Clene (CLNN) 10-Q 12 May 23 2023 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 09, 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	Q1
Document Fiscal Year Focus	2023
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		78,393,865
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

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 18,442	$ 18,332
Marketable securities	0	4,983
Accounts receivable	63	189
Inventory	88	43
Prepaid expenses and other current assets	6,229	5,648
Total current assets	24,822	29,195
Restricted cash	58	58
Operating lease right-of-use assets	4,494	4,602
Property and equipment, net	10,514	10,638
TOTAL ASSETS	39,888	44,493
Current liabilities:
Accounts payable	608	3,014
Accrued liabilities	5,933	3,863
Operating lease obligations, current portion	508	488
Finance lease obligations, current portion	76	74
Notes payable, current portion	9,751	6,418
Total current liabilities	16,876	13,857
Operating lease obligations, net of current portion	5,399	5,557
Finance lease obligations, net of current portion	3	34
Notes payable, net of current portion	6,713	9,483
Convertible notes payable	9,907	9,770
Clene Nanomedicine contingent earn-out liability	2,319	2,264
Initial Stockholders contingent earn-out liability	298	291
TOTAL LIABILITIES	41,515	41,256
Commitments and contingencies (Note 9)
Stockholders’ equity (deficit):
Common stock, $0.0001 par value: 150,000,000 shares authorized; 77,987,349 and 74,759,591 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	8	7
Additional paid-in capital	203,133	196,246
Accumulated deficit	(204,989)	(193,219)
Accumulated other comprehensive income	221	203
TOTAL STOCKHOLDERS’ EQUITY (DEFICIT)	(1,627)	3,237
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)	$ 39,888	$ 44,493

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2023	Dec. 31, 2022	Dec. 30, 2020
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	77,987,349	74,759,591
Common stock, shares outstanding (in shares)	77,987,349	74,759,591

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue:
Total revenue	$ 107	$ 30
Operating expenses:
Cost of revenue	5	0
Research and development	7,395	8,580
General and administrative	3,439	4,786
Total operating expenses	10,839	13,366
Loss from operations	(10,732)	(13,336)
Other income (expense), net:
Interest income	172	24
Interest expense	(1,066)	(782)
Gain on termination of lease	0	420
Commitment share expense	(399)	0
Change in fair value of common stock warrant liability	0	(18)
Change in fair value of Clene Nanomedicine contingent earn-out liability	(55)	(57)
Change in fair value of Initial Stockholders contingent earn-out liability	(7)	(12)
Research and development tax credits and unrestricted grants	314	299
Other income (expense), net	3	108
Total other income (expense), net	(1,038)	(18)
Net loss before income taxes	(11,770)	(13,354)
Income tax expense	0	0
Net loss	(11,770)	(13,354)
Other comprehensive income:
Unrealized gain (loss) on available-for-sale securities	14	(50)
Foreign currency translation adjustments	4	50
Total other comprehensive income	18	0
Comprehensive loss	$ (11,752)	$ (13,354)
Net loss per share – basic and diluted (in dollars per share)	$ (0.15)	$ (0.21)
Weighted average common shares used to compute basic and diluted net loss per share (in shares)	76,049,665	62,852,863
Product [Member]
Revenue:
Total revenue	$ 64	$ 7
Royalty [Member]
Revenue:
Total revenue	$ 43	$ 23

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) - 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
Stock-based compensation expense	0	2,202	0	0	2,202
Unrealized gain on available-for-sale securities	0	0	0	(50)	(50)
Foreign currency translation adjustments	0	0	0	50	50
Net loss	$ 0	0	(13,354)	0	(13,354)
Balances (in shares) at Mar. 31, 2022	63,246,545
Balances at Mar. 31, 2022	$ 6	178,433	(176,655)	233	2,017
Reclassification of common stock warrant liability to permanent equity	$ 0	305	0	0	305
Exercise of stock options (in shares)	934,448
Exercise of stock options	$ 0	267	0	0	267
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)	3,227,758
Issuance of common stock	$ 1	4,664	0	0	4,665
Stock-based compensation expense	0	2,223	0	0	2,223
Unrealized gain on available-for-sale securities	0	0	0	14	14
Foreign currency translation adjustments	0	0	0	4	4
Net loss	$ 0	0	(11,770)	0	(11,770)
Balances (in shares) at Mar. 31, 2023	77,987,349
Balances at Mar. 31, 2023	$ 8	$ 203,133	$ (204,989)	$ 221	(1,627)
Reclassification of common stock warrant liability to permanent equity					$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (11,770)	$ (13,354)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	402	195
Non-cash lease expense	108	52
Commitment share expense	399	0
Change in fair value of common stock warrant liability	0	18
Change in fair value of Clene Nanomedicine contingent earn-out liability	55	57
Change in fair value of Initial Stockholders contingent earn-out liability	7	12
Stock-based compensation expense	2,223	2,202
Gain on termination of lease	0	(420)
Accretion of debt discount	250	227
Non-cash interest expense	82	45
Changes in operating assets and liabilities:
Accounts receivable	126	49
Inventory	(45)	3
Prepaid expenses and other current assets	(581)	(1,691)
Accounts payable	(2,406)	1,389
Accrued liabilities	2,070	(2,069)
Operating lease obligations	(138)	201
Net cash used in operating activities	(9,218)	(13,084)
Cash flows from investing activities:
Purchases of marketable securities	0	(23,586)
Proceeds from maturities of marketable securities	5,000	0
Purchases of property and equipment	(278)	(936)
Net cash provided by (used in) investing activities	4,722	(24,522)
Cash flows from financing activities:
Proceeds from exercise of stock options	0	267
Proceeds from issuance of common stock, net of offering costs	4,266	0
Payments of finance lease obligations	(28)	(32)
Proceeds from the issuance of notes payable	350	0
Net cash provided by financing activities	4,588	235
Effect of foreign exchange rate changes on cash and restricted cash	18	13
Net increase (decrease) in cash, cash equivalents and restricted cash	110	(37,358)
Cash, cash equivalents and restricted cash – beginning of period	18,390	50,346	$ 50,346
Cash, cash equivalents and restricted cash – end of period	18,500	12,988	$ 18,390
Reconciliation of cash, cash equivalents and restricted cash to the consolidated balance sheets
Cash and cash equivalents	18,442	12,930
Restricted cash	58	58
Cash, cash equivalents and restricted cash	18,500	12,988
Supplemental disclosure of non-cash investing and financing activities:
Lease liability arising from obtaining right-of-use assets, leasehold improvements, and lease incentives	0	2,343
Lease liability settled through termination of lease	0	602
Reclassification of common stock warrant liability to permanent equity	0	305
Supplemental cash flow information:
Cash paid for interest expense	$ 982	$ 493

Note 1 - Nature of the Business

Note 1 - Nature of the Business	3 Months Ended
	Mar. 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 $10.7 million and $13.3 million for the three March 31, 2023 2022 March 31, 2023 December 31, 2022 March 31, 2023 December 31, 2022 three March 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 March 31, 2023 not one The accompanying condensed 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 condensed consolidated financial statements do not may Impact of the COVID- 19 We are subject to risks and uncertainties as a result of the COVID- 19 19 19 19 may third We are monitoring the potential impact of the COVID- 19 19 one not 19 not 19 may 19,

Note 2 - Summary of Significant

Note 2 - Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Significant Accounting Policies [Text Block]	Note 2. Basis of Presentation The accompanying condensed 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 condensed consolidated financial statements in accordance with United States (“U.S.”) Generally Accepted Accounting Principles (“GAAP”) for interim financial reporting and as required by Regulation S- X, 10 01. three March 31, 2023 2022 Results of operations for the three March 31, 2023 2022 not three March 31, 2023 2022 10 Use of Estimates The preparation of condensed 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 The product candidates we develop require approvals from regulatory agencies prior to commercial sales. There can be no 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 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 condensed 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 Inventory Inventory is stated at historic cost on a first first March 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. 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. Convertible Debt In accordance with ASU 2020 06, Debt—Debt with Conversion and Other Options (Subtopic 470 20 815 40 not not not no 815, Derivatives and Hedging 815” 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 of 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 Our policy is to not twelve Certain lease agreements may not Leases may not Contingent Earn-Out Liabilities In connection with the Reverse Recapitalization, certain of Clene Nanomedicine’s stockholders are entitled to receive additional shares (the “Clene Nanomedicine Contingent Earn-out”) of Common Stock as follows: (i) 3,338,483 shares of Common Stock 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 and applicable authoritative guidance. The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, 480, 815, 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 condensed consolidated statements of operations and comprehensive loss 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 in the condensed consolidated balance sheets if the conditions or performance obligations are expected to be met within the next twelve not three March 31, 2023 2022 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 condensed 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 (deficit) is translated using historical rates. Adjustments resulting from the translation of the condensed 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 (deficit). 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 (deficit) 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. Segment Information We have determined that our chief executive officer is the chief operating decision maker (“CODM”). Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the CODM in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in two 1 2 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 condensed 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 condensed 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. Recently Adopted Accounting Pronouncements In June 2016, 2016 13, Financial Instruments—Credit Losses (Topic 326 December 15, 2022. not

Note 3 - Marketable Securities

Note 3 - Marketable Securities	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Cash, Cash Equivalents, and Marketable Securities [Text Block]	Note 3. Available-for-Sale Securities We had no available-for-sale securities as of March 31, 2023 December 31, 2022 December 31, 2022 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Commercial paper $ 3,496 $ — $ (14 ) $ 3,482 Corporate debt securities 1,501 — — 1,501 Total $ 4,997 $ — $ (14 ) $ 4,983 We received proceeds from maturities of available-for-sale securities of $5.0 million and $0 for the three March 31, 2023 2022 December 31, 2022 not

Note 4 - Prepaid Expenses and O

Note 4 - Prepaid Expenses and Other Current Assets	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Prepaid Expenses and Other Current Assets [Text Block]	Note 4. Prepaid expenses and other current assets as of March 31, 2023 December 31, 2022 March 31, December 31, (in thousands) 2023 2022 Research and development tax credits receivable $ 3,051 $ 2,777 Metals to be used in research and development 2,216 2,290 Other 962 581 Total prepaid expenses and other current assets $ 6,229 $ 5,648

Note 5 - Property and Equipment

Note 5 - Property and Equipment, Net	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	Note 5. Property and equipment, net, as of March 31, 2023 December 31, 2022 March 31, December 31, (in thousands) 2023 2022 Lab equipment $ 3,923 $ 3,934 Office equipment 178 177 Computer software 459 459 Leasehold improvements 9,966 5,677 Construction in progress 1,652 5,664 16,178 15,911 Less accumulated depreciation (5,664 ) (5,273 ) Total property and equipment, net $ 10,514 $ 10,638 Depreciation expense recorded in research and development expense and general and administrative expense for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 General and administrative $ 67 $ 29 Research and development 335 166 Total depreciation expense $ 402 $ 195

Note 6 - Accrued Liabilities

Note 6 - Accrued Liabilities	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	Note 6. Accrued liabilities as of March 31, 2023 December 31, 2022 March 31, December 31, (in thousands) 2023 2022 Accrued compensation and benefits $ 2,638 $ 2,007 Accrued CRO and clinical fees 2,752 1,297 Other 543 559 Total accrued liabilities $ 5,933 $ 3,863

Note 7 - Leases

Note 7 - Leases	3 Months Ended
	Mar. 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. 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 March 31, 2023 December 31, 2022 Finance Leases Assets recorded under finance lease obligations and included in property and equipment as of March 31, 2023 December 31, 2022 March 31, December 31, (in thousands) 2023 2022 Lab equipment $ 408 $ 408 Work in process 228 228 Total 636 636 Less accumulated depreciation (346 ) (326 ) Net $ 290 $ 310 As of March 31, 2023 December 31, 2022 Maturity Analysis of Leases The maturity analysis of our finance and operating leases as of March 31, 2023 (in thousands) Finance Leases Operating Leases 2023 (remainder) $ 65 $ 767 2024 27 1,171 2025 — 1,202 2026 — 1,231 2027 — 1,129 2028 — 1,092 Thereafter — 1,694 Total undiscounted cash flows 92 8,286 Less amount representing interest/discounting (13 ) (2,379 ) Present value of future lease payments 79 5,907 Less lease obligations, current portion (76 ) (508 ) Lease obligations, long term portion $ 3 $ 5,399 We expect that, in the normal course of business, the existing leases will be renewed or replaced by similar leases. Components of Lease Cost The components of finance and operating lease costs for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 Finance lease costs: Amortization $ 20 $ 20 Interest on lease liabilities 6 5 Operating lease costs 253 230 Variable lease costs 50 65 Total lease costs $ 329 $ 320 Supplemental Cash Flow Information Three Months Ended March 31, (in thousands) 2023 2022 Operating cash flows from operating leases $ (303 ) $ (295 ) Operating cash flows from finance leases $ (6 ) $ (5 ) Financing cash flows from finance leases $ (28 ) $ (32 )

Note 8 - Notes Payable and Conv

Note 8 - Notes Payable and Convertible Notes Payable	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Debt Disclosure [Text Block]	Note 8. Our notes payable and convertible notes payable as of March 31, 2023 December 31, 2022 Stated March 31, December 31, (in thousands, except interest rates) Interest Rate 2023 2022 Notes payable Advance Cecil, Inc. (commenced April 2019) 8.00 % $ 132 $ 130 Maryland DHCD (commenced February 2019) 8.00 % 664 654 Maryland DHCD (commenced May 2022) 6.00 % 1,032 682 Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 14.60 % 15,000 15,000 16,828 16,466 Accrued and unpaid interest 35 22 Less unamortized discount and debt issuance costs (399 ) (587 ) Less notes payable, current portion, net of unamortized discount and debt issuance costs (9,751 ) (6,418 ) Total notes payable, net of current portion $ 6,713 $ 9,483 Convertible notes payable Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 14.60 % $ 5,000 $ 5,000 Maryland DHCD (commenced December 2022) 6.00 % 5,000 5,000 10,000 10,000 Accrued and unpaid interest 83 7 Less unamortized discount and debt issuance costs (176 ) (237 ) Total convertible notes payable $ 9,907 $ 9,770 Maryland DHCD Loans In February 2019, “2019 not 2019 February 22, 2034, March 31, 2023 December 31, 2022 2019 three March 31, 2023 2022 In May 2022, “2022 March 31, 2023 May 17, 2024. first twelve July 1, 2022, eighteen $15,000; thirty July 1, 2027. first three March 31, 2023 In December 2022, “2022 first twelve January 1, 2023, 48 January 1, 2028. December 8, 2023, may, 30 not three March 31, 2023 Cecil County Loan In April 2019, “2019 2019 April 30, 2034, March 31, 2023 December 31, 2022 2019 three March 31, 2023 2022 Avenue Loan In May 2021, “2021 March 31, 2023 December 31, 2022 first May 2021 September 2021 ( 1” 2” not December 31, 2022. first twelve twelve December 1, 2024. At any time between May 21, 2022 May 21, 2024, may, not March 31, 2023 December 31, 2022 three March 31, 2023 2022 We are subject to covenants until maturity, including limitations on our ability to retire, repurchase, or redeem our Common Stock, options, and warrants other than per the terms of the securities; limitations on our ability to pay dividends of cash or property; and we are required to maintain unrestricted cash and cash equivalents of at least $5.0 million. We are not 2021 2021 2021 three March 31, 2023 2022 Additionally, we issued a warrant to purchase Common Stock to Avenue based on the amount of funded principal, equal to 115,851 shares of Common Stock at an exercise price of $8.63 per share (the “Avenue Warrant”). A portion of net proceeds from the issuance of the 2021 Debt Maturities Future principal payments, net of unamortized discounts, 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 2023 (remainder) $ — $ — $ 6,667 $ — $ — 2024 — — 13,333 — — 2025 — — — 347 — 2026 — — — 369 — 2027 — — — 317 — 2028 — — — — 5,000 Thereafter 664 132 — — — Subtotal of future principal payments 664 132 20,000 1,033 5,000 Accrued and unpaid interest — — — 35 83 Less unamortized discount and debt issuance costs — — (497 ) (26 ) (52 ) Total $ 664 $ 132 $ 19,503 $ 1,042 $ 5,031

Note 9 - Commitments and Contin

Note 9 - Commitments and Contingencies	3 Months Ended
	Mar. 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 March 31, 2023 December 31, 2022 Contingencies From time to time, we may not In September 2019, 2 Au8 first not twelve Au8 Au8 third Au8 March 31, 2023 not not 450, Contingencies no

Note 10 - Income Taxes

Note 10 - Income Taxes	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Income Tax Disclosure [Text Block]	Note 10. The components of loss before income taxes for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 United States $ (11,546 ) $ (12,957 ) Foreign (224 ) (397 ) Net loss before income taxes $ (11,770 ) $ (13,354 ) 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	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	Note 11. 401 Our 401 401 401 three March 31, 2023 2022 Stock Compensation Plans The Clene Nanomedicine, Inc. 2014 2014 July 2014. no may 2014 March 31, 2023 2014 The Clene Inc. 2020 “2020 December 2020 March 31, 2023 2020 May 9, 2023, 2020 Stock-Based Compensation Expense Stock-based compensation expense recorded in research and development expense and general and administrative expense for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 General and administrative $ 1,250 $ 1,458 Research and development 973 744 Total stock-based compensation expense $ 2,223 $ 2,202 Stock-based compensation expense by award type for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 Stock options $ 2,222 $ 2,202 Stock awards 1 — Total stock-based compensation expense $ 2,223 $ 2,202 Stock Options Outstanding stock options and related activity for the three March 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 1,077,432 1.30 9.89 — Forfeited (132,325 ) 5.83 — — Outstanding – March 31, 2023 16,205,404 $ 2.85 7.22 $ 2,923 Vested and exercisable – March 31, 2023 8,085,513 $ 2.76 5.29 $ 2,855 Vested, exercisable or expected to vest – March 31, 2023 16,205,404 $ 2.85 7.22 $ 2,923 As of March 31, 2023 December 31, 2022 The weighted-average grant-date fair value of stock options granted during the three March 31, 2023 2022 three March 31, 2023 2022 Three Months Ended March 31, 2023 2022 Expected stock price volatility 96.22% – 103.24% 89.57% – 93.07% Risk-free interest rate 3.38% – 3.98% 1.65% – 2.02% Expected dividend yield 0.00 % 0.00 % Expected term of options (in years) 5.00 – 6.08 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 three March 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 Forfeited (448 ) 9.84 Unvested balance – March 31, 2023 812,170 $ 9.38 As of March 31, 2023 December 31, 2022

Note 12 - Fair Value

Note 12 - Fair Value	3 Months Ended
	Mar. 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 March 31, 2023 March 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 15,981 $ — $ — $ 15,981 Clene Nanomedicine contingent earn-out liability — — 2,319 2,319 Initial Stockholders contingent earn-out liability — — 298 298 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 three March 31, 2023 (in thousands) Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2022 $ 2,264 $ 291 Change in fair value 55 7 Balance – March 31, 2023 $ 2,319 $ 298 Changes in the fair value of our Level 3 three March 31, 2022 (in thousands) Common Stock Warrant Liability Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2021 $ 474 $ 18,100 $ 2,317 Change in fair value 18 57 12 Reclassification from liability to equity (305 ) — — Balance – March 31, 2022 $ 187 $ 18,157 $ 2,329 Valuation of Notes Payable and Convertible Notes Payable The 2019 2019 8 2021 2022 2022 3 Valuation of the Common Stock Warrant Liability The Avenue Warrant, comprised of the Tranche 1 2 2021 March 31, 2022, 1 1 March 31, 2022 1 2 December 31, 2022 2 December 31, 2022. 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 March 31, December 31, 2023 2022 Expected stock price volatility 115.00 % 115.00 % Risk-free interest rate 3.90 % 4.20 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 2.75 3.00

Note 13 - Capital Stock

Note 13 - Capital Stock	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Equity [Text Block]	Note 13. As of March 31, 2023 December 31, 2022 March 31, 2023 December 31, 2022 74,759,591 May 9, 2023, Our common stockholders are entitled to one No not Common Stock Warrants As of March 31, 2023 December 31, 2022 Date Exercisable Number of Shares Issuable Exercise Price Expiration December 2020 2,407,500 (1) $ 11.50 December 2025 December 2020 24,583 (2) $ 11.50 December 2025 December 2020 1,929,111 (3) $ 1.97 April 2023 May 2021 115,851 (4) $ 8.63 May 2026 Total 4,477,045 ( 1 Consists of 2,407,500 shares of Common Stock underlying warrants to purchase one 1/2 one may not twenty thirty March 31, 2023 December 31, 2022 ( 2 Consists of 24,583 shares of Common Stock underlying warrants to purchase one 1/2 one July 2021. March 31, 2023 December 31, 2022 ( 3 Consists of 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. March 31, 2023 December 31, 2022 April 2023, ( 4 Consists of 115,851 shares of Common Stock underlying the Avenue Warrant. As of March 31, 2023 December 31, 2022 not Public Offerings In October 2022, 3 333 264299 April 26, 2022, Common Stock Sales Agreement In April 2022, December 2022, may 3 333 264299 April 26, 2022, Subject to terms of the ATM Agreement, the Placement Agent is not three March 31, 2023 Common Stock Purchase Agreement On March 3, 2023, March 7, 2023. 3 333 264299 April 26, 2022, Pursuant to the Purchase Agreement, we may may not not not may may We evaluated the Purchase Agreement under ASC 815 40 Derivatives and Hedging—Contracts on an Entity's Own Equity not March 31, 2023 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 three March 31, 2023 not

Note 14 - Net Loss Per Share

Note 14 - Net Loss Per Share	3 Months Ended
	Mar. 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 three March 31, 2023 2022 Three Months Ended March 31, (in thousands, except share and per share data) 2023 2022 Numerator: Net loss attributable to common stockholders $ (11,770 ) $ (13,354 ) Denominator: Weighted average common shares outstanding 76,049,665 62,852,863 Net loss per share attributable to common stockholders – basic and diluted $ (0.15 ) $ (0.21 ) The following shares of potentially dilutive securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the three March 31, 2023 2022 not Three Months Ended March 31, 2023 2022 Convertible notes payable (see Note 8) 1,732,703 482,703 Common stock warrants (see Note 13) 4,477,045 4,477,045 Options to purchase common stock (see Note 11) 16,205,404 11,944,789 Unvested restricted stock awards (see Note 11) 812,170 914,876 Contingent earn-out shares (see Note 2) 6,592,334 6,592,334 Total 29,819,656 24,411,747

Note 15 - Related Party Transac

Note 15 - Related Party Transactions	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	Note 15. License and Supply Agreements In August 2018, “4Life 4Life’s 4Life 4Life five 4Life April 2021, five 4Life 4Life 4Life 4Life may Total revenue under the 4Life three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 Product revenue from related parties $ 63 $ — Royalty revenue from related parties 43 23 Total revenue from related parties $ 106 $ 23

Note 16 - Segment Information

Note 16 - Segment Information	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	Note 16. Our operating segment profit measure is segment loss from operations, which is calculated as revenue less cost of revenue, research and development, and general and administrative expenses. Profit and loss information by reportable segment for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 Drugs: Revenue from external customers $ — $ — Loss from operations (10,798 ) (13,343 ) Supplements: Revenue from external customers $ 107 $ 30 Income from operations 66 7 Consolidated: Revenue from external customers $ 107 $ 30 Loss from operations (10,732 ) (13,336 ) A reconciliation of the total of the reportable segments’ loss from operations to consolidated net loss before income taxes for the three March 31, 2023 2022 Three Months Ended March 31, (in thousands) 2023 2022 Segment loss from operations $ (10,732 ) $ (13,336 ) Total other income (expense), net (1,038 ) (18 ) Net loss before income taxes $ (11,770 ) $ (13,354 ) Segment assets exclude corporate assets, such as cash, restricted cash, and corporate facilities. Total assets by reportable segment as of March 31, 2023 December 31, 2022 March 31, December 31, (in thousands) 2023 2022 Total assets: Drugs $ 20,875 $ 20,476 Supplements 272 386 Corporate 18,741 23,631 Consolidated $ 39,888 $ 44,493

Note 17 - Subsequent Events

Note 17 - Subsequent Events	3 Months Ended
	Mar. 31, 2023
Notes to Financial Statements
Subsequent Events [Text Block]	Note 17. Common Stock Purchase Agreement Subsequent to March 31, 2023 3 333 264299 April 26, 2022,

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying condensed 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 condensed consolidated financial statements in accordance with United States (“U.S.”) Generally Accepted Accounting Principles (“GAAP”) for interim financial reporting and as required by Regulation S- X, 10 01. three March 31, 2023 2022 Results of operations for the three March 31, 2023 2022 not three March 31, 2023 2022 10
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of condensed 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 The product candidates we develop require approvals from regulatory agencies prior to commercial sales. There can be no 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
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 condensed 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
Inventory, Policy [Policy Text Block]	Inventory Inventory is stated at historic cost on a first first March 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.
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.
Convertible Notes [Policy Text Block]	Convertible Debt In accordance with ASU 2020 06, Debt—Debt with Conversion and Other Options (Subtopic 470 20 815 40 not not not no 815, Derivatives and Hedging 815”
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 of 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 Our policy is to 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 of Clene Nanomedicine’s stockholders are entitled to receive additional shares (the “Clene Nanomedicine Contingent Earn-out”) of Common Stock as follows: (i) 3,338,483 shares of Common Stock 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 and applicable authoritative guidance. The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, 480, 815,
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 condensed consolidated statements of operations and comprehensive loss 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 in the condensed consolidated balance sheets if the conditions or performance obligations are expected to be met within the next twelve not three March 31, 2023 2022
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 condensed 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 (deficit) is translated using historical rates. Adjustments resulting from the translation of the condensed 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 (deficit). 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 (deficit) 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.
Segment Reporting, Policy [Policy Text Block]	Segment Information We have determined that our chief executive officer is the chief operating decision maker (“CODM”). Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the CODM in making decisions regarding resource allocation and assessing performance. We view our operations and manage our business in two 1 2
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 condensed 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 condensed 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.
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

Note 3 - Marketable Securities

Note 3 - Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Marketable Securities [Table Text Block]	December 31, 2022 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Commercial paper $ 3,496 $ — $ (14 ) $ 3,482 Corporate debt securities 1,501 — — 1,501 Total $ 4,997 $ — $ (14 ) $ 4,983

Note 4 - Prepaid Expenses and_2

Note 4 - Prepaid Expenses and Other Current Assets (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]	March 31, December 31, (in thousands) 2023 2022 Research and development tax credits receivable $ 3,051 $ 2,777 Metals to be used in research and development 2,216 2,290 Other 962 581 Total prepaid expenses and other current assets $ 6,229 $ 5,648

Note 5 - Property and Equipme_2

Note 5 - Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Property, Plant and Equipment [Table Text Block]	March 31, December 31, (in thousands) 2023 2022 Lab equipment $ 3,923 $ 3,934 Office equipment 178 177 Computer software 459 459 Leasehold improvements 9,966 5,677 Construction in progress 1,652 5,664 16,178 15,911 Less accumulated depreciation (5,664 ) (5,273 ) Total property and equipment, net $ 10,514 $ 10,638
Depreciation Of Property Plant And Equipment [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 General and administrative $ 67 $ 29 Research and development 335 166 Total depreciation expense $ 402 $ 195

Note 6 - Accrued Liabilities (T

Note 6 - Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Accrued Liabilities [Table Text Block]	March 31, December 31, (in thousands) 2023 2022 Accrued compensation and benefits $ 2,638 $ 2,007 Accrued CRO and clinical fees 2,752 1,297 Other 543 559 Total accrued liabilities $ 5,933 $ 3,863

Note 7 - Leases (Tables)

Note 7 - Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Assets Under Finance Lease [Table Text Block]	March 31, December 31, (in thousands) 2023 2022 Lab equipment $ 408 $ 408 Work in process 228 228 Total 636 636 Less accumulated depreciation (346 ) (326 ) Net $ 290 $ 310
Finance and Operating Lease Liability, Maturity [Table Text Block]	(in thousands) Finance Leases Operating Leases 2023 (remainder) $ 65 $ 767 2024 27 1,171 2025 — 1,202 2026 — 1,231 2027 — 1,129 2028 — 1,092 Thereafter — 1,694 Total undiscounted cash flows 92 8,286 Less amount representing interest/discounting (13 ) (2,379 ) Present value of future lease payments 79 5,907 Less lease obligations, current portion (76 ) (508 ) Lease obligations, long term portion $ 3 $ 5,399
Lease, Cost [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 Finance lease costs: Amortization $ 20 $ 20 Interest on lease liabilities 6 5 Operating lease costs 253 230 Variable lease costs 50 65 Total lease costs $ 329 $ 320
Schedule of Cash Flow, Supplemental Disclosures, Leases [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 Operating cash flows from operating leases $ (303 ) $ (295 ) Operating cash flows from finance leases $ (6 ) $ (5 ) Financing cash flows from finance leases $ (28 ) $ (32 )

Note 8 - Notes Payable and Co_2

Note 8 - Notes Payable and Convertible Notes Payable (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Long-Term Debt Instruments [Table Text Block]	Stated March 31, December 31, (in thousands, except interest rates) Interest Rate 2023 2022 Notes payable Advance Cecil, Inc. (commenced April 2019) 8.00 % $ 132 $ 130 Maryland DHCD (commenced February 2019) 8.00 % 664 654 Maryland DHCD (commenced May 2022) 6.00 % 1,032 682 Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 14.60 % 15,000 15,000 16,828 16,466 Accrued and unpaid interest 35 22 Less unamortized discount and debt issuance costs (399 ) (587 ) Less notes payable, current portion, net of unamortized discount and debt issuance costs (9,751 ) (6,418 ) Total notes payable, net of current portion $ 6,713 $ 9,483 Convertible notes payable Avenue Venture Opportunities Fund, L.P. (commenced May 2021) 14.60 % $ 5,000 $ 5,000 Maryland DHCD (commenced December 2022) 6.00 % 5,000 5,000 10,000 10,000 Accrued and unpaid interest 83 7 Less unamortized discount and debt issuance costs (176 ) (237 ) Total convertible notes payable $ 9,907 $ 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 2023 (remainder) $ — $ — $ 6,667 $ — $ — 2024 — — 13,333 — — 2025 — — — 347 — 2026 — — — 369 — 2027 — — — 317 — 2028 — — — — 5,000 Thereafter 664 132 — — — Subtotal of future principal payments 664 132 20,000 1,033 5,000 Accrued and unpaid interest — — — 35 83 Less unamortized discount and debt issuance costs — — (497 ) (26 ) (52 ) Total $ 664 $ 132 $ 19,503 $ 1,042 $ 5,031

Note 10 - Income Taxes (Tables)

Note 10 - Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 United States $ (11,546 ) $ (12,957 ) Foreign (224 ) (397 ) Net loss before income taxes $ (11,770 ) $ (13,354 )

Note 11 - Benefit Plans (Tables

Note 11 - Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Share-Based Payment Arrangement, Cost by Plan [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 General and administrative $ 1,250 $ 1,458 Research and development 973 744 Total stock-based compensation expense $ 2,223 $ 2,202 Three Months Ended March 31, (in thousands) 2023 2022 Stock options $ 2,222 $ 2,202 Stock awards 1 — Total stock-based compensation expense $ 2,223 $ 2,202
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 1,077,432 1.30 9.89 — Forfeited (132,325 ) 5.83 — — Outstanding – March 31, 2023 16,205,404 $ 2.85 7.22 $ 2,923 Vested and exercisable – March 31, 2023 8,085,513 $ 2.76 5.29 $ 2,855 Vested, exercisable or expected to vest – March 31, 2023 16,205,404 $ 2.85 7.22 $ 2,923
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Three Months Ended March 31, 2023 2022 Expected stock price volatility 96.22% – 103.24% 89.57% – 93.07% Risk-free interest rate 3.38% – 3.98% 1.65% – 2.02% Expected dividend yield 0.00 % 0.00 % Expected term of options (in years) 5.00 – 6.08 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 Forfeited (448 ) 9.84 Unvested balance – March 31, 2023 812,170 $ 9.38

Note 12 - Fair Value (Tables)

Note 12 - Fair Value (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	March 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 15,981 $ — $ — $ 15,981 Clene Nanomedicine contingent earn-out liability — — 2,319 2,319 Initial Stockholders contingent earn-out liability — — 298 298 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) Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2022 $ 2,264 $ 291 Change in fair value 55 7 Balance – March 31, 2023 $ 2,319 $ 298 (in thousands) Common Stock Warrant Liability Clene Nanomedicine Contingent Earn-out Initial Stockholders Contingent Earn-out Balance – December 31, 2021 $ 474 $ 18,100 $ 2,317 Change in fair value 18 57 12 Reclassification from liability to equity (305 ) — — Balance – March 31, 2022 $ 187 $ 18,157 $ 2,329
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	March 31, December 31, 2023 2022 Expected stock price volatility 115.00 % 115.00 % Risk-free interest rate 3.90 % 4.20 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 2.75 3.00

Note 13 - Capital Stock (Tables

Note 13 - Capital Stock (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Date Exercisable Number of Shares Issuable Exercise Price Expiration December 2020 2,407,500 (1) $ 11.50 December 2025 December 2020 24,583 (2) $ 11.50 December 2025 December 2020 1,929,111 (3) $ 1.97 April 2023 May 2021 115,851 (4) $ 8.63 May 2026 Total 4,477,045

Note 14 - Net Loss Per Share (T

Note 14 - Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, (in thousands, except share and per share data) 2023 2022 Numerator: Net loss attributable to common stockholders $ (11,770 ) $ (13,354 ) Denominator: Weighted average common shares outstanding 76,049,665 62,852,863 Net loss per share attributable to common stockholders – basic and diluted $ (0.15 ) $ (0.21 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	Three Months Ended March 31, 2023 2022 Convertible notes payable (see Note 8) 1,732,703 482,703 Common stock warrants (see Note 13) 4,477,045 4,477,045 Options to purchase common stock (see Note 11) 16,205,404 11,944,789 Unvested restricted stock awards (see Note 11) 812,170 914,876 Contingent earn-out shares (see Note 2) 6,592,334 6,592,334 Total 29,819,656 24,411,747

Note 15 - Related Party Trans_2

Note 15 - Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Schedule of Related Party Transactions [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 Product revenue from related parties $ 63 $ — Royalty revenue from related parties 43 23 Total revenue from related parties $ 106 $ 23

Note 16 - Segment Information (

Note 16 - Segment Information (Tables)	3 Months Ended
	Mar. 31, 2023
Notes Tables
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 Drugs: Revenue from external customers $ — $ — Loss from operations (10,798 ) (13,343 ) Supplements: Revenue from external customers $ 107 $ 30 Income from operations 66 7 Consolidated: Revenue from external customers $ 107 $ 30 Loss from operations (10,732 ) (13,336 )
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]	Three Months Ended March 31, (in thousands) 2023 2022 Segment loss from operations $ (10,732 ) $ (13,336 ) Total other income (expense), net (1,038 ) (18 ) Net loss before income taxes $ (11,770 ) $ (13,354 )
Reconciliation of Assets from Segment to Consolidated [Table Text Block]	March 31, December 31, (in thousands) 2023 2022 Total assets: Drugs $ 20,875 $ 20,476 Supplements 272 386 Corporate 18,741 23,631 Consolidated $ 39,888 $ 44,493

Note 1 - Nature of the Busine_2

Note 1 - Nature of the Business (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Apr. 01, 2023	Mar. 31, 2023	Mar. 31, 2022	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)		$ (10,732)	$ (13,336)
Retained Earnings (Accumulated Deficit)		(204,989)		$ (193,219)
Cash, Cash Equivalents, and Short-Term Investments		18,400		$ 23,300
Net Cash Provided by (Used in) Operating Activities		(9,218)	(13,084)
Minimum Cash Balance For Loan Covenant		5,000
Proceeds from Issuance of Common Stock		$ 4,266	$ 0
Subsequent Event [Member]
Proceeds from Issuance of Common Stock	$ 400

Note 2 - Summary of Significa_2

Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)	Dec. 30, 2020	Mar. 31, 2023	Dec. 31, 2022
Inventory, Raw Materials, Gross		$ 100,000	$ 29,000
Inventory, Finished Goods, Gross		$ 19,000	$ 14,000
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 - Marketable Securitie_2

Note 3 - Marketable Securities (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Debt Securities, Available-for-Sale, Total	$ 0		$ 4,983
Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale	$ 5,000	$ 0
Debt Securities, Available-for-Sale, Allowance for Credit Loss			$ 0

Note 3 - Marketable Securitie_3

Note 3 - Marketable Securities - Available for Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Amortized cost		$ 4,997
Gross unrealized gains		0
Gross unrealized losses		(14)
Fair value	$ 0	4,983
Commercial Paper [Member]
Amortized cost		3,496
Gross unrealized gains		0
Gross unrealized losses		(14)
Fair value		3,482
Corporate Debt Securities [Member]
Amortized cost		1,501
Gross unrealized gains		0
Gross unrealized losses		0
Fair value		$ 1,501

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	Mar. 31, 2023	Dec. 31, 2022
Research and development tax credits receivable	$ 3,051	$ 2,777
Metals to be used in research and development	2,216	2,290
Other	962	581
Total prepaid expenses and other current assets	$ 6,229	$ 5,648

Note 5 - Property and Equipme_3

Note 5 - Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property and equipment, gross	$ 16,178	$ 15,911
Less accumulated depreciation	(5,664)	(5,273)
Total property and equipment, net	10,514	10,638
Equipment [Member]
Property and equipment, gross	3,923	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	9,966	5,677
Construction in Progress [Member]
Property and equipment, gross	$ 1,652	$ 5,664

Note 5 - Property and Equipme_4

Note 5 - Property and Equipment, Net - Schedule of Depreciation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Depreciation	$ 402	$ 195
General and Administrative Expense [Member]
Depreciation	67	29
Research and Development Expense [Member]
Depreciation	$ 335	$ 166

Note 6 - Accrued Liabilities -

Note 6 - Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accrued compensation and benefits	$ 2,638	$ 2,007
Accrued CRO and clinical fees	2,752	1,297
Other	543	559
Total accrued liabilities	$ 5,933	$ 3,863

Note 7 - Leases (Details Textua

Note 7 - Leases (Details Textual) $ in Thousands	1 Months Ended			3 Months Ended		12 Months Ended
	Sep. 30, 2022	Feb. 28, 2022	Sep. 30, 2021	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	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)				7 years 1 month 6 days		7 years 3 months 18 days
Finance Lease, Weighted Average Discount Rate, Percent				10.80%		10.20%
Finance Lease, Weighted Average Remaining Lease Term (Year)				1 year		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	Mar. 31, 2023	Dec. 31, 2022
Finance lease asset, gross	$ 636	$ 636
Less accumulated depreciation	(346)	(326)
Net	290	310
Equipment [Member]
Finance lease asset, gross	408	408
Construction in Progress [Member]
Finance lease asset, gross	$ 228	$ 228

Note 7 - Leases - Maturity Anal

Note 7 - Leases - Maturity Analysis of Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
2022 (remainder), finance leases	$ 65
2023 (remainder), operating leases	767
2024, finance leases	27
2024, operating leases	1,171
2025, finance leases	0
2025, operating leases	1,202
2026, finance leases	0
2026, operating leases	1,231
2027, finance leases	0
2027, operating leases	1,129
2028, finance leases	0
2028, operating leases	1,092
Thereafter, finance leases	0
Thereafter, operating leases	1,694
Total undiscounted cash flows, finance leases	92
Total undiscounted cash flows, operating leases	8,286
Less amount representing interest/discounting, finance leases	(13)
Less amount representing interest/discounting, operating leases	(2,379)
Present value of future lease payments, finance leases	79
Present value of future lease payments, operating leases	5,907
Less lease obligations, current portion, finance leases	76	$ 74
Less lease obligations, current portion, operating leases	508	488
Lease obligations, long term portion, finance leases	3	34
Lease obligations, long term portion, operating leases	$ 5,399	$ 5,557

Note 7 - Leases - Components of

Note 7 - Leases - Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Amortization	$ 20	$ 20
Interest on lease liabilities	6	5
Operating lease costs	253	230
Variable lease costs	50	65
Total lease costs	$ 329	$ 320

Note 7 - Leases - Supplemental

Note 7 - Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating cash flows from operating leases	$ (303)	$ (295)
Operating cash flows from finance leases	(6)	(5)
Payments of finance lease obligations	$ (28)	$ (32)

Note 8 - Notes Payable and Co_3

Note 8 - Notes Payable and Convertible Notes Payable (Details Textual)			1 Months Ended				3 Months Ended		12 Months Ended
	Apr. 30, 2019 USD ($)	Feb. 28, 2019 USD ($)	Dec. 31, 2022 USD ($) $ / shares	May 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	May 31, 2021 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) $ / shares
Proceeds from Notes Payable, Total							$ 350,000	$ 0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares							4,477,045
Avenue [Member] | Warrants Issued with 2021 Avenue Loan [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares						115,851
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares						$ 8.63
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%
Debt Instrument, Convertible, Number of Equity Instruments		119,907
Interest Expense, Debt							$ 10,000	10,000
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							12,000
Proceeds from Loans							$ 1,000,000
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
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							$ 74,000
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) | $ / shares			$ 4						$ 4
Coupon Interest Expense							75,000
Amortization of Debt Issuance Costs and Discounts							$ 1,000
Debt Instrument, Interest Rate, Effective Percentage							5.91%
The 2019 Cecil Loan [Member] | Advance Cecil Inc. [Member]
Debt Instrument, Face Amount	$ 100,000
Debt Instrument, Interest Rate, Stated Percentage	8%
Debt Instrument, Convertible, Number of Equity Instruments	23,981
Interest Expense, Debt							$ 2,000	2,000
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							$ 1,000,000	700,000
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares							$ 10.36
Debt Instrument, Interest Rate During Period							14.60%		14.10%
Debt Instrument, Interest Only Payments, Period (Month)						12 months
Debt Instrument, First Interest-only Period Extension (Month)						12 months
Debt Instrument, Term (Month)						42 months
Additional Payment at Debt Maturity, Percentage of Principal						4.25%
Additional Payment at Debt Maturity						$ 900,000
Debt Issuance Costs, Net							$ 600,000
Debt Issuance Costs Expensed							47,000
Debt Instrument, Convertible, Maximum Conversion Amount							5,000,000
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net			$ 200,000				100,000		$ 200,000
Debt Instrument, Covenant, Cash and Certain Cash Equivalents, Minimum						5,000,000
Warrants and Rights Outstanding						1,500,000
The 2021 Avenue Loan [Member] | Avenue [Member] | Convertible Notes Payable [Member]
Interest Expense, Debt							240,000	180,000
Coupon Interest Expense							177,000	123,000
Amortization of Debt Issuance Costs and Discounts							$ 63,000	$ 57,000
Debt Instrument, Interest Rate, Effective Percentage							20.17%	15.71%
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 - Note Payable and Conve

Note 8 - Note Payable and Convertible Notes Payable - Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Less notes payable, current portion, net of unamortized discount and debt issuance costs	$ (9,751)	$ (6,418)
Notes payable, net of current portion	6,713	9,483
Convertible notes payable	9,907	9,770
Notes Payable [Member]
Total	16,828	16,466
Notes payable	16,828	16,466
Accrued and unpaid interest	35	22
Less unamortized discount and debt issuance costs	(399)	(587)
Less notes payable, current portion, net of unamortized discount and debt issuance costs	(9,751)	(6,418)
Notes payable, net of current portion	6,713	9,483
Convertible Notes Payable [Member]
Total	10,000	10,000
Notes payable	10,000	10,000
Accrued and unpaid interest	83	7
Less unamortized discount and debt issuance costs	(176)	(237)
Convertible notes payable	$ 9,907	9,770
The 2019 Cecil Loan [Member] | Notes Payable [Member]
Interest Rate	8%
Total	$ 132	130
Notes payable	132	130
Accrued and unpaid interest	$ 0
The 2019 Maryland DHCD [Member] | Notes Payable [Member]
Interest Rate	8%
Total	$ 664	654
Notes payable	$ 664	654
The 2022 Maryland DHCD [Member] | Notes Payable [Member]
Interest Rate	6%
Total	$ 1,032	682
Notes payable	$ 1,032	682
Avenue [Member] | Notes Payable [Member]
Interest Rate	14.60%
Total	$ 15,000	15,000
Notes payable	$ 15,000	15,000
Avenue [Member] | Convertible Notes Payable [Member]
Interest Rate	14.60%
Total	$ 5,000	5,000
Notes payable	5,000	5,000
The 2022 DHCD Loan [Member] | Notes Payable [Member]
Total	5,031
Notes payable	5,031
Accrued and unpaid interest	$ 83
The 2022 DHCD Loan [Member] | Convertible Notes Payable [Member]
Interest Rate	6%
Total	$ 5,000	5,000
Notes payable	$ 5,000	$ 5,000

Note 8 - Notes Payable and Co_4

Note 8 - Notes Payable and Convertible Notes Payable - Schedule of Future Payments (Details) - Notes Payable [Member] - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accrued and unpaid interest	$ 35	$ 22
Total	16,828	16,466
The 2019 MD Loan [Member]
2023 (remainder)	0
2024	0
2025	0
2026	0
2027	0
2028	0
Thereafter	664
Subtotal of future principal payments	664
Accrued and unpaid interest	0
Less unamortized discount and debt issuance costs	0
Total	664
The 2019 Cecil Loan [Member]
2023 (remainder)	0
2024	0
2025	0
2026	0
2027	0
2028	0
Thereafter	132
Subtotal of future principal payments	132
Accrued and unpaid interest	0
Less unamortized discount and debt issuance costs	0
Total	132	$ 130
The 2021 Avenue Loan [Member]
2023 (remainder)	6,667
2024	13,333
2025	0
2026	0
2027	0
2028	0
Thereafter	0
Subtotal of future principal payments	20,000
Accrued and unpaid interest	0
Less unamortized discount and debt issuance costs	(497)
Total	19,503
The 2022 MD Loan [Member]
2023 (remainder)	0
2024	0
2025	347
2026	369
2027	317
2028	0
Thereafter	0
Subtotal of future principal payments	1,033
Accrued and unpaid interest	35
Less unamortized discount and debt issuance costs	(26)
Total	1,042
The 2022 DHCD Loan [Member]
2023 (remainder)	0
2024	0
2025	0
2026	0
2027	0
2028	5,000
Thereafter	0
Subtotal of future principal payments	5,000
Accrued and unpaid interest	83
Less unamortized discount and debt issuance costs	(52)
Total	$ 5,031

Note 9 - Commitments and Cont_2

Note 9 - Commitments and Contingencies (Details Textual) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Sep. 30, 2019	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Government Assistance, Amount		$ 314	$ 299
Grant Funding Related to VISIONARY-MS Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member]
Government Assistance, Amount	$ 300
Other Commitment, Repayment, Percentage of Grant Funding Upon First Commercial Product Sale	50%
Other Commitment, Repayment, Additional Percentage of Grant Funding, Tranche One	50%
Other Commitment, Repayment, Cumulative Sales, Tranche One	$ 10,000
Other Commitment, Repayment, Additional Percentage of Grant Funding, Tranche Two	150%
Other Commitment, Repayment, Cumulative Sales, Tranche Two	$ 50,000
Other Commitment, Repayment, Additional Percentage of Grant Funding, Tranche Three	200%
Other Commitment, Repayment, Cumulative Sales, Tranche Three	$ 100,000
Other Commitment, Repayment, Maximum Percentage of Grant Funding When All Milestones Achieved	450%
Other Commitment, Aggregate Repayment, Percentage of Grant Funding	300%
Other Commitment, Repayment, Percentage of Grant Funding Upon Closing	300%
Other Commitment, Repayment Amount Upon Closing	$ 1,000
Grant Funding Related to VISIONARY-MS Phase 2 Clinical Trial [Member] | National Multiple Sclerosis Society [Member] | Minimum [Member]
Other Commitment, Possible Loss, Percentage of Grant Funding	50%
Other Commitment, 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]
Other Commitment, Possible Loss, Percentage of Grant Funding	450%
Other Commitment, Possible Loss Between Minimum and Maximum Repayment Amounts	$ 1,500
Capital Addition Purchase Commitments [Member]
Long-Term Purchase Commitment, Amount		$ 500		$ 1,600

Note 10 - Income Taxes - Compon

Note 10 - Income Taxes - Components of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
United States	$ (11,546)	$ (12,957)
Foreign	(224)	(397)
Net loss before income taxes	$ (11,770)	$ (13,354)

Note 11 - Benefit Plans (Detail

Note 11 - Benefit Plans (Details Textual) - USD ($)		3 Months Ended		12 Months Ended
	May 09, 2023	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)		16,205,404		15,260,297
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)		1,077,432
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount		$ 100,000		$ 0
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		11 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)		$ 0.99	$ 2.25
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount		$ 16,800,000		$ 18,200,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		2 years 4 months 9 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)		5,367,340
The 2020 Stock Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)		12,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)		11,933,488
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)		66,512
Common Stock, Capital Shares Reserved for Future Issuance, (Increase) (Decrease) During Period (in shares)	6,400,000
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		$ 100,000	$ 100,000

Note 11 - Benefit Plans - Stock

Note 11 - Benefit Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total stock-based compensation expense	$ 2,223	$ 2,202
Share-Based Payment Arrangement, Option [Member]
Total stock-based compensation expense	2,222	2,202
Restricted Stock Awards [Member]
Total stock-based compensation expense	1	0
General and Administrative Expense [Member]
Total stock-based compensation expense	1,250	1,458
Research and Development Expense [Member]
Total stock-based compensation expense	$ 973	$ 744

Note 11 - Benefit Plans - Activ

Note 11 - Benefit Plans - Activity Related to Outstanding Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Beginning balance outstanding, number of options (in shares)	15,260,297
Beginning balance outstanding, weighted average exercise price per share (in dollars per share)	$ 2.98
Outstanding, weighted average remaining term (Year)	7 years 2 months 19 days	7 years 3 months 10 days
Outstanding, intrinsic value	$ 2,923	$ 2,348
Granted, number of options (in shares)	1,077,432
Granted, weighted average exercise price per share (in dollars per share)	$ 1.30
Granted, weighted average remaining term (Year)	9 years 10 months 20 days
Forfeited, number of options (in shares)	(132,325)
Forfeited, weighted average exercise price per share (in dollars per share)	$ 5.83
Ending balance outstanding, number of options (in shares)	16,205,404	15,260,297
Ending balance outstanding, weighted average exercise price per share (in dollars per share)	$ 2.85	$ 2.98
Vested and exercisable, number of options (in shares)	8,085,513
Vested and exercisable, weighted average exercise price per share (in dollars per share)	$ 2.76
Vested and exercisable, weighted average remaining term (Year)	5 years 3 months 14 days
Vested and exercisable, intrinsic value	$ 2,855
Vested, exercisable and expected to vest, number of options (in shares)	16,205,404
Vested, exercisable and expected to vest, weighted average exercise price per share (in dollars per share)	$ 2.85
Vested, exercisable or expected to vest – March 31, 2023 (Year)	7 years 2 months 19 days
Vested, exercisable or expected to vest – March 31, 2023	$ 2,923

Note 11 - Benefit Plans - Assum

Note 11 - Benefit Plans - Assumptions of Stock Options (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Expected dividend yield	0%	0%
Minimum [Member]
Expected stock price volatility	96.22%	89.57%
Risk-free interest rate	3.38%	1.65%
Expected term of options (in years) (Year)	5 years	5 years
Maximum [Member]
Expected stock price volatility	103.24%	93.07%
Risk-free interest rate	3.98%	2.02%
Expected term of options (in years) (Year)	6 years 29 days	6 years 11 months 23 days

Note 11 - Benefit Plans - Act_2

Note 11 - Benefit Plans - Activity Related to Restricted Stock Awards (Details)	3 Months Ended
	Mar. 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
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	(448)
Forfeited, weighted average grant date fair value (in dollars per share) | $ / shares	$ 9.84
Unvested balance, number of restricted stock awards (in shares) | shares	812,170
Unvested balance, weighted average grant date fair value (in dollars per share) | $ / shares	$ 9.38

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	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Clene Nanomedicine contingent earn-out liability	$ 2,319		$ 2,264
Initial Stockholders contingent earn-out liability	298		291
Fair value	0		4,983
Commercial Paper [Member]
Fair value			3,482
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] | 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] | Corporate Debt Securities [Member]
Fair value			1,501
Fair Value, Inputs, Level 3 [Member]
Clene Nanomedicine contingent earn-out liability	2,319		2,264
Initial Stockholders contingent earn-out liability	298		291
Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member]
Fair value			0
Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member]
Fair value			0
Money Market Funds [Member]
Cash Equivalents	15,981		14,317
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash Equivalents	15,981		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
Clene Nanomedicine Contingent Earn-out [Member]
Balance	2,264	$ 18,100
Change in fair value	55	57
Balance – March 31, 2023	2,319	18,157
Reclassification from liability to equity		0
Initial Stockholders Contingent Earn-out [Member]
Balance	291	2,317
Change in fair value	7	12
Balance – March 31, 2023	$ 298	2,329
Reclassification from liability to equity		0
Common Stock Warrant Liability [Member]
Balance		474
Change in fair value		18
Balance – March 31, 2023		187
Reclassification from liability to equity		$ (305)

Note 12 - Fair Value - Unobserv

Note 12 - Fair Value - Unobservable Inputs (Details) - Contingent Earnout Shares [Member]	Mar. 31, 2023	Dec. 31, 2022
Measurement Input, Price Volatility [Member]
Derivative, unobservable input		1.1500
Measurement Input, Price Volatility [Member] | Minimum [Member]
Derivative, unobservable input	1.1500
Measurement Input, Risk Free Interest Rate [Member]
Derivative, unobservable input		0.0420
Measurement Input, Risk Free Interest Rate [Member] | Minimum [Member]
Derivative, unobservable input	0.0390
Measurement Input, Expected Dividend Rate [Member]
Derivative, unobservable input		0
Measurement Input, Expected Dividend Rate [Member] | Minimum [Member]
Derivative, unobservable input	0
Measurement Input, Expected Term [Member]
Derivative, unobservable input		3
Measurement Input, Expected Term [Member] | Minimum [Member]
Derivative, unobservable input	2.75

Note 13 - Capital Stock (Detail

Note 13 - Capital Stock (Details Textual) - USD ($)					1 Months Ended	3 Months Ended		12 Months Ended
	Apr. 01, 2023	Mar. 03, 2023	Apr. 14, 2022	Dec. 30, 2020	Oct. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	May 09, 2023	May 31, 2021
Common Stock, Shares Authorized (in shares)						150,000,000		150,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)				$ 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)						77,987,349		74,759,591
Preferred Stock, Shares Issued (in shares)						0		0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)						4,477,045
Proceeds from Issuance of Common Stock						$ 4,266,000	$ 0
Purchase Price, Sales						$ 0
Common Stock, Shares, Outstanding (in shares)						77,987,349		74,759,591
Preferred Stock, Shares Outstanding (in shares)						0		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%
Derivative, Notional Amount		$ 0
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%
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
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
ATM Facility [Member]
Stock Issued During Period, Shares, New Issues (in shares)						2,895,090
Proceeds from Issuance of Common Stock						$ 4,500,000
Aggregate Offering Price			$ 50,000,000
Fixed Commission Rate Percentage			3%
Payments for Commissions						$ 100,000
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)				$ 16.50
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
Class of Warrant or Right, Exercised During Period (in shares)						0		0
Warrants with Tranche 2 of 2021 Avenue Loan [Member]
Class of Warrant or Right, Exercised During Period (in shares)						0		0
Subsequent Event [Member]
Common Stock, Shares Authorized (in shares)									300,000,000
Proceeds from Issuance of Common Stock	$ 400,000

Note 13 - Capital Stock - Outst

Note 13 - Capital Stock - Outstanding Warrants (Details)	Mar. 31, 2023 $ / shares shares
Number of shares issuable (in shares)	4,477,045
Common Stock Warrant Exercisable on December 2020, One [Member]
Number of shares issuable (in shares)	2,407,500	[1]
Exercise price (in dollars per share) | $ / shares	$ 11.50
Common Stock Warrant Exercisable on December 2020, Two [Member]
Number of shares issuable (in shares)	24,583	[2]
Exercise price (in dollars per share) | $ / shares	$ 11.50
Common Stock Warrant Exercisable on December 2020, Three [Member]
Number of shares issuable (in shares)	1,929,111	[3]
Exercise price (in dollars per share) | $ / shares	$ 1.97
Common Stock Warrant Exercisable on May 2021 [Member]
Number of shares issuable (in shares)	115,851	[4]
Exercise price (in dollars per share) | $ / shares	$ 8.63
[1]Consists of 2,407,500 shares of Common Stock underlying warrants to purchase one-half (1/2) of one share of Common Stock, issued in connection with Tottenham’s initial public offering. We may redeem the outstanding warrants, in whole and not in part, at $0.01 per warrant if the last sales price of our Common Stock equals or exceeds $16.50 per share for any twenty trading days within a thirty-trading day period. As of March 31, 2023 and December 31, 2022, no warrants had been exercised.[2]Consists of 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 March 31, 2023 and December 31, 2022, no warrants had been exercised.[3]Consists of 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 March 31, 2023 and December 31, 2022, no warrants had been exercised. As of April 2023, the warrants expired.[4]Consists of 115,851 shares of Common Stock underlying the Avenue Warrant. As of March 31, 2023 and December 31, 2022, the warrant had not 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	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net loss	$ (11,770)	$ (13,354)
Weighted average common shares used to compute basic and diluted net loss per share (in shares)	76,049,665	62,852,863
Net loss per share – basic and diluted (in dollars per share)	$ (0.15)	$ (0.21)

Note 14 - Net Loss Per Share At

Note 14 - Net Loss Per Share Attributable to Common Stockholders - Antidilutive Securities Excluded from Computation (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive securities (in shares)	29,819,656	24,411,747
Convertible Notes Payable [Member]
Antidilutive securities (in shares)	1,732,703	482,703
Common Stock Warrants [Member]
Antidilutive securities (in shares)	4,477,045	4,477,045
Share-Based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	16,205,404	11,944,789
Restricted Stock [Member]
Antidilutive securities (in shares)	812,170	914,876
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) - 4Life [Member] - Supply Agreement [Member]	1 Months Ended
	Aug. 31, 2018
Related Party Transaction, Exclusive License Term (Year)	5 years
Related Party Transaction, Royalty Fee Rate for Revenues	3%

Note 15 - Related Party Trans_4

Note 15 - Related Party Transactions - Revenue From 4Life Agreement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue	$ 107	$ 30
Related Party [Member]
Revenue	106	23
Product [Member]
Revenue	64	7
Product [Member] | Related Party [Member]
Revenue	63	0
Royalty [Member]
Revenue	43	23
Royalty [Member] | Related Party [Member]
Revenue	$ 43	$ 23

Note 16 - Segment Information -

Note 16 - Segment Information - Profit and Loss Information by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue from external customers	$ 107	$ 30
Segment loss from operations	(10,732)	(13,336)
Operating Segments [Member] | Drugs Segment [Member]
Revenue from external customers	0	0
Segment loss from operations	(10,798)	(13,343)
Operating Segments [Member] | Supplements Segment [Member]
Revenue from external customers	107	30
Segment loss from operations	$ 66	$ 7

Note 16 - Segment Information_2

Note 16 - Segment Information - Reconciliation of the Reportable Segments' Loss From Operations to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment loss from operations	$ (10,732)	$ (13,336)
Total other income (expense), net	(1,038)	(18)
Net loss before income taxes	$ (11,770)	$ (13,354)

Note 16 - Segment Information_3

Note 16 - Segment Information - Assets by Reportable Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Total assets	$ 39,888	$ 44,493
Operating Segments [Member] | Drugs Segment [Member]
Total assets	20,875	20,476
Operating Segments [Member] | Supplements Segment [Member]
Total assets	272	386
Corporate, Non-Segment [Member]
Total assets	$ 18,741	$ 23,631

Note 17 - Subsequent Events (De

Note 17 - Subsequent Events (Details Textual) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
	Apr. 01, 2023	May 09, 2023	Mar. 31, 2023	Mar. 31, 2022
Proceeds from Issuance of Common Stock			$ 4,266	$ 0
Subsequent Event [Member]
Proceeds from Issuance of Common Stock	$ 400
Subsequent Event [Member] | Lincoln Park [Member] | Purchase Agreement [Member]
Stock Issued During Period, Shares, New Issues (in shares)		400,000
Proceeds from Issuance of Common Stock		$ 400
Subsequent Event [Member] | Lincoln Park [Member] | Purchase Agreement [Member] | Commitment Shares [Member]
Stock Issued During Period, Shares, New Issues (in shares)		2,893