Clene (CLNN) 10-K 13 Mar 24 2023 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2023	Mar. 08, 2024	Jun. 30, 2023
Document Information [Line Items]
Entity Central Index Key	0001822791
Entity Registrant Name	Clene Inc.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	01-39834
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-2828339
Entity Address, Address Line One	6550 South Millrock Drive, Suite G50
Entity Address, City or Town	Salt Lake City
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84121
City Area Code	801
Local Phone Number	676-9695
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 78,100,000
Entity Common Stock, Shares Outstanding		128,430,098
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	Salt Lake City, UT
Common Stock Warrant [Member]
Document Information [Line Items]
Title of 12(b) Security	Warrants, to acquire one-half of one share of Common Stock for $11.50 per share
Trading Symbol	CLNNW
Security Exchange Name	NASDAQ
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	CLNN
Security Exchange Name	NASDAQ

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 28,821	$ 18,332
Marketable securities	6,179	4,983
Accounts receivable	143	189
Inventory	37	43
Prepaid expenses and other current assets	3,672	5,648
Total current assets	38,852	29,195
Restricted cash	58	58
Operating lease right-of-use assets	4,168	4,602
Property and equipment, net	9,263	10,638
TOTAL ASSETS	52,341	44,493
Current liabilities:
Accounts payable	1,504	3,014
Accrued liabilities	3,720	3,863
Operating lease obligations, current portion	576	488
Finance lease obligations, current portion	27	74
Notes payable, current portion	14,627	6,418
Convertible notes payable, current portion	4,876	0
Total current liabilities	25,330	13,857
Operating lease obligations, net of current portion	4,903	5,557
Finance lease obligations, net of current portion	0	34
Notes payable, net of current portion	1,894	9,483
Convertible notes payable, net of current portion	5,258	9,770
Common stock warrant liabilities	1,481	0
Clene Nanomedicine contingent earn-out liability	75	2,264
Initial Stockholders contingent earn-out liability	10	291
TOTAL LIABILITIES	38,951	41,256
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock, $0.0001 par value: 300,000,000 and 150,000,000 shares authorized at December 31, 2023 and December 31, 2022, respectively; 128,422,851 and 74,759,591 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively	13	7
Additional paid-in capital	255,901	196,246
Accumulated deficit	(242,723)	(193,219)
Accumulated other comprehensive income	199	203
TOTAL STOCKHOLDERS’ EQUITY	13,390	3,237
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 52,341	$ 44,493

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000	150,000,000
Common stock, shares issued (in shares)	128,422,851	74,759,591
Common stock, shares outstanding (in shares)	128,422,851	74,759,591

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue:
Total revenue	$ 654	$ 473
Operating expenses:
Cost of revenue	121	26
Research and development	26,655	31,920
General and administrative	14,418	16,936
Total operating expenses	41,194	48,882
Loss from operations	(40,540)	(48,409)
Other income (expense), net:
Interest income	1,389	225
Interest expense	(4,558)	(3,296)
Gain on termination of lease	0	420
Commitment share expense	(402)	0
Issuance costs for common stock warrant liabilities	(333)	0
Loss on initial issuance of equity	(14,840)	0
Change in fair value of common stock warrant liabilities	6,337	169
Change in fair value of Clene Nanomedicine contingent earn-out liability	2,189	15,836
Change in fair value of Initial Stockholders contingent earn-out liability	281	2,026
Research and development tax credits and unrestricted grants	963	3,079
Other income, net	10	32
Total other income (expense), net	(8,964)	18,491
Net loss before income taxes	(49,504)	(29,918)
Income tax benefit	0	0
Net loss	(49,504)	(29,918)
Other comprehensive loss:
Unrealized gain (loss) on available-for-sale securities	16	(14)
Foreign currency translation adjustments	(20)	(16)
Total other comprehensive loss	(4)	(30)
Comprehensive loss	$ (49,508)	$ (29,948)
Net loss per share – basic and diluted (in dollars per share)	$ (0.47)	$ (0.46)
Weighted average common shares used to compute basic and diluted net loss per share (in shares)	104,938,819	65,204,663
Product [Member]
Revenue:
Total revenue	$ 498	$ 329
Royalty [Member]
Revenue:
Total revenue	$ 156	$ 144

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balances (in shares) at Dec. 31, 2021	62,312,097
Balances at Dec. 31, 2021	$ 6	$ 175,659	$ (163,301)	$ 233	$ 12,597
Issuance of common stock (in shares)	11,082,695
Issuance of common stock	$ 1	11,459	0	0	11,460
Reclassification of common stock warrant liability to permanent equity	$ 0	305	0	0	305
Exercise of stock options (in shares)	1,219,360
Exercise of stock options	$ 0	310	0	0	310
Stock-based compensation expense	$ 0	8,513	0	0	8,513
Issuance of common stock upon vesting of restricted stock awards (in shares)	145,439
Issuance of common stock upon vesting of restricted stock awards	$ 0	0	0	0	0
Unrealized loss on available-for-sale securities	0	0	0	(14)	(14)
Foreign currency translation adjustments	0	0	0	(16)	(16)
Net loss	$ 0	0	(29,918)	0	(29,918)
Balances (in shares) at Dec. 31, 2022	74,759,591
Balances at Dec. 31, 2022	$ 7	196,246	(193,219)	203	3,237
Issuance of common stock (in shares)	53,630,651
Issuance of common stock	$ 6	45,568	0	0	45,574
Reclassification of common stock warrant liability to permanent equity					0
Stock-based compensation expense	$ 0	9,117	0	0	9,117
Issuance of common stock upon vesting of restricted stock awards (in shares)	32,609
Issuance of common stock upon vesting of restricted stock awards	$ 0	0	0	0	0
Unrealized loss on available-for-sale securities	0	0	0	16	16
Foreign currency translation adjustments	0	0	0	(20)	(20)
Net loss	0	0	(49,504)	0	(49,504)
Issuance of equity-classified warrants	$ 0	4,970	0	0	4,970
Balances (in shares) at Dec. 31, 2023	128,422,851
Balances at Dec. 31, 2023	$ 13	$ 255,901	$ (242,723)	$ 199	$ 13,390

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (49,504)	$ (29,918)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,705	1,019
Non-cash lease expense	434	389
Commitment share expense	402	0
Issuance costs for common stock warrant liabilities	333	0
Loss on initial issuance of equity	14,840	0
Change in fair value of common stock warrant liabilities	(6,337)	(169)
Change in fair value of Clene Nanomedicine contingent earn-out liability	(2,189)	(15,836)
Change in fair value of Initial Stockholders contingent earn-out liability	(281)	(2,026)
Stock-based compensation expense	9,117	8,513
Gain on termination of lease	0	(420)
Loss on sale of marketable securities	0	2
Accretion of debt discount	1,150	863
Non-cash interest expense	350	112
Changes in operating assets and liabilities:
Accounts receivable	46	(140)
Inventory	6	(2)
Prepaid expenses and other current assets	1,976	(1,443)
Accounts payable	(1,510)	285
Accrued liabilities	(143)	253
Operating lease obligations	(566)	(493)
Net cash used in operating activities	(30,171)	(39,011)
Cash flows from investing activities:
Purchases of marketable securities	(6,169)	(24,614)
Proceeds from maturities of marketable securities	5,000	12,015
Proceeds from sales of marketable securities	0	7,614
Purchases of property and equipment	(330)	(5,179)
Net cash used in investing activities	(1,499)	(10,164)
Cash flows from financing activities:
Proceeds from exercise of stock options	0	310
Proceeds from issuance of common stock and warrants, net of offering costs	42,094	11,460
Payments of finance lease obligations	(81)	(135)
Proceeds from the issuance of notes payable	350	5,695
Payments of notes payable issuance costs	0	(81)
Payments of notes payable modification fees	(200)	0
Net cash provided by financing activities	42,163	17,249
Effect of foreign exchange rate changes on cash and restricted cash	(4)	(30)
Net increase (decrease) in cash, cash equivalents and restricted cash	10,489	(31,956)
Cash, cash equivalents and restricted cash – beginning of period	18,390	50,346
Cash, cash equivalents and restricted cash – end of period	28,879	18,390
Reconciliation of cash, cash equivalents and restricted cash to the consolidated balance sheets
Cash and cash equivalents	28,821	18,332
Restricted cash	58	58
Cash, cash equivalents and restricted cash	28,879	18,390
Supplemental disclosure of non-cash investing and financing activities:
Common stock warrant liability recorded upon debt modification	692	0
Common stock warrant liability recorded upon public stock offering	7,126	0
Lease liability arising from obtaining right-of-use assets, leasehold improvements, and lease incentives	0	2,343
Lease incentive realized	0	500
Lease liability settled through termination of lease	0	602
Reclassification of common stock warrant liability to permanent equity	0	305
Purchases of property and equipment in accounts payable	0	806
Supplemental cash flow information:
Cash paid for interest expense	$ 3,059	$ 2,320

Note 1 - Nature of the Business

Note 1 - Nature of the Business	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Business Description and Basis of Presentation [Text Block]	Note 1. Clene Inc. (the “Company,” “we,” “us,” or similar such references) is a clinical-stage pharmaceutical company pioneering the discovery, development, and commercialization of novel clean-surfaced nanotechnology therapeutics. We have developed an electro-crystal-chemistry drug development platform which enables production of concentrated, stable, highly active, clean-surfaced nanocrystal suspensions. We have multiple drug assets currently in development for applications primarily in neurology. Our efforts are currently focused on addressing the high unmet medical needs in central nervous system disorders including amyotrophic lateral sclerosis (“ALS”), multiple sclerosis (“MS”), and Parkinson’s disease (“PD”). Our patented electro-crystal-chemistry manufacturing platform further enables us to develop very low concentration dietary supplements to advance the health and well-being of broad populations. These dietary supplements can vary greatly and include nanocrystals of varying composition, shapes and sizes as well as ionic solutions with diverse metallic constituents. Dietary supplements are marketed and distributed through our wholly owned subsidiary, dOrbital, Inc., or through an exclusive license with 4Life “4Life” 15 Clene Nanomedicine, Inc. (“Clene Nanomedicine”) became a public company on December 30, 2020 ( Going Concern We incurred a loss from operations of $40.5 million and $48.4 million for the years ended December 31, 2023 2022 December 31, 2023 2022 December 31, 2023 2022 December 31, 2023 2022 We have incurred significant losses and negative cash flows from operations since our inception. We have not not twelve not 8 To mitigate our funding needs, we plan to raise additional funding, including exploring equity financing and offerings, debt financing, licensing or collaboration arrangements with third third no not one The accompanying consolidated financial statements have been prepared assuming we will continue as a going concern, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. As a result, the accompanying consolidated financial statements do not may

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Basis of Presentation The accompanying consolidated financial statements include the accounts of Clene Inc. and our wholly-owned subsidiaries, Clene Nanomedicine, Inc., a subsidiary incorporated in Delaware, Clene Australia Pty Ltd (“Clene Australia”), a subsidiary incorporated in Australia, Clene Netherlands B.V. (“Clene Netherlands”), a subsidiary incorporated in the Netherlands, and dOrbital, Inc., a subsidiary incorporated in Delaware, after elimination of all intercompany accounts and transactions. We have prepared the accompanying consolidated financial statements in accordance with United States (“U.S.”) Generally Accepted Accounting Principles (“GAAP”) In the opinion of management, the consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and disclosure of contingent assets and liabilities, and the reported amounts of expenses. We base our estimates on historical experience and various other assumptions that we believe to be reasonable. Actual results may Risks and Uncertainties We are subject to certain risks and uncertainties and believe that changes in any of the following areas could have a material adverse effect on future financial condition, results of operations, or cash flows: ability to obtain additional financing; regulatory approval and market acceptance of, and reimbursement for, product candidates; performance of third no Concentrations of Credit Risk Financial instruments which potentially subject us to significant concentrations of credit risk consist primarily of cash. Our cash is held in financial institutions and amounts on deposit may not not Cash and Cash Equivalents We consider all short-term investments with original maturities of 90 Restricted Cash We classify cash as restricted when it is unavailable for withdrawal or use in our general operating activities. Restricted cash is classified as current and noncurrent on the consolidated balance sheets based on the nature of the restriction. Our restricted cash balance includes contractually restricted deposits related to our corporate credit card. Marketable Securities Marketable securities are investments with original maturities of more than 90 not one Accounts Receivable Accounts receivable are stated at invoice value less estimated allowances for sales returns and doubtful accounts. We estimate the allowance for sales returns based on historical percentage of returns over a 12 may may no no no Inventory Inventory is stated at historic cost on a first first December 31, 2023 December 31, 2022 Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Property and equipment consist of laboratory and office equipment, computer software, and leasehold improvements. Depreciation is calculated using the straight-line method over the estimated economic useful lives of the assets, which are 3-5 years for laboratory equipment, 3-7 years for furniture and fixtures, and 2-5 years for computer software. Leasehold improvements are amortized over the lesser of the estimated lease term or the estimated useful life of the assets. Costs for capital assets not not We capitalize costs to obtain or develop computer software for internal use, including development costs incurred during the software development stage and costs to obtain software for access and conversion of historical data. We also capitalize costs to modify, upgrade, or enhance existing internal-use software that result in additional functionality. We expense costs incurred during the preliminary project stage, training costs, data conversion costs, and maintenance costs. Impairment of Long-Lived Assets Long-lived assets are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not not December 31, 2023 2022 Debt When debt is issued and a derivative is required to be separated (e.g., bifurcated conversion option) or another separate freestanding financial instrument (e.g., warrant) is issued, costs and fees incurred are allocated to the instruments issued (or bifurcated) in proportion to the allocation of proceeds. When some portions of the costs and fees relate to a bifurcated derivative or freestanding financial instrument that is being subsequently measured at fair value, those allocated costs are expensed immediately. Debt discounts, debt premiums, and debt issuance costs related to debt are recorded as deductions that net against the principal value of the debt and are amortized to interest expense over the contractual term of the debt using the effective interest method. In accordance with ASC 470 20, Debt with Conversion and Other Options not 480, Distinguishing Liabilities from Equity 480” Convertible Debt In accordance with ASU 2020 06, Debt with Conversion and Other Options (Subtopic 470 20 Contracts in Entity s Own Equity (Subtopic 815 40 s Own Equity not not not no 815, Derivatives and Hedging 815” Deferred Offering Costs We capitalize certain third December 31, 2023 2022 not Leases At inception of a contract, we determine if a contract meets the definition of a lease. We determine if the contract conveys the right to control the use of an identified asset for a period of time. We assess throughout the period of use whether we have both of the following: (i) the right to obtain substantially all the economic benefits from use of the identified asset, and (ii) the right to direct the use of the identified asset. This determination is reassessed if the terms of the contract are changed. Leases are classified as operating or finance leases based on the terms of the lease agreement and certain characteristics of the identified asset. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of the future lease payments less any lease incentives received. At the lease commencement date, the discount rate implicit in the lease is used to discount the lease liability if readily determinable. If not not not twelve Certain lease agreements may not Leases may not Contingent Earn-Out Liabilities In connection with the Reverse Recapitalization, certain Clene Nanomedicine stockholders are entitled to receive additional shares of Common Stock (the “Clene Nanomedicine Contingent Earn-out”) as follows: (i) 3,338,483 shares if (a) the volume-weighted average price (“VWAP”) of our Common Stock equals or exceeds $15.00 (the “Milestone 1 twenty thirty three 1 three 1” 2 twenty thirty five 2 five 2” 1 not 2 1. 1; 2. 1 not 2 1. In accordance with ASC 815, not Common Stock Warrants We account for common stock warrants as either equity-classified instruments or liability-classified instruments based on an assessment of the warrant terms. The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, 480, 815, Revenue Recognition Under ASC 606, Revenue from Contracts with Customers 606” 606, five five Once a contract is determined to be within the scope of ASC 606 December 31, 2023 2022 Grant Funding We may 20, Accounting for Government Grants and Disclosure of Government Assistance 20” 4 We recognize grant funding with conditions or continuing performance obligations as a reduction in research and development expenses in the period during which the related qualifying expenses are incurred and as the conditions or performance obligations are fulfilled. Any amount received in advance of fulfilling such conditions or performance obligations is recorded in accrued liabilities (see Note 6 twelve December 31, 2023 2022 Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one three ● Level 1 ● Level 2 1, not ● Level 3 We review the fair value hierarchy classification of our applicable assets and liabilities on a quarterly basis. Changes in the observability of valuation inputs may 1, 2, 3 Foreign Currency Translation and Transactions Our functional currency is the U.S. dollar. Clene Australia determined its functional currency to be the Australian dollar and Clene Netherlands determined its functional currency to be the Euro. We use the U.S. dollar as our reporting currency for the consolidated financial statements. The results of our non-U.S. dollar based functional currency operations are translated to U.S. dollars at the average exchange rates during the period. Our assets and liabilities are translated using the current exchange rate as of the balance sheet date and stockholders’ equity is translated using historical rates. Adjustments resulting from the translation of the consolidated financial statements of our foreign functional currency subsidiaries into U.S. dollars are excluded from the determination of net loss and are accumulated in a separate component of stockholders’ equity. We also incur foreign exchange transaction gains and losses for purchases denominated in foreign currencies. Foreign exchange transaction gains and losses are included in other income (expense), net, as incurred. Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. The only elements of other comprehensive loss in any periods presented were translation of foreign currency denominated balances of Clene Australia and Clene Netherlands to U.S. dollars for consolidation and unrealized gain (loss) on available-for-sale securities. Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated using our weighted-average outstanding common shares. Diluted net loss per share attributable to common stockholders is calculated using our weighted-average outstanding common shares including the dilutive effect of securities as determined under the treasury stock method, except for the dilutive effect of convertible notes payable, which is calculated under the if-converted method, even if the embedded conversion option is out-of-the-money. In periods in which we report a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not Segment Information We report segment information based on ASC 280 280” may fourth 2023, 280, two not Income Taxes We account for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in our tax returns. Deferred tax assets and liabilities are determined based on the differences between the financial statement basis and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. We assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe, based upon the weight of available evidence, that it is more likely than not not We account for uncertainty in income taxes recognized in the consolidated financial statements by applying a two not may 50% Stock-Based Compensation We account for stock-based compensation arrangements using a fair value-based method for costs related to all share-based payments including stock options and stock awards. Stock-based compensation expense is recorded in research and development and general and administrative expenses based on the classification of the work performed by the grantees. The fair value is recognized over the period during which a grantee is required to provide services in exchange for the option award and service-based stock awards, known as the requisite service period (usually the vesting period), on a straight-line basis. For stock awards with market conditions, the fair value is recognized over the period based on the expected milestone achievement dates as the derived service period (usually the vesting period), on a straight-line basis. For stock awards with performance conditions, the grant-date fair value of these awards is the market price on the applicable grant date, and compensation expense will be recognized when the conditions become probable of being satisfied. We recognize a cumulative true-up adjustment once the conditions become probable of being satisfied as the related service period had been completed in a prior period. We elect to account for forfeitures as they occur, rather than estimating expected forfeitures. We determine the fair value of each share of Common Stock underlying stock-based awards using a Black-Scholes option pricing model based on the closing price of our Common Stock as reported by Nasdaq on the date of grant. The fair value of stock awards with market conditions are determined using a Monte Carlo valuation model. Research and Development Research and development costs are expensed as incurred. We account for nonrefundable advance payments for goods and services that will be used in future research and development activities as expenses when the goods have been received or when the service has been performed. Research and development expenses consist of costs incurred for the discovery and development of our product candidates. Research and development costs include, but are not Clinical Trial Accrual Our clinical trial accrual process accounts for expenses resulting from obligations under contracts with CROs, consultants, and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may not not four ● CRO Start-Up no ● CRO Site and Study Management ● CRO Close-Down and Reporting no ● Third-Party Contracts third not third no Recently Adopted Accounting Pronouncements In June 2016, 2016 13, Financial Instruments—Credit Losses (Topic 326 December 15, 2022. not Recent Accounting Pronouncements Not In November 2023, 2023 07, Segment Reporting (Topic 280 2023 07” 2023 07 280 2023 07, December 15, 2023, December 15, 2024. 2023 07. In December 2023, 2023 09, Income Taxes (Topic 740 2023 09” 2023 09 December 15, 2024. 2023 09.

Note 3 - Cash, Cash Equivalents

Note 3 - Cash, Cash Equivalents, and Marketable Securities	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Cash, Cash Equivalents, and Marketable Securities [Text Block]	Note 3. Available-for-Sale Securities Available-for-sale securities as of December 31, 2023 December 31, 2023 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents (contractual maturity within 90 days): U.S. Treasury securities $ 19,883 $ 1 $ — $ 19,884 Money market funds 5,113 — — 5,113 Total cash equivalents 24,996 1 — 24,997 Cash 3,824 — — 3,824 Total cash and cash equivalents $ 28,820 $ 1 $ — $ 28,821 Marketable securities (contractual maturity greater than 90 days but less than 1 year): U.S. Treasury securities 6,179 — — 6,179 Total marketable securities $ 6,179 $ — $ — $ 6,179 Available-for-sale securities as of December 31, 2022 December 31, 2022 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents (contractual maturity within 90 days): Money market funds $ 14,317 $ — $ — $ 14,317 Total cash equivalents 14,317 — — 14,317 Cash 4,015 — — 4,015 Total cash and cash equivalents $ 18,332 $ — $ — $ 18,332 Marketable securities (contractual maturity greater than 90 days but less than 1 year): Commercial paper $ 3,496 $ — $ (14 ) $ 3,482 Corporate debt securities 1,501 — — 1,501 Total marketable securities $ 4,997 $ — $ (14 ) $ 4,983 Proceeds from the sale and maturity of marketable securities held as available-for-sale were as follows: Year Ended December 31, (in thousands) 2023 2022 Proceeds from maturities of marketable securities $ 5,000 $ 12,015 Proceeds from sales of marketable securities — 7,614 Total $ 5,000 $ 19,629 Realized gains and losses included in earnings from the sale of available-for-sale securities were insignificant. As of December 31, 2023 2022 not

Note 4 - Prepaid Expenses and O

Note 4 - Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Prepaid Expenses and Other Current Assets [Text Block]	Note 4. Prepaid expenses and other current assets as of December 31, 2023 2022 December 31, December 31, (in thousands) 2023 2022 Research and development tax credits receivable $ 1,195 $ 2,777 Metals to be used in research and development 1,909 2,290 Other 568 581 Total prepaid expenses and other current assets $ 3,672 $ 5,648

Note 5 - Property and Equipment

Note 5 - Property and Equipment, Net	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	Note 5. Property and equipment, net, as of December 31, 2023 2022 December 31, December 31, (in thousands) 2023 2022 Lab equipment $ 4,092 $ 3,934 Office equipment 178 177 Computer software 459 459 Leasehold improvements 9,983 5,677 Construction in progress 1,438 5,664 16,150 15,911 Less accumulated depreciation (6,887 ) (5,273 ) Total property and equipment, net $ 9,263 $ 10,638 Depreciation expense recorded in research and development expense and general and administrative expense for the years ended December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 General and administrative $ 267 $ 229 Research and development 1,438 790 Total depreciation expense $ 1,705 $ 1,019

Note 6 - Accrued Liabilities

Note 6 - Accrued Liabilities	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	Note 6. Accrued liabilities as of December 31, 2023 2022 December 31, December 31, (in thousands) 2023 2022 Accrued compensation and benefits $ 2,120 $ 2,007 Accrued CRO and clinical fees 481 1,297 Other 1,119 559 Total accrued liabilities $ 3,720 $ 3,863

Note 7 - Leases

Note 7 - Leases	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Lessee, Operating and Finance Leases [Text Block]	Note 7. We lease laboratory and office space and certain laboratory equipment under non-cancellable operating and finance leases. The carrying value of our right-of-use lease assets is substantially concentrated in our real estate leases, while the volume of lease agreements is primarily concentrated in equipment leases. We expect that, in the normal course of business, the existing leases will be renewed or replaced by similar leases. Operating Leases Operating leases primarily consist of real estate leases for office and laboratory space. We have three real estate leases: (i) a laboratory and manufacturing facility which commenced in September 2021 ten two five February 2022 seven two five December 31, 2022 September 2022 seven five not not As of December 31, 2023 2022 Finance Leases Assets recorded under finance lease obligations and included within property and equipment as of December 31, 2023 2022 December 31, December 31, (in thousands) 2023 2022 Lab equipment $ 636 $ 408 Work in process — 228 Total 636 636 Less accumulated depreciation (449 ) (326 ) Net $ 187 $ 310 As of December 31, 2023 2022 Maturity Analysis of Lease Obligations The maturity analysis of our finance and operating lease obligations as of December 31, 2023 (in thousands) Finance Leases Operating Leases 2024 27 1,082 2025 — 1,208 2026 — 1,236 2027 — 1,132 2028 — 1,093 Thereafter — 1,694 Total minimum lease payments 27 7,445 Less amount representing interest/discounting — (1,966 ) Present value of minimum lease payments 27 5,479 Less lease obligations, current portion (27 ) (576 ) Lease obligations, net of current portion $ — $ 4,903 Components of Lease Cost The components of finance and operating lease costs for the years ended December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 Finance lease costs: Amortization $ 112 $ 82 Interest on lease liabilities 11 16 Operating lease costs 1,011 948 Short-term lease costs 3 1 Variable lease costs 262 304 Total lease costs $ 1,399 $ 1,351 Supplemental Cash Flow Information Year Ended December 31, (in thousands) 2023 2022 Operating cash flows from operating leases $ (1,276 ) $ (1,253 ) Operating cash flows from finance leases $ (11 ) $ (16 ) Financing cash flows from finance leases $ (81 ) $ (135 )

Note 8 - Notes Payable and Conv

Note 8 - Notes Payable and Convertible Notes Payable	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Debt Disclosure [Text Block]	Note 8. Our notes payable and convertible notes payable as of December 31, 2023 2022 Stated December 31, December 31, (in thousands, except interest rates) Interest Rate 2023 2022 Notes payable Advance Cecil, Inc. (commenced April 2019) 8.00 % $ 138 $ 130 Maryland DHCD (commenced February 2019) 8.00 % 694 654 Maryland DHCD (commenced May 2022) 6.00 % 1,083 704 Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 15.10 % 15,000 15,000 16,915 16,488 Less unamortized discount and debt issuance costs (394 ) (587 ) Less notes payable, current portion, net of unamortized discount and debt issuance costs (14,627 ) (6,418 ) Total notes payable, net of current portion $ 1,894 $ 9,483 Convertible notes payable Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 15.10 % $ 5,000 $ 5,000 Maryland DHCD (commenced December 2022) 6.00 % 5,308 5,007 10,308 10,007 Less unamortized discount and debt issuance costs (174 ) (237 ) Less convertible notes payable, current portion, net of unamortized discount and debt issuance costs (4,876 ) — Total convertible notes payable, net of current portion $ 5,258 $ 9,770 Maryland Loans In February 2019, “2019 not 2019 2019 February 22, 2034, December 31, 2023 2022 2019 December 31, 2023 2022 In April 2019, “2019 2019 2019 April 30, 2034, December 31, 2023 2022 2019 December 31, 2023 2022 In May 2022, “2022 December 31, 2023 May 17, 2024. first 12 July 1, 2022, 18 $15,000 30 July 1, 2027. December 31, 2023 2022 first December 31, 2023 2022 In December 2022, “2022 first 12 January 1, 2023, 48 January 1, 2028. December 31, 2023 2022 December 8, 2023, may, 30 not December 31, 2023 2022 Avenue Loan In May 2021, “2021 December 31, 2023 2022 May 2021 September 2021 ( 1” 2” not first 12 12 12 June 30, 2024), June 2023 ( June 2023 ( 1” may December 31, 2024, 1, June 30, 2024 ( 2” December 1, 2024, may December 1, 2025, no 2 At any time between May 21, 2022, May 21, 2024, may, not December 31, 2023 2022 December 31, 2023 2022 We are subject to covenants until maturity, including limitations on our ability to retire, repurchase, or redeem our stock, options, and warrants other than per the terms of the securities; limitations on our ability to pay dividends; and we are required to maintain unrestricted cash and cash equivalents of at least $5.0 million. We are not 2021 2021 December 31, 2023 2022 At the inception of the 2021 2021 may no Debt Maturities Future debt payments, net of unamortized discounts and debt issuance costs, and without giving effect to any potential future exercise of conversion features, are as follows: (in thousands) 2019 MD Loan 2019 Cecil Loan 2021 Avenue Loan 2022 MD Loan 2022 DHCD Loan 2024 $ — $ — $ 20,000 $ — $ — 2025 — — — 347 — 2026 — — — 369 — 2027 — — — 317 — 2028 — — — — 5,000 Thereafter 500 100 — — — Total debt principal payments 500 100 20,000 1,033 5,000 Accrued and unpaid interest 194 38 — 50 308 Less unamortized discount and debt issuance costs — — (497 ) (21 ) (50 ) Future debt payments, net $ 694 $ 138 $ 19,503 $ 1,062 $ 5,258

Note 9 - Commitments and Contin

Note 9 - Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 9. Commitments We enter into agreements in the normal course of business with CROs for clinical trials and with vendors for preclinical studies and other services and products for operating purposes, which are cancelable at any time by us, subject to payment of our remaining obligations under binding purchase orders and, in certain cases, nominal early termination fees. These commitments are not As of December 31, 2023 2022 Contingencies From time to time, we may not We received the following grants from the National Multiple Sclerosis Society (“NMSS”): (i) $0.3 million in September 2019 ( “2019 2 May 2023 ( “2023 2 Au8 first not 2019 2023 2019 2023 twelve Au8 Au8 third Au8 2019 Au8 2023 December 31, 2023 not not 450, Contingencies no 2019 2023

Note 10 - Income Taxes

Note 10 - Income Taxes	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Income Tax Disclosure [Text Block]	Note 10. The components of loss before income taxes for the years ended December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 United States $ (48,578 ) $ (26,941 ) Foreign (926 ) (2,977 ) Net loss before income taxes $ (49,504 ) $ (29,918 ) We had no income tax expense or benefit for the years ended December 31, 2023 2022 December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 Income tax expense (benefit) at federal statutory rate $ (10,383 ) $ (6,282 ) State income taxes (net of federal benefit) (1,402 ) (320 ) Loss on initial issuance of equity 3,186 — Change in fair value of common stock warrant liabilities (1,331 ) (36 ) Change in fair value of contingent earn-outs (519 ) (3,029 ) Research and development tax credits (982 ) (423 ) Stock compensation 431 (170 ) Foreign rate differential (80 ) (261 ) Adjustment for change in tax rate (1,277 ) — Other (266 ) 67 Change in valuation allowance 12,623 10,454 Income tax benefit $ — $ — Our effective tax rate was 0.00% and 0.00% during the years ended December 31, 2023 2022 December 31, 2023 2022 December 31, December 31, (in thousands) 2023 2022 Deferred tax assets (liabilities): Net operating loss carryforwards $ 35,246 $ 30,460 Depreciation and amortization 1,281 1,131 Research and development tax credits 5,538 3,808 Lease liability 1,335 1,312 Right-of-use asset (1,016 ) (999 ) Capitalized research and development expenses 8,424 4,712 Non-qualified stock options and restricted stock awards 6,037 3,849 Accrued compensation 510 396 Other (40 ) 20 Total deferred tax assets (liabilities) 57,315 44,689 Less: valuation allowance (57,315 ) (44,689 ) Net deferred tax assets (liabilities) $ — $ — In assessing the realizability of deferred tax assets, we consider whether it is more likely than not not not not We have federal and state net operating losses (“NOLs”) of approximately $147.1 million and $96.7 million as of December 31, 2023 may 80% 2034. 80% 2032. 2034 not Under the provisions of Section 382 1986, may may We have not December 31, 2023 2022 no not December 31, 2023 2022 We are subject to taxation in the U.S., Australia, Netherlands, and various state jurisdictions. Our tax returns from 2016 no

Note 11 - Benefit Plans

Note 11 - Benefit Plans	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	Note 11. 401 Our 401 401 401 December 31, 2023 2022 Stock Compensation Plans The Clene Nanomedicine, Inc. 2014 “2014 July 2014. no may 2014 December 31, 2023 2014 The Clene Inc. 2020 “2020 December 2020 May 2023 December 31, 2023 2020 Stock-Based Compensation Expense Stock-based compensation expense recorded in research and development expense and general and administrative expense for the years ended December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 General and administrative $ 5,056 $ 5,248 Research and development 4,061 3,265 Total stock-based compensation expense $ 9,117 $ 8,513 Stock-based compensation expense by award type for the years ended December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 Stock options $ 9,079 $ 8,513 Stock awards 38 — Total stock-based compensation expense $ 9,117 $ 8,513 Stock Options Outstanding stock options and related activity for the year ended December 31, 2023 (in thousands, except share, per share, and term data) Number of Options Weighted Average Exercise Price Per Share Weighted Average Remaining Term (Years) Intrinsic Value Outstanding – December 31, 2022 15,260,297 $ 2.98 7.28 $ 2,348 Granted 7,053,200 0.92 9.47 — Forfeited (467,109 ) 5.45 — — Outstanding – December 31, 2023 21,846,388 $ 2.26 7.28 $ 302 Vested and exercisable – December 31, 2023 11,717,679 $ 2.58 5.84 $ 302 Vested, exercisable or expected to vest – December 31, 2023 21,846,388 $ 2.26 7.28 $ 302 As of December 31, 2023 2022 The weighted-average grant-date fair value of stock options granted during the year ended December 31, 2023 2022 December 31, 2023 2022 Year Ended December 31, 2023 2022 Expected stock price volatility 96.22% –103.31 % 89.57% –99.77 % Risk-free interest rate 3.26% –4.66 % 1.65% –4.31 % Expected dividend yield 0.00 % 0.00 % Expected term of options (in years) 5.00 –6.43 5.00 –6.98 Stock Awards Stock awards include rights to restricted stock awards with market-based vesting conditions and restricted stock units with service-based vesting conditions. Outstanding stock awards and related activity for the year ended December 31, 2023 Number of Stock Awards Weighted Average Grant Date Fair Value Unvested balance – December 31, 2022 769,139 $ 9.84 Granted 43,479 1.15 Converted to shares of Common Stock upon vesting (32,609 ) 1.15 Forfeited (1,194 ) 9.84 Unvested balance – December 31, 2023 778,815 $ 9.72 As of December 31, 2023 December 31, 2022

Note 12 - Fair Value

Note 12 - Fair Value	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Fair Value Disclosures [Text Block]	Note 12. Cash, cash equivalents, and marketable securities are carried at fair value. Financial instruments, including accounts receivable, accounts payable, and accrued expenses are carried at cost, which approximates fair value given their short-term nature. Our remaining fair value measures are discussed below. Financial Instruments with Fair Value Measurements on a Recurring Basis The fair value hierarchy for financial instruments measured at fair value on a recurring basis as of December 31, 2023 December 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Cash equivalents: U.S. Treasury securities $ — $ 19,884 $ — $ 19,884 Money market funds 5,113 — — 5,113 Marketable securities: U.S. Treasury securities — 6,179 — 6,179 Common stock warrant liabilities — — 1,481 1,481 Clene Nanomedicine contingent earn-out liability — — 75 75 Initial Stockholders contingent earn-out liability — — 10 10 The fair value hierarchy for financial instruments measured at fair value on a recurring basis as of December 31, 2022 December 31, 2022 (in thousands) Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 14,317 $ — $ — $ 14,317 Marketable securities: Commercial paper — 3,482 — 3,482 Corporate debt securities — 1,501 — 1,501 Clene Nanomedicine contingent earn-out liability — — 2,264 2,264 Initial Stockholders contingent earn-out liability — — 291 291 There were no 1, 2, 3 Changes in the fair value of our Level 3 December 31, 2023 (in thousands) Common Stock Warrant Liabilities Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2022 $ — $ 2,264 $ 291 Initial fair value of instruments 7,818 — — Change in fair value (6,337 ) (2,189 ) (281 ) Balance – December 31, 2023 $ 1,481 $ 75 $ 10 Changes in the fair value of our Level 3 December 31, 2022 (in thousands) Common Stock Warrant Liabilities Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2021 $ 474 $ 18,100 $ 2,317 Change in fair value — (15,836 ) (2,026 ) Reclassification from liability to equity (305 ) — — Extinguishment of instrument (169 ) — — Balance – December 31, 2022 $ — $ 2,264 $ 291 Valuation of Notes Payable and Convertible Notes Payable The 2019 2019 8 2021 2022 2022 3 Valuation of the Common Stock Warrant Liabilities The Original Avenue Warrant, comprised of the Tranche 1 2 2021 March 31, 2022, 1 2 December 31, 2022 December 31, 2022. The New Avenue Warrant is classified as a liability and carried at fair value. We estimate the fair value using a Black-Scholes option-pricing model with probability weights for the occurrence of the following events: (i) settlement of the instrument upon a change of control transaction, (ii) dissolution of the Company, or (iii) another outcome outside of (i)-(ii). These estimates require significant judgment. The carrying amount may may December 31, 2023 Expected stock price volatility 105.00% –110.00 % Risk-free interest rate 3.88% –5.03 % Expected dividend yield 0.00 % Expected term (in years) 0.75 –4.5 Probability of change of control 25.00 % Probability of dissolution 50.00 % Probability of other outcome 25.00 % The Tranche A Warrants are classified as a liability and carried at fair value (the Tranche B Warrants qualified for equity classification at issuance). We estimate the fair value using a Black-Scholes option-pricing model with probability weights for the occurrence of the following events: (i) FDA acceptance of an NDA for CNM- Au8, may may December 31, 2023 Expected stock price volatility 100.00% –110.00 % Risk-free interest rate 4.13% –4.74 % Expected dividend yield 0.00 % Expected term (in years) 1.08 –2.46 Probability of NDA acceptance 20.00 % Probability of fundamental transaction 25.00 % Probability of dissolution 50.00 % Probability of other outcome 5.00 % Valuation of the Contingent Earn-Out Liabilities The Contingent Earn-outs are carried at fair value, determined using a Monte Carlo valuation model in order to simulate the future path of our stock price over the earn-out periods. The carrying amount of the liabilities may may December 31, December 31, 2023 2022 Expected stock price volatility 115.00 % 115.00 % Risk-free interest rate 4.20 % 4.20 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 2.00 3.00

Note 13 - Capital Stock

Note 13 - Capital Stock	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Equity [Text Block]	Note 13. As of December 31, 2023 2022 December 31, 2023 2022 Our common stockholders are entitled to one No not Common Stock Warrants As of December 31, 2023 2022 Number of Shares Issuable December 31, December 31, Date Exercisable Exercise Price Expiration Classification 2023 2022 December 2020 $ 11.50 December 2025 (1) Equity 2,407,500 2,407,500 December 2020 $ 11.50 December 2025 (2) Equity 24,583 24,583 December 2020 $ 1.97 April 2023 (3) Equity — 1,929,111 May 2021 $ 8.63 May 2026 (4) Equity — 115,851 June 2023 $ 0.80 June 2028 (5) Liability 3,000,000 — June 2023 $ 1.10 June 2026 (6) Liability 50,000,000 — June 2023 $ 1.50 June 2030 (7) Equity 50,000,000 — Total 105,432,083 4,477,045 ( 1 Represents 2,407,500 shares of Common Stock underlying warrants to purchase one 1/2 one may 20 30 December 31, 2023 2022 ( 2 Represents 24,583 shares of Common Stock underlying warrants to purchase one 1/2 one July 2021. December 31, 2023 2022 ( 3 Represents 1,929,111 shares of Common Stock underlying warrants to purchase one share of Common Stock, issued by Clene Nanomedicine as Series A preferred stock warrants and senior equity warrants in August 2013. April 2023, ( 4 Represents 115,851 shares of Common Stock underlying the Original Avenue Warrant. As of June 2023, not 8 ( 5 Represents 3,000,000 shares of Common Stock underlying the New Avenue Warrant, issued pursuant to the Second Amendment (see Note 8 December 31, 2023 not ( 6 Represents 50,000,000 shares of Common Stock underlying the Tranche A Warrants to purchase one share of Common Stock, issued in our June 2023 December 31, 2023 ( 7 Represents 50,000,000 shares of Common Stock underlying the Tranche B Warrants to purchase one share of Common Stock, issued in our June 2023 December 31, 2023 Public Offerings In October 2022, 3 333 264299 April 26, 2022, In June 2023, may sixty 60 Au8 June 16, 2026. sixty 60 Au8 June 16, 2030. 3 333 264299 April 26, 2022, 462 333 272692 June 16, 2023, 815, Common Stock Sales Agreement In April 2022, December 2022 ( may 3 333 264299 April 26, 2022. June 16, 2023, November 7, 2023, Pursuant to the ATM Agreement, Canaccord is not December 31, 2023 December 31, 2022 Common Stock Purchase Agreement In March 2023, March 7, 2023. 3 333 264299 April 26, 2022. June 16, 2023, not Pursuant to the Purchase Agreement, we may may not not not may may On the date of the Purchase Agreement, we issued 332,668 shares of Common Stock (the “Initial Commitment Shares”) to Lincoln Park as an initial fee for its commitment under the Purchase Agreement. We recorded the fair value of the Initial Commitment Shares on the date of issuance in other income (expense), net. We may may first may, not 61st may one We evaluated the Purchase Agreement under ASC 815 40 Derivatives and Hedging—Contracts on an Entity's Own Equity not December 31, 2023 December 31, 2023

Note 14 - Net Loss Per Share

Note 14 - Net Loss Per Share	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Earnings Per Share [Text Block]	Note 14. The computation of basic and diluted net loss per share attributable to common stockholders for the years ended December 31, 2023 2022 Year Ended December 31, (in thousands, except share and per share data) 2023 2022 Numerator: Net loss attributable to common stockholders $ (49,504 ) $ (29,918 ) Denominator: Weighted average common shares outstanding 104,938,819 65,204,663 Net loss per share attributable to common stockholders – basic and diluted $ (0.47 ) $ (0.46 ) The following shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the years ended December 31, 2023 2022 not Year Ended December 31, 2023 2022 Convertible notes payable (see Note 8) 1,732,703 1,732,703 Common stock warrants (see Note 13) 105,432,083 4,477,045 Options to purchase common stock (see Note 11) 21,846,388 15,260,297 Unvested restricted stock awards (see Note 11) 778,815 769,139 Contingent earn-out shares (see Note 2) 6,592,334 6,592,334 Total 136,382,323 28,831,518

Note 15 - Related Party Transac

Note 15 - Related Party Transactions	12 Months Ended
	Dec. 31, 2023
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	Note 15. License and Supply Agreements In August 2018, 4Life’s ● License Agreement. 4Life 4Life 4Life 4Life may five July 2020, five ● Supply Agreement. 4Life 4Life’s 4Life five April 2021, five We currently provide an aqueous zinc-silver ion dietary (mineral) supplement to 4Life 4Life 4Life December 31, 2023 2022 Year Ended December 31, (in thousands) 2023 2022 Product revenue from related parties $ 462 $ 316 Royalty revenue from related parties 156 144 Total revenue from related parties $ 618 $ 460

Insider Trading Arrangements

Insider Trading Arrangements	12 Months Ended
	Dec. 31, 2023
Insider Trading Arr Line Items
Material Terms of Trading Arrangement [Text Block]	9B. During the three December 31, 2023 none 10b5 1 10b5 1 408
Rule 10b5-1 Arrangement Adopted [Flag]	false
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying consolidated financial statements include the accounts of Clene Inc. and our wholly-owned subsidiaries, Clene Nanomedicine, Inc., a subsidiary incorporated in Delaware, Clene Australia Pty Ltd (“Clene Australia”), a subsidiary incorporated in Australia, Clene Netherlands B.V. (“Clene Netherlands”), a subsidiary incorporated in the Netherlands, and dOrbital, Inc., a subsidiary incorporated in Delaware, after elimination of all intercompany accounts and transactions. We have prepared the accompanying consolidated financial statements in accordance with United States (“U.S.”) Generally Accepted Accounting Principles (“GAAP”) In the opinion of management, the consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and disclosure of contingent assets and liabilities, and the reported amounts of expenses. We base our estimates on historical experience and various other assumptions that we believe to be reasonable. Actual results may
Risk and Uncertainties [Policy Text Block]	Risks and Uncertainties We are subject to certain risks and uncertainties and believe that changes in any of the following areas could have a material adverse effect on future financial condition, results of operations, or cash flows: ability to obtain additional financing; regulatory approval and market acceptance of, and reimbursement for, product candidates; performance of third no
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentrations of Credit Risk Financial instruments which potentially subject us to significant concentrations of credit risk consist primarily of cash. Our cash is held in financial institutions and amounts on deposit may not not
Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents We consider all short-term investments with original maturities of 90
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash We classify cash as restricted when it is unavailable for withdrawal or use in our general operating activities. Restricted cash is classified as current and noncurrent on the consolidated balance sheets based on the nature of the restriction. Our restricted cash balance includes contractually restricted deposits related to our corporate credit card.
Marketable Securities, Policy [Policy Text Block]	Marketable Securities Marketable securities are investments with original maturities of more than 90 not one
Accounts Receivable [Policy Text Block]	Accounts Receivable Accounts receivable are stated at invoice value less estimated allowances for sales returns and doubtful accounts. We estimate the allowance for sales returns based on historical percentage of returns over a 12 may may no no no
Inventory, Policy [Policy Text Block]	Inventory Inventory is stated at historic cost on a first first December 31, 2023 December 31, 2022
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Property and equipment consist of laboratory and office equipment, computer software, and leasehold improvements. Depreciation is calculated using the straight-line method over the estimated economic useful lives of the assets, which are 3-5 years for laboratory equipment, 3-7 years for furniture and fixtures, and 2-5 years for computer software. Leasehold improvements are amortized over the lesser of the estimated lease term or the estimated useful life of the assets. Costs for capital assets not not We capitalize costs to obtain or develop computer software for internal use, including development costs incurred during the software development stage and costs to obtain software for access and conversion of historical data. We also capitalize costs to modify, upgrade, or enhance existing internal-use software that result in additional functionality. We expense costs incurred during the preliminary project stage, training costs, data conversion costs, and maintenance costs.
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Impairment of Long-Lived Assets Long-lived assets are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not not December 31, 2023 2022
Debt, Policy [Policy Text Block]	Debt When debt is issued and a derivative is required to be separated (e.g., bifurcated conversion option) or another separate freestanding financial instrument (e.g., warrant) is issued, costs and fees incurred are allocated to the instruments issued (or bifurcated) in proportion to the allocation of proceeds. When some portions of the costs and fees relate to a bifurcated derivative or freestanding financial instrument that is being subsequently measured at fair value, those allocated costs are expensed immediately. Debt discounts, debt premiums, and debt issuance costs related to debt are recorded as deductions that net against the principal value of the debt and are amortized to interest expense over the contractual term of the debt using the effective interest method. In accordance with ASC 470 20, Debt with Conversion and Other Options not 480, Distinguishing Liabilities from Equity 480”
Convertible Notes [Policy Text Block]	Convertible Debt In accordance with ASU 2020 06, Debt with Conversion and Other Options (Subtopic 470 20 Contracts in Entity s Own Equity (Subtopic 815 40 s Own Equity not not not no 815, Derivatives and Hedging 815”
Deferred Charges, Policy [Policy Text Block]	Deferred Offering Costs We capitalize certain third December 31, 2023 2022 not
Lessee, Leases [Policy Text Block]	Leases At inception of a contract, we determine if a contract meets the definition of a lease. We determine if the contract conveys the right to control the use of an identified asset for a period of time. We assess throughout the period of use whether we have both of the following: (i) the right to obtain substantially all the economic benefits from use of the identified asset, and (ii) the right to direct the use of the identified asset. This determination is reassessed if the terms of the contract are changed. Leases are classified as operating or finance leases based on the terms of the lease agreement and certain characteristics of the identified asset. Right-of-use assets and lease liabilities are recognized at the lease commencement date based on the present value of the future lease payments less any lease incentives received. At the lease commencement date, the discount rate implicit in the lease is used to discount the lease liability if readily determinable. If not not not twelve Certain lease agreements may not Leases may not
Contingent Earnout [Policy Text Block]	Contingent Earn-Out Liabilities In connection with the Reverse Recapitalization, certain Clene Nanomedicine stockholders are entitled to receive additional shares of Common Stock (the “Clene Nanomedicine Contingent Earn-out”) as follows: (i) 3,338,483 shares if (a) the volume-weighted average price (“VWAP”) of our Common Stock equals or exceeds $15.00 (the “Milestone 1 twenty thirty three 1 three 1” 2 twenty thirty five 2 five 2” 1 not 2 1. 1; 2. 1 not 2 1. In accordance with ASC 815, not
Common Stock Warrants [Policy Text Block]	Common Stock Warrants We account for common stock warrants as either equity-classified instruments or liability-classified instruments based on an assessment of the warrant terms. The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, 480, 815,
Revenue from Contract with Customer [Policy Text Block]	Revenue Recognition Under ASC 606, Revenue from Contracts with Customers 606” 606, five five Once a contract is determined to be within the scope of ASC 606 December 31, 2023 2022
Government Assistance [Policy Text Block]	Grant Funding We may 20, Accounting for Government Grants and Disclosure of Government Assistance 20” 4 We recognize grant funding with conditions or continuing performance obligations as a reduction in research and development expenses in the period during which the related qualifying expenses are incurred and as the conditions or performance obligations are fulfilled. Any amount received in advance of fulfilling such conditions or performance obligations is recorded in accrued liabilities (see Note 6 twelve December 31, 2023 2022
Fair Value Measurement, Policy [Policy Text Block]	Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one three ● Level 1 ● Level 2 1, not ● Level 3 We review the fair value hierarchy classification of our applicable assets and liabilities on a quarterly basis. Changes in the observability of valuation inputs may 1, 2, 3
Foreign Currency Transactions and Translations Policy [Policy Text Block]	Foreign Currency Translation and Transactions Our functional currency is the U.S. dollar. Clene Australia determined its functional currency to be the Australian dollar and Clene Netherlands determined its functional currency to be the Euro. We use the U.S. dollar as our reporting currency for the consolidated financial statements. The results of our non-U.S. dollar based functional currency operations are translated to U.S. dollars at the average exchange rates during the period. Our assets and liabilities are translated using the current exchange rate as of the balance sheet date and stockholders’ equity is translated using historical rates. Adjustments resulting from the translation of the consolidated financial statements of our foreign functional currency subsidiaries into U.S. dollars are excluded from the determination of net loss and are accumulated in a separate component of stockholders’ equity. We also incur foreign exchange transaction gains and losses for purchases denominated in foreign currencies. Foreign exchange transaction gains and losses are included in other income (expense), net, as incurred.
Comprehensive Income, Policy [Policy Text Block]	Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. The only elements of other comprehensive loss in any periods presented were translation of foreign currency denominated balances of Clene Australia and Clene Netherlands to U.S. dollars for consolidation and unrealized gain (loss) on available-for-sale securities.
Earnings Per Share, Policy [Policy Text Block]	Net Loss Per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated using our weighted-average outstanding common shares. Diluted net loss per share attributable to common stockholders is calculated using our weighted-average outstanding common shares including the dilutive effect of securities as determined under the treasury stock method, except for the dilutive effect of convertible notes payable, which is calculated under the if-converted method, even if the embedded conversion option is out-of-the-money. In periods in which we report a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not
Segment Reporting, Policy [Policy Text Block]	Segment Information We report segment information based on ASC 280 280” may fourth 2023, 280, two not
Income Tax, Policy [Policy Text Block]	Income Taxes We account for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in our tax returns. Deferred tax assets and liabilities are determined based on the differences between the financial statement basis and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. We assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe, based upon the weight of available evidence, that it is more likely than not not We account for uncertainty in income taxes recognized in the consolidated financial statements by applying a two not may 50%
Share-Based Payment Arrangement [Policy Text Block]	Stock-Based Compensation We account for stock-based compensation arrangements using a fair value-based method for costs related to all share-based payments including stock options and stock awards. Stock-based compensation expense is recorded in research and development and general and administrative expenses based on the classification of the work performed by the grantees. The fair value is recognized over the period during which a grantee is required to provide services in exchange for the option award and service-based stock awards, known as the requisite service period (usually the vesting period), on a straight-line basis. For stock awards with market conditions, the fair value is recognized over the period based on the expected milestone achievement dates as the derived service period (usually the vesting period), on a straight-line basis. For stock awards with performance conditions, the grant-date fair value of these awards is the market price on the applicable grant date, and compensation expense will be recognized when the conditions become probable of being satisfied. We recognize a cumulative true-up adjustment once the conditions become probable of being satisfied as the related service period had been completed in a prior period. We elect to account for forfeitures as they occur, rather than estimating expected forfeitures. We determine the fair value of each share of Common Stock underlying stock-based awards using a Black-Scholes option pricing model based on the closing price of our Common Stock as reported by Nasdaq on the date of grant. The fair value of stock awards with market conditions are determined using a Monte Carlo valuation model.
Research and Development Expense, Policy [Policy Text Block]	Research and Development Research and development costs are expensed as incurred. We account for nonrefundable advance payments for goods and services that will be used in future research and development activities as expenses when the goods have been received or when the service has been performed. Research and development expenses consist of costs incurred for the discovery and development of our product candidates. Research and development costs include, but are not
Clinical Trial Accrual [Policy Text Block]	Clinical Trial Accrual Our clinical trial accrual process accounts for expenses resulting from obligations under contracts with CROs, consultants, and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may not not four ● CRO Start-Up no ● CRO Site and Study Management ● CRO Close-Down and Reporting no ● Third-Party Contracts third not third no
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Pronouncements In June 2016, 2016 13, Financial Instruments—Credit Losses (Topic 326 December 15, 2022. not Recent Accounting Pronouncements Not In November 2023, 2023 07, Segment Reporting (Topic 280 2023 07” 2023 07 280 2023 07, December 15, 2023, December 15, 2024. 2023 07. In December 2023, 2023 09, Income Taxes (Topic 740 2023 09” 2023 09 December 15, 2024. 2023 09.

Note 3 - Cash, Cash Equivalen_2

Note 3 - Cash, Cash Equivalents, and Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Cash and Cash Equivalents [Table Text Block]	December 31, 2023 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents (contractual maturity within 90 days): U.S. Treasury securities $ 19,883 $ 1 $ — $ 19,884 Money market funds 5,113 — — 5,113 Total cash equivalents 24,996 1 — 24,997 Cash 3,824 — — 3,824 Total cash and cash equivalents $ 28,820 $ 1 $ — $ 28,821 Marketable securities (contractual maturity greater than 90 days but less than 1 year): U.S. Treasury securities 6,179 — — 6,179 Total marketable securities $ 6,179 $ — $ — $ 6,179 December 31, 2022 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents (contractual maturity within 90 days): Money market funds $ 14,317 $ — $ — $ 14,317 Total cash equivalents 14,317 — — 14,317 Cash 4,015 — — 4,015 Total cash and cash equivalents $ 18,332 $ — $ — $ 18,332 Marketable securities (contractual maturity greater than 90 days but less than 1 year): Commercial paper $ 3,496 $ — $ (14 ) $ 3,482 Corporate debt securities 1,501 — — 1,501 Total marketable securities $ 4,997 $ — $ (14 ) $ 4,983
Summary of Proceeds from Sale and Maturity of Available for Sale Securities [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 Proceeds from maturities of marketable securities $ 5,000 $ 12,015 Proceeds from sales of marketable securities — 7,614 Total $ 5,000 $ 19,629

Note 4 - Prepaid Expenses and_2

Note 4 - Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]	December 31, December 31, (in thousands) 2023 2022 Research and development tax credits receivable $ 1,195 $ 2,777 Metals to be used in research and development 1,909 2,290 Other 568 581 Total prepaid expenses and other current assets $ 3,672 $ 5,648

Note 5 - Property and Equipme_2

Note 5 - Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Property, Plant and Equipment [Table Text Block]	December 31, December 31, (in thousands) 2023 2022 Lab equipment $ 4,092 $ 3,934 Office equipment 178 177 Computer software 459 459 Leasehold improvements 9,983 5,677 Construction in progress 1,438 5,664 16,150 15,911 Less accumulated depreciation (6,887 ) (5,273 ) Total property and equipment, net $ 9,263 $ 10,638
Depreciation Of Property Plant And Equipment [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 General and administrative $ 267 $ 229 Research and development 1,438 790 Total depreciation expense $ 1,705 $ 1,019

Note 6 - Accrued Liabilities (T

Note 6 - Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Accrued Liabilities [Table Text Block]	December 31, December 31, (in thousands) 2023 2022 Accrued compensation and benefits $ 2,120 $ 2,007 Accrued CRO and clinical fees 481 1,297 Other 1,119 559 Total accrued liabilities $ 3,720 $ 3,863

Note 7 - Leases (Tables)

Note 7 - Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Assets Under Finance Lease [Table Text Block]	December 31, December 31, (in thousands) 2023 2022 Lab equipment $ 636 $ 408 Work in process — 228 Total 636 636 Less accumulated depreciation (449 ) (326 ) Net $ 187 $ 310
Finance and Operating Lease Liability, Maturity [Table Text Block]	(in thousands) Finance Leases Operating Leases 2024 27 1,082 2025 — 1,208 2026 — 1,236 2027 — 1,132 2028 — 1,093 Thereafter — 1,694 Total minimum lease payments 27 7,445 Less amount representing interest/discounting — (1,966 ) Present value of minimum lease payments 27 5,479 Less lease obligations, current portion (27 ) (576 ) Lease obligations, net of current portion $ — $ 4,903
Lease, Cost [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 Finance lease costs: Amortization $ 112 $ 82 Interest on lease liabilities 11 16 Operating lease costs 1,011 948 Short-term lease costs 3 1 Variable lease costs 262 304 Total lease costs $ 1,399 $ 1,351
Schedule of Cash Flow, Supplemental Disclosures, Leases [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 Operating cash flows from operating leases $ (1,276 ) $ (1,253 ) Operating cash flows from finance leases $ (11 ) $ (16 ) Financing cash flows from finance leases $ (81 ) $ (135 )

Note 8 - Notes Payable and Co_2

Note 8 - Notes Payable and Convertible Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Long-Term Debt Instruments [Table Text Block]	Stated December 31, December 31, (in thousands, except interest rates) Interest Rate 2023 2022 Notes payable Advance Cecil, Inc. (commenced April 2019) 8.00 % $ 138 $ 130 Maryland DHCD (commenced February 2019) 8.00 % 694 654 Maryland DHCD (commenced May 2022) 6.00 % 1,083 704 Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 15.10 % 15,000 15,000 16,915 16,488 Less unamortized discount and debt issuance costs (394 ) (587 ) Less notes payable, current portion, net of unamortized discount and debt issuance costs (14,627 ) (6,418 ) Total notes payable, net of current portion $ 1,894 $ 9,483 Convertible notes payable Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 15.10 % $ 5,000 $ 5,000 Maryland DHCD (commenced December 2022) 6.00 % 5,308 5,007 10,308 10,007 Less unamortized discount and debt issuance costs (174 ) (237 ) Less convertible notes payable, current portion, net of unamortized discount and debt issuance costs (4,876 ) — Total convertible notes payable, net of current portion $ 5,258 $ 9,770
Schedule of Maturities of Long-Term Debt [Table Text Block]	(in thousands) 2019 MD Loan 2019 Cecil Loan 2021 Avenue Loan 2022 MD Loan 2022 DHCD Loan 2024 $ — $ — $ 20,000 $ — $ — 2025 — — — 347 — 2026 — — — 369 — 2027 — — — 317 — 2028 — — — — 5,000 Thereafter 500 100 — — — Total debt principal payments 500 100 20,000 1,033 5,000 Accrued and unpaid interest 194 38 — 50 308 Less unamortized discount and debt issuance costs — — (497 ) (21 ) (50 ) Future debt payments, net $ 694 $ 138 $ 19,503 $ 1,062 $ 5,258

Note 10 - Income Taxes (Tables)

Note 10 - Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 United States $ (48,578 ) $ (26,941 ) Foreign (926 ) (2,977 ) Net loss before income taxes $ (49,504 ) $ (29,918 )
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 Income tax expense (benefit) at federal statutory rate $ (10,383 ) $ (6,282 ) State income taxes (net of federal benefit) (1,402 ) (320 ) Loss on initial issuance of equity 3,186 — Change in fair value of common stock warrant liabilities (1,331 ) (36 ) Change in fair value of contingent earn-outs (519 ) (3,029 ) Research and development tax credits (982 ) (423 ) Stock compensation 431 (170 ) Foreign rate differential (80 ) (261 ) Adjustment for change in tax rate (1,277 ) — Other (266 ) 67 Change in valuation allowance 12,623 10,454 Income tax benefit $ — $ —
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	December 31, December 31, (in thousands) 2023 2022 Deferred tax assets (liabilities): Net operating loss carryforwards $ 35,246 $ 30,460 Depreciation and amortization 1,281 1,131 Research and development tax credits 5,538 3,808 Lease liability 1,335 1,312 Right-of-use asset (1,016 ) (999 ) Capitalized research and development expenses 8,424 4,712 Non-qualified stock options and restricted stock awards 6,037 3,849 Accrued compensation 510 396 Other (40 ) 20 Total deferred tax assets (liabilities) 57,315 44,689 Less: valuation allowance (57,315 ) (44,689 ) Net deferred tax assets (liabilities) $ — $ —

Note 11 - Benefit Plans (Tables

Note 11 - Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 General and administrative $ 5,056 $ 5,248 Research and development 4,061 3,265 Total stock-based compensation expense $ 9,117 $ 8,513 Year Ended December 31, (in thousands) 2023 2022 Stock options $ 9,079 $ 8,513 Stock awards 38 — Total stock-based compensation expense $ 9,117 $ 8,513
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	(in thousands, except share, per share, and term data) Number of Options Weighted Average Exercise Price Per Share Weighted Average Remaining Term (Years) Intrinsic Value Outstanding – December 31, 2022 15,260,297 $ 2.98 7.28 $ 2,348 Granted 7,053,200 0.92 9.47 — Forfeited (467,109 ) 5.45 — — Outstanding – December 31, 2023 21,846,388 $ 2.26 7.28 $ 302 Vested and exercisable – December 31, 2023 11,717,679 $ 2.58 5.84 $ 302 Vested, exercisable or expected to vest – December 31, 2023 21,846,388 $ 2.26 7.28 $ 302
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Year Ended December 31, 2023 2022 Expected stock price volatility 96.22% –103.31 % 89.57% –99.77 % Risk-free interest rate 3.26% –4.66 % 1.65% –4.31 % Expected dividend yield 0.00 % 0.00 % Expected term of options (in years) 5.00 –6.43 5.00 –6.98
Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]	Number of Stock Awards Weighted Average Grant Date Fair Value Unvested balance – December 31, 2022 769,139 $ 9.84 Granted 43,479 1.15 Converted to shares of Common Stock upon vesting (32,609 ) 1.15 Forfeited (1,194 ) 9.84 Unvested balance – December 31, 2023 778,815 $ 9.72

Note 12 - Fair Value (Tables)

Note 12 - Fair Value (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	December 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Cash equivalents: U.S. Treasury securities $ — $ 19,884 $ — $ 19,884 Money market funds 5,113 — — 5,113 Marketable securities: U.S. Treasury securities — 6,179 — 6,179 Common stock warrant liabilities — — 1,481 1,481 Clene Nanomedicine contingent earn-out liability — — 75 75 Initial Stockholders contingent earn-out liability — — 10 10 December 31, 2022 (in thousands) Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 14,317 $ — $ — $ 14,317 Marketable securities: Commercial paper — 3,482 — 3,482 Corporate debt securities — 1,501 — 1,501 Clene Nanomedicine contingent earn-out liability — — 2,264 2,264 Initial Stockholders contingent earn-out liability — — 291 291 (in thousands) Common Stock Warrant Liabilities Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2022 $ — $ 2,264 $ 291 Initial fair value of instruments 7,818 — — Change in fair value (6,337 ) (2,189 ) (281 ) Balance – December 31, 2023 $ 1,481 $ 75 $ 10 (in thousands) Common Stock Warrant Liabilities Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2021 $ 474 $ 18,100 $ 2,317 Change in fair value — (15,836 ) (2,026 ) Reclassification from liability to equity (305 ) — — Extinguishment of instrument (169 ) — — Balance – December 31, 2022 $ — $ 2,264 $ 291
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	December 31, 2023 Expected stock price volatility 105.00% –110.00 % Risk-free interest rate 3.88% –5.03 % Expected dividend yield 0.00 % Expected term (in years) 0.75 –4.5 Probability of change of control 25.00 % Probability of dissolution 50.00 % Probability of other outcome 25.00 % December 31, 2023 Expected stock price volatility 100.00% –110.00 % Risk-free interest rate 4.13% –4.74 % Expected dividend yield 0.00 % Expected term (in years) 1.08 –2.46 Probability of NDA acceptance 20.00 % Probability of fundamental transaction 25.00 % Probability of dissolution 50.00 % Probability of other outcome 5.00 % December 31, December 31, 2023 2022 Expected stock price volatility 115.00 % 115.00 % Risk-free interest rate 4.20 % 4.20 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 2.00 3.00

Note 13 - Capital Stock (Tables

Note 13 - Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Number of Shares Issuable December 31, December 31, Date Exercisable Exercise Price Expiration Classification 2023 2022 December 2020 $ 11.50 December 2025 (1) Equity 2,407,500 2,407,500 December 2020 $ 11.50 December 2025 (2) Equity 24,583 24,583 December 2020 $ 1.97 April 2023 (3) Equity — 1,929,111 May 2021 $ 8.63 May 2026 (4) Equity — 115,851 June 2023 $ 0.80 June 2028 (5) Liability 3,000,000 — June 2023 $ 1.10 June 2026 (6) Liability 50,000,000 — June 2023 $ 1.50 June 2030 (7) Equity 50,000,000 — Total 105,432,083 4,477,045

Note 14 - Net Loss Per Share (T

Note 14 - Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Year Ended December 31, (in thousands, except share and per share data) 2023 2022 Numerator: Net loss attributable to common stockholders $ (49,504 ) $ (29,918 ) Denominator: Weighted average common shares outstanding 104,938,819 65,204,663 Net loss per share attributable to common stockholders – basic and diluted $ (0.47 ) $ (0.46 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Year Ended December 31, 2023 2022 Convertible notes payable (see Note 8) 1,732,703 1,732,703 Common stock warrants (see Note 13) 105,432,083 4,477,045 Options to purchase common stock (see Note 11) 21,846,388 15,260,297 Unvested restricted stock awards (see Note 11) 778,815 769,139 Contingent earn-out shares (see Note 2) 6,592,334 6,592,334 Total 136,382,323 28,831,518

Note 15 - Related Party Trans_2

Note 15 - Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2023
Notes Tables
Schedule of Related Party Transactions [Table Text Block]	Year Ended December 31, (in thousands) 2023 2022 Product revenue from related parties $ 462 $ 316 Royalty revenue from related parties 156 144 Total revenue from related parties $ 618 $ 460

Note 1 - Nature of the Busine_2

Note 1 - Nature of the Business (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 30, 2020
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Operating Income (Loss)	$ (40,540)	$ (48,409)
Retained Earnings (Accumulated Deficit)	(242,723)	(193,219)
Cash, Cash Equivalents, and Short-Term Investments	35,000	23,300
Net Cash Provided by (Used in) Operating Activities	(30,171)	$ (39,011)
Minimum Cash Balance For Loan Covenant	$ 5,000

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)		12 Months Ended
	Dec. 30, 2020	Dec. 31, 2023	Dec. 31, 2022
Inventory, Raw Materials, Gross		$ 23,000	$ 29,000
Inventory, Finished Goods, Gross		14,000	14,000
Tangible Asset Impairment Charges		0	0
Deferred Offering Costs		0	0
Research and Development Expense		26,655,000	31,920,000
Grant Funding on Conditional Grants [Member]
Research and Development Expense		$ 300,000	$ 0
Reverse Recapitalization [Member] | Clene Nanomedicine Contingent Earn-out [Member]
Business Combination, Contingent Earnout Shares, Milestone One (in shares)	3,338,483
Business Combination, Contingent Earnout, Milestone One, Minimum Price (in dollars per share)	$ 15
Business Combination, Contingent Earnout, Milestone One, Consecutive Trading Days (Day)	20 days
Business Combination, Contingent Earnout, Milestone One, Trading Day Period (Day)	30 days
Business Combination, Contingent Earnout, Milestone One, Period (Year)	3 years
Business Combination, Contingent Earnout Shares, Milestone Two (in shares)	2,503,851
Business Combination, Contingent Earnout, Milestone Two, Minimum Price (in dollars per share)	$ 20
Business Combination, Contingent Earnout, Milestone Two, Consecutive Trading Days (Day)	20 days
Business Combination, Contingent Earnout, Milestone Two, Trading Day Period (Day)	30 days
Business Combination, Contingent Earnout, Milestone Two, Period (Year)	5 years
Business Combination, Contingent Earnout, Milestone Two, Change of Control Period (Year)	5 years
Reverse Recapitalization [Member] | Initial Stockholders Contingent Earn-out [Member]
Business Combination, Contingent Earnout Shares, Milestone One (in shares)	375,000
Business Combination, Contingent Earnout Shares, Milestone Two (in shares)	375,000
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		3 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		7 years
Computer Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)		2 years
Computer Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)		5 years

Note 3 - Cash, Cash Equivalen_3

Note 3 - Cash, Cash Equivalents, and Marketable Securities (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 0	$ 0

Note 3 - Cash, Cash Equivalen_4

Note 3 - Cash, Cash Equivalents, and Marketable Securities - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
US Treasury Securities [Member]
Amortized cost	$ 19,883
Gross unrealized gains	1
Gross unrealized losses	0
Fair value	19,884
Gross unrealized losses	0
Money Market Funds [Member]
Amortized cost	5,113	$ 14,317
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	5,113	14,317
Gross unrealized losses	0	0
Cash Equivalents [Member]
Amortized cost	24,996	14,317
Gross unrealized gains	1	0
Gross unrealized losses	0	0
Fair value	24,997	14,317
Gross unrealized losses	0	0
Cash [Member]
Amortized cost	3,824	4,015
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	3,824	4,015
Gross unrealized losses	0	0
Cash and Cash Equivalents [Member]
Amortized cost	28,820	18,332
Gross unrealized gains	1	0
Gross unrealized losses	0	0
Fair value	28,821	18,332
Gross unrealized losses	0	0
Commercial Paper [Member]
Amortized cost		3,496
Gross unrealized gains		0
Gross unrealized losses		14
Fair value		3,482
Gross unrealized losses		(14)
Us Treasury Securities with Maturity Greater than 90 Days but Less than 1 Year [Member]
Amortized cost	6,179
Gross unrealized gains	0
Gross unrealized losses	0
Fair value	6,179
Gross unrealized losses	0
Corporate Debt Securities [Member]
Amortized cost		1,501
Gross unrealized gains		0
Gross unrealized losses		0
Fair value		1,501
Gross unrealized losses		0
Marketable Securities [Member]
Amortized cost	6,179	4,997
Gross unrealized gains	0	0
Gross unrealized losses	0	14
Fair value	6,179	4,983
Gross unrealized losses	$ 0	$ (14)

Note 3 - Cash, Cash Equivalen_5

Note 3 - Cash, Cash Equivalents, and Marketable Securities - Proceeds From Sale and Maturity of Available-for Sale Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Proceeds from maturities of marketable securities	$ 5,000	$ 12,015
Proceeds from sales of marketable securities	0	7,614
Total	$ 5,000	$ 19,629

Note 4 - Prepaid Expenses and_3

Note 4 - Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Research and development tax credits receivable	$ 1,195	$ 2,777
Metals to be used in research and development	1,909	2,290
Other	568	581
Total prepaid expenses and other current assets	$ 3,672	$ 5,648

Note 5 - Property and Equipme_3

Note 5 - Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property and equipment, gross	$ 16,150	$ 15,911
Less accumulated depreciation	(6,887)	(5,273)
Total property and equipment, net	9,263	10,638
Equipment [Member]
Property and equipment, gross	4,092	3,934
Office Equipment [Member]
Property and equipment, gross	178	177
Computer Equipment [Member]
Property and equipment, gross	459	459
Leasehold Improvements [Member]
Property and equipment, gross	9,983	5,677
Construction in Progress [Member]
Property and equipment, gross	$ 1,438	$ 5,664

Note 5 - Property and Equipme_4

Note 5 - Property and Equipment, Net - Schedule of Depreciation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Depreciation	$ 1,705	$ 1,019
General and Administrative Expense [Member]
Depreciation	267	229
Research and Development Expense [Member]
Depreciation	$ 1,438	$ 790

Note 6 - Accrued Liabilities -

Note 6 - Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accrued compensation and benefits	$ 2,120	$ 2,007
Accrued CRO and clinical fees	481	1,297
Other	1,119	559
Total accrued liabilities	$ 3,720	$ 3,863

Note 7 - Leases (Details Textua

Note 7 - Leases (Details Textual) $ in Thousands	1 Months Ended			12 Months Ended
	Sep. 30, 2022	Feb. 28, 2022	Sep. 30, 2021	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Number of Real Estate Leases				3
Gain (Loss) on Termination of Lease				$ 0	$ 420
Operating Lease, Weighted Average Discount Rate, Percent				9.60%	9.60%
Operating Lease, Weighted Average Remaining Lease Term (Year)				6 years 4 months 24 days	7 years 3 months 18 days
Finance Lease, Weighted Average Discount Rate, Percent				11%	10.20%
Finance Lease, Weighted Average Remaining Lease Term (Year)				4 months 24 days	1 year 2 months 12 days
Lease for Laboratory Space [Member]
Lessee, Operating Lease, Term of Contract (Year)		7 years	10 years
Lessee, Operating Lease, Option To Extend Period (Year)	5 years	10 years	10 years
Gain (Loss) on Termination of Lease					$ 400
Lessee, Operating Lease, Renewal Term (Year)	7 years

Note 7 - Leases - Assets Record

Note 7 - Leases - Assets Recorded Under Finance Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Finance lease asset, gross	$ 636	$ 636
Less accumulated depreciation	(449)	(326)
Net	187	310
Equipment [Member]
Finance lease asset, gross	636	408
Construction in Progress [Member]
Finance lease asset, gross	$ 0	$ 228

Note 7 - Leases - Maturity Anal

Note 7 - Leases - Maturity Analysis of Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
2024, finance leases	$ 27
2024, operating leases	1,082
2025, finance leases	0
2025, operating leases	1,208
2026, finance leases	0
2026, operating leases	1,236
2027, finance leases	0
2027, operating leases	1,132
2028, finance leases	0
2028, operating leases	1,093
Thereafter, finance leases	0
Thereafter, operating leases	1,694
Total minimum lease payments, finance leases	27
Total minimum lease payments, operating leases	7,445
Less amount representing interest/discounting, finance leases	0
Less amount representing interest/discounting, operating leases	(1,966)
Present value of minimum lease payments, finance leases	27
Present value of minimum lease payments, operating leases	5,479
Less lease obligations, current portion, finance leases	27	$ 74
Less lease obligations, current portion, operating leases	576	488
Lease obligations, net of current portion, finance leases	0	34
Lease obligations, net of current portion, operating leases	$ 4,903	$ 5,557

Note 7 - Leases - Components of

Note 7 - Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Amortization	$ 112	$ 82
Interest on lease liabilities	11	16
Operating lease costs	1,011	948
Short-term lease costs	3	1
Variable lease costs	262	304
Total lease costs	$ 1,399	$ 1,351

Note 7 - Leases - Supplemental

Note 7 - Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating cash flows from operating leases	$ (1,276)	$ (1,253)
Operating cash flows from finance leases	(11)	(16)
Payments of finance lease obligations	$ (81)	$ (135)

Note 8 - Notes Payable and Co_3

Note 8 - Notes Payable and Convertible Notes Payable (Details Textual) - USD ($)			1 Months Ended					12 Months Ended
	Apr. 30, 2019	Feb. 28, 2019	Jun. 30, 2023	Dec. 31, 2022	May 31, 2022	Sep. 30, 2021	May 31, 2021	Dec. 31, 2023	Dec. 31, 2022	May 21, 2022
Proceeds from Notes Payable, Total								$ 350,000	$ 5,695,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				4,477,045				105,432,083	4,477,045
New Avenue Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)								3,000,000
Avenue [Member] | Warrants Issued with 2021 Avenue Loan [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							115,851
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)							$ 8.63
Warrants and Rights Outstanding							$ 1,500,000
Avenue [Member] | New Avenue Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)							3,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)							$ 0.8
Warrants and Rights Outstanding							$ 700,000
Avenue [Member] | Minimum [Member] | Public Equity Offering [Member]
Equity Milestone 1 Condition for Extended Interest Only Period			$ 35,000,000
Equity Milestone 2 Condition for Extended Interest Only Period			$ 40,000,000
The 2019 MD Loan [Member] | Department of Housing and Community Development [Member]
Debt Instrument, Face Amount		$ 500,000
Debt Instrument, Interest Rate, Stated Percentage		8%
Phantom Shares for Potential Repayment (in shares)		119,907
Interest Expense, Debt								$ 40,000	$ 40,000
The 2019 Cecil Loan [Member] | Advance Cecil Inc. [Member]
Debt Instrument, Face Amount	$ 100,000
Debt Instrument, Interest Rate, Stated Percentage	8%
Phantom Shares for Potential Repayment (in shares)	23,981
Interest Expense, Debt								8,000	8,000
The 2022 MD Loan [Member] | Department of Housing and Community Development [Member]
Debt Instrument, Face Amount					$ 3,000,000
Debt Instrument, Interest Rate, Stated Percentage					6%
Interest Expense, Debt								100,000	23,000
Proceeds from Loans								1,100,000
Debt Instrument, Monthly Interest-only Payments, Maximum Amount, First Eighteen Installments					$ 15,000
Debt Instrument, Monthly Principal and Interest Payment, for the Next Thirty Installments					33,306
Interest Payable				$ 22,000				$ 100,000	22,000
Debt Issuance Costs, Gross					$ 31,000
The 2022 DHCD Loan [Member] | Convertible Notes Payable [Member]
Debt Instrument, Interest Rate, Stated Percentage								6%
The 2022 DHCD Loan [Member] | Department of Housing and Community Development [Member]
Debt Instrument, Face Amount				$ 5,000,000					$ 5,000,000
Debt Instrument, Interest Rate, Stated Percentage				6%					6%
Interest Expense, Debt								$ 300,000	$ 7,200
Interest Payable				$ 8,000				300,000	8,000
Debt Issuance Costs, Gross				100,000					100,000
Debt Instrument, Convertible, Minimum Increment of Principal for Exercise				$ 1,000,000					$ 1,000,000
Debt Conversion, Conversion Price, Percent of 30-day Trailing Volume-weighted Average Sale Price of Common Stock				97%
Debt Instrument, Convertible, Conversion Price (in dollars per share)				$ 4					$ 4
Coupon Interest Expense								300,000	$ 7,500
Amortization of Debt Issuance Costs and Discounts								$ 1,000	300
Debt Instrument, Interest Rate, Effective Percentage								5.91%
The 2021 Avenue Loan [Member] | Avenue [Member]
Debt Instrument, Face Amount							$ 30,000,000
Debt Instrument, Interest Rate, Stated Percentage							3.25%
Interest Expense, Debt								$ 4,100,000	$ 3,200,000
Debt Instrument, Convertible, Conversion Price (in dollars per share)							$ 10.36
Debt Instrument, Interest Rate During Period								15.10%	14.10%
Debt Issuance Costs, Net							$ 800,000
Debt Issuance Costs Expensed							$ 47,000
Debt Instrument, Interest Only Payments, Period (Month)							12 months
Debt Instrument, First Interest-only Period Extension (Month)							12 months
Additional Payment at Debt Maturity, Percentage of Principal							4.25%
Additional Payment at Debt Maturity							$ 900,000
Debt Instrument, Convertible, Maximum Conversion Amount							5,000,000
Debt Instrument, Covenant, Cash and Certain Cash Equivalents, Minimum										$ 5,000,000
The 2021 Avenue Loan [Member] | Avenue [Member] | Convertible Notes Payable [Member]
Interest Expense, Debt								$ 1,000,000	$ 800,000
Coupon Interest Expense								800,000	600,000
Amortization of Debt Issuance Costs and Discounts								$ 300,000	$ 200,000
Debt Instrument, Interest Rate During Period								22.79%	19.69%
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net				$ 200,000				$ 100,000	$ 200,000
The 2021 Avenue Loan [Member] | Avenue [Member] | Notes Payable, Tranche 1 [Member]
Proceeds from Notes Payable, Total						$ 5,000,000	15,000,000
The 2021 Avenue Loan [Member] | Avenue [Member] | Notes Payable, Tranche 2 [Member]
Debt Instrument, Unfunded Balance							$ 10,000,000
The 2021 Avenue Loan [Member] | Avenue [Member] | Prime Rate [Member]
Debt Instrument, Basis Spread on Variable Rate							6.60%

Note 8 - Notes Payable and Co_4

Note 8 - Notes Payable and Convertible Notes Payable - Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Future debt payments, net	$ 16,915	$ 16,488
Less notes payable, current portion, net of unamortized discount and debt issuance costs	(14,627)	(6,418)
Notes payable, net of current portion	1,894	9,483
Notes payable	16,915	16,488
Convertible notes payable, net of current portion	5,258	9,770
Notes Payable [Member]
Less unamortized discount and debt issuance costs	(394)	(587)
Less notes payable, current portion, net of unamortized discount and debt issuance costs	(14,627)	(6,418)
Notes payable, net of current portion	1,894	9,483
Convertible Notes Payable [Member]
Less unamortized discount and debt issuance costs	(174)	(237)
Less convertible notes payable, current portion, net of unamortized discount and debt issuance costs	(4,876)	0
Convertible notes payable, net of current portion	$ 5,258	9,770
The 2019 Cecil Loan [Member] | Notes Payable [Member]
Interest Rate	8%
Future debt payments, net	$ 138	130
Notes payable	$ 138	130
The 2019 Maryland DHCD [Member] | Notes Payable [Member]
Interest Rate	8%
Future debt payments, net	$ 694	654
Notes payable	$ 694	654
The 2022 Maryland DHCD [Member] | Notes Payable [Member]
Interest Rate	6%
Future debt payments, net	$ 1,083	704
Notes payable	$ 1,083	704
Avenue [Member] | Notes Payable [Member]
Interest Rate	15.10%
Future debt payments, net	$ 15,000	15,000
Notes payable	$ 15,000	15,000
Avenue [Member] | Convertible Notes Payable [Member]
Interest Rate	15.10%
Future debt payments, net	$ 5,000	5,000
Notes payable	5,000	5,000
The 2022 DHCD Loan [Member] | Notes Payable [Member]
Future debt payments, net	5,258
Notes payable	$ 5,258
The 2022 DHCD Loan [Member] | Convertible Notes Payable [Member]
Interest Rate	6%
Future debt payments, net	$ 5,308	5,007
Notes payable	$ 5,308	$ 5,007

Note 8 - Notes Payable and Co_5

Note 8 - Notes Payable and Convertible Notes Payable - Schedule of Future Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Future debt payments, net	$ 16,915	$ 16,488
Notes Payable [Member] | The 2019 MD Loan [Member]
2024	0
2025	0
2026	0
2027	0
2028	0
Thereafter	500
Total debt principal payments	500
Accrued and unpaid interest	194
Less unamortized discount and debt issuance costs	0
Future debt payments, net	694
Notes Payable [Member] | The 2019 Cecil Loan [Member]
2024	0
2025	0
2026	0
2027	0
2028	0
Thereafter	100
Total debt principal payments	100
Accrued and unpaid interest	38
Less unamortized discount and debt issuance costs	0
Future debt payments, net	138	$ 130
Notes Payable [Member] | The 2021 Avenue Loan [Member]
2024	20,000
2025	0
2026	0
2027	0
2028	0
Thereafter	0
Total debt principal payments	20,000
Accrued and unpaid interest	0
Less unamortized discount and debt issuance costs	(497)
Future debt payments, net	19,503
Notes Payable [Member] | The 2022 MD Loan [Member]
2024	0
2025	347
2026	369
2027	317
2028	0
Thereafter	0
Total debt principal payments	1,033
Accrued and unpaid interest	50
Less unamortized discount and debt issuance costs	(21)
Future debt payments, net	1,062
Notes Payable [Member] | The 2022 DHCD Loan [Member]
2024	0
2025	0
2026	0
2027	0
2028	5,000
Thereafter	0
Total debt principal payments	5,000
Accrued and unpaid interest	308
Less unamortized discount and debt issuance costs	(50)
Future debt payments, net	$ 5,258

Note 9 - Commitments and Cont_2

Note 9 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	May 31, 2023	Sep. 30, 2019	Dec. 31, 2023	Dec. 31, 2022
Government Assistance, Amount			$ 963	$ 3,079
Grant Funding Related to VISIONARY-MS Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member]
Government Assistance, Amount	$ 700	$ 300
Government Assistance, Repayment, Percentage of Grant Funding Upon First Commercial Product Sale		50%
Government Assistance, Repayment, Additional Percentage of Grant Funding, Tranche One		50%
Government Assistance, Repayment, Cumulative Sales, Tranche One		$ 10,000
Government Assistance, Repayment, Additional Percentage of Grant Funding, Tranche Two		150%
Government Assistance, Repayment, Cumulative Sales, Tranche Two		$ 50,000
Government Assistance, Repayment, Additional Percentage of Grant Funding, Tranche Three		200%
Government Assistance, Repayment, Cumulative Sales, Tranche Three		$ 100,000
Government Assistance, Repayment, Maximum Percentage of Grant Funding When All Milestones Achieved		450%
Government Assistance, Aggregate Repayment, Percentage of Grant Funding	150%	300%
Government Assistance, Repayment, Percentage of Grant Funding Upon Closing	150%	300%
Government Assistance, Repayment Amount Upon Closing	$ 1,000	$ 1,000
Grant Funding Related to VISIONARY-MS Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member] | Minimum [Member]
Government Assistance, Possible Loss, Percentage of Grant Funding		50%
Government Assistance, Possible Loss Between Minimum and Maximum Repayment Amounts		$ 200
Grant Funding Related to VISIONARY-MS Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member] | Maximum [Member]
Government Assistance, Possible Loss, Percentage of Grant Funding		450%
Government Assistance, Possible Loss Between Minimum and Maximum Repayment Amounts		$ 1,500
Grant Funding Related to REPAIR-MS and REPAIR-PD Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member] | Minimum [Member]
Government Assistance, Possible Loss Between Minimum and Maximum Repayment Amounts	300
Grant Funding Related to REPAIR-MS and REPAIR-PD Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member] | Maximum [Member]
Government Assistance, Possible Loss Between Minimum and Maximum Repayment Amounts	$ 3,000
Capital Addition Purchase Commitments [Member]
Long-Term Purchase Commitment, Amount			$ 400	$ 1,600

Note 10 - Income Taxes (Details

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Expense (Benefit)	$ 0	$ 0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21%	21%
Effective Income Tax Rate Reconciliation, Percent	0%	0%
Unrecognized Tax Benefits	$ 0	$ 0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	$ 0	$ 0
Open Tax Year	2016 2017 2018 2019 2020 2021 2022 2023
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 5,600
Tax Credit Carryforward, Expiration Date	Dec. 31, 2034
Domestic Tax Authority [Member]
Operating Loss Carryforwards	$ 147,100
Operating Loss Carryforwards Not Subject to Expiration	113,700
Operating Loss Carryforwards Subject to Expiration	$ 33,400
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2034
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	$ 96,700
Operating Loss Carryforwards Not Subject to Expiration	83,700
Operating Loss Carryforwards Subject to Expiration	$ 12,900
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032

Note 10 - Income Taxes - Compon

Note 10 - Income Taxes - Components of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
United States	$ (48,578)	$ (26,941)
Foreign	(926)	(2,977)
Net loss before income taxes	$ (49,504)	$ (29,918)

Note 10 - Income Taxes - Reconc

Note 10 - Income Taxes - Reconciliation of Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income tax expense (benefit) at federal statutory rate	$ (10,383)	$ (6,282)
State income taxes (net of federal benefit)	(1,402)	(320)
Loss on initial issuance of equity	3,186	0
Change in fair value of common stock warrant liabilities	(1,331)	(36)
Change in fair value of contingent earn-outs	(519)	(3,029)
Research and development tax credits	982	423
Stock compensation	431	(170)
Foreign rate differential	(80)	(261)
Adjustment for change in tax rate	(1,277)	0
Other	(266)	67
Change in valuation allowance	12,623	10,454
Income tax benefit	$ 0	$ 0

Note 10 - Income Taxes - Signif

Note 10 - Income Taxes - Significant Components of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Net operating loss carryforwards	$ 35,246	$ 30,460
Depreciation and amortization	1,281	1,131
Research and development tax credits	5,538	3,808
Lease liability	1,335	1,312
Right-of-use asset	(1,016)	(999)
Capitalized research and development expenses	8,424	4,712
Non-qualified stock options and restricted stock awards	6,037	3,849
Accrued compensation	510	396
Other	(40)	20
Total deferred tax assets (liabilities)	57,315	44,689
Less: valuation allowance	(57,315)	(44,689)
Net deferred tax assets (liabilities)	$ 0	$ 0

Note 11 - Benefit Plans (Detail

Note 11 - Benefit Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	May 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)	21,846,388	15,260,297
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	7,053,200
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 11,000	$ 0
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	2 months 23 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 0.73	$ 1.49
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 13,700,000	$ 18,200,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	2 years 1 month 6 days	2 years 6 months 29 days
The 2014 Stock Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)	5,360,658
The 2020 Stock Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)			18,400,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	17,580,408
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	819,592
The 401(k) Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	3%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount	$ 4,500
Defined Contribution Plan, Cost	$ 200,000	$ 200,000

Note 11 - Benefit Plans - Stock

Note 11 - Benefit Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Total stock-based compensation expense	$ 9,117	$ 8,513
Share-Based Payment Arrangement, Option [Member]
Total stock-based compensation expense	9,079	8,513
Restricted Stock Awards [Member]
Total stock-based compensation expense	38	0
General and Administrative Expense [Member]
Total stock-based compensation expense	5,056	5,248
Research and Development Expense [Member]
Total stock-based compensation expense	$ 4,061	$ 3,265

Note 11 - Benefit Plans - Activ

Note 11 - Benefit Plans - Activity Related to Outstanding Stock Options (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Beginning balance outstanding, number of options (in shares) | shares	15,260,297
Beginning balance outstanding, weighted average exercise price per share (in dollars per share) | $ / shares	$ 2.98
Outstanding, weighted average remaining term (Year)	7 years 3 months 10 days
Outstanding, intrinsic value | $	$ 2,348
Granted, number of options (in shares) | shares	7,053,200
Granted, weighted average exercise price per share (in dollars per share) | $ / shares	$ 0.92
Granted, weighted average remaining term (Year)	9 years 5 months 19 days
Forfeited, number of options (in shares) | shares	(467,109)
Forfeited, weighted average exercise price per share (in dollars per share) | $ / shares	$ 5.45
Ending balance outstanding, number of options (in shares) | shares	21,846,388
Ending balance outstanding, weighted average exercise price per share (in dollars per share) | $ / shares	$ 2.26
Outstanding, intrinsic value | $	$ 302
Vested and exercisable, number of options (in shares) | shares	11,717,679
Vested and exercisable, weighted average exercise price per share (in dollars per share) | $ / shares	$ 2.58
Vested and exercisable, weighted average remaining term (Year)	5 years 10 months 2 days
Vested and exercisable, intrinsic value | $	$ 302
Vested, exercisable and expected to vest, number of options (in shares) | shares	21,846,388
Vested, exercisable and expected to vest, weighted average exercise price per share (in dollars per share) | $ / shares	$ 2.26
Vested, exercisable or expected to vest, weighted average remaining term (Year)	7 years 3 months 10 days
Vested, exercisable or expected to vest, intrinsic value | $	$ 302

Note 11 - Benefit Plans - Assum

Note 11 - Benefit Plans - Assumptions of Stock Options (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Expected dividend yield	0%	0%
Minimum [Member]
Expected stock price volatility	96.22%	89.57%
Risk-free interest rate	3.26%	1.65%
Expected term of options (in years) (Year)	5 years	5 years
Maximum [Member]
Expected stock price volatility	103.31%	99.77%
Risk-free interest rate	4.66%	4.31%
Expected term of options (in years) (Year)	6 years 5 months 4 days	6 years 11 months 23 days

Note 11 - Benefit Plans - Act_2

Note 11 - Benefit Plans - Activity Related to Restricted Stock Awards (Details)	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Granted, number of restricted stock awards (in shares) | shares	43,479
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.15
Converted to shares of Common Stock upon vesting, number of restricted stock awards (in shares) | shares	(32,609)
Converted to shares of Common Stock upon vesting, weighted average grant date fair value (in dollars per share) | $ / shares	$ 1.15
Restricted Stock [Member]
Unvested balance, number of restricted stock awards (in shares) | shares	769,139
Unvested balance, weighted average grant date fair value (in dollars per share) | $ / shares	$ 9.84
Forfeited, number of restricted stock awards (in shares) | shares	(1,194)
Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares	$ 9.84
Unvested balance, number of restricted stock awards (in shares) | shares	778,815
Unvested balance, weighted average grant date fair value (in dollars per share) | $ / shares	$ 9.72

Note 12 - Fair Value (Details T

Note 12 - Fair Value (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)
Common Stock Warrant Liability [Member]
Unrealized Gain (Loss) on Derivatives	$ 0.2

Note 12 - Fair Value - Assets a

Note 12 - Fair Value - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Clene Nanomedicine contingent earn-out liability	$ 75	$ 2,264
Initial Stockholders contingent earn-out liability	10	291
Commercial Paper [Member]
Fair value		3,482
Us Treasury Securities with Maturity Greater than 90 Days but Less than 1 Year [Member]
Fair value	6,179
Corporate Debt Securities [Member]
Fair value		1,501
Fair Value, Inputs, Level 1 [Member]
Clene Nanomedicine contingent earn-out liability	0	0
Initial Stockholders contingent earn-out liability	0	0
Fair Value, Inputs, Level 1 [Member] | Commercial Paper [Member]
Fair value		0
Fair Value, Inputs, Level 1 [Member] | Us Treasury Securities with Maturity Greater than 90 Days but Less than 1 Year [Member]
Fair value	0
Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member]
Fair value		0
Fair Value, Inputs, Level 2 [Member]
Clene Nanomedicine contingent earn-out liability	0	0
Initial Stockholders contingent earn-out liability	0	0
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Fair value		3,482
Fair Value, Inputs, Level 2 [Member] | Us Treasury Securities with Maturity Greater than 90 Days but Less than 1 Year [Member]
Fair value	6,179
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Fair value		1,501
Fair Value, Inputs, Level 3 [Member]
Clene Nanomedicine contingent earn-out liability	75	2,264
Initial Stockholders contingent earn-out liability	10	291
Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member]
Fair value		0
Fair Value, Inputs, Level 3 [Member] | Us Treasury Securities with Maturity Greater than 90 Days but Less than 1 Year [Member]
Fair value	0
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Fair value		0
US Treasury Securities [Member]
Cash Equivalents	19,884
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Cash Equivalents	0
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Cash Equivalents	19,884
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Cash Equivalents	0
Money Market Funds [Member]
Cash Equivalents	5,113	14,317
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash Equivalents	5,113	14,317
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Cash Equivalents	0	0
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Cash Equivalents	0	0
Common Stock Warrant Liability [Member]
Common stock warrant liabilities	1,481
Balance	0	474
Initial fair value of instruments	7,818
Change in fair value	(6,337)	0
Balance	1,481	0
Reclassification from liability to equity		(305)
Extinguishment of instrument		(169)
Common Stock Warrant Liability [Member] | Fair Value, Inputs, Level 1 [Member]
Common stock warrant liabilities	0
Common Stock Warrant Liability [Member] | Fair Value, Inputs, Level 2 [Member]
Common stock warrant liabilities	0
Common Stock Warrant Liability [Member] | Fair Value, Inputs, Level 3 [Member]
Common stock warrant liabilities	1,481
Clene Nanomedicine Contingent Earn-out [Member]
Balance	2,264	18,100
Initial fair value of instruments	0
Change in fair value	(2,189)	(15,836)
Balance	75	2,264
Reclassification from liability to equity		0
Extinguishment of instrument		0
Initial Stockholders Contingent Earn-out [Member]
Balance	291	2,317
Initial fair value of instruments	0
Change in fair value	(281)	(2,026)
Balance	$ 10	291
Reclassification from liability to equity		0
Extinguishment of instrument		$ 0

Note 12 - Fair Value - Unobserv

Note 12 - Fair Value - Unobservable Inputs (Details)	Dec. 31, 2023	Dec. 31, 2022
Measurement Input, Price Volatility [Member] | Contingent Earnout Shares [Member]
Derivative, unobservable input	1.15	1.15
Measurement Input, Price Volatility [Member] | Minimum [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	1.05
Measurement Input, Price Volatility [Member] | Minimum [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	1
Measurement Input, Price Volatility [Member] | Maximum [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	1.10
Measurement Input, Price Volatility [Member] | Maximum [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	1.10
Measurement Input, Risk Free Interest Rate [Member] | Contingent Earnout Shares [Member]
Derivative, unobservable input	0.042	0.042
Measurement Input, Risk Free Interest Rate [Member] | Minimum [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	0.0388
Measurement Input, Risk Free Interest Rate [Member] | Minimum [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	0.0413
Measurement Input, Risk Free Interest Rate [Member] | Maximum [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	0.0503
Measurement Input, Risk Free Interest Rate [Member] | Maximum [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	0.0474
Measurement Input, Expected Dividend Rate [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	0
Measurement Input, Expected Dividend Rate [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	0
Measurement Input, Expected Dividend Rate [Member] | Contingent Earnout Shares [Member]
Derivative, unobservable input	0	0
Measurement Input, Expected Term [Member] | Contingent Earnout Shares [Member]
Derivative, unobservable input	2	3
Measurement Input, Expected Term [Member] | Minimum [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	0.75
Measurement Input, Expected Term [Member] | Minimum [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	1.08
Measurement Input, Expected Term [Member] | Maximum [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	4.5
Measurement Input, Expected Term [Member] | Maximum [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	2.46
Measurement Input, Probability of Change of Control [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	25
Measurement Input, Probability of NDA Acceptance [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	20
Measurement Input, Probability of Dissolution [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	0.50
Measurement Input, Probability of Dissolution [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	0.50
Measurement Input, Probability of Fundamental Transaction [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	25
Measurement Input, Probability of Other Outcome [Member] | New Avenue Warrant [Member]
Derivative, unobservable input	0.25
Measurement Input, Probability of Other Outcome [Member] | Tranche A Warrant [Member]
Derivative, unobservable input	0.05

Note 13 - Capital Stock (Detail

Note 13 - Capital Stock (Details Textual) - USD ($)					1 Months Ended			6 Months Ended	12 Months Ended
	Nov. 07, 2023	Mar. 03, 2023	Apr. 26, 2022	Dec. 30, 2020	Jun. 30, 2023	Dec. 31, 2022	Oct. 31, 2022	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	May 31, 2021
Common Stock, Shares Authorized (in shares)						150,000,000			300,000,000	150,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)				$ 0.0001		$ 0.0001			$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized (in shares)									1,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)									$ 0.0001
Common Stock, Shares, Issued (in shares)						74,759,591			128,422,851	74,759,591
Preferred Stock, Shares Issued (in shares)									0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)						4,477,045			105,432,083	4,477,045
Gain (Loss) on Issuance of Equity									$ (14,840,000)	$ 0
Lincoln Park Capital Fund, LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares)		332,668
Purchase Agreement, Commencing Period (Month)		36 months
Purchase Agreement, Regular Purchase (in shares)		75,000
Purchase Agreement, Regular Purchase, Shares, Closing Price One (in shares)		100,000
Purchase Agreement, Closing Price One (in dollars per share)		$ 1
Purchase Agreement, Regular Purchase, Shares, Closing Price Two (in shares)		150,000
Purchase Agreement, Closing Price Two (in dollars per share)		$ 2
Purchase Agreement, Regular Purchase, Shares, Closing Price Three (in shares)		200,000
Purchase Agreement, Closing Price Three (in dollars per share)		$ 4
Purchase Agreement, Accelerated Purchase, Maximum Percentage of Regular Purchase		300%
Purchase Agreement, Accelerated Purchase, Maximum Percentage Of Prior Day Volume		30%
Purchase Agreement, Additional Accelerated Purchase, Maximum Percentage of Regular Purchase		300%
Purchase Agreement, Additional Accelerated Purchase, Maximum Percentage of Prior Day Volume		30%
Purchase Agreement, Price Discount of Additional Purchases		97%
Purchase Agreement, Additional Commitment Shares (in shares)		166,334
Purchase Agreement, Shares Sell Limitation (in shares)		15,310,115
Purchase Agreement, Shares Sell Limitation, Percentage Of Outstanding Shares		19.99%
Percentage of Common Stock Beneficial Ownership		4.99%
Derivative, Notional Amount									$ 0
Lincoln Park Capital Fund, LLC [Member] | Maximum [Member]
Purchase Agreement, Amount Of Shares Commit To Purchase		$ 25,000,000
Percentage of Common Stock Beneficial Ownership		9.99%
Lincoln Park Capital Fund, LLC [Member] | Minimum [Member]
Purchase Agreement, Minimum Average Price Per Share To Avoid Sell Limitation (in dollars per share)		$ 1.2404
Lincoln Park [Member] | Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)									400,000
Proceeds from Issuance or Sale of Equity									$ 400,000
Offering Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)							10,723,926
Shares Issued, Price Per Share (in dollars per share)							$ 1.01
Proceeds from Issuance of Common Stock							$ 10,800,000
Payments of Stock Issuance Costs							$ 25,000
Underwriting Agreement [Member] | Canaccord [Member]
Payments of Stock Issuance Costs					$ 200,000
Unit Issued During Period, Units, New Issues (in shares)					50,000,000
Unit Issued, Price Per Unit (in dollars per share)					$ 0.8			$ 0.8
Each Unit, Number of Common Stock (in shares)					1			1
Proceeds from Issuance or Sale of Equity					$ 40,000,000
Payment for Underwriting Fees and Commissions					2,400,000
Gain (Loss) on Issuance of Equity					$ (14,800,000)
ATM Facility [Member]
Stock Issued During Period, Shares, New Issues (in shares)									2,895,090	358,769
Proceeds from Issuance of Common Stock									$ 4,500,000	$ 800,000
Aggregate Offering Price	$ 15,000,000					$ 50,000,000
Fixed Commission Rate Percentage			3%
Payments for Commissions									$ 100,000
Commitment Shares [Member] | Lincoln Park [Member] | Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)									2,893
Warrants with Tranche 2 of 2021 Avenue Loan [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)											115,851
Warrants Originally Issued by Tottenham Acquisition I Limited [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				2,407,500
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				0.5
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.01
Class of Warrant or Right, Redemption, Threshold Stock Price Trigger (in dollars per share)				$ 16.5
Class of Warrant or Right, Redemption, Threshold Consecutive Trading Days (Day)				20 days
Class of Warrant or Right, Redemption, Threshold Trading Days (Day)				30 days
Class of Warrant or Right, Exercised During Period (in shares)									0	0
Chardan Unit Purchase Option [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				24,583
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				0.5
Class of Warrant or Right, Exercised During Period (in shares)									0	0
Warrants Originally Issued by Clene Nanomedicine [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)				1,929,111
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				1
Warrants with Tranche 2 of 2021 Avenue Loan [Member]
Class of Warrant or Right, Exercised During Period (in shares)								0
New Avenue Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)									3,000,000
Class of Warrant or Right, Exercised During Period (in shares)									0
Tranche A Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)									50,000,000
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)									1
Class of Warrant or Right, Exercised During Period (in shares)									0
Tranche A Warrant [Member] | Canaccord [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)					1			1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)					$ 1.1			$ 1.1
Each Unit, Number of Warrant (in shares)					1			1
Tranche B Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)					50,000,000			50,000,000
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)					1			1
Class of Warrant or Right, Exercised During Period (in shares)									0
Tranche B Warrant [Member] | Canaccord [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)					1			1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)					$ 1.5			$ 1.5
Each Unit, Number of Warrant (in shares)					1			1

Note 13 - Capital Stock - Outst

Note 13 - Capital Stock - Outstanding Warrants (Details) - $ / shares		Dec. 31, 2023	Dec. 31, 2022
Number of shares issuable (in shares)		105,432,083	4,477,045
Common Stock Warrant Exercisable on December 2020, One [Member]
Exercise price (in dollars per share)	[1]	$ 11.5
Number of shares issuable (in shares)	[1]	2,407,500	2,407,500
Common Stock Warrant Exercisable on December 2020, Two [Member]
Exercise price (in dollars per share)	[2]	$ 11.5
Number of shares issuable (in shares)	[2]	24,583	24,583
Common Stock Warrant Exercisable on December 2020, Three [Member]
Exercise price (in dollars per share)	[3]	$ 1.97
Number of shares issuable (in shares)	[3]	0	1,929,111
Common Stock Warrant Exercisable on May 2021 [Member]
Exercise price (in dollars per share)	[4]	$ 8.63
Number of shares issuable (in shares)	[4]	0	115,851
Common Stock Warrant Exercisable on June 2023, One [Member]
Exercise price (in dollars per share)	[5]	$ 0.8
Number of shares issuable (in shares)	[5]	3,000,000	0
Common Stock Warrant Exercisable on June 2023, Two [Member]
Exercise price (in dollars per share)	[6]	$ 1.1
Number of shares issuable (in shares)	[6]	50,000,000	0
Common Stock Warrant Exercisable on June 2023, Three [Member]
Exercise price (in dollars per share)	[7]	$ 1.5
Number of shares issuable (in shares)	[7]	50,000,000	0
[1]Represents 2,407,500 shares of Common Stock underlying warrants to purchase one-half (1/2) of one share of Common Stock, issued during Tottenham’s initial public offering. We may redeem the outstanding warrants at $0.01 per warrant if the last sales price of our Common Stock equals or exceeds $16.50 per share for any 20 trading days within a 30-trading day period. As of December 31, 2023 and 2022, no warrants had been exercised.[2]Represents 24,583 shares of Common Stock underlying warrants to purchase one-half (1/2) of one share of Common Stock, issued to the financial advisor and lead underwriter of Tottenham’s initial public offering upon their exercise of a unit purchase option in July 2021. As of December 31, 2023 and 2022, no warrants had been exercised.[3]Represents 1,929,111 shares of Common Stock underlying warrants to purchase one share of Common Stock, issued by Clene Nanomedicine as Series A preferred stock warrants and senior equity warrants in August 2013. As of April 2023, the warrants expired.[4]Represents 115,851 shares of Common Stock underlying the Original Avenue Warrant. As of June 2023, the warrant had not been exercised and was cancelled pursuant to the Second Amendment (see Note 8)[5]Represents 3,000,000 shares of Common Stock underlying the New Avenue Warrant, issued pursuant to the Second Amendment (see Note 8). As of December 31, 2023, the warrant had not been exercised.[6]Represents 50,000,000 shares of Common Stock underlying the Tranche A Warrants to purchase one share of Common Stock, issued in our June 2023 public equity offering. As of December 31, 2023, no warrants had been exercised.[7]Represents 50,000,000 shares of Common Stock underlying the Tranche B Warrants to purchase one share of Common Stock, issued in our June 2023 public equity offering. As of December 31, 2023, no warrants had been exercised.

Note 14 - Net Loss Per Share -

Note 14 - Net Loss Per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Net loss	$ (49,504)	$ (29,918)
Weighted average common shares used to compute basic and diluted net loss per share (in shares)	104,938,819	65,204,663
Net loss per share – basic and diluted (in dollars per share)	$ (0.47)	$ (0.46)

Note 14 - Net Loss Per Share _2

Note 14 - Net Loss Per Share - Antidilutive Securities Excluded from Computation (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive securities (in shares)	136,382,323	28,831,518
Convertible Notes Payable [Member]
Antidilutive securities (in shares)	1,732,703	1,732,703
Common Stock Warrants [Member]
Antidilutive securities (in shares)	105,432,083	4,477,045
Share-Based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	21,846,388	15,260,297
Restricted Stock [Member]
Antidilutive securities (in shares)	778,815	769,139
Contingent Earnout Shares [Member]
Antidilutive securities (in shares)	6,592,334	6,592,334

Note 15 - Related Party Trans_3

Note 15 - Related Party Transactions (Details Textual)		1 Months Ended
	Apr. 30, 2021	Jul. 30, 2020	Aug. 31, 2018
Related Party Transaction, Royalty Fee Rate for Revenues			3%
4Life [Member] | License Agreement [Member]
Related Party Transaction, Exclusive License Term (Year)		5 years
4Life [Member] | Supply Agreement [Member]
Related Party Transaction, Rate			20%
Related Party Transaction, Exclusive Supply Term (Year)	5 years

Note 15 - Related Party Trans_4

Note 15 - Related Party Transactions - Revenue From 4Life Agreement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Revenue	$ 654	$ 473
Related Party [Member]
Revenue	618	460
Product [Member]
Revenue	498	329
Product [Member] | Related Party [Member]
Revenue	462	316
Royalty [Member]
Revenue	156	144
Royalty [Member] | Related Party [Member]
Revenue	$ 156	$ 144