BioCardia (BCDA) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 01, 2021
Document Information [Line Items]
Entity Central Index Key	0000925741
Entity Registrant Name	BioCardia, Inc.
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-38999
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2753988
Entity Address, Address Line One	125 Shoreway Road, Suite B
Entity Address, City or Town	San Carlos
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94070
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
Entity Common Stock, Shares Outstanding		16,871,265
Warrant [Member]
Document Information [Line Items]
Title of 12(b) Security	Warrant to Purchase Common Stock
Trading Symbol	BCDAW
Security Exchange Name	NASDAQ
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.001
Trading Symbol	BCDA
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 15,888	$ 21,407
Accounts receivable, net of allowance for doubtful accounts of $15 and $16 as of September 30, 2021 and December 31, 2020	198	232
Prepaid expenses and other current assets	358	401
Other receivable due from related party	562	618
Total current assets	17,006	22,658
Property and equipment, net	175	145
Operating lease right-of-use asset, net	149	567
Other assets	0	54
Total assets	17,330	23,424
Current liabilities:
Accounts payable	846	746
Accrued expenses and other current liabilities	2,025	2,205
Deferred revenue	886	683
Operating lease liability - current	161	614
Total liabilities	3,918	4,248
Commitments and contingencies (Notes 2, 5 and 12)
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized as of September 30, 2021 and December 31, 2020; no shares issued and outstanding as of September 30, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value, 100,000,000 shares authorized as of September 30, 2021 and December 31, 2020; 16,871,265 and 16,297,381 shares issued and outstanding as of September 30, 2021 and December 31, 2020	17	16
Additional paid-in capital	138,631	135,234
Accumulated deficit	(125,236)	(116,074)
Total stockholders’ equity	13,412	19,176
Total liabilities and stockholders’ equity	$ 17,330	$ 23,424

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Allowance for doubtful accounts	$ 15	$ 16
Preferred stock, par value (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 value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	16,871,265	16,297,381
Common stock, shares outstanding (in shares)	16,871,265	16,297,381

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Total revenue	$ 821	$ 34	$ 936	$ 99
Costs and expenses:
Cost of goods sold	0	0	0	4
Research and development	2,240	2,474	6,443	7,484
Selling, general and administrative	1,289	1,408	3,662	4,642
Total costs and expenses	3,529	3,882	10,105	12,130
Operating loss	(2,708)	(3,848)	(9,169)	(12,031)
Other income (expense):
Interest income	2	1	8	19
Other expense	0	(1)	(1)	(3)
Total other income (expense), net	2	0	7	16
Net loss	$ (2,706)	$ (3,848)	$ (9,162)	$ (12,015)
Net loss per share, basic and diluted (in dollars per share)	$ (0.16)	$ (0.30)	$ (0.54)	$ (1.33)
Weighted-average shares used in computing net loss per share, basic and diluted (in shares)	17,066,068	12,618,285	16,867,652	9,059,433
Product [Member]
Revenue:
Total revenue	$ 1	$ 8	$ 1	$ 13
Collaboration Agreement [Member]
Revenue:
Total revenue	$ 820	$ 26	$ 935	$ 86

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Restricted Stock Units (RSUs) [Member]Board of Directors [Member]Additional Paid-in Capital [Member]	Restricted Stock Units (RSUs) [Member]Board of Directors [Member]	Restricted Stock Units (RSUs) [Member]Management [Member]Additional Paid-in Capital [Member]	Restricted Stock Units (RSUs) [Member]Management [Member]	Restricted Stock Units (RSUs) [Member]Common Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2019						6,825,183
Balance at Dec. 31, 2019						$ 7	$ 103,433	$ (101,070)	$ 2,370
Restricted stock units vested and issued (in shares)						23,172
Share-based compensation							941		941
Net loss								(4,594)	(4,594)
Balance (in shares) at Mar. 31, 2020						6,848,355
Share-based compensation							941		941
Balance at Mar. 31, 2020						$ 7	104,374	(105,664)	(1,283)
Balance (in shares) at Dec. 31, 2019						6,825,183
Balance at Dec. 31, 2019						$ 7	103,433	(101,070)	2,370
Net loss									(12,015)
Balance (in shares) at Sep. 30, 2020						12,428,794
Balance at Sep. 30, 2020						$ 12	117,186	(113,085)	4,113
Balance (in shares) at Mar. 31, 2020						6,848,355
Balance at Mar. 31, 2020						$ 7	104,374	(105,664)	(1,283)
Restricted stock units vested and issued (in shares)						71,624
Sale of common stock (in shares)						5,476,190
Sale of common stock						$ 5	10,335		10,340
Share-based compensation							655		655
Net loss						$ 0		(3,573)	(3,573)
Restricted stock units issued to settle management bonus obligations	$ 613	$ 613	$ 391	$ 391
Balance (in shares) at Jun. 30, 2020						12,425,794
Stock grants to former directors (in shares)						29,625
Stock grants to former directors							148		148
Share-based compensation							655		655
Issuance costs from sale of common stock in prior quarter									(1,160)
Balance at Jun. 30, 2020						$ 12	116,516	(109,237)	7,291
Restricted stock units vested and issued (in shares)						3,000
Share-based compensation							737		737
Net loss								(3,848)	(3,848)
Balance (in shares) at Sep. 30, 2020						12,428,794
Share-based compensation							737		737
Issuance costs from sale of common stock in prior quarter							(67)		(67)
Balance at Sep. 30, 2020						$ 12	117,186	(113,085)	4,113
Balance (in shares) at Dec. 31, 2020						16,297,381
Balance at Dec. 31, 2020						$ 16	135,234	(116,074)	19,176
Restricted stock units vested and issued (in shares)					40,100
Sale of common stock (in shares)						453,832
Sale of common stock						$ 1			1,934
Exercise of common stock options (in shares)						1,580
Exercise of common stock options							5		5
Share-based compensation							416		416
Net loss								(2,969)	(2,969)
Balance (in shares) at Mar. 31, 2021						16,792,893
Share-based compensation							416		416
Balance at Mar. 31, 2021						$ 17	137,588	(119,043)	18,562
Balance (in shares) at Dec. 31, 2020						16,297,381
Balance at Dec. 31, 2020						$ 16	135,234	(116,074)	$ 19,176
Exercise of common stock options (in shares)									1,580
Net loss									$ (9,162)
Balance (in shares) at Sep. 30, 2021						16,871,265
Balance at Sep. 30, 2021						$ 17	138,631	(125,236)	13,412
Balance (in shares) at Mar. 31, 2021						16,792,893
Balance at Mar. 31, 2021						$ 17	137,588	(119,043)	18,562
Restricted stock units vested and issued (in shares)					78,372
Share-based compensation							384		384
Net loss								(3,487)	(3,487)
Restricted stock units issued to settle management bonus obligations							214		214
Balance (in shares) at Jun. 30, 2021						16,871,265
Share-based compensation							384		384
Balance at Jun. 30, 2021						$ 17	138,186	(122,530)	15,673
Share-based compensation							437		437
Net loss								(2,706)	(2,706)
Balance (in shares) at Sep. 30, 2021						16,871,265
Refund of issuance costs on sale of common stock							8		8
Share-based compensation							437		437
Balance at Sep. 30, 2021						$ 17	$ 138,631	$ (125,236)	$ 13,412

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Jun. 30, 2020
Issuance costs	$ 67	$ 1,160

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities:
Net loss	$ (9,162)	$ (12,015)
Adjustments to reconcile net loss to net cash used in operating activities:
Write-off of inventory	0	3
Depreciation	45	52
Reduction in the carrying amount of right-of-use assets	418	368
Non-cash board compensation expense	0	115
Share-based compensation	1,237	2,333
Changes in operating assets and liabilities:
Accounts receivable	34	(157)
Inventory	0	1
Prepaid expenses and other current assets	97	510
Other receivable due from related party	56	(762)
Accounts payable	100	294
Accrued liabilities and other current liabilities	34	715
Deferred revenue	203	(8)
Operating lease liability - current	(453)	64
Operating lease liability - noncurrent	0	(453)
Net cash used in operating activities	(7,391)	(8,940)
Investing activities:
Purchase of property and equipment	(75)	(32)
Net cash used in investing activities	(75)	(32)
Financing activities:
Proceeds from sales of common stock	2,001	11,500
Issuance costs of sale of common stock	(59)	(1,227)
Proceeds from note payable	0	506
Proceeds from exercise of common stock options	5	0
Net cash provided by financing activities	1,947	10,779
Net change in cash and cash equivalents	(5,519)	1,807
Cash and cash equivalents at beginning of period	21,407	5,585
Cash and cash equivalents at end of period	15,888	7,392
Supplemental disclosure for noncash investing and financing activities:
Issuance of restricted stock units in lieu of cash bonus obligations	393	391
Issuance of restricted stock units in lieu of board cash compensation obligations	0	613
Issuance of common stock in lieu of board cash compensation obligations	0	148
Non-cash interest expense accretion to loan payable	$ 0	$ 2

Note 1 - Summary of Business an

Note 1 - Summary of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Business Description and Basis of Presentation [Text Block]	( 1 Summary of Business and Basis of Presentation (a) 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. The Company’s lead therapeutic candidate is the CardiAMP® Cell Therapy System, which provides an autologous bone marrow derived cell therapy for treatment in two second 1 BioCardia also has three 1 2 3

Note 2 - Significant Accounting

Note 2 - Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
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, and cash flows as of September 30, 2021 three nine September 30, 2021 2020 September 30, 2021, three nine September 30, 2021 2020, nine September 30, 2021 2020. three nine September 30, 2021 not December 31, 2021 These condensed consolidated financial statements should be read in conjunction with the audited financial statements and related notes included in the Company’s Annual Report on Form 10 December 31, 2020, March 30, 2021. (b) Liquidity and Other Risks and Uncertainties Liquidity September 30, 2021. September 30, 2021 12 10 (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 share-based compensation, the useful lives of property and equipment, right-of-use assets and related liabilities, incremental borrowing rate, allowances for doubtful accounts and sales returns, derivative instruments, clinical accruals, inventory valuation, 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) Changes to Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 10 March 30, 2021 December 31, 2020. no (f) Recent Accounting Pronouncements Recent accounting pronouncements issued by the Financial Accounting Standards Board (FASB), including its Emerging Issues Task Force did not not

Note 3 - Fair Value Measurement

Note 3 - Fair Value Measurement	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Fair Value Disclosures [Text Block]	( 3 Fair Value Measurement The fair value of financial instruments reflects the amounts that the Company estimates 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). The Company follows a fair value hierarchy that prioritizes the use of inputs used in valuation techniques into the following three Level 1 Level 2 not Level 3 no The following table shows the fair value of its financial assets measured on a recurring basis as of September 30, 2021 December 31, 2020 As of September 30, 2021 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 15,746 $ — $ — $ 15,746 Cash in checking account — — — 142 Total cash and cash equivalents $ 15,746 $ — $ — $ 15,888 As of December 31, 2020 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 20,662 $ — $ — $ 20,662 Cash in checking account — — — 745 Total cash and cash equivalents $ 20,662 $ — $ — $ 21,407

Note 4 - Property and Equipment

Note 4 - Property and Equipment, Net	9 Months Ended
	Sep. 30, 2021
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, 2021 2020 Computer equipment and software $ 188 $ 159 Laboratory and manufacturing equipment 574 550 Furniture and fixtures 59 59 Leasehold improvements 332 332 Construction in progress 92 70 Property and equipment, gross 1,245 1,170 Less accumulated depreciation (1,070 ) (1,025 ) Property and equipment, net $ 175 $ 145 Depreciation expense totaled $15,000 and $45,000 for the three nine September 30, 2021, three nine September 30, 2020,

Note 5 - Operating Lease Right-

Note 5 - Operating Lease Right-of-use Asset, Net	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Lessee, Operating Leases [Text Block]	( 5 Operating Lease Right-of-Use Asset, Net The Company’s operating lease is a property lease for its laboratory and corporate offices. BioCardia’s lease agreement does not Right-of-use (ROU) assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company’s lease does not not no The lease expense for the three nine September 30, 2021 three nine September 30, 2020 three nine September 30, 2021 three nine September 30, 2020 September 30, 2021, Future minimum lease payments under the operating lease as of September 30, 2021 Operating Lease September 30, 2021 Remainder of 2021 Total undiscounted lease payments $ 162 Less imputed interest 1 Total operating lease liabilities $ 161

Note 6 - Accrued Expenses and O

Note 6 - Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2021
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, 2021 2020 Accrued expenses $ 79 $ 87 Accrued salaries and employee benefits 900 961 Accrued clinical trial costs 350 452 Grant liability 600 615 Customer deposits 96 90 Total $ 2,025 $ 2,205

Note 7 - Stockholders' Equity

Note 7 - Stockholders' Equity	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	( 7 Stockholders Equity Warrants Number of Weighted Common Stock Average Warrants Exercise Price Balance, December 31, 2020 2,424,724 $ 6.36 Warrants for common stock sold — — Warrants for common stock exercised — — Balance, September 30, 2021 2,424,724 $ 6.36 Lincoln Park Capital stock purchase agreement - March 29, 2021, $20 Pursuant to the Purchase Agreement, Lincoln Park purchased 373,832 shares of common stock, at a price of $5.35 per share, for a total gross purchase price of $2 million (the Initial Purchase) and the Company issued 80,000 shares of common stock as commitment shares, which included 5,000 commitment shares issued on a pro rata basis for the initial $2 one 36 not $2 may may may not may The Company controls the timing and amount of any sales of its common stock to Lincoln Park. There is no no may $4.2736 may not 9.99% The Purchase Agreement does not 36 may not may no As of September 30, 2021, not

Note 8 - Share-based Compensati

Note 8 - Share-based Compensation	9 Months Ended
	Sep. 30, 2021
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 three nine September 30, 2021 2020 Three months ended Nine months ended September 30, September 30, 2021 2020 2021 2020 Research and development $ 196 $ 357 $ 613 $ 1,088 Selling, general and administrative 241 380 624 1,245 Total share-based compensation $ 437 $ 737 $ 1,237 $ 2,333 On January 29, 2020 ( No The repricing on January 29, 2020 three The following table summarizes the activity of stock options and related information: Options outstanding Number of shares Weighted average exercise price Weighted average remaining contractual term (years) Aggregate intrinsic value (in thousands) Balance, December 31, 2020 1,114,306 $ 5.89 7.5 $ 177.1 Stock options granted 772,435 3.56 Stock options exercised (1,580 ) 2.49 Stock options forfeited (200,970 ) 4.71 Stock options expired (125 ) 5.32 Balance, September 30, 2021 1,684,066 $ 4.97 8.1 $ 118.9 Exercisable, September 30, 2021 691,317 $ 6.91 6.4 $ 34.9 Unrecognized share-based compensation for employee and nonemployee options granted through September 30, 2021 Share-Based Compensation (RSUs) The following summarizes the activity of non-vested RSUs: Weighted average grant date Number of fair value shares per share Balance, December 31, 2020 224,311 $ 4.12 RSUs granted 131,375 3.61 RSUs released (118,472 ) 3.73 RSUs forfeited (36,943 ) 3.49 Balance, September 30, 2021 200,271 $ 4.13 Of the 200,271 RSUs outstanding on September 30, 2021, not not September 30, 2021

Note 9 - Net Loss Per Share

Note 9 - Net Loss Per Share	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Earnings Per Share [Text Block]	( 9 Net Loss per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of common shares outstanding for the period. 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. For all periods presented, there is no 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, 2021 2020 Stock options to purchase common stock 1,684,066 1,078,813 Unvested restricted stock units 5,468 8,200 Common stock warrants 2,424,724 2,435,807 Total 4,114,258 3,522,820

Note 10 - Income Taxes

Note 10 - Income Taxes	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Income Tax Disclosure [Text Block]	( 10 Income Taxes During the three nine September 30, 2021 2020, As of September 30, 2021, not not

Note 11 - Related Party Transac

Note 11 - Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	( 11 Related Party Transactions On April 9, 2020, No. 3:19 05645 Under the terms of the Funding Agreement, the Funder agreed to fund the legal fees and costs incurred by the Company in connection with the Litigation on and after March 1, 2020 (a) 50% of the remaining Litigation Proceeds, up to three (b) 30% of the remaining Litigation Proceeds. Although the Company is required under the terms of the Funding Agreement to consult with the Funder regarding any settlement in connection with the Litigation and to allow Funder to participate in any real-time settlement negotiations, the Company has the sole and exclusive right to settle on whatever terms it deems acceptable. On April 12, 2021, not September 30, 2021.

Note 12 - Contingencies and Unc

Note 12 - Contingencies and Uncertainties	9 Months Ended
	Sep. 30, 2021
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	( 12 Contingencies and Uncertainties Contingencies may not Uncertainties three nine September 30, 2021 not December 31, 2021 19, 19, While the direct effects of the virus and these responses on our workforce have largely been mitigated, the overall impact of the pandemic has resulted in significant disruption to the Company’s business and in delays in the Company’s development programs and regulatory and commercial timelines. These factors may third may may may

Significant Accounting Policies

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
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, and cash flows as of September 30, 2021 three nine September 30, 2021 2020 September 30, 2021, three nine September 30, 2021 2020, nine September 30, 2021 2020. three nine September 30, 2021 not December 31, 2021 These condensed consolidated financial statements should be read in conjunction with the audited financial statements and related notes included in the Company’s Annual Report on Form 10 December 31, 2020, March 30, 2021.
Liquidity and Other Risks and Uncertainties, Policy [Policy Text Block]	(b) Liquidity and Other Risks and Uncertainties Liquidity September 30, 2021. September 30, 2021 12 10
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 share-based compensation, the useful lives of property and equipment, right-of-use assets and related liabilities, incremental borrowing rate, allowances for doubtful accounts and sales returns, derivative instruments, clinical accruals, inventory valuation, 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.
Change to Significant Accounting Policies [Policy Text Block]	(e) Changes to Significant Accounting Policies The Company’s significant accounting policies are described in Note 2 10 March 30, 2021 December 31, 2020. no
New Accounting Pronouncements, Policy [Policy Text Block]	(f) Recent Accounting Pronouncements Recent accounting pronouncements issued by the Financial Accounting Standards Board (FASB), including its Emerging Issues Task Force did not not

Note 3 - Fair Value Measureme_2

Note 3 - Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	As of September 30, 2021 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 15,746 $ — $ — $ 15,746 Cash in checking account — — — 142 Total cash and cash equivalents $ 15,746 $ — $ — $ 15,888 As of December 31, 2020 Level 1 Level 2 Level 3 Total Assets: Money market funds $ 20,662 $ — $ — $ 20,662 Cash in checking account — — — 745 Total cash and cash equivalents $ 20,662 $ — $ — $ 21,407

Note 4 - Property and Equipme_2

Note 4 - Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Property, Plant and Equipment [Table Text Block]	September 30, December 31, 2021 2020 Computer equipment and software $ 188 $ 159 Laboratory and manufacturing equipment 574 550 Furniture and fixtures 59 59 Leasehold improvements 332 332 Construction in progress 92 70 Property and equipment, gross 1,245 1,170 Less accumulated depreciation (1,070 ) (1,025 ) Property and equipment, net $ 175 $ 145

Note 5 - Operating Lease Righ_2

Note 5 - Operating Lease Right-of-use Asset, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Operating Lease September 30, 2021 Remainder of 2021 Total undiscounted lease payments $ 162 Less imputed interest 1 Total operating lease liabilities $ 161

Note 6 - Accrued Expenses and_2

Note 6 - Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Schedule of Accrued Liabilities and Other Current Liabilities [Table Text Block]	September 30, December 31, 2021 2020 Accrued expenses $ 79 $ 87 Accrued salaries and employee benefits 900 961 Accrued clinical trial costs 350 452 Grant liability 600 615 Customer deposits 96 90 Total $ 2,025 $ 2,205

Note 7 - Stockholders' Equity (

Note 7 - Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Number of Weighted Common Stock Average Warrants Exercise Price Balance, December 31, 2020 2,424,724 $ 6.36 Warrants for common stock sold — — Warrants for common stock exercised — — Balance, September 30, 2021 2,424,724 $ 6.36

Note 8 - Share-based Compensa_2

Note 8 - Share-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Schedule of Share-based Compensation, Expense [Table Text Block]	Three months ended Nine months ended September 30, September 30, 2021 2020 2021 2020 Research and development $ 196 $ 357 $ 613 $ 1,088 Selling, general and administrative 241 380 624 1,245 Total share-based compensation $ 437 $ 737 $ 1,237 $ 2,333
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Options outstanding Number of shares Weighted average exercise price Weighted average remaining contractual term (years) Aggregate intrinsic value (in thousands) Balance, December 31, 2020 1,114,306 $ 5.89 7.5 $ 177.1 Stock options granted 772,435 3.56 Stock options exercised (1,580 ) 2.49 Stock options forfeited (200,970 ) 4.71 Stock options expired (125 ) 5.32 Balance, September 30, 2021 1,684,066 $ 4.97 8.1 $ 118.9 Exercisable, September 30, 2021 691,317 $ 6.91 6.4 $ 34.9
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	Weighted average grant date Number of fair value shares per share Balance, December 31, 2020 224,311 $ 4.12 RSUs granted 131,375 3.61 RSUs released (118,472 ) 3.73 RSUs forfeited (36,943 ) 3.49 Balance, September 30, 2021 200,271 $ 4.13

Note 9 - Net Loss Per Share (Ta

Note 9 - Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Notes Tables
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	September 30, 2021 2020 Stock options to purchase common stock 1,684,066 1,078,813 Unvested restricted stock units 5,468 8,200 Common stock warrants 2,424,724 2,435,807 Total 4,114,258 3,522,820

Note 2 - Significant Accounti_2

Note 2 - Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Retained Earnings (Accumulated Deficit), Ending Balance	$ (125,236)	$ (116,074)
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 15,888	$ 21,407

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, 2021	Dec. 31, 2020
Cash and Cash Equivalents, Fair Value	$ 15,888	$ 21,407
Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value	15,746	20,662
Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value	142	745
Fair Value, Inputs, Level 1 [Member]
Cash and Cash Equivalents, Fair Value	15,746	20,662
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value	15,746	20,662
Fair Value, Inputs, Level 1 [Member] | Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value	0	0
Fair Value, Inputs, Level 2 [Member]
Cash and Cash Equivalents, Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value	0	0
Fair Value, Inputs, Level 3 [Member]
Cash and Cash Equivalents, Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value	$ 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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Depreciation, Total	$ 15,000	$ 15,000	$ 45,000	$ 52,000

Note 4 - Property and Equipme_4

Note 4 - Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property and equipment, gross	$ 1,245	$ 1,170
Less accumulated depreciation	(1,070)	(1,025)
Property and equipment, net	175	145
Computer Equipment and Software [Member]
Property and equipment, gross	188	159
Laboratory and Manufacturing Equipment [Member]
Property and equipment, gross	574	550
Furniture and Fixtures [Member]
Property and equipment, gross	59	59
Leasehold Improvements [Member]
Property and equipment, gross	332	332
Construction in Progress [Member]
Property and equipment, gross	$ 92	$ 70

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Lease, Expense	$ 150,000	$ 150,000	$ 451,000	$ 451,000
Operating Lease, Payments	$ 162,000	$ 158,000	$ 486,000	$ 473,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	3 months		3 months
Operating Lease, Weighted Average Discount Rate, Percent	12.05%		12.05%

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, 2021USD ($)
Total undiscounted lease payments	$ 162
Less imputed interest	1
Total operating lease liabilities	$ 161

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, 2021	Dec. 31, 2020
Accrued expenses	$ 79	$ 87
Accrued salaries and employee benefits	900	961
Accrued clinical trial costs	350	452
Grant liability	600	615
Customer deposits	96	90
Total	$ 2,025	$ 2,205

Note 7 - Stockholders' Equity_2

Note 7 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	Mar. 29, 2021	Sep. 30, 2021	Sep. 30, 2020
Proceeds from Issuance of Common Stock		$ 2,001	$ 11,500
Purchase Agreement with Lincoln Park [Member]
Sale of Stock, Aggregate Value, Maximum	$ 20,000
Stock Issuable, Shares, Commitment Fess (in shares)	75,000
Stock Issuable, Commitment Shares on Pro Rata Basis (in shares)	50,000
Stock Issued During Period, Shares, New Issues (in shares)	373,832	0
Shares Issued, Price Per Share (in dollars per share)	$ 5.35
Proceeds from Issuance of Common Stock	$ 2,000
Stock Issued During the Period, Shares, Commission Fees (in shares)	80,000
Stock Issued During the Period, Commitment Shares Issued on Pro Rata Basis (in shares)	5,000
Conditional Issuance, Maximum Number of Shares Allowed to be Purchased (in shares)	100,000
Stock Purchase Agreement Accelerated Purchase, Maximum, Percent of Shares Purchased on the Same Trading Day	300.00%
Stock Purchase Agreement Accelerated Purchase, Maximum, Percent of Total Common Shares Traded During Specified Period	30.00%
Maximum Number of Shares Allowed to be Issued Including Commitment Shares (in shares)	3,266,177
Percentage of Common Stock Outstanding	19.99%

Note 7 - Stockholders' Equity -

Note 7 - Stockholders' Equity - Warrants (Details)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Balance, beginning (in shares) | shares	2,424,724
Balance, beginning, weighted average exercise price (in dollars per share) | $ / shares	$ 6.36
Warrants for common stock sold (in shares) | shares	0
Warrants for common stock sold, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Warrants for common stock exercised (in shares) | shares	0
Warrants for common stock exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Balance, ending (in shares) | shares	2,424,724
Balance, ending, weighted average exercise price (in dollars per share) | $ / shares	$ 6.36

Note 8 - Share-based Compensa_3

Note 8 - Share-based Compensation (Details Textual) - USD ($)	Jan. 29, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 5.32				$ 3.56
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	515,036				772,435
Share-based Payment Arrangement, Expensed and Capitalized, Amount, Total	$ 569,000
Share-based Payment Arrangement, Expense	412,000	$ 437,000	$ 737,000		$ 1,237,000	$ 2,333,000
Share-based Payment Arrangement, Amount Capitalized	$ 157,000
Share-based Compensation Arrangement by Share-based Payment Award, Remaining Weighted Average Award Vesting Period (Year)	3 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares)					118,472
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)		200,271			200,271		224,311
Non-employee Directors and Employees [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 3			$ 3
Non-employee Directors and Employees [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)				2 years 10 months 24 days
Non-employee Directors and Employees [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 0.5			$ 0.5
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance (in shares)		200,271			200,271
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares)					194,803
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)		5,468			5,468
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount		$ 64,000			$ 64,000
Minimum [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 10.05
Maximum [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 97.21

Note 8 - Share-based Compensa_4

Note 8 - Share-based Compensation - Share-based Compensation Expense (Details) - USD ($)	Jan. 29, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based compensation expense	$ 412,000	$ 437,000	$ 737,000	$ 1,237,000	$ 2,333,000
Research and Development Expense [Member]
Share-based compensation expense		196,000	357,000	613,000	1,088,000
Selling, General and Administrative Expenses [Member]
Share-based compensation expense		$ 241,000	$ 380,000	$ 624,000	$ 1,245,000

Note 8 - Share-based Compensa_5

Note 8 - Share-based Compensation - Stock Option Activity (Details) - USD ($)	Jan. 29, 2020	Sep. 30, 2021	Dec. 31, 2020
Stock options outstanding, beginning of period (in shares)		1,114,306
Balance, weighted average exercise price, beginning of period (in dollars per share)		$ 5.89
Stock options outstanding, weighted average remaining contractual term (Year)		8 years 1 month 6 days	7 years 6 months
Stock options outstanding, aggregate intrinsic value		$ 118,900	$ 177,100
Stock options granted (in shares)	515,036	772,435
Stock options granted, weighted average exercise price (in dollars per share)	$ 5.32	$ 3.56
Stock options exercised (in shares)		(1,580)
Stock options exercised, weighted average exercise price (in dollars per share)		$ 2.49
Stock options forfeited (in shares)		(200,970)
Stock options forfeited, weighted average exercise price (in dollars per share)		$ 4.71
Stock options expired (in shares)		(125)
Stock options expired, weighted average exercise price (in dollars per share)		$ 5.32
Stock options outstanding, end of period (in shares)		1,684,066	1,114,306
Balance, weighted average exercise price, end of period (in dollars per share)		$ 4.97	$ 5.89
Exercisable, September 30, 2021 (in shares)		691,317
Options exercisable, weighted average exercise price (in dollars per share)		$ 6.91
Options exercisable, weighted average remaining contractual term (Year)		6 years 4 months 24 days
Options exercisable, aggregate intrinsic value		$ 34,900

Note 8 - Share-based Compensa_6

Note 8 - Share-based Compensation - Summary of Non-vested RSUs (Details) - Restricted Stock Units (RSUs) [Member]	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Balance, shares (in shares) | shares	224,311
Balance, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 4.12
RSUs granted, shares (in shares) | shares	131,375
RSUs granted, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 3.61
RSUs released, shares (in shares) | shares	(118,472)
RSUs released, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 3.73
RSUs forfeited, shares (in shares) | shares	(36,943)
RSUs forfeited, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 3.49
Balance, shares (in shares) | shares	200,271
Balance, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 4.13

Note 9 - Net Loss Per Share - A

Note 9 - Net Loss Per Share - Anti-dilutive Securities (Details) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive securities (in shares)	4,114,258	3,522,820
Share-based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	1,684,066	1,078,813
Restricted Stock Units (RSUs) [Member]
Antidilutive securities (in shares)	5,468	8,200
Warrant [Member]
Antidilutive securities (in shares)	2,424,724	2,435,807

Note 10 - Income Taxes (Details

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Expense (Benefit), Total	$ 0	$ 0	$ 0	$ 0

Note 11 - Related Party Trans_2

Note 11 - Related Party Transactions (Details Textual) - BSLF, L.L.C. [Member] - Funding Agreement [Member]	9 Months Ended
	Sep. 30, 2021USD ($)
Percentage of Remaining Litigation Proceeds Up to Three Times the Actual Funding Amount	50.00%
Percentage of Remaining Litigation Proceeds	30.00%
Due from Related Parties, Total	$ 562,000