BioCardia (BCDA) 10-Q 13 May 21 2021 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 01, 2021
Document Information [Line Items]
Entity Registrant Name	BioCardia, Inc.
Entity Central Index Key	0000925741
Trading Symbol	bcda
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)		16,792,893
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Title of 12(b) Security	Common Stock, par value $0.001

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 21,502	$ 21,407
Accounts receivable, net of allowance for doubtful accounts of $16 at both March 31, 2021 and December 31, 2020	190	232
Prepaid expenses and other current assets	344	401
Other receivable due from related party	623	618
Total current assets	22,659	22,658
Property and equipment, net	164	145
Operating lease right-of-use asset, net	432	567
Other assets	53	54
Total assets	23,308	23,424
Current liabilities:
Accounts payable	850	746
Accrued expenses and other current liabilities	2,248	2,205
Deferred revenue	1,180	683
Operating lease liability - current	468	614
Total liabilities	4,746	4,248
Stockholders’ equity:
Preferred stock, $0.001 par value, 25,000,000 shares authorized as of March 31, 2021 and December 31, 2020; no shares issued and outstanding as of March 31, 2021 and December 31, 2020
Common stock, $0.001 par value, 100,000,000 shares authorized as of March 31, 2021 and December 31, 2020; 16,792,893 and 16,297,381 shares issued and outstanding as of March 31, 2021 and December 31, 2020	17	16
Additional paid-in capital	137,588	135,234
Accumulated deficit	(119,043)	(116,074)
Total stockholders’ equity	18,562	19,176
Total liabilities and stockholders’ equity	$ 23,308	$ 23,424

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Allowance for doubtful accounts	$ 16	$ 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)	16,792,893	16,297,381
Common stock, shares outstanding (in shares)	16,792,893	16,297,381

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue:
Total revenue	$ 46	$ 38
Costs and expenses:
Cost of goods sold		4
Research and development	1,841	2,786
Selling, general and administrative	1,177	1,857
Total costs and expenses	3,018	4,647
Operating loss	(2,972)	(4,609)
Other income (expense):
Interest income	4	16
Other expense	(1)	(1)
Total other income (expense), net	3	15
Net loss	$ (2,969)	$ (4,594)
Net loss per share, basic and diluted (in dollars per share)	$ (0.18)	$ (0.67)
Weighted-average shares used in computing net loss per share, basic and diluted (in shares)	16,569,268	6,831,976
Product [Member]
Revenue:
Total revenue		$ 5
Collaboration Agreement [Member]
Revenue:
Total revenue	$ 46	$ 33

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Restricted Stock Units (RSUs) [Member]Common Stock [Member]	Restricted Stock Units (RSUs) [Member]Additional Paid-in Capital [Member]	Restricted Stock Units (RSUs) [Member]Retained Earnings [Member]	Restricted Stock Units (RSUs) [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)
Restricted stock units vested and issued
Balance (in shares) at Mar. 31, 2020					6,848,355
Balance at Mar. 31, 2020					$ 7	104,374	(105,664)	(1,283)
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	1,933		$ 1,934
Exercise of common stock options (in shares)					1,580			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
Balance at Mar. 31, 2021					$ 17	$ 137,588	$ (119,043)	$ 18,562

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net loss	$ (2,969)	$ (4,594)
Adjustments to reconcile net loss to net cash used in operating activities:
Write-off of inventory		3
Depreciation	14	22
Reduction in the carrying amount of right-of-use assets	135	118
Share-based compensation	416	941
Changes in operating assets and liabilities:
Accounts receivable	42	(32)
Inventory		1
Prepaid expenses and other current assets	57	189
Other receivable due from related party	(5)
Accounts payable	99	194
Accrued liabilities and other current liabilities	(23)	293
Deferred revenue	497	(2)
Operating lease liability - current	(146)	20
Operating lease liability - noncurrent		(146)
Net cash used in operating activities	(1,883)	(2,993)
Investing activities:
Purchase of property and equipment	(27)	(5)
Net cash used in investing activities	(27)	(5)
Financing activities:
Proceeds from sales of common stock	2,000
Proceeds from exercise of common stock options	5
Net cash provided by financing activities	2,005
Net change in cash and cash equivalents	95	(2,998)
Cash and cash equivalents at beginning of period	21,407	5,585
Cash and cash equivalents at end of period	21,502	2,587
Supplemental disclosure for noncash investing and financing activities:
Unpaid issuance costs of common stock	$ 66

Note 1 - Summary of Business an

Note 1 - Summary of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 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 regenerative medicine company developing novel therapeutics for cardiovascular and respiratory 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	3 Months Ended
	Mar. 31, 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 March 31, 2021 three March 31, 2021 2020 March 31, 2021, three March 31, 2021 2020, three March 31, 2021 2020. three March 31, 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 - $119.0 March 31, 2021. $21.5 March 31, 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. 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	3 Months Ended
	Mar. 31, 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 sets forth the fair value of its financial assets measured on a recurring basis as of March 31, 2021 December 31, 2020 As of March 31, 2021 Level 1 Level 2 Level 3 Total Assets Money market funds $ 20,583 $ — $ — $ 20,583 Cash in checking account — — — 919 Total cash and cash equivalents $ 20,583 $ — $ — $ 21,502 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	3 Months Ended
	Mar. 31, 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): March 31, December 31, 2021 2020 Computer equipment and software $ 166 $ 159 Laboratory and manufacturing equipment 574 550 Furniture and fixtures 59 59 Leasehold improvements 332 332 Construction in progress 72 70 Property and equipment, gross 1,203 1,170 Less accumulated depreciation (1,039 ) (1,025 ) Property and equipment, net $ 164 $ 145 Depreciation expense totaled approximately $14,000 $22,000 three March 31, 2021 2020,

Note 5 - Operating Lease Right-

Note 5 - Operating Lease Right-of-use Asset, Net	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 $150,000 three March 31, 2021 2020 $162,000 $158,000, March 31, 2021, 0.75 12.05%. Future minimum lease payments under the operating lease as of March 31, 2021 Operating Lease March 31, 2021 Remainder of 2021 $ 486 Total undiscounted lease payments 486 Less imputed interest 18 Total operating lease liabilities $ 468

Note 6 - Accrued Expenses and O

Note 6 - Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 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): March 31, December 31, 2021 2020 Accrued expenses $ 240 $ 87 Accrued salaries and employee benefits 851 961 Accrued clinical trial costs 457 452 Grant liability 610 615 Customer deposits 90 90 Total $ 2,248 $ 2,205

Note 7 - Stockholders' Equity

Note 7 - Stockholders' Equity	3 Months Ended
	Mar. 31, 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, March 31, 2021 2,424,724 $ 6.36 Lincoln Park Capital stock purchase agreement - March 29, 2021, $20 75,000 50,000 $20 Pursuant to the Purchase Agreement, Lincoln Park purchased 373,832 $5.35 $2 80,000 5,000 $2 one 36 100,000 not $2 may may may not 300% 30% may The Company controls the timing and amount of any sales of its common stock to Lincoln Park. There is no no may 3,266,177 19.99% $4.2736 may not 9.99% The Purchase Agreement does not 36 may not may no As of March 31, 2021, not

Note 8 - Share-based Compensati

Note 8 - Share-based Compensation	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Three Months ended March 31, 2021 2020 Research and development $ 206 $ 413 Selling, general and administrative 210 528 Total share-based compensation $ 416 $ 941 On January 29, 2020 ( $5.32 No 515,036 $10.05 $97.21, The repricing on January 29, 2020 $569,000, $412,000 $157,000 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 intrisinsic value (in thousands) Balance, December 31, 2020 1,114,306 $ 5.89 7.5 $ 177.1 Stock options granted 18,850 4.63 Stock options exercised (1,580 ) 2.49 Stock options forfeited (44,643 ) 4.30 Stock options expired (125 ) 5.32 Balance, March 31, 2021 1,086,808 $ 5.94 6.9 $ 423.8 Exercisable, March 31, 2021 661,430 $ 7.29 5.6 $ 73.0 Unrecognized share-based compensation for employee and nonemployee options granted through March 31, 2021 $1.7 2.2 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 18,792 4.34 RSUs released (40,100 ) 4.20 Balance, March 31, 2021 203,003 $ 4.12 Unrecognized share-based compensation for employee and nonemployee RSUs granted through March 31, 2021 $24,000 2.1

Note 9 - Net Loss Per Share

Note 9 - Net Loss Per Share	3 Months Ended
	Mar. 31, 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: March 31, December 31, 2021 2020 Stock options to purchase common stock 1,086,808 1,114,306 Unvested restricted stock units 8,200 8,200 Common stock warrants 2,424,724 2,424,724 Total 3,519,732 3,547,230

Note 10 - Income Taxes

Note 10 - Income Taxes	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Income Tax Disclosure [Text Block]	( 10 Income Taxes During the three March 31, 2021 2020, no As of March 31, 2021, not not

Note 11 - Related Party Transac

Note 11 - Related Party Transactions	3 Months Ended
	Mar. 31, 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% three (b) 30% 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. The Funding Agreement may ten may ten ten March 31, 2021 $623,000.

Note 12 - Concentrations and Un

Note 12 - Concentrations and Uncertainties	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	( 12 Contingencies and Uncertainties Contingencies may not Uncertainties three March 31, 2021 not December 31, 2021 19, 19, Beginning March 17, 2020, April 6, 2020, March 31, 2021, may 19 As the outbreak continues to mutate and spread, it may third may may 19 may may Additionally, while the potential economic impact brought by, and the duration of, a coronavirus pandemic is difficult to assess or predict, the impact of the coronavirus on the global financial markets may 2020. not third

Note 13 - Subsequent Events

Note 13 - Subsequent Events	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Subsequent Events [Text Block]	( 13 Subsequent Events On April 12, 2021, not On April 26, 2021, second 2021. $500,000, one

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 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 March 31, 2021 three March 31, 2021 2020 March 31, 2021, three March 31, 2021 2020, three March 31, 2021 2020. three March 31, 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.
Going Concern and Liquidity [Policy Text Block]	(b) Liquidity and Other Risks and Uncertainties Liquidity - $119.0 March 31, 2021. $21.5 March 31, 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. 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)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	As of March 31, 2021 Level 1 Level 2 Level 3 Total Assets Money market funds $ 20,583 $ — $ — $ 20,583 Cash in checking account — — — 919 Total cash and cash equivalents $ 20,583 $ — $ — $ 21,502 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)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Property, Plant and Equipment [Table Text Block]	March 31, December 31, 2021 2020 Computer equipment and software $ 166 $ 159 Laboratory and manufacturing equipment 574 550 Furniture and fixtures 59 59 Leasehold improvements 332 332 Construction in progress 72 70 Property and equipment, gross 1,203 1,170 Less accumulated depreciation (1,039 ) (1,025 ) Property and equipment, net $ 164 $ 145

Note 5 - Operating Lease Righ_2

Note 5 - Operating Lease Right-of-use Asset, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Operating Lease March 31, 2021 Remainder of 2021 $ 486 Total undiscounted lease payments 486 Less imputed interest 18 Total operating lease liabilities $ 468

Note 6 - Accrued Expenses and_2

Note 6 - Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Accrued Liabilities and Other Current Liabilities [Table Text Block]	March 31, December 31, 2021 2020 Accrued expenses $ 240 $ 87 Accrued salaries and employee benefits 851 961 Accrued clinical trial costs 457 452 Grant liability 610 615 Customer deposits 90 90 Total $ 2,248 $ 2,205

Note 7 - Stockholders' Equity (

Note 7 - Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 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, March 31, 2021 2,424,724 $ 6.36

Note 8 - Share-based Compensa_2

Note 8 - Share-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Share-based Compensation, Expense [Table Text Block]	Three Months ended March 31, 2021 2020 Research and development $ 206 $ 413 Selling, general and administrative 210 528 Total share-based compensation $ 416 $ 941
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 intrisinsic value (in thousands) Balance, December 31, 2020 1,114,306 $ 5.89 7.5 $ 177.1 Stock options granted 18,850 4.63 Stock options exercised (1,580 ) 2.49 Stock options forfeited (44,643 ) 4.30 Stock options expired (125 ) 5.32 Balance, March 31, 2021 1,086,808 $ 5.94 6.9 $ 423.8 Exercisable, March 31, 2021 661,430 $ 7.29 5.6 $ 73.0
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 18,792 4.34 RSUs released (40,100 ) 4.20 Balance, March 31, 2021 203,003 $ 4.12

Note 9 - Net Loss Per Share (Ta

Note 9 - Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	March 31, December 31, 2021 2020 Stock options to purchase common stock 1,086,808 1,114,306 Unvested restricted stock units 8,200 8,200 Common stock warrants 2,424,724 2,424,724 Total 3,519,732 3,547,230

Note 2 - Significant Accounti_2

Note 2 - Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Retained Earnings (Accumulated Deficit), Ending Balance	$ (119,043)	$ (116,074)
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 21,502	$ 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	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents, Fair Value	$ 21,502	$ 21,407
Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value	20,583	20,662
Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value	919	745
Fair Value, Inputs, Level 1 [Member]
Cash and Cash Equivalents, Fair Value	20,583	20,662
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value	20,583	20,662
Fair Value, Inputs, Level 1 [Member] | Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value
Fair Value, Inputs, Level 2 [Member]
Cash and Cash Equivalents, Fair Value
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value
Fair Value, Inputs, Level 2 [Member] | Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value
Fair Value, Inputs, Level 3 [Member]
Cash and Cash Equivalents, Fair Value
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Cash and Cash Equivalents, Fair Value
Fair Value, Inputs, Level 3 [Member] | Demand Deposits [Member]
Cash and Cash Equivalents, Fair Value

Note 4 - Property and Equipme_3

Note 4 - Property and Equipment, Net (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Depreciation, Total	$ 14,000	$ 22,000

Note 4 - Property and Equipme_4

Note 4 - Property and Equipment, Net - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property and equipment, gross	$ 1,203	$ 1,170
Less accumulated depreciation	(1,039)	(1,025)
Property and equipment, net	164	145
Computer Equipment and Software [Member]
Property and equipment, gross	166	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	$ 72	$ 70

Note 5 - Operating Lease Righ_3

Note 5 - Operating Lease Right-of-use Asset, Net (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Lease, Expense	$ 150,000	$ 150,000
Operating Lease, Payments	$ 162,000	$ 158,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	273 days
Operating Lease, Weighted Average Discount Rate, Percent	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	Mar. 31, 2021USD ($)
Remainder of 2021	$ 486
Total undiscounted lease payments	486
Less imputed interest	18
Total operating lease liabilities	$ 468

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	Mar. 31, 2021	Dec. 31, 2020
Accrued expenses	$ 240	$ 87
Accrued salaries and employee benefits	851	961
Accrued clinical trial costs	457	452
Grant liability	610	615
Customer deposits	90	90
Total	$ 2,248	$ 2,205

Note 7 - Stockholders' Equity_2

Note 7 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2021	Mar. 29, 2021	Mar. 31, 2021	Mar. 31, 2020
Proceeds from Issuance of Common Stock			$ 2,000
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)	0	373,832
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)	3 Months Ended
	Mar. 31, 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
Warrants for common stock sold, weighted average exercise price (in dollars per share) | $ / shares
Warrants for common stock exercised (in shares) | shares
Warrants for common stock exercised, weighted average exercise price (in dollars per share) | $ / shares
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	Mar. 31, 2021	Mar. 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	$ 4.63
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	515,036	18,850
Share-based Payment Arrangement, Expensed and Capitalized, Amount, Total	$ 569,000
Share-based Payment Arrangement, Expense	412,000	$ 416,000	$ 941,000
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
Non-employee Directors and Employees [Member]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount		$ 1,700,000
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 73 days
Non-employee Directors and Employees [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		2 years 36 days
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount		$ 24,000
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	Mar. 31, 2021	Mar. 31, 2020
Share-based compensation expense	$ 412,000	$ 416,000	$ 941,000
Research and Development Expense [Member]
Share-based compensation expense		206,000	413,000
Selling, General and Administrative Expenses [Member]
Share-based compensation expense		$ 210,000	$ 528,000

Note 8 - Share-based Compensa_5

Note 8 - Share-based Compensation - Stock Option Activity (Details) - USD ($)	Jan. 29, 2020	Mar. 31, 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)		6 years 328 days	7 years 182 days
Stock options outstanding, aggregate intrinsic value		$ 423,800	$ 177,100
Stock options granted (in shares)	515,036	18,850
Stock options granted, weighted average exercise price (in dollars per share)	$ 5.32	$ 4.63
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)		(44,643)
Stock options forfeited, weighted average exercise price (in dollars per share)		$ 4.30
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)		1,086,808	1,114,306
Balance, weighted average exercise price, end of period (in dollars per share)		$ 5.94	$ 5.89
Exercisable, March 31, 2021 (in shares)		661,430
Options exercisable, weighted average exercise price (in dollars per share)		$ 7.29
Options exercisable, weighted average remaining contractual term (Year)		5 years 219 days
Options exercisable, aggregate intrinsic value		$ 73,000

Note 8 - Share-based Compensa_6

Note 8 - Share-based Compensation - Summary of Non-vested RSUs (Details) - Restricted Stock Units (RSUs) [Member]	3 Months Ended
	Mar. 31, 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	18,792
RSUs granted, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 4.34
RSUs released (in shares) | shares	(40,100)
RSUs released (in dollars per share) | $ / shares	$ 4.20
Balance, shares (in shares) | shares	203,003
Balance, weighted average grant date fair value per share (in dollars per share) | $ / shares	$ 4.12

Note 9 - Net Loss Per Share - A

Note 9 - Net Loss Per Share - Anti-dilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive securities (in shares)	3,519,732	3,547,230
Share-based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	1,086,808	1,114,306
Restricted Stock Units (RSUs) [Member]
Antidilutive securities (in shares)	8,200	8,200
Warrant [Member]
Antidilutive securities (in shares)	2,424,724	2,424,724

Note 10 - Income Taxes (Details

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Expense (Benefit), Total	$ 0	$ 0

Note 11 - Related Party Trans_2

Note 11 - Related Party Transactions (Details Textual) - BSLF, L.L.C. [Member] - Funding Agreement [Member]	3 Months Ended
	Mar. 31, 2021USD ($)
Percentage of Remaining Litigation Proceeds Up to Three Times the Actual Funding Amount	50.00%
Percentage of Remaining Litigation Proceeds	30.00%
Agreement Termination Period (Day)	10 days
Due from Related Parties, Total	$ 623,000

Note 13 - Subsequent Events (De

Note 13 - Subsequent Events (Details Textual)	Apr. 26, 2021USD ($)
Helix Biotherapeutic Delivery System [Member] | Subsequent Event [Member]
Proceeds From Agreement	$ 500,000