 2023 are certain to be collected, and no amount has been recognized for doubtful accounts. In addition, for the clinical trial revenue, most participants pay in advance of treatment. Advanced grant funds and prepayments for the clinical trial revenue are recorded to deferred revenue. Advance contract manufacturing payments are recorded to deferred revenue. Accounts and grants receivable by source, as of (in thousands): March 31, December 31, National Institutes of Health – Grant $ 96 $ 96 Accounts receivable from customers 82 15 Total $ 178 $ 111
Deferred offering costs	Deferred offering costs: The Company recorded certain legal, professional and other third-party fees that were directly associated with in-process equity financings as deferred offering costs until the applicable equity financing was consummated. After consummation of an equity financing, these costs are recorded in stockholders’ equity as a reduction of proceeds generated as a result of the offering.
Property and equipment	Property and equipment: Property and equipment, including improvements that extend the useful lives of related assets, are recorded at cost, while maintenance and repairs are charged to operations as incurred. Depreciation is calculated using the straight-line method based on the estimated useful lives of the assets. Leasehold improvements are amortized over the shorter of the estimated useful life of the asset or the original term of the lease. Depreciation expense is recorded in the research and development line of the condensed statements of operations as the assets are primarily related to the Company’s clinical programs.
Intangible assets	Intangible assets: Intangible assets include payments on license agreements with the Company’s co-founder and Chief Scientific Officer (“CSO”) and the University of Miami (“UM”) (see Note 9) and legal costs incurred related to patents and trademarks. License agreements have been recorded at the value of cash consideration, common stock and membership units transferred to the respective parties when acquired. Payments for license agreements are amortized using the straight-line method over the estimated term of the agreements, which range from 5-20 years. Patents are amortized over their estimated useful life, once issued. The Company considers trademarks to have an indefinite useful life and evaluates them for impairment on an annual basis. Amortization expense is recorded in the research and development line of the condensed statements of operations as the assets are primarily related to the Company’s clinical programs.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets: The Company evaluates long-lived assets for impairment, including property and equipment and intangible assets, when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Upon the occurrence of a triggering event, the asset is reviewed to assess whether the estimated undiscounted cash flows expected from the use of the asset plus the residual value from the ultimate disposal exceeds the carrying value of the asset. If the carrying value exceeds the estimated recoverable amounts, the asset is written down to the estimated fair value. Any resulting impairment loss is reflected in the condensed statements of operations. Upon evaluation, management determined that there was no impairment of long-lived assets during the three months ended March 31, 2024 and 2023.
Deferred revenue	Deferred revenue: The unearned portion of advanced grant funds and prepayments for clinical trial and contract manufacturing revenues, which will be recognized as revenue when the Company meets the respective performance obligations, has been presented as deferred revenue in the accompanying condensed balance sheets. For both of the three months ended March 31, 2024 and 2023, the Company recognized $0 of funds that were previously classified as deferred revenue due to the MSCRF – Technology Development Corporation (“TEDCO”) – grant Acute Respiratory Distress Syndrome (“ARDS”) program being discontinued. The $0.4 million recorded as deferred revenue will be reversed when the funds are returned to MSCRF – TEDCO.
Revenue recognition	Revenue recognition: The Company recognizes revenue when performance obligations related to respective revenue streams are met. For grant revenue, the Company considers the performance obligation met when the grant related expenses are incurred or supplies and materials are received. The Company is paid in tranches pursuant to terms of the related grant agreements, and then applies payments based on regular expense reimbursement submissions to grantors. There are no remaining performance obligations or variable consideration once grant expense reporting to the grantor is complete. For clinical trial revenue, the Company considers the performance obligation met when the participant has received the treatment. The Company usually receives prepayment for these services or receives payment at the time the treatment is provided, and there are no remaining performance obligations or variable consideration once the participant receives the treatment. For contract manufacturing revenue, the Company considers the performance obligation met when the contractual obligation and/or statement of work has been satisfied. Payment terms may vary depending on specific contract terms. There are no significant judgments affecting the determination of the amount and timing of revenue recognition. Revenue by source (in thousands): Three months ended 2024 2023 NIH - grant $ - $ 41 Clinical trial revenue 515 238 Contract manufacturing 33 - Total $ 548 $ 279 The Company records cost of revenues based on expenses directly related to revenue. For grants, the Company records allocated expenses for research and development costs to a grant as a cost of revenues. For the clinical trial revenue, directly related expenses for that program are expensed as incurred. These expenses are similar to those described under “Research and development expense” below. For the contract manufacturing, the Company records costs incurred under the contract as cost of revenues.
Research and development expense	Research and development expense: Research and development costs are charged to expense when incurred in accordance with ASC 730 Research and Development
Concentrations of credit risk	Concentrations of credit risk: Financial instruments which potentially subject the Company to credit risk consist principally of cash and cash equivalents, marketable securities and accounts and grants receivable. Cash and cash equivalents are held in U.S. financial institutions. At times, the Company may maintain balances in excess of the federally insured amounts.
Income taxes	Income taxes: The Company’s tax provision consists of taxes currently payable or receivable, plus any change during the period in deferred tax assets and liabilities. The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their respective tax basis. 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 income in the period that includes the enactment date. In addition, a valuation allowance is established to reduce any deferred tax asset for which it is determined that it is more likely than not that some portion of the deferred tax asset will not be realized. The Company’s tax provision was $0 for the three months ended March 31, 2024 and 2023 due to net operating losses. The Company has not recorded any tax benefit for the net operating losses incurred due to the offset created by the Company’s valuation allowance. The Company recognizes the tax benefits from uncertain tax positions that the Company has taken or expects to take on a tax return. In the unlikely event an uncertain tax position exists in which the Company could incur income taxes, the Company would evaluate whether there is a probability that the uncertain tax position taken would be sustained upon examination by a taxing authority. Reserves for uncertain tax positions would then be recorded if the Company determined it is probable that either a position would not be sustained upon examination, or a payment would have to be made to a taxing authority and the amount was reasonably estimable. As of March 31, 2024 and December 31, 2023, the Company does not believe it has any uncertain tax positions that would result in the Company having a liability to a taxing authority. It is the Company’s policy to expense any interest and penalties associated with its tax obligations when they are probable and estimable.
Equity-based compensation	Equity-based compensation: The Company accounts for equity-based compensation expense by the measurement and recognition of compensation expense for stock-based awards based on estimated fair values on the date of grant. The fair value of the stock options is estimated at the date of the grant using the Black-Scholes option-pricing model. The Black-Scholes option-pricing model requires the input of highly subjective assumptions, the most significant of which are the expected share price volatility, the expected life of the stock option award, the risk-free rate of return, and dividends during the expected term. Because the option-pricing model is sensitive to changes in the input assumptions, different determinations of the required inputs may result in different fair value estimates of the stock options. Neither the Company’s stock options nor its restricted stock units (“RSUs”) trade on an active market. Volatility is a measure of the amount by which a financial variable, such as a stock price, has fluctuated (historical volatility) or is expected to fluctuate (expected volatility) during a period. Given the Company’s limited historical data, the Company utilizes the average historical volatility of similar publicly traded companies that are in the same industry. The risk-free interest rate is the average U.S. treasury rate (having a term that most closely approximates the expected life of the option) for the period in which the stock option was granted. The expected life is the period of time that the stock options granted are expected to remain outstanding. Stock options granted have a maximum term of ten years. The Company has insufficient historical data to utilize in determining its expected life assumptions and, therefore, uses the simplified method for determining expected life.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies [Abstract]
Schedule of Accounts and Grants Receivable	Accounts and grants receivable by source, as of (in thousands): March 31, December 31, National Institutes of Health – Grant $ 96 $ 96 Accounts receivable from customers 82 15 Total $ 178 $ 111
Schedule of Revenue	Revenue by source (in thousands): Three months ended 2024 2023 NIH - grant $ - $ 41 Clinical trial revenue 515 238 Contract manufacturing 33 - Total $ 548 $ 279

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2024
Marketable Securities [Abstract]
Schedule of Marketable Securities	The following is summary of marketable securities that the Company measures at fair value (in thousands): Fair Value at March 31, 2024 Level 1 Level 2 Level 3 Total Corporate bonds $ - $ 351 $ - $ 351 Money market funds (1) 796 - - 796 Accrued income 13 - - 13 Total marketable securities $ 809 $ 351 $ - $ 1,160 (1) Money market funds are included in cash and cash equivalents in the condensed balance sheet. Fair Value at December 31, 2023 Level 1 Level 2 Level 3 Total Corporate bonds $ - $ 412 $ - $ 412 Money market funds (1) 3,948 - - 3,948 Accrued income 16 - - 16 Total marketable securities $ 3,964 $ 412 $ - $ 4,376

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Property and Equipment, Net [Abstract]
Schedule of Major Components of Property and Equipment	Major components of property and equipment are as follows (in thousands): Useful Lives March 31, December 31, Leasehold improvements 10 years $ 4,328 $ 4,328 Furniture/Lab equipment 7 years 2,499 2,483 Computer equipment 5 years 120 120 Software/Website 3 years 38 38 Total property and equipment 6,985 6,969 Less accumulated depreciation and amortization 4,637 4,440 Property and equipment, net $ 2,348 $ 2,529

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Intangible Assets, Net [Abstract]
Schedule of Major Components of Intangible Assets	Major components of intangible assets as of March 31, 2024, are as follows (in thousands): Useful Lives Cost Accumulated Total License agreements 20 years $ 2,043 $ (964 ) $ 1,079 Patent costs 980 - 980 Trademark costs 204 - 204 Total $ 3,227 $ (964 ) $ 2,263 Useful Lives Cost Accumulated Total License agreements 20 years $ 2,043 $ (909 ) $ 1,134 Patent costs 959 - 959 Trademark costs 194 - 194 Total $ 3,196 $ (909 ) $ 2,287
Schedule of Future Amortization Expense for Intangible Assets	Future amortization expense for intangible assets as of March 31, 2024 is as follows (in thousands): Year Ending December 31, Amount 2024 (remaining nine months) $ 168 2025 224 2026 224 2027 224 2028 224 Thereafter 15 Total $ 1,079

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Schedule of Future Minimum Payments Under the Operating Leases	Future minimum payments under the operating leases as of March 31, 2024, are as follows (in thousands): Year Ending December 31, Amount 2024 (remaining nine months) $ 511 2025 682 2026 682 2027 170 Total 2,046 Less: Interest 149 Present value of operating lease liability $ 1,896

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	3 Months Ended
	Mar. 31, 2024
Equity Securities, Restricted [Abstract]
Schedule of RSU Activity	RSU activity for the three months ended March 31, 2024, was as follows: Number of Outstanding (unvested) at December 31, 2023 11,239 RSU granted 3,000 RSUs vested (3,306 ) RSU expired/forfeited (3,000 ) Outstanding (unvested) at March 31, 2024 7,933
Schedule of Issued and Outstanding Options	For the three months ended March 31, 2024: Number of Stock options vested (based on ratable vesting) 22,599 Stock options unvested 19,605 Total stock options outstanding at March 31, 2024 42,204 Number of Stock options vested (based on ratable vesting) 16,091 Stock options unvested 27,695 Total stock options outstanding at December 31, 2023 43,786
Schedule of Stock Option Activity	Stock option activity for the three months ended March 31, 2024, was as follows: Number of Weighted Outstanding at December 31, 2023 43,786 $ 49.60 Options granted - - Options exercised - - Options expired/forfeited (1,582 ) (77.29 ) Outstanding at March 31, 2024 42,204 $ 48.61

Loss Per Share (Tables)

Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Loss Per Share [Abstract]
Schedule of Diluted Net Loss per Share	The following instruments (in thousands) were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended 2024 2023 RSUs 8 36 Stock options 42 47 Warrants 774 127 Total 824 210

Nature of Business, Basis of _2

Nature of Business, Basis of Presentation, and Liquidity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Nature of Business, Basis of Presentation, and Liquidity (Details) [Line Items]
Net loss	$ (4,058)	$ (4,647)
Accumulated deficit	(89,042)	(89,000)	$ (84,984)
Cash and cash equivalents	1,940	1,900	4,949
Marketable securities	$ 351	$ 400	$ 412
Expenditure commitments		1 year
Over-Allotment Option [Member] | Class A Common Stock [Member]
Nature of Business, Basis of Presentation, and Liquidity (Details) [Line Items]
Received amount		$ 16,000
Recognized revenue amount		$ 11,500

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Summary of Significant Accounting Policies [Line Items]
Net unrealized losses	$ 0	$ 100
Deferred revenue	0	0
Tax provision	$ 0	$ 0
Options granted maximum term	10 years
Finite-Lived Intangible Assets [Member]
Summary of Significant Accounting Policies [Line Items]
Deferred revenue	$ 400
Minimum [Member] | Finite-Lived Intangible Assets [Member]
Summary of Significant Accounting Policies [Line Items]
Intangible assets estimated useful life	5 years
Maximum [Member] | Finite-Lived Intangible Assets [Member]
Summary of Significant Accounting Policies [Line Items]
Intangible assets estimated useful life	20 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - Schedule of Accounts and Grants Receivable - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule of Accounts and Grants Receivable [Line Items]
Accounts and grants receivable	$ 178	$ 111
National Institutes of Health – Grant [Member]
Schedule of Accounts and Grants Receivable [Line Items]
Accounts and grants receivable	96	96
Accounts receivable from customers [Member]
Schedule of Accounts and Grants Receivable [Line Items]
Accounts and grants receivable	$ 82	$ 15

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Details) - Schedule of Revenue - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule of Revenue [Line Items]
Total revenue	$ 548	$ 279
MSCRF – TEDCO - grants [Member]
Schedule of Revenue [Line Items]
Total revenue		41
Clinical trial revenue [Member]
Schedule of Revenue [Line Items]
Total revenue	515	238
Contract manufacturing [Member]
Schedule of Revenue [Line Items]
Total revenue	$ 33

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Marketable Securities [Line Items]
Accrued interest receivable amount	$ 0.1	$ 0.1

Marketable Securities (Detail_2

Marketable Securities (Details) - Schedule of Marketable Securities - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Schedule of Marketable Securities [Line Items]
Marketable Securities		$ 1,160	$ 4,376
Level 1 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities		809	3,964
Level 2 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities		351	412
Level 3 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
Corporate bonds [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities		351
Corporate bonds [Member] | Level 1 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
Corporate bonds [Member] | Level 2 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities		351
Corporate bonds [Member] | Level 3 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
Money market funds [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities	[1]	796	3,948
Money market funds [Member] | Level 1 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities	[1]	796	3,948
Money market funds [Member] | Level 2 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities	[1]
Money market funds [Member] | Level 3 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities	[1]
Accrued income [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities		13	16
Accrued income [Member] | Level 1 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities		13	16
Accrued income [Member] | Level 2 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
Accrued income [Member] | Level 3 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
Corporate Bonds [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities			412
Corporate Bonds [Member] | Level 1 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
Corporate Bonds [Member] | Level 2 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities			412
Corporate Bonds [Member] | Level 3 [Member]
Schedule of Marketable Securities [Line Items]
Marketable Securities
[1] Money market funds are included in cash and cash equivalents in the condensed balance sheet.

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property and Equipment, Net [Abstract]
Depreciation and amortization expense	$ 0.2	$ 0.2

Property and Equipment, Net (_2

Property and Equipment, Net (Details) - Schedule of Major Components of Property and Equipment - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule of Major Components of Property and Equipment [Line Items]
Total Property and Equipment	$ 6,985	$ 6,969
Less accumulated depreciation and amortization	4,637	4,440
Property and equipment, net	$ 2,348	2,529
Leasehold Improvements [Member]
Schedule of Major Components of Property and Equipment [Line Items]
Property and Equipment, Useful Lives	10 years
Total Property and Equipment	$ 4,328	4,328
Furniture/Lab Equipment [Member]
Schedule of Major Components of Property and Equipment [Line Items]
Property and Equipment, Useful Lives	7 years
Total Property and Equipment	$ 2,499	2,483
Computer Equipment [Member]
Schedule of Major Components of Property and Equipment [Line Items]
Property and Equipment, Useful Lives	5 years
Total Property and Equipment	$ 120	120
Software/Website [Member]
Schedule of Major Components of Property and Equipment [Line Items]
Property and Equipment, Useful Lives	3 years
Total Property and Equipment	$ 38	$ 38

Intangible Assets, Net (Details

Intangible Assets, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Intangible Assets, Net [Abstract]
Amortization expense related to intangible assets	$ 0.1	$ 0.1

Intangible Assets, Net (Detai_2

Intangible Assets, Net (Details) - Schedule of Major Components of Intangible Assets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Schedule of Major Components of Intangible Assets [Line items]
Cost	$ 3,227	$ 3,196
Accumulated Amortization	(964)	(909)
Total	$ 2,263	$ 2,287
License agreements [Member]
Schedule of Major Components of Intangible Assets [Line items]
Useful Lives	20 years	20 years
Cost	$ 2,043	$ 2,043
Accumulated Amortization	(964)	(909)
Total	1,079	1,134
Patent costs [Member]
Schedule of Major Components of Intangible Assets [Line items]
Cost	980	959
Accumulated Amortization
Total	980	959
Trademark costs [Member]
Schedule of Major Components of Intangible Assets [Line items]
Cost	204	194
Accumulated Amortization
Total	$ 204	$ 194

Intangible Assets, Net (Detai_3

Intangible Assets, Net (Details) - Schedule of Future Amortization Expense for Intangible Assets $ in Thousands	Mar. 31, 2024 USD ($)
Schedule of Future Amortization Expense for Intangible Assets [Abstract]
2024 (remaining nine months)	$ 168
2025	224
2026	224
2027	224
2028	224
Thereafter	15
Total	$ 1,079

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Leases [Line Items]
Operating lease asset	$ 1,139		$ 1,221
Operating lease liability	1,896
Lease costs	200	$ 200
Minimum [Member]
Leases [Line Items]
Operating lease asset	1,100
Operating lease liability	$ 1,900
Maximum [Member]
Leases [Line Items]
Operating lease asset			1,200
Operating lease liability			$ 2,000

Leases (Details) - Schedule of

Leases (Details) - Schedule of Future Minimum Payments Under the Operating Leases $ in Thousands	Mar. 31, 2024 USD ($)
Schedule of Future Minimum Payments Under the Operating Leases [Abstract]
2024 (remaining nine months)	$ 511
2025	682
2026	682
2027	170
Total	2,046
Less: Interest	149
Present value of operating lease liability	$ 1,896

Stockholders_ Equity (Details)

Stockholders’ Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	12 Months Ended
	Aug. 16, 2023	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2021
Stockholders’ Equity [Line Items]
Conversion of outstanding shares		200,000
Valuation Technique, Consensus Pricing Model [Member]
Stockholders’ Equity [Line Items]
Warrants exercise price per share (in Dollars per share)	$ 52.5
Fair value of warrants (in Dollars)	$ 800
Class B Common Stock [Member]
Stockholders’ Equity [Line Items]
Conversion of outstanding shares		1,570,284
Common stock voting rights		five
Stockholders share exchanged		1,555	3,555
Warrants purchase (in Dollars per share)		$ 0.001	$ 0.001
Class A Common Stock [Member]
Stockholders’ Equity [Line Items]
Common stock voting rights		one
Stockholders share exchanged		1,555	3,555
Warrants to purchase		10,640
Warrants purchase (in Dollars per share)		$ 0.001	$ 0.001
warrant term		5 years
Number of warrants or rights outstanding.		2,399,744
Class A Common Stock [Member] | Warrant [Member]
Stockholders’ Equity [Line Items]
Warrants purchase (in Dollars per share)		$ 120
Warrant purchase shares		500,000
Net proceeds (in Dollars)			$ 612,732
Class A Common Stock [Member] | Underwriters Warrants [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares		16,971
Warrants exercise price per share (in Dollars per share)		$ 20.625
Underwriters [Member] | Warrant [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares				9,576
Warrant [Member] | Class A Common Stock [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares			5,107
Warrants exercise price per share (in Dollars per share)			$ 120
2021 PIPE Offering [Member]
Stockholders’ Equity [Line Items]
Warrants exercise price per share (in Dollars per share)		$ 175
warrant term		5 years
2021 PIPE Offering [Member] | Warrant [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares		116,935
2021 PIPE Offering [Member] | Class A Common Stock [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares		4,679
Warrants exercise price per share (in Dollars per share)		$ 175
October 2023 Offering [Member] | Series B warrants [Member]
Stockholders’ Equity [Line Items]
Warrants exercise price per share (in Dollars per share)		$ 16.5
Number of warrants or rights outstanding.		242,425
October 2023 Offering [Member] | Series A warrants [Member]
Stockholders’ Equity [Line Items]
Warrants exercise price per share (in Dollars per share)		$ 16.5
October 2023 Offering [Member] | Series A warrants [Member]
Stockholders’ Equity [Line Items]
Number of warrants or rights outstanding.		242,425
December 2023 Offering [Member] | Underwriters Warrants [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares		9,489
Warrants exercise price per share (in Dollars per share)		$ 21.813
December 2023 Offering [Member] | Class A Common Stock [Member]
Stockholders’ Equity [Line Items]
Warrant purchase shares		135,531
Warrants exercise price per share (in Dollars per share)		$ 16.2

Equity Incentive Plan (Details)

Equity Incentive Plan (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Equity Incentive Plan [Line Items]
Unvested shares (in Shares)			11,239
Stock options exercisable term	4 years
Stock option expiration term	10 years
Share percentage	5%
Dividend yield	0%
Expected life	10 years
Stock option issued and outstanding (in Shares)			43,782
Exercise price (in Dollars per share)	$ 48.61		$ 49.6
unrecognized equity-based compensation (in Dollars)	$ 0.9
unrecognized equity-based compensation term	1 year 219 days
Restricted Stock Units (RSUs) [Member]
Equity Incentive Plan [Line Items]
Unvested shares (in Shares)	7,933		11,239
Stock option issued and outstanding (in Shares)	42,200
Stock Option [Member]
Equity Incentive Plan [Line Items]
Stock option issued and outstanding (in Shares)	42,204		43,786
Exercise price (in Dollars per share)	$ 48.61		$ 49.6
Equity-based compensation expense (in Dollars)	$ 0.3	$ 0.4
Minimum [Member]
Equity Incentive Plan [Line Items]
Risk-free interest rate	90%
Minimum [Member] | Restricted Stock Units (RSUs) [Member]
Equity Incentive Plan [Line Items]
Risk-free interest rate	3.89%
Maximum [Member]
Equity Incentive Plan [Line Items]
Risk-free interest rate	95%
Maximum [Member] | Restricted Stock Units (RSUs) [Member]
Equity Incentive Plan [Line Items]
Risk-free interest rate	4.01%

Equity Incentive Plan (Detail_2

Equity Incentive Plan (Details) - Schedule of RSU Activity - Restricted Stock Units (RSUs) [Member]	3 Months Ended
	Mar. 31, 2024 shares
Schedule of RSU Activity [Line Items]
Number of RSU Outstanding (unvested) at December 31, 2023	11,239
Number of RSUs granted	3,000
Number of RSUs vested	(3,306)
Number of RSU expired/forfeited	(3,000)
Number of RSU Outstanding (unvested) at March 31, 2024	7,933

Equity Incentive Plan (Detail_3

Equity Incentive Plan (Details) - Schedule of Issued and Outstanding Options - Stock Option [Member] - shares	Mar. 31, 2024	Dec. 31, 2023
Schedule of Issued and Outstanding Options [Line Items]
Stock options vested (based on ratable vesting)	22,599	16,091
Stock options unvested	19,605	27,695
Total stock options outstanding	42,204	43,786

Equity Incentive Plan (Detail_4

Equity Incentive Plan (Details) - Schedule of Stock Option Activity - Stock Option [Member]	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Equity Incentive Plan (Details) - Schedule of Stock Option Activity [Line Items]
Number of Stock Options, Outstanding at Beginning | shares	43,786
Weighted Average Exercise Price, Outstanding at Beginning | $ / shares	$ 49.6
Number of Stock Options, Options granted | shares
Weighted Average Exercise Price, Options granted | $ / shares
Number of Stock Options, Options exercised | shares
Weighted Average Exercise Price, Options exercised | $ / shares
Number of Stock Options, Options expired/forfeited | shares	(1,582)
Weighted Average Exercise Price, Options expired/forfeited | $ / shares	$ (77.29)
Number of Stock Options, Outstanding at ending | shares	42,204
Weighted Average Exercise Price, Outstanding at ending | $ / shares	$ 48.61

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)					3 Months Ended	12 Months Ended
	Nov. 16, 2022	Dec. 23, 2016	Dec. 22, 2016	Nov. 20, 2014	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2021
Commitments and Contingencies [Line Items]
Expenditures amount				$ 265,000
Payments term					2 years	2 years
Issued RSUs shares (in Shares)	4,814
Aggregate value	$ 200,000
Accrued expenses						$ 100,000
Accounts payable					$ 100,000
License fee				5,000
Cash payment				$ 50,000
Terms of agreement				20 years
Milestone payment					500,000
Milestone fees payable						50,000
Annual net sales percentage			1%
Net sales of sub licensees percentage			10%
Initial fee paid		$ 250,000
License agreement amount		500,000
Professional fees		$ 27,000
license agreement		20 years
Incurred terms		20 years
Award amount					3,000,000
UM Agreements [Member]
Commitments and Contingencies [Line Items]
Milestone fees payable					77,500	15,000
UM License [Member]
Commitments and Contingencies [Line Items]
Payments to UM					365,000
Technology Services Agreement [Member]
Commitments and Contingencies [Line Items]
Accounts payable					0	0
UM License [Member]
Commitments and Contingencies [Line Items]
License fee							$ 100,000
Master Services Agreements [Member]
Commitments and Contingencies [Line Items]
Expenditures amount					1,400,000	$ 1,500,000
Chief Science Officer [Member]
Commitments and Contingencies [Line Items]
Accrued expenses					$ 100,000
Class A Common Stock [Member]
Commitments and Contingencies [Line Items]
Unregistered shares (in Shares)				11,039
Series C Units [Member]
Commitments and Contingencies [Line Items]
Shares issued (in Shares)		10,000
Company value amount		$ 250,000

Employee Benefits Plan (Details

Employee Benefits Plan (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Employee Benefits Plan [Abstract]
Company contributed amount	$ 46,000	$ 38,000

Loss Per Share (Details) - Sche

Loss Per Share (Details) - Schedule of Diluted Net Loss per Share - shares shares in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule of Diluted Net Loss per Share [Line Items]
Total	824	210
RSUs [Member]
Schedule of Diluted Net Loss per Share [Line Items]
Total	8	36
Stock options [Member]
Schedule of Diluted Net Loss per Share [Line Items]
Total	42	47
Warrants [Member]
Schedule of Diluted Net Loss per Share [Line Items]
Total	774	127

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)					3 Months Ended
	Apr. 18, 2024	Apr. 08, 2024	Oct. 13, 2023	Apr. 10, 2023	Mar. 31, 2024
Subsequent Events [Line Items]
Exercise price				$ 2.35
Debt Conversion, Converted Instrument, Expiration or Due Date			Apr. 13, 2029
Exercise price per share					$ 2.35
Inducement Letter Agreement [Member]
Subsequent Events [Line Items]
Aggregate amount (in Dollars)				$ 1,914,984
Series B Warrants [Member]
Subsequent Events [Line Items]
Warrant per share			$ 0.125
Aggregate gross (in Dollars)			$ 60,606,250	5,250,000
Net proceeds (in Dollars)				$ 4,700,000
Series B Warrants [Member] | Inducement Letter Agreement [Member]
Subsequent Events [Line Items]
Exercise price				$ 2.35
Subsequent Event [Member]
Subsequent Events [Line Items]
Public offering shares (in Shares)		661,149
Aggregate shares (in Shares)		2,234,043
Public offering price per share		$ 2.35
Exercise price		$ 2.349
Warrant term		5 years
Class A Common Stock [Member]
Subsequent Events [Line Items]
Exercise price			$ 16.5
Warrant term					5 years
Reverse stock split (in Shares)			242,425
Warrant shares (in Shares)					2,399,744
Class A Common Stock [Member] | Subsequent Event [Member]
Subsequent Events [Line Items]
Aggregate shares (in Shares)		1,572,894
Class B Common Stock [Member] | Series A Warrants [Member]
Subsequent Events [Line Items]
Exercise price			$ 2.35
Class B Common Stock [Member] | Minimum [Member]
Subsequent Events [Line Items]
Reverse stock split (in Shares)			242,425
Class B Common Stock [Member] | Maximum [Member]
Subsequent Events [Line Items]
Exercise price			$ 16.5
Series D Warrant [Member]
Subsequent Events [Line Items]
Warrant shares (in Shares)					2,399,744
New Warrant Shares [Member]
Subsequent Events [Line Items]
Exercise price					$ 2.35
Warrant issued					$ 0.125
Warrant shares (in Shares)					4,799,488
New Warrant Shares [Member] | Subsequent Event [Member]
Subsequent Events [Line Items]
Net proceeds (in Dollars)	$ 5,600,000
New Warrant Shares [Member] | Subsequent Event [Member] | Warrant [Member]
Subsequent Events [Line Items]
Net proceeds (in Dollars)	$ 6,200,000