BioCardia (BCDA) 10-Q13 Nov 242024 Q3 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
Document And Entity Information - shares	Sep. 30, 2024	Nov. 05, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-38999
Entity Registrant Name	BioCardia, Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2753988
Entity Address, Address Line One	320 Soquel Way
Entity Address, City or Town	Sunnyvale
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94085
City Area Code	650
Local Phone Number	226-0120
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $0.001
Trading Symbol	BCDA
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding (in shares)		4,584,285
Entity Central Index Key	0000925741
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Cash and cash equivalents	$ 4,930	$ 1,103
Accounts receivable, net of allowance for doubtful accounts of $0 and $34 as of September 30, 2024 and December 31, 2023, respectively	10	63
Prepaid expenses and other current assets	116	295
Total current assets	5,056	1,461
Property and equipment, net	47	94
Operating lease right-of-use asset, net	993	1,261
Other assets	171	171
Total assets	6,267	2,987
Accounts payable	569	890
Accrued expenses and other current liabilities	1,900	2,385
Operating lease liability - current	371	333
Total current liabilities	2,840	3,608
Operating lease liability - noncurrent	674	982
Total liabilities	3,514	4,590
Commitments and Contingencies
Preferred stock, $0.001 par value, 25,000,000 shares authorized and no shares issued and outstanding as of September 30, 2024 and December 31, 2023	0	0
Common stock, $0.001 par value, 50,000,000 and 100,000,000 shares authorized, 4,523,876 and 1,577,769 shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively	5	2
Additional paid-in capital	160,573	150,570
Accumulated deficit	(157,825)	(152,175)
Total stockholders’ equity (deficit)	2,753	(1,603)
Total liabilities and stockholders’ equity (deficit)	$ 6,267	$ 2,987

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accounts Receivable, Allowance for Credit Loss, Current	$ 0	$ 34
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized (in shares)	25,000,000	25,000,000
Preferred Stock, Shares Issued (in shares)	0	0
Preferred Stock, Shares Outstanding (in shares)	0	0
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001	$ 0.001
Common Stock, Shares Authorized (in shares)	50,000,000	100,000,000
Common Stock, Shares Authorized (in shares)	50,000,000	100,000,000
Common Stock, Shares, Issued (in shares)	4,523,876	1,577,769
Common Stock, Shares, Outstanding (in shares)	4,523,876	1,577,769

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Total revenue	$ 0	$ 357	$ 58	$ 464
Research and development	931	1,872	2,972	6,570
Selling, general and administrative	825	1,083	2,766	3,454
Total costs and expenses	1,756	2,955	5,738	10,024
Operating loss	(1,756)	(2,598)	(5,680)	(9,560)
Total other income, net	19	24	30	61
Net loss	$ (1,737)	$ (2,574)	$ (5,650)	$ (9,499)
Net loss per share, basic and diluted (in dollars per share)	$ (0.61)	$ (1.79)	$ (2.65)	$ (6.87)
Weighted-average shares used in computing net loss per share, basic and diluted (in shares)	2,827,492	1,441,043	2,129,258	1,382,070

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member] ATM [Member]	Common Stock [Member] Restricted Stock Units (RSUs) [Member] Management [Member]	Common Stock [Member]	Additional Paid-in Capital [Member] ATM [Member]	Additional Paid-in Capital [Member] Restricted Stock Units (RSUs) [Member] Management [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member] ATM [Member]	Retained Earnings [Member] Restricted Stock Units (RSUs) [Member] Management [Member]	Retained Earnings [Member]	ATM [Member]	Restricted Stock Units (RSUs) [Member] Management [Member]	Total
Balance (in shares) at Dec. 31, 2022			1,338,451
Balance at Dec. 31, 2022			$ 1			$ 145,495			$ (140,604)			$ 4,892
Sale of common stock, net of issuance costs (in shares)	7,083
Sale of common stock, net of issuance costs	$ 0			$ 231			$ 0			$ 231
Exercise of common stock options (in shares)			13
Exercise of common stock options						0						0
Stock Issued During Period, Shares, Restricted Stock Award, Gross (in shares)			1,253
Share-based compensation						278						278
Net loss									(3,501)			(3,501)
Share-based compensation						278						278
Balance (in shares) at Mar. 31, 2023			1,346,800
Balance at Mar. 31, 2023			$ 1			146,004			(144,105)			1,900
Balance (in shares) at Dec. 31, 2022			1,338,451
Balance at Dec. 31, 2022			$ 1			145,495			(140,604)			4,892
Balance (in shares) at Jun. 30, 2023			1,439,077
Balance at Jun. 30, 2023			$ 1			149,163			(147,529)			1,635
Balance (in shares) at Dec. 31, 2022			1,338,451
Balance at Dec. 31, 2022			$ 1			145,495			(140,604)			4,892
Net loss												(9,499)
Balance (in shares) at Sep. 30, 2023			1,441,296
Balance at Sep. 30, 2023			$ 1			149,442			(150,103)			(660)
Balance (in shares) at Mar. 31, 2023			1,346,800
Balance at Mar. 31, 2023			$ 1			146,004			(144,105)			1,900
Sale of common stock, net of issuance costs (in shares)	1,907		75,543
Sale of common stock, net of issuance costs	$ 0		$ 0	29		2,471	0		0	29		2,471
Stock Issued During Period, Shares, Restricted Stock Award, Gross (in shares)			14,827
Share-based compensation			$ 0			317			0			317
Net loss			0			0			(3,424)			(3,424)
Restricted stock units issued to settle management bonus obligations		$ 0			$ 342			$ 0			$ 342
Share-based compensation			$ 0			317			0			317
Balance (in shares) at Jun. 30, 2023			1,439,077
Balance at Jun. 30, 2023			$ 1			149,163			(147,529)			1,635
Sale of common stock, net of issuance costs (in shares)	2,219		0
Sale of common stock, net of issuance costs	$ 0		$ 0	45		17	0		0	45		17
Share-based compensation			0			251			0			251
Net loss			0			0			(2,574)			(2,574)
Share-based compensation			$ 0			251			0			251
Balance (in shares) at Sep. 30, 2023			1,441,296
Balance at Sep. 30, 2023			$ 1			149,442			(150,103)			(660)
Balance (in shares) at Dec. 31, 2023			1,577,769
Balance at Dec. 31, 2023			$ 2			150,570			(152,175)			(1,603)
Sale of common stock, net of issuance costs (in shares)	77,127		134,199
Sale of common stock, net of issuance costs	$ 0		$ 0	559		832	0		0	559		832
Share-based compensation			0			204			0			204
Net loss			0			0			(2,267)			(2,267)
Share-based compensation			$ 0			204			0			204
Balance (in shares) at Mar. 31, 2024			1,789,095
Balance at Mar. 31, 2024			$ 2			152,165			(154,442)			(2,275)
Balance (in shares) at Dec. 31, 2023			1,577,769
Balance at Dec. 31, 2023			$ 2			150,570			(152,175)			(1,603)
Net loss												(5,650)
Balance (in shares) at Sep. 30, 2024			4,523,876
Balance at Sep. 30, 2024			$ 5			160,573			(157,825)			2,753
Balance (in shares) at Mar. 31, 2024			1,789,095
Balance at Mar. 31, 2024			$ 2			152,165			(154,442)			(2,275)
Sale of common stock, net of issuance costs (in shares)	335,112
Sale of common stock, net of issuance costs	$ 0			$ 1,776			$ 0			$ 1,776
Share-based compensation			0			184			0			184
Net loss			$ 0			0			(1,646)			(1,646)
Reverse stock split fractional share true up (in shares)			(331)
Share-based compensation			$ 0			184			0			184
Balance (in shares) at Jun. 30, 2024			2,123,876
Balance at Jun. 30, 2024			$ 2			154,125			(156,088)			(1,961)
Sale of common stock, net of issuance costs (in shares)			2,400,000
Sale of common stock, net of issuance costs			$ 3			6,271			0			6,274
Share-based compensation			0			177			0			177
Net loss			0			0			(1,737)			(1,737)
Share-based compensation			$ 0			177			0			177
Balance (in shares) at Sep. 30, 2024			4,523,876
Balance at Sep. 30, 2024			$ 5			$ 160,573			$ (157,825)			$ 2,753

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - USD ($) $ in Thousands		3 Months Ended
	Jun. 30, 2023	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023
ATM [Member]
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 29		$ 71	$ 32	$ 48		$ 13
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs		$ 926		$ 43		$ 177

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating activities:
Net loss	$ (5,650)	$ (9,499)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation	52	64
Reduction in the carrying amount of right-of-use assets	268	242
Share-based compensation	565	846
Loss on disposal of property and equipment	0	4
Allowance for doubtful accounts	(34)	11
Changes in operating assets and liabilities:
Accounts receivable	87	86
Prepaid expenses and other current assets	179	123
Accounts payable	(165)	(24)
Accrued expenses and other current liabilities	(485)	598
Deferred revenue	0	(341)
Operating lease liability	(270)	(233)
Net cash used in operating activities	(5,453)	(8,123)
us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract
Purchase of property and equipment	(5)	(12)
Net cash used in investing activities	(5)	(12)
us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract
Proceeds from sales of common stock	10,513	3,042
Issuance costs of sale of common stock	(1,228)	(435)
Net cash provided by financing activities	9,285	2,607
Net change in cash and cash equivalents	3,827	(5,528)
Cash and cash equivalents at beginning of period	1,103	7,363
Cash and cash equivalents at end of period	4,930	1,835
us-gaap_SupplementalCashFlowElementsAbstract
Unpaid issuance costs of common stock	40	20
Issuance of restricted stock units in lieu of cash bonus obligations	$ 0	$ 564

Note 1 - Summary of Business an

Note 1 - Summary of Business and Basis of Presentation	9 Months Ended
Note 1 - Summary of Business and Basis of Presentation	Sep. 30, 2024
Notes to Financial Statements
Business Description and Basis of Presentation [Text Block]	(1) Summary of Business and Basis of Presentation Description of Business BioCardia, Inc. (we, us, our, BioCardia or the Company), is a clinical-stage company focused on developing cellular and cell-derived therapeutics for the treatment of cardiovascular and pulmonary diseases with significant unmet medical needs. Our CardiAMP® autologous mononuclear cell therapy platform is being advanced in pivotal trials for two clinical indications: ischemic heart failure with reduced ejection fraction (HFrEF) and refractory angina resulting from chronic myocardial ischemia (CMI). Our allogeneic mesenchymal stem cell (MSC) therapy platform is being advanced as an “off the shelf” cell therapy for two clinical indications: the treatment of ischemic HFrEF and for acute respiratory distress syndrome (ARDS). Our autologous and our allogeneic cell therapies intended for cardiac indications are enabled by our Helix™ minimally invasive intramyocardial therapeutic delivery platform. We partner this therapeutic delivery platform selectively with others seeking to develop biotherapeutic interventions for local delivery to the heart. To date, we have devoted substantially all our resources to research and development efforts relating to our therapeutic candidates and biotherapeutic delivery systems including conducting clinical trials, developing manufacturing and sales capabilities, in-licensing related intellectual property, providing general and administrative support for these operations and protecting our intellectual property. We manage our operations as a single segment for the purposes of assessing performance and making operating decisions.

Note 2 - Significant Accounting

Note 2 - Significant Accounting Policies	9 Months Ended
Note 2 - Significant Accounting Policies	Sep. 30, 2024
Notes to Financial Statements
Significant Accounting Policies [Text Block]	(2) Significant Accounting Policies (a) Basis of Preparation The accompanying condensed consolidated balance sheets, statements of operations, stockholders’ equity (deficit), and cash flows as of September 30, 2024, and for the three and nine months ended September 30, 2024 and 2023 are unaudited. The condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information and on a basis consistent with the annual financial statements and, in the opinion of management, reflect all adjustments which include only normal recurring adjustments, necessary to present fairly our financial position as of September 30, 2024, results of operations for the three and nine months ended September 30, 2024 and 2023, and cash flows for the nine months ended September 30, 2024 and 2023. The results for the three and nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the year ended December 31, 2024 or for any other interim period or for any other future year. These condensed consolidated financial statements should be read in conjunction with the audited financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 27, 2024. (b) Liquidity Going Concern We have incurred net losses and negative cash flows from operations since our inception and had an accumulated deficit of approximately $157.8 million as of September 30, 2024. Management expects operating losses and negative cash flows to continue through at least the next several years. We expect to incur increasing costs as we advance our trials and development activities. Therefore, absent additional funding, management believes cash and cash equivalents of approximately $4.9 million as of September 30, 2024 are not sufficient to fund our planned expenditures and meet our obligations beyond the second quarter of 2025. These factors raise substantial doubt about our ability to continue as a going concern beyond one year from the date these financial statements are issued. The financial statements do not include any adjustments that might result from the outcome of this uncertainty. Our ability to continue as a going concern and to continue further development of our therapeutic candidates beyond the second quarter of 2025 will require us to raise additional capital. We plan to raise additional capital, potentially including debt and equity arrangements, to finance our future operations. While management believes this plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. If adequate funds are not available, we may be required to reduce operating expenses, delay or reduce the scope of our product development programs, obtain funds through arrangements with others that may require us to relinquish rights to certain of our technologies or products that we would otherwise seek to develop or commercialize, or cease operations. (c) Use of Estimates The preparation of the financial statements in accordance with U.S. GAAP requires management to make certain estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ materially from those estimates. Significant items subject to such estimates and assumptions include clinical accruals, share-based compensation, right-of-use assets and related liabilities, incremental borrowing rate, the useful lives of property and equipment, allowances for doubtful accounts and sales returns, and assumptions used for revenue recognition. (d) Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, BioCardia Lifesciences, Inc. All intercompany accounts and transactions have been eliminated during the consolidation process. (e) Concentration of Credit Risk Financial instruments that potentially subject us to a concentration of credit risk consist of cash and cash equivalents. Our cash at times exceeds federally insured limits of $250,000 per customer. On September 30, 2024, approximately 99% of our cash and cash equivalents were held by one financial institution and total cash and cash equivalents were approximately $4.6 million in excess of FDIC insurance limits. We have not recognized any losses from credit risks on such accounts since inception. (f) Changes to Significant Accounting Policies Our significant accounting policies are described in Note 2 of the notes to the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 27, 2024. There have been no changes to those policies. (g) Recent Accounting Pronouncements Recent accounting pronouncements issued by the Financial Accounting Standards Board (FASB), including its Emerging Issues Task Force, did not or are not believed by management to have a material impact on our financial statement presentation or disclosures.

Note 3 - Fair Value Measurement

Note 3 - Fair Value Measurement	9 Months Ended
Note 3 - Fair Value Measurement	Sep. 30, 2024
Notes to Financial Statements
Fair Value Disclosures [Text Block]	(3) Fair Value Measurement The fair value of financial instruments reflects the amounts that we estimate to receive in connection with the sale of an asset or paid in connection with the transfer of a liability in an orderly transaction between market participants at the measurement date (exit price). We follow a fair value hierarchy that prioritizes the use of inputs used in valuation techniques into the following three levels: Level 1 – quoted prices in active markets for identical assets and liabilities. Level 2 – observable inputs other than quoted prices in active markets for identical assets and liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The following table shows the fair value of our financial assets measured on a recurring basis and indicates the fair value hierarchy utilized to determine such fair value (in thousands): As of September 30, 2024 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 2 $ — $ — $ 2 Cash in savings account — — — 4,739 Cash in checking account — — — 189 Total cash and cash equivalents $ 2 $ — $ — $ 4,930 As of December 31, 2023 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 2 $ — $ — $ 2 Cash in savings account — — — 1,072 Cash in checking account — — — 29 Total cash and cash equivalents $ 2 $ — $ — $ 1,103

Note 4 - Property and Equipment

Note 4 - Property and Equipment, Net	9 Months Ended
Note 4 - Property and Equipment, Net	Sep. 30, 2024
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	(4) Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2024 2023 Computer equipment and software $ 165 $ 161 Laboratory and manufacturing equipment 575 574 Furniture and fixtures 27 27 Leasehold improvements 26 26 Property and equipment, gross 793 788 Less accumulated depreciation (746 ) (694 ) Property and equipment, net $ 47 $ 94 Depreciation expense totaled $16,000 and $52,000 for the three and nine months ended September 30, 2024, respectively. Depreciation expense totaled $21,000 and $64,000 for the three and nine months ended September 30, 2023, respectively.

Note 5 - Operating Lease Right-

Note 5 - Operating Lease Right-of-use Asset, Net	9 Months Ended
Note 5 - Operating Lease Right-of-use Asset, Net	Sep. 30, 2024
Notes to Financial Statements
Lessee, Operating Leases [Text Block]	(5) Operating Lease Right-of-Use (ROU) Asset, Net We determine if an arrangement is a lease at inception by assessing whether it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Our operating lease relates to a property lease for its laboratory and corporate offices which expires in January 2027. BioCardia’s lease agreement does not contain any material residual guarantees or material restrictive covenants. ROU assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. Our lease does not provide an implicit rate. We used an adjusted historical incremental borrowing rate, based on the information available at the approximate lease commencement date, to determine the present value of lease payments. Variable rent expense is made up of expenses for common area maintenance and shared utilities and were not included in the determination of the present value of lease payments. We have no finance leases. Our lease expense was $121,000 for both the three months ended September 30, 2024 and 2023, and $362,000 for both the nine months ended September 30, 2024 and 2023. The cash paid under the operating lease for base rent was $122,000 and $364,000 for the three and nine months ended September 30, 2024, respectively, and was $117,000 and $353,000 for the three and nine months ended September 30, 2023, respectively. On September 30, 2024, the weighted average remaining lease term was 2.34 years, and the weighted average discount rate was 10.74%. Future minimum lease payments under the operating lease as of September 30, 2024 were as follows (in thousands): Remainder of 2024 $ 121 2025 499 2026 514 2027 44 Total undiscounted lease payments 1,178 Less imputed interest 133 Total operating lease liabilities $ 1,045

Note 6 - Accrued Expenses and O

Note 6 - Accrued Expenses and Other Current Liabilities	9 Months Ended
Note 6 - Accrued Expenses and Other Current Liabilities	Sep. 30, 2024
Notes to Financial Statements
Accrued Liabilities and Other Current Liabilities Disclosure [Text Block]	(6) Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2024 2023 Accrued expenses $ 28 $ 75 Accrued salaries and employee benefits 736 661 Accrued clinical trial costs 597 1,017 Grant liability 470 471 Customer deposits 69 90 Payable to related party — 71 Total $ 1,900 $ 2,385

Note 7 - Stockholders' Equity

Note 7 - Stockholders' Equity	9 Months Ended
Note 7 - Stockholders' Equity	Sep. 30, 2024
Notes to Financial Statements
Equity [Text Block]	(7) Stockholders Equity Warrants Number of Weighted Common Stock Average Equivalents Exercise Price Balance as of December 31, 2023 141,889 $ 94.50 Warrants for common stock sold 2,467,104 3.10 Warrants expired (141,889 ) 94.50 Balance as of September 30, 2024 2,467,104 $ 3.10 Reverse Stock Split September 2024 Financing - February 2024 Financing - At-the-Market (ATM) Offerings On December 6, 2023, we entered into an At The Market Offering Agreement (the Sales Agreement) with H.C. Wainwright & Co., LLC (HCW). Under the Sales Agreement, we may offer and sell our common stock, from time to time having an aggregate offering price of up to $2.75 million during the term of the Sales Agreement through or to HCW as sales agent or principal, of which $264,000 was available as of September 30, 2024. We have filed a prospectus supplement relating to the offer and sale of the shares pursuant to the Sales Agreement. The offering and sale of the shares will be made pursuant to the Company’s previously filed and effective Registration Statement on Form S-3 (File No. 333-275099), which was initially filed with the Securities and Exchange Commission (the SEC) on October 19, 2023 and declared effective on December 5, 2023. We have agreed to pay HCW a commission equal to 3% of the gross proceeds from the sales of shares and have agreed to provide HCW with customary indemnification and contribution rights. During the three months ended September 30, 2024 and 2023, we sold 0 and 2,219 shares of common stock under the ATM Offerings at then-market prices for total gross proceeds of $0 and $93,000, with associated issuance costs of $0 and $48,000, respectively. During the nine months ended September 30, 2024 and 2023, we sold 412,239 and 11,209 shares of common stock under the ATM Offerings at then-market prices for total gross proceeds of approximately $2.4 million and $395,000, respectively, with associated issuance costs of $103,000 and $90,000, respectively.

Note 8 - Share-based Compensati

Note 8 - Share-based Compensation	9 Months Ended
Note 8 - Share-based Compensation	Sep. 30, 2024
Notes to Financial Statements
Share-Based Payment Arrangement [Text Block]	(8) Share-Based Compensation The share-based compensation expense is recorded in research and development, and selling, general and administrative expenses based on the employee's or non-employee’s respective function. No share-based compensation was capitalized during the periods presented. Share-based compensation expense for the three and nine months ended September 30, 2024 and 2023 was recorded as follows (in thousands): Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Research and development $ 98 $ 118 $ 315 $ 391 Selling, general and administrative 79 133 250 455 Total share-based compensation $ 177 $ 251 $ 565 $ 846 The following table summarizes the activity of stock options and related information: Number of shares Weighted average exercise price Weighted average remaining contractual term (years) Aggregate intrinsic value Balance, December 31, 2023 165,784 $ 52.67 6.8 $ 43 Stock options forfeited (3,177 ) 33.97 Stock options expired (9,317 ) 63.09 Balance, September 30, 2024 153,290 $ 52.43 6.5 $ — Exercisable, September 30, 2024 109,830 $ 63.83 5.8 $ — Unrecognized share-based compensation for employee and nonemployee options granted through September 30, 2024 is $837,000 to be recognized over a remaining weighted average service period of 1.8 years. Share-Based Compensation (RSUs) There were no

Note 9 - Net Loss Per Share

Note 9 - Net Loss Per Share	9 Months Ended
Note 9 - Net Loss Per Share	Sep. 30, 2024
Notes to Financial Statements
Earnings Per Share [Text Block]	(9) Net Loss per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding and fully vested restricted stock units. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method. Common stock equivalents are comprised of unvested restricted stock units, warrants to purchase common stock and options outstanding under the stock option plans. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding since the effects of potentially dilutive securities are antidilutive due to the net loss position. The following outstanding common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: September 30, 2024 2023 Stock options to purchase common stock 153,290 162,934 Common stock warrants 2,467,104 161,648 Total 2,620,394 324,582

Note 10 - Income Taxes

Note 10 - Income Taxes	9 Months Ended
Note 10 - Income Taxes	Sep. 30, 2024
Notes to Financial Statements
Income Tax Disclosure [Text Block]	(10) Income Taxes During the three and nine months ended September 30, 2024 and 2023, there was no As of September 30, 2024, we retain a full valuation allowance on our deferred tax assets in all jurisdictions. The realization of our deferred tax assets depends primarily on our ability to generate future taxable income which is uncertain. We do not believe that our deferred tax assets are realizable on a more-likely-than-not basis; therefore, the net deferred tax assets have been fully offset by a valuation allowance.

Note 11 - Related Party Transac

Note 11 - Related Party Transactions	9 Months Ended
Note 11 - Related Party Transactions	Sep. 30, 2024
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	(11) Related Party Transactions On April 9, 2020, we entered into a Litigation Funding Agreement (Funding Agreement) with BSLF, L.L.C. (Funder), an entity owned and controlled by Andrew Blank, Chair of BioCardia’s board of directors, for the purpose of funding our legal proceedings and any and all claims, actions and/or proceedings relating to or arising from the case captioned Boston Scientific Corp., et al., v. BioCardia Inc., Case No. 3:19-05645-VC, U.S.D.C., N. D. Cal (the Litigation). On April 12, 2021, all parties to the Litigation entered into a confidential settlement agreement and all claims were dismissed. In March 2022, we entered into confidential settlement agreements with our litigation service providers and the Funder to terminate the Funding Agreement and conclude all remaining matters thereunder (the Litigation Funding Settlement). Under the terms of the Litigation Funding Settlement, litigation and corporate counsel provided credits and refunds of legal fees totaling $688,000, which offset the amounts owed to us by the Funder under the Funding Agreement, and provided up to $300,000 in future discounts on legal services. As a result of the Litigation Funding Settlement, we remitted the discounts, as received, to the Funder on a quarterly basis. During the three and nine months ended September 30, 2024, we received discounts totaling $0 and $42,000, respectively. During the three and nine months ended September 30, 2023, we received discounts totaling $57,000 and $110,000, respectively. As of September 30, 2024 and December 31, 2023, we recorded a related party payable for discounts owed to the Funder in accrued expenses and other current liabilities of $0 and $71,000, respectively. As of September 30, 2024, all of the future potential discounts have been collected and remitted to the Funder.

Note 12 - Contingencies

Note 12 - Contingencies	9 Months Ended
Note 12 - Contingencies	Sep. 30, 2024
Notes to Financial Statements
Contingencies Disclosure [Text Block]	(12) Contingencies We may be subject to various claims, complaints, and legal actions that arise from time to time in the normal course of business. Management is not aware of any current legal or administrative proceedings that are likely to have an adverse effect on our business, financial position, results of operations, or cash flows.

Insider Trading Arrangements

Insider Trading Arrangements	9 Months Ended
Insider Trading Arrangements	Sep. 30, 2024
Insider Trading Arr Line Items
Material Terms of Trading Arrangement [Text Block]	ITEM 5. OTHER INFORMATION During the three months ended September 30, 2024, none
Rule 10b5-1 Arrangement Adopted [Flag]	false
Non-Rule 10b5-1 Arrangement Adopted [Flag]	false
Rule 10b5-1 Arrangement Terminated [Flag]	false
Non-Rule 10b5-1 Arrangement Terminated [Flag]	false

Significant Accounting Policies

Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	(a) Basis of Preparation The accompanying condensed consolidated balance sheets, statements of operations, stockholders’ equity (deficit), and cash flows as of September 30, 2024, and for the three and nine months ended September 30, 2024 and 2023 are unaudited. The condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) for interim financial information and on a basis consistent with the annual financial statements and, in the opinion of management, reflect all adjustments which include only normal recurring adjustments, necessary to present fairly our financial position as of September 30, 2024, results of operations for the three and nine months ended September 30, 2024 and 2023, and cash flows for the nine months ended September 30, 2024 and 2023. The results for the three and nine months ended September 30, 2024 are not necessarily indicative of the results to be expected for the year ended December 31, 2024 or for any other interim period or for any other future year. These condensed consolidated financial statements should be read in conjunction with the audited financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 27, 2024.
Going Concern and Liquidity [Policy Text Block]	(b) Liquidity Going Concern We have incurred net losses and negative cash flows from operations since our inception and had an accumulated deficit of approximately $157.8 million as of September 30, 2024. Management expects operating losses and negative cash flows to continue through at least the next several years. We expect to incur increasing costs as we advance our trials and development activities. Therefore, absent additional funding, management believes cash and cash equivalents of approximately $4.9 million as of September 30, 2024 are not sufficient to fund our planned expenditures and meet our obligations beyond the second quarter of 2025. These factors raise substantial doubt about our ability to continue as a going concern beyond one year from the date these financial statements are issued. The financial statements do not include any adjustments that might result from the outcome of this uncertainty. Our ability to continue as a going concern and to continue further development of our therapeutic candidates beyond the second quarter of 2025 will require us to raise additional capital. We plan to raise additional capital, potentially including debt and equity arrangements, to finance our future operations. While management believes this plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. If adequate funds are not available, we may be required to reduce operating expenses, delay or reduce the scope of our product development programs, obtain funds through arrangements with others that may require us to relinquish rights to certain of our technologies or products that we would otherwise seek to develop or commercialize, or cease operations.
Use of Estimates, Policy [Policy Text Block]	(c) Use of Estimates The preparation of the financial statements in accordance with U.S. GAAP requires management to make certain estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ materially from those estimates. Significant items subject to such estimates and assumptions include clinical accruals, share-based compensation, right-of-use assets and related liabilities, incremental borrowing rate, the useful lives of property and equipment, allowances for doubtful accounts and sales returns, and assumptions used for revenue recognition.
Consolidation, Policy [Policy Text Block]	(d) Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, BioCardia Lifesciences, Inc. All intercompany accounts and transactions have been eliminated during the consolidation process.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	(e) Concentration of Credit Risk Financial instruments that potentially subject us to a concentration of credit risk consist of cash and cash equivalents. Our cash at times exceeds federally insured limits of $250,000 per customer. On September 30, 2024, approximately 99% of our cash and cash equivalents were held by one financial institution and total cash and cash equivalents were approximately $4.6 million in excess of FDIC insurance limits. We have not recognized any losses from credit risks on such accounts since inception.
Change to Significant Accounting Policies [Policy Text Block]	(f) Changes to Significant Accounting Policies Our significant accounting policies are described in Note 2 of the notes to the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 27, 2024. There have been no changes to those policies.
New Accounting Pronouncements, Policy [Policy Text Block]	(g) Recent Accounting Pronouncements Recent accounting pronouncements issued by the Financial Accounting Standards Board (FASB), including its Emerging Issues Task Force, did not or are not believed by management to have a material impact on our financial statement presentation or disclosures.

Note 3 - Fair Value Measureme_2

Note 3 - Fair Value Measurement (Tables)	9 Months Ended
Note 3 - Fair Value Measurement (Tables)	Sep. 30, 2024
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	As of September 30, 2024 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 2 $ — $ — $ 2 Cash in savings account — — — 4,739 Cash in checking account — — — 189 Total cash and cash equivalents $ 2 $ — $ — $ 4,930 As of December 31, 2023 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 2 $ — $ — $ 2 Cash in savings account — — — 1,072 Cash in checking account — — — 29 Total cash and cash equivalents $ 2 $ — $ — $ 1,103

Note 4 - Property and Equipme_2

Note 4 - Property and Equipment, Net (Tables)	9 Months Ended
Note 4 - Property and Equipment, Net (Tables)	Sep. 30, 2024
Notes Tables
Property, Plant and Equipment [Table Text Block]	September 30, December 31, 2024 2023 Computer equipment and software $ 165 $ 161 Laboratory and manufacturing equipment 575 574 Furniture and fixtures 27 27 Leasehold improvements 26 26 Property and equipment, gross 793 788 Less accumulated depreciation (746 ) (694 ) Property and equipment, net $ 47 $ 94

Note 5 - Operating Lease Righ_2

Note 5 - Operating Lease Right-of-use Asset, Net (Tables)	9 Months Ended
Note 5 - Operating Lease Right-of-use Asset, Net (Tables)	Sep. 30, 2024
Notes Tables
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]	Remainder of 2024 $ 121 2025 499 2026 514 2027 44 Total undiscounted lease payments 1,178 Less imputed interest 133 Total operating lease liabilities $ 1,045

Note 6 - Accrued Expenses and_2

Note 6 - Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2024
Notes Tables
Schedule of Accrued Liabilities and Other Current Liabilities [Table Text Block]	September 30, December 31, 2024 2023 Accrued expenses $ 28 $ 75 Accrued salaries and employee benefits 736 661 Accrued clinical trial costs 597 1,017 Grant liability 470 471 Customer deposits 69 90 Payable to related party — 71 Total $ 1,900 $ 2,385

Note 7 - Stockholders' Equity (

Note 7 - Stockholders' Equity (Tables)	9 Months Ended
Note 7 - Stockholders' Equity (Tables)	Sep. 30, 2024
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Number of Weighted Common Stock Average Equivalents Exercise Price Balance as of December 31, 2023 141,889 $ 94.50 Warrants for common stock sold 2,467,104 3.10 Warrants expired (141,889 ) 94.50 Balance as of September 30, 2024 2,467,104 $ 3.10

Note 8 - Share-based Compensa_2

Note 8 - Share-based Compensation (Tables)	9 Months Ended
Note 8 - Share-based Compensation (Tables)	Sep. 30, 2024
Notes Tables
Schedule of Share-based Compensation, Expense [Table Text Block]	Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Research and development $ 98 $ 118 $ 315 $ 391 Selling, general and administrative 79 133 250 455 Total share-based compensation $ 177 $ 251 $ 565 $ 846
Share-Based Payment Arrangement, Option, Activity [Table Text Block]	Number of shares Weighted average exercise price Weighted average remaining contractual term (years) Aggregate intrinsic value Balance, December 31, 2023 165,784 $ 52.67 6.8 $ 43 Stock options forfeited (3,177 ) 33.97 Stock options expired (9,317 ) 63.09 Balance, September 30, 2024 153,290 $ 52.43 6.5 $ — Exercisable, September 30, 2024 109,830 $ 63.83 5.8 $ —

Note 9 - Net Loss Per Share (Ta

Note 9 - Net Loss Per Share (Tables)	9 Months Ended
Note 9 - Net Loss Per Share (Tables)	Sep. 30, 2024
Notes Tables
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	September 30, 2024 2023 Stock options to purchase common stock 153,290 162,934 Common stock warrants 2,467,104 161,648 Total 2,620,394 324,582

Note 2 - Significant Accounti_2

Note 2 - Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Retained Earnings (Accumulated Deficit)	$ (157,825)	$ (152,175)
Cash and Cash Equivalents, at Carrying Value	$ 4,930	$ 1,103
Cash, Percentage Held in One Financial Institution	99%
Cash, Uninsured Amount	$ 4,600

Note 3 - Fair Value Measureme_3

Note 3 - Fair Value Measurement - Fair Value of Assets Measured on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Total cash and cash equivalents	$ 4,930	$ 1,103
Fair Value, Inputs, Level 1 [Member]
Total cash and cash equivalents	2	2
Fair Value, Inputs, Level 2 [Member]
Total cash and cash equivalents	0	0
Fair Value, Inputs, Level 3 [Member]
Total cash and cash equivalents	0	0
Money Market Funds [Member]
Total cash and cash equivalents	2	2
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Total cash and cash equivalents	2	2
Money Market Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Total cash and cash equivalents	0	0
Money Market Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Total cash and cash equivalents	0	0
Savings Account [Member]
Total cash and cash equivalents	4,739	1,072
Savings Account [Member] \| Fair Value, Inputs, Level 1 [Member]
Total cash and cash equivalents	0	0
Savings Account [Member] \| Fair Value, Inputs, Level 2 [Member]
Total cash and cash equivalents	0	0
Savings Account [Member] \| Fair Value, Inputs, Level 3 [Member]
Total cash and cash equivalents	0	0
Demand Deposits [Member]
Total cash and cash equivalents	189	29
Demand Deposits [Member] \| Fair Value, Inputs, Level 1 [Member]
Total cash and cash equivalents	0	0
Demand Deposits [Member] \| Fair Value, Inputs, Level 2 [Member]
Total cash and cash equivalents	0	0
Demand Deposits [Member] \| Fair Value, Inputs, Level 3 [Member]
Total cash and cash equivalents	$ 0	$ 0

Note 4 - Property and Equipme_3

Note 4 - Property and Equipment, Net (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Depreciation	$ 16,000	$ 21,000	$ 52,000	$ 64,000

Note 4 - Property and Equipme_4

Note 4 - Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property and equipment, gross	$ 793	$ 788
Less accumulated depreciation	(746)	(694)
Property and equipment, net	47	94
Computer Equipment and Software [Member]
Property and equipment, gross	165	161
Laboratory and Manufacturing Equipment [Member]
Property and equipment, gross	575	574
Furniture and Fixtures [Member]
Property and equipment, gross	27	27
Leasehold Improvements [Member]
Property and equipment, gross	$ 26	$ 26

Note 5 - Operating Lease Righ_3

Note 5 - Operating Lease Right-of-use Asset, Net (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Lease, Payments	$ 121,000	$ 121,000	$ 362,000	$ 362,000
Operating Lease, Payments	$ 122,000	$ 117,000	$ 364,000	$ 353,000
Operating Lease, Weighted Average Remaining Lease Term	2 years 4 months 2 days		2 years 4 months 2 days
Operating Lease, Weighted Average Discount Rate, Percent	10.74%		10.74%

Note 5 - Operating Lease Righ_4

Note 5 - Operating Lease Right-of-use Asset, Net - Future Minimum Lease Payments Under Operating Lease (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Remainder of 2024	$ 121
2025	499
2026	514
2027	44
Total undiscounted lease payments	1,178
Less imputed interest	133
Total operating lease liabilities	$ 1,045

Note 6 - Accrued Expenses and_3

Note 6 - Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accrued expenses	$ 28	$ 75
Accrued salaries and employee benefits	736	661
Accrued clinical trial costs	597	1,017
Grant liability	470	471
Customer deposits	69	90
Total	1,900	2,385
Related Party [Member]
Payable to related party	$ 0	$ 71

Note 7 - Stockholders' Equity_2

Note 7 - Stockholders' Equity (Details Textual)						3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
Note 7 - Stockholders' Equity (Details Textual)	Sep. 03, 2024 USD ($) $ / shares shares	Aug. 29, 2024 $ / shares shares	May 30, 2024	Feb. 09, 2024 USD ($) $ / shares shares	Apr. 12, 2022 USD ($)	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 USD ($) shares	Jun. 30, 2023 USD ($) shares	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 06, 2023
Common Stock, Shares Authorized (in shares) \| shares						50,000,000			50,000,000		100,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) \| $ / shares						$ 0.001			$ 0.001		$ 0.001
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares						$ 3.1			$ 3.1		$ 94.5
Payments of Stock Issuance Costs \| $									$ 1,228,000	$ 435,000
Proceeds from Issuance of Common Stock \| $									$ 10,513,000	$ 3,042,000
Common Warrants With Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares		1,377,990				2,400,000			2,400,000
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares	$ 3	$ 3
Common Warrants With Stock [Member] \| Company Directors and Executive Officers [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares		211,000
Common Warrants Issued With Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares		1,022,010
Prefunded Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares		1,022,010
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares		$ 2.999
Warrants To Purchase Common Stock [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares				67,104
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares				$ 6.6
Common Stock In 2024 Agreement [Member]
Stock Issued During Period, Shares, New Issues \| shares		1,377,990
Common Stock, Par or Stated Value Per Share (in dollars per share) \| $ / shares		$ 0.001
Common Warrants With Stock [Member]
Stock Issued During Period, Shares, New Issues \| shares	2,400,000
September 2024 Financing [Member]
Proceeds from Issuance or Sale of Equity \| $	$ 7,200,000
Payments of Stock Issuance Costs \| $	$ 926,000
September 2024 Financing [Member] \| Company Directors and Executive Officers [Member]
Stock Issued During Period, Shares, New Issues \| shares									211,000
February 2024 Financing [Member]
Stock Issued During Period, Shares, New Issues \| shares				134,199
Proceeds from Issuance or Sale of Equity \| $				$ 875,000
Payments of Stock Issuance Costs \| $				$ 43,000
Sales Agreement with Cantor Fitzgerald Co (Cantor) [Member]
Stock Issued During Period, Shares, New Issues \| shares						0	2,219	11,209	412,239
Payments of Stock Issuance Costs \| $						$ 0	$ 48,000	$ 90,000	$ 103,000
Sale of Stock, Aggregate Value, Maximum \| $					$ 10,500,000
Accrued Sales Commission, Current, Percentage					3%
Proceeds from Issuance of Common Stock \| $						0	$ 93,000	$ 395,000	2,400,000
Sales Agreement With H.C. Wainwright & Co., LLC [Member]
Sale of Stock, Aggregate Value, Maximum \| $											$ 2,750,000
Accrued Sales Commission, Current, Percentage												3%
Sale of Stock, Available Value \| $						$ 264,000			$ 264,000
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio			15

Note 7 - Stockholders' Equity -

Note 7 - Stockholders' Equity - Warrants (Details)	9 Months Ended
Note 7 - Stockholders' Equity - Warrants (Details)	Sep. 30, 2024 $ / shares shares
Balance , number of common stock warrants (in shares) \| shares	141,889
Balance, weighted average exercise price (in dollars per share) \| $ / shares	$ 94.5
Warrants for common stock sold , number of common stock warrants (in shares) \| shares	2,467,104
Warrants for common stock sold, weighted average exercise price (in dollars per share) \| $ / shares	$ 3.1
Warrants expired (in shares) \| shares	(141,889)
Warrants expired (in dollars per share) \| $ / shares	$ 94.5
Balance , number of common stock warrants (in shares) \| shares	2,467,104
Balance as, weighted average exercise price (in dollars per share) \| $ / shares	$ 3.1

Note 8 - Share-based Compensa_3

Note 8 - Share-based Compensation (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Restricted Stock Units (RSUs) [Member]
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount	$ 0	$ 0
Employees, Non-employees and Non-employee Directors [Member]
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount	$ 837,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 9 months 18 days

Note 8 - Share-based Compensa_4

Note 8 - Share-based Compensation - Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Total share-based compensation	$ 177	$ 251	$ 565	$ 846
Research and Development Expense [Member]
Total share-based compensation	98	118	315	391
Selling, General and Administrative Expenses [Member]
Total share-based compensation	$ 79	$ 133	$ 250	$ 455

Note 8 - Share-based Compensa_5

Note 8 - Share-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Balance, number of shares (in shares)		165,784
Balance, weighted average exercise price (in dollars per share)		$ 52.67
Balance, weighted average remaining contractual term (Year)	6 years 6 months	6 years 9 months 18 days
Balance, aggregate intrinsic value	$ 0	$ 43
Stock options granted, number of shares (in shares)	3,177
Stock options granted, weighted average exercise price (in dollars per share)	$ 33.97
Stock options expired (in shares)	(9,317)
Stock options expired (in dollars per share)	$ 63.09
Balance, number of shares (in shares)	153,290
Balance, weighted average exercise price (in dollars per share)	$ 52.43
Exercisable, number of shares (in shares)	109,830
Exercisable, weighted average exercise price (in dollars per share)	$ 63.83
Exercisable, weighted average remaining contractual term (Year)	5 years 9 months 18 days
Exercisable, aggregate intrinsic value	$ 0

Note 9 - Net Loss Per Share - A

Note 9 - Net Loss Per Share - Anti-dilutive Securities (Details) - shares	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Antidilutive securities (in shares)	2,620,394	324,582
Share-Based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	153,290	162,934
Warrant [Member]
Antidilutive securities (in shares)	2,467,104	161,648

Note 10 - Income Taxes (Details

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Expense (Benefit)	$ 0	$ 0	$ 0	$ 0

Note 11 - Related Party Trans_2

Note 11 - Related Party Transactions (Details Textual) - Funding Agreement [Member] - BSLF, L.L.C. [Member] - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2022	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Legal Fees	$ 688,000
Maximum Discount on Legal Service	$ 300,000
Litigation Service, Expense		$ 0	$ 57,000	$ 42,000	$ 110,000
Other Liabilities, Current		$ 0		$ 0		$ 71,000