CervoMed (CRVO) 10-Q 11 May 20 2020 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 08, 2020
Document Information [Line Items]
Entity Registrant Name	Diffusion Pharmaceuticals Inc.
Entity Central Index Key	0001053691
Trading Symbol	dffn
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)		45,989,932
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false
Title of 12(b) Security	Common Stock, par value $0.001 per share

Consolidated Balance Sheets (Cu

Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 10,828,228	$ 14,177,349
Prepaid expenses, deposits and other current assets	888,234	472,464
Total current assets	11,716,462	14,649,813
Property and equipment, net	225,346	252,366
Intangible asset	8,639,000	8,639,000
Right of use asset	223,757	247,043
Other assets	252,561	322,301
Total assets	21,057,126	24,110,523
Current liabilities:
Accounts payable	655,298	1,251,412
Accrued expenses and other current liabilities	519,552	358,532
Current operating lease liability	111,970	111,477
Total current liabilities	1,286,820	1,721,421
Deferred income taxes	1,756,894	2,119,274
Noncurrent operating lease liability	111,787	135,566
Total liabilities	3,155,501	3,976,261
Commitments and Contingencies (Note 7)
Stockholders’ Equity:
Common stock, $0.001 par value: 1,000,000,000 shares authorized; 34,604,436 and 33,480,365 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	34,605	33,481
Additional paid-in capital	112,149,913	111,824,859
Accumulated deficit	(94,282,893)	(91,724,078)
Total stockholders' equity	17,901,625	20,134,262
Total liabilities and stockholders' equity	$ 21,057,126	$ 24,110,523

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	34,604,436	33,480,365
Common stock, shares outstanding (in shares)	34,604,436	33,480,365

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating expenses:
Research and development	$ 1,534,467	$ 1,699,845
General and administrative	1,393,808	1,200,728
Depreciation	27,020	18,272
Loss from operations	2,955,295	2,918,845
Other income:
Interest income	(34,100)	(20,684)
Loss from operations before income tax benefit	(2,921,195)	(2,898,161)
Income tax benefit	(362,380)	(150,352)
Net loss	$ (2,558,815)	$ (2,747,809)
Per share information:
Net loss per share of common stock, basic and diluted (in dollars per share)	$ (0.07)	$ (0.81)
Weighted average shares outstanding, basic and diluted (in dollars per share)	$ 34,507,496	$ 3,376,230

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2018	3,376,230
Balance at Dec. 31, 2018	$ 3,377	$ 95,532,881	$ (79,924,699)	$ 15,611,559
Stock-based compensation expense		91,204		91,204
Net loss			(2,747,809)	(2,747,809)
Balance (in shares) at Mar. 31, 2019	3,376,230
Balance at Mar. 31, 2019	$ 3,377	95,624,085	(82,672,508)	12,954,954
Balance (in shares) at Dec. 31, 2019	33,480,365
Balance at Dec. 31, 2019	$ 33,481	111,824,859	(91,724,078)	20,134,262
Stock-based compensation expense		191,380		191,380
Net loss			(2,558,815)	(2,558,815)
Issuance of common stock upon exercise of warrants, net (in shares)	1,124,071
Issuance of common stock upon exercise of warrants, net	$ 1,124	133,674		134,798
Balance (in shares) at Mar. 31, 2020	34,604,436
Balance at Mar. 31, 2020	$ 34,605	$ 112,149,913	$ (94,282,893)	$ 17,901,625

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net loss	$ (2,558,815)	$ (2,747,809)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	27,020	18,272
Stock-based compensation expense	191,380	91,204
Change in deferred income taxes	(362,380)	(150,352)
Changes in operating assets and liabilities:
Prepaid expenses, deposits and other assets	(346,030)	(119,644)
Accounts payable, accrued expenses and other liabilities	(455,489)	250,871
Net cash used in operating activities	(3,504,314)	(2,657,458)
Cash flows provided by financing activities:
Proceeds received from the exercise of common stock warrants	393,425
Payment of financing costs that were previously classified in accounts payable	(238,232)
Net cash provided by financing activities	155,193
Net decrease in cash and cash equivalents	(3,349,121)	(2,657,458)
Cash and cash equivalents at beginning of period	14,177,349	7,991,172
Cash and cash equivalents at end of period	10,828,228	5,333,714
Supplemental disclosure of non-cash investing and financing activities:
Offering costs in accounts payable and accrued expenses	258,627	28,549
Operating lease right of use asset and current and noncurrent liability		$ 334,205

Note 1 - Organization and Descr

Note 1 - Organization and Description of Business	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Nature of Operations [Text Block]	1. Organization and Description of Business Diffusion Pharmaceuticals Inc. (“Diffusion” or the “Company”), a Delaware corporation, is a clinical stage biotechnology company developing new treatments for life-threatening conditions by improving the body’s ability to bring oxygen to the areas where it is needed most. The Company is developing its lead product candidate, transcrocetinate sodium, also known as trans sodium crocetinate (“TSC”), for use in those life-threatening conditions in which cellular oxygen deprivation (“hypoxia”) is the basis for significant unmet medical needs. TSC is designed to safely and selectively target and re-oxygenate the micro-environment of hypoxic cells, and can potentially be used in many indications, including stroke, oncology and cardiovascular disease. In stroke, TSC helps promote the diffusion of oxygen into those brain cells in which oxygen-deprivation causes neuronal death resulting in patient mortality or morbidity. In cancer, TSC re-oxygenates treatment-resistant cancerous tissue, making the cancer cells up to three 529, may 529 PI3K/Akt/mTOR two 1 529

Note 2 - Liquidity

Note 2 - Liquidity	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Liquidity Disclosure [Text Block]	2. Liquidity The Company has not No The Company regularly explores alternative means of financing its operations and seeks funding through various sources, including public and private securities offerings, collaborative arrangements with third not may third may not Operations of the Company are subject to certain risks and uncertainties including various internal and external factors that will affect whether and when the Company’s product candidates become approved drugs and how significant their market share will be, some of which are outside of the Company’s control. The length of time and cost of developing and commercializing these product candidates and/or failure of them at any stage of the drug approval process will materially affect the Company’s financial condition and future operations. The Company believes its cash and cash equivalents as of March 31, 2020, $4.8 second 2020 third 2021.

Note 3 - Basis of Presentation

Note 3 - Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Significant Accounting Policies [Text Block]	3. Basis of Presentation and Summary of Significant Accounting Policies The Summary of Significant Accounting Policies included in the Company's Form 10 December 31, 2019, March 17, 2020, not Basis of Presentation The accompanying unaudited interim consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information as found in the Accounting Standard Codification (“ASC”) and Accounting Standards Updates (“ASUs”) of the Financial Accounting Standards Board (“FASB”), and with the instructions to Form 10 10 X March 31, 2020, three March 31, 2020 2019. three March 31, 2020 not may December 31, 2020. not December 31, 2019 10 March 17, 2020. Use of Estimates The preparation of the unaudited interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date the financial statements and reported amounts of expense during the reporting period. The full extent to which the COVID- 19 may 19 19, 19 may may Fair Value of Financial Instruments Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The carrying amounts of certain of the Company’s financial instruments, including cash equivalents and accounts payable are shown at cost, which approximates fair value due to the short-term nature of these instruments. The Company follows the provisions of FASB ASC Topic 820, Fair Value Measurement one three • Level 1: • Level 2: not • Level 3: no The following fair value hierarchy table presents information about the Company’s cash equivalents measured at fair value on a recurring basis: March 31, 2020 (Level 1) (Level 2) (Level 3) Assets Cash equivalents $ 9,916,053 $ — $ — December 31, 2019 (Level 1) (Level 2) (Level 3) Assets Cash equivalents $ 14,006,193 $ — $ — Intangible Asset The Company's RES- 529 October 1 no 529 three March 31, 2020 2019. Net Loss Per Common Share Basic net loss per share is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during each period. Diluted net loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible debt, convertible preferred stock, common stock warrants, stock options and unvested restricted stock that would result in the issuance of incremental shares of common stock. In computing the basic and diluted net loss per share applicable to common stockholders, the weighted average number of shares remains the same for both calculations due to the fact that when a net loss exists, dilutive shares are not The following potentially dilutive securities outstanding as of March 31, 2020 2019 March 31, 2020 2019 Common stock warrants 21,261,070 2,087,012 Stock options 1,182,629 256,057 Unvested restricted stock awards 98,100 — 22,541,799 2,343,069 Recently Adopted Accounting Pronouncements In August 2018, 2018 13, Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurements, 820. 820's No. 2018 13 first 2020 not

Note 4 - Other Accrued Expenses

Note 4 - Other Accrued Expenses and Liabilities	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	4. Other Accrued Expenses and Liabilities Other accrued expenses and liabilities consisted of the following: March 31, 2020 December 31, 2019 Accrued payroll and payroll related expenses $ 149,620 $ 182,708 Accrued professional fees 338,627 48,338 Accrued clinical studies expenses 9,100 57,378 Other accrued expenses 22,205 70,108 Total $ 519,552 $ 358,532

Note 5 - Stockholders' Equity a

Note 5 - Stockholders' Equity and Common Stock Warrants	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	5. Stockholders' Equity and Common Stock Warrants 2019 In December 2019, “December 2019 6,266,787 6,266,787 $0.5585 $3.0 December 2019 June 13, 2025 $0.4335 In addition, at the closing of the December 2019 313,339 $0.6981 five In November 2019, “November 2019 5,104,429 6,324,143 one 22,857,144 $0.35 $3.3 $0.35 11,428,572 18 11,428,572 five December 31, 2019, 11,091,716 $3.9 In addition, at the closing of the November 2019 571,429 $0.4375 five In May 2019, “May 2019 1,317,060 1,317,060 $4.895 $5.6 November 29, 2024 $5.00. In addition, at the closing of the May 2019 65,853 $6.11875 five Common Stock Warrants As of March 31, 2020, Outstanding Range of exercise price per share Expiration dates Common stock warrants issued in 2017 related to Series A convertible preferred stock offering 903,870 $33.30 March 2022 Common stock warrants issued in 2018 related to the common stock offering 1,181,375 $12.00 - $15.00 January 2023 Common stock warrants issued related to the May 2019 Offering 1,382,913 $5.00 - $6.11875 May and December 2024 Common stock warrants issued related to the November 2019 Offering 11,212,786 $0.35 - $0.4375 May 2024 Common stock warrants issued related to the December 2019 Offering 6,580,126 $0.4335 - $0.6981 December 2024 and June 2025 21,261,070 During the three March 31, 2020, no 1,124,071 $0.35

Note 6 - Stock-based Compensati

Note 6 - Stock-based Compensation	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	6. Stock-Based Compensation 2015 The Diffusion Pharmaceuticals Inc. 2015 "2015 January 1 4.0% December 31, 1,339,215 January 1, 2020, may 2015 March 31, 2020, 485,602 2015 The Company recorded stock-based compensation expense in the following expense categories of its unaudited interim consolidated statements of operations for the periods indicated: Three Months Ended March 31, 2020 2019 Research and development $ 96,530 $ 13,596 General and administrative 94,850 77,608 Total stock-based compensation expense $ 191,380 $ 91,204 The following table summarizes the activity related to all stock option grants for the three March 31, 2020: Number of Options Weighted average exercise price per share Weighted average remaining contractual life (in years) Aggregate intrinsic value Balance at January 1, 2020 309,276 $ 55.78 $ — Granted 873,500 0.47 Expired (147 ) 142.50 Outstanding at March 31, 2020 1,182,629 $ 14.91 9.0 $ — Exercisable at March 31, 2020 560,524 $ 30.60 8.2 $ — The weighted average grant date fair value of stock option awards granted was $0.36 three March 31, 2020. three March 31, 2020 2019 $0.2 $0.2 No March 31, 2020, $0.4 1.81 Options granted were valued using the Black-Scholes model and assumptions used to value the options granted during the three March 31, 2020 Expected term (in years) 5.70 Risk-free interest rate 1.7 % Expected volatility 113.7 % Dividend yield — Restricted Stock Awards During the three March 31, 2020, 98,100 three March 31, 2020 $0.51. 18 $4,000 three March 31, 2020 March 31, 2020, $46,000 2.83

Note 7 - Commitments and Contin

Note 7 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	7. Commitments and Contingencies Office Space Rental The Company has a non-cancelable operating lease for office and laboratory space in Charlottesville, Virginia, which began in April 2017 December 31, 2019, 2.3 842 first 2019 $0.1 $0.2 842 10%. second 2022 five not March 31, 2020. Rent expense related to the Company's operating lease was approximately $30,000 $20,000 three March 31, 2020 2019, March 31, 2020: Rental Commitments 2020 (remaining) $ 87,691 2021 118,519 2022 39,735 Total 245,945 Less: imputed interest (22,188 ) Current and noncurrent operating lease liability $ 223,757 Research and Development Arrangements In the course of normal business operations, the Company enters into agreements with universities and contract research organizations, or CROs, to assist in the performance of research and development activities and contract manufacturers to assist with chemistry, manufacturing, and controls related expenses. Expenditures to CROs represent a significant cost in clinical development for the Company. The Company could also enter into additional collaborative research, contract research, manufacturing, and supplier agreements in the future, which may Defined Contribution Retirement Plan The Company has established a 401 “401 may 401 90% 4% 401 $17,000 $18,000 three March 31, 2020 2019, Legal Proceedings On August 7, 2014, Paul Feller v. RestorGenex Corporation, Pro Sports & Entertainment, Inc., ProElite, Inc. and Stratus Media Group, GmbH No. BC553996 December 30, 2014, April 1, 2015, April 14, 2015, January 8, 2016, November 19, 2018 not November 2020. may

Note 8 - Subsequent Events

Note 8 - Subsequent Events	3 Months Ended
	Mar. 31, 2020
Notes to Financial Statements
Subsequent Events [Text Block]	8. Subsequent Events In April 2020, 19 60 19 From April 1, 2020 May 8, 2020, 6,385,496 $2.5 On May 8, 2020, 5,000,000 5,000,000 $2.4 $0.5263 five one 250,000 “May 2020 May 2020 $0.5938 five one

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The accompanying unaudited interim consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information as found in the Accounting Standard Codification (“ASC”) and Accounting Standards Updates (“ASUs”) of the Financial Accounting Standards Board (“FASB”), and with the instructions to Form 10 10 X March 31, 2020, three March 31, 2020 2019. three March 31, 2020 not may December 31, 2020. not December 31, 2019 10 March 17, 2020.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the unaudited interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of assets and liabilities at the date the financial statements and reported amounts of expense during the reporting period. The full extent to which the COVID- 19 may 19 19, 19 may may
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The carrying amounts of certain of the Company’s financial instruments, including cash equivalents and accounts payable are shown at cost, which approximates fair value due to the short-term nature of these instruments. The Company follows the provisions of FASB ASC Topic 820, Fair Value Measurement one three • Level 1: • Level 2: not • Level 3: no The following fair value hierarchy table presents information about the Company’s cash equivalents measured at fair value on a recurring basis: March 31, 2020 (Level 1) (Level 2) (Level 3) Assets Cash equivalents $ 9,916,053 $ — $ — December 31, 2019 (Level 1) (Level 2) (Level 3) Assets Cash equivalents $ 14,006,193 $ — $ —
Goodwill and Intangible Assets, Policy [Policy Text Block]	Intangible Asset The Company's RES- 529 October 1 no 529 three March 31, 2020 2019.
Earnings Per Share, Policy [Policy Text Block]	Net Loss Per Common Share Basic net loss per share is computed by dividing net loss attributable to common stockholders by the weighted average number of shares of common stock outstanding during each period. Diluted net loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible debt, convertible preferred stock, common stock warrants, stock options and unvested restricted stock that would result in the issuance of incremental shares of common stock. In computing the basic and diluted net loss per share applicable to common stockholders, the weighted average number of shares remains the same for both calculations due to the fact that when a net loss exists, dilutive shares are not The following potentially dilutive securities outstanding as of March 31, 2020 2019 March 31, 2020 2019 Common stock warrants 21,261,070 2,087,012 Stock options 1,182,629 256,057 Unvested restricted stock awards 98,100 — 22,541,799 2,343,069
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Pronouncements In August 2018, 2018 13, Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurements, 820. 820's No. 2018 13 first 2020 not

Note 3 - Basis of Presentatio_2

Note 3 - Basis of Presentation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2020
Notes Tables
Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]	March 31, 2020 (Level 1) (Level 2) (Level 3) Assets Cash equivalents $ 9,916,053 $ — $ — December 31, 2019 (Level 1) (Level 2) (Level 3) Assets Cash equivalents $ 14,006,193 $ — $ —
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]	March 31, 2020 2019 Common stock warrants 21,261,070 2,087,012 Stock options 1,182,629 256,057 Unvested restricted stock awards 98,100 — 22,541,799 2,343,069

Note 4 - Other Accrued Expens_2

Note 4 - Other Accrued Expenses and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2020
Notes Tables
Other Current Liabilities [Table Text Block]	March 31, 2020 December 31, 2019 Accrued payroll and payroll related expenses $ 149,620 $ 182,708 Accrued professional fees 338,627 48,338 Accrued clinical studies expenses 9,100 57,378 Other accrued expenses 22,205 70,108 Total $ 519,552 $ 358,532

Note 5 - Stockholders' Equity_2

Note 5 - Stockholders' Equity and Common Stock Warrants (Tables)	3 Months Ended
	Mar. 31, 2020
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Outstanding Range of exercise price per share Expiration dates Common stock warrants issued in 2017 related to Series A convertible preferred stock offering 903,870 $33.30 March 2022 Common stock warrants issued in 2018 related to the common stock offering 1,181,375 $12.00 - $15.00 January 2023 Common stock warrants issued related to the May 2019 Offering 1,382,913 $5.00 - $6.11875 May and December 2024 Common stock warrants issued related to the November 2019 Offering 11,212,786 $0.35 - $0.4375 May 2024 Common stock warrants issued related to the December 2019 Offering 6,580,126 $0.4335 - $0.6981 December 2024 and June 2025 21,261,070

Note 6 - Stock-based Compensa_2

Note 6 - Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2020
Notes Tables
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]	Three Months Ended March 31, 2020 2019 Research and development $ 96,530 $ 13,596 General and administrative 94,850 77,608 Total stock-based compensation expense $ 191,380 $ 91,204
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Number of Options Weighted average exercise price per share Weighted average remaining contractual life (in years) Aggregate intrinsic value Balance at January 1, 2020 309,276 $ 55.78 $ — Granted 873,500 0.47 Expired (147 ) 142.50 Outstanding at March 31, 2020 1,182,629 $ 14.91 9.0 $ — Exercisable at March 31, 2020 560,524 $ 30.60 8.2 $ —
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	Expected term (in years) 5.70 Risk-free interest rate 1.7 % Expected volatility 113.7 % Dividend yield —

Note 7 - Commitments and Cont_2

Note 7 - Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2020
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Rental Commitments 2020 (remaining) $ 87,691 2021 118,519 2022 39,735 Total 245,945 Less: imputed interest (22,188 ) Current and noncurrent operating lease liability $ 223,757

Note 2 - Liquidity (Details Tex

Note 2 - Liquidity (Details Textual) - USD ($)	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Mar. 31, 2019
Proceeds from Warrant Exercises		$ 393,425
Forecast [Member]
Proceeds from Warrant Exercises	$ 4,800,000

Note 3 - Basis of Presentatio_3

Note 3 - Basis of Presentation and Summary of Significant Accounting Policies - Fair Value on Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Inputs, Level 1 [Member]
Cash equivalents	$ 9,916,053	$ 14,006,193
Fair Value, Inputs, Level 2 [Member]
Cash equivalents
Fair Value, Inputs, Level 3 [Member]
Cash equivalents

Note 3 - Basis of Presentatio_4

Note 3 - Basis of Presentation and Summary of Significant Accounting Policies - Outstanding Dilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Anti-dilutive securities (in shares)	22,541,799	2,343,069
Warrant [Member]
Anti-dilutive securities (in shares)	21,261,070	2,087,012
Share-based Payment Arrangement, Option [Member]
Anti-dilutive securities (in shares)	1,182,629	256,057
Restricted Stock [Member]
Anti-dilutive securities (in shares)	98,100

Note 4 - Other Accrued Expens_3

Note 4 - Other Accrued Expenses and Liabilities - Summary of Accrued Expenses (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Accrued payroll and payroll related expenses	$ 149,620	$ 182,708
Accrued professional fees	338,627	48,338
Accrued clinical studies expenses	9,100	57,378
Other accrued expenses	22,205	70,108
Total	$ 519,552	$ 358,532

Note 5 - Stockholders' Equity_3

Note 5 - Stockholders' Equity and Common Stock Warrants (Details Textual) - USD ($)	1 Months Ended			3 Months Ended		12 Months Ended
	Dec. 31, 2019	Nov. 30, 2019	May 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 0.35
Proceeds from Warrant Exercises				$ 393,425
Class of Warrant or Rights, Expired (in shares)				0
Class of Warrant or Right, Exercised (in shares)				1,124,071
Warrants Issued in Connection with the December 2019 Offering [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	6,266,787					6,266,787
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.4335					$ 0.4335
Placement Agent Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	313,339	571,429	65,853			313,339
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.6981	$ 0.4375	$ 6.11875			$ 0.6981
Warrants and Rights Outstanding, Term (Year)	5 years	5 years	5 years			5 years
Warrants Issued in Connection with the November 2019 Offering [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 0.35
Class of Warrant or Right, Issued During Period (in shares)		6,324,143
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		1
Class of Warrant or Right, Exercised During Period (in shares)						11,091,716
Proceeds from Warrant Exercises						$ 3,900,000
Warrants with 18 Months Term Issued in Connection with the November 2019 Offering [Member]
Warrants and Rights Outstanding, Term (Year)		1 year 180 days
Class of Warrant or Right, Issued During Period (in shares)		11,428,572
Warrants with 5 Years Term Issued in Connection with the November 2019 Offering [Member]
Warrants and Rights Outstanding, Term (Year)		5 years
Class of Warrant or Right, Issued During Period (in shares)		11,428,572
December 2019 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	6,266,787
Shares Issued, Price Per Share (in dollars per share)	$ 0.5585					$ 0.5585
Proceeds from Issuance or Sale of Equity, Total	$ 3,000,000
November 2019 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)		5,104,429
Shares Issued, Price Per Share (in dollars per share)		$ 0.35
Proceeds from Issuance or Sale of Equity, Total		$ 3,300,000
Stock and Warrants Issued During Period, Number of Securities Called by Stock and Warrants (in shares)		22,857,144
May 2019 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)			1,317,060
Shares Issued, Price Per Share (in dollars per share)			$ 4.895
Proceeds from Issuance or Sale of Equity, Total			$ 5,600,000
Warrants Issued in Connection with May 2019 Public Offering [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			1,317,060
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 5

Note 5 - Stockholders' Equity_4

Note 5 - Stockholders' Equity and Common Stock Warrants - Warrants Outstanding to Acquire Shares of Its Common Stock (Details) - $ / shares	Mar. 31, 2020	Dec. 31, 2019	Nov. 30, 2019
Common stock warrants, outstanding (in shares)	21,261,070
Range of exercise price (in dollars per share)	$ 0.35
Warrants Attached to Series A Convertible Preferred Stock [Member]
Common stock warrants, outstanding (in shares)	903,870
Range of exercise price (in dollars per share)	$ 33.30
Warrants Issued in Connection with the January 2018 Offering [Member]
Common stock warrants, outstanding (in shares)	1,181,375
Warrants Issued in Connection with the January 2018 Offering [Member] | Minimum [Member]
Range of exercise price (in dollars per share)	$ 12
Warrants Issued in Connection with the January 2018 Offering [Member] | Maximum [Member]
Range of exercise price (in dollars per share)	$ 15
Warrants Issued in Connection with May 2019 Public Offering [Member]
Common stock warrants, outstanding (in shares)	1,382,913
Warrants Issued in Connection with May 2019 Public Offering [Member] | Minimum [Member]
Range of exercise price (in dollars per share)	$ 5
Warrants Issued in Connection with May 2019 Public Offering [Member] | Maximum [Member]
Range of exercise price (in dollars per share)	$ 6.11875
Warrants Issued in Connection with the November 2019 Offering [Member]
Common stock warrants, outstanding (in shares)	11,212,786
Range of exercise price (in dollars per share)			$ 0.35
Warrants Issued in Connection with the November 2019 Offering [Member] | Minimum [Member]
Range of exercise price (in dollars per share)	$ 0.35
Warrants Issued in Connection with the November 2019 Offering [Member] | Maximum [Member]
Range of exercise price (in dollars per share)	$ 0.4375
Warrants Issued in Connection with the December 2019 Offering [Member]
Common stock warrants, outstanding (in shares)	6,580,126
Range of exercise price (in dollars per share)		$ 0.4335
Warrants Issued in Connection with the December 2019 Offering [Member] | Minimum [Member]
Range of exercise price (in dollars per share)	$ 0.4335
Warrants Issued in Connection with the December 2019 Offering [Member] | Maximum [Member]
Range of exercise price (in dollars per share)	$ 0.6981

Note 6 - Stock-based Compensa_3

Note 6 - Stock-based Compensation (Details Textual) - USD ($)	Jan. 01, 2020	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)		$ 0.36
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value		$ 200,000	$ 200,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)		0	0
Share-based Payment Arrangement, Expense		$ 191,380	$ 91,204
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 400,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		1 year 295 days
Restricted Stock [Member] | Director [Member]
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total		$ 46,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)		2 years 302 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)		98,100
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)		$ 0.51
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Month)		1 year 180 days
Share-based Payment Arrangement, Expense		$ 4,000
Equity Incentive Plan 2015 [Member]
Percentage of Total Shares Eligible for Plan Reserve, On an Annual Basis		4.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)	1,339,215
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)		485,602

Note 6 - Stock-based Compensa_4

Note 6 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock-based compensation expense	$ 191,380	$ 91,204
Research and Development Expense [Member]
Stock-based compensation expense	96,530	13,596
General and Administrative Expense [Member]
Stock-based compensation expense	$ 94,850	$ 77,608

Note 6 - Stock-based Compensa_5

Note 6 - Stock-based Compensation - Stock Option Activity (Details)	3 Months Ended
	Mar. 31, 2020USD ($)$ / sharesshares
Options outstanding, number (in shares) | shares	309,276
Options outstanding, weighted-average exercise price (in dollars per share) | $ / shares	$ 55.78
Granted (in shares) | shares	873,500
Granted, weighted-average exercise price (in dollars per share) | $ / shares	$ 0.47
Expired (in shares) | shares	(147)
Expired, weighted-average exercise price (in dollars per share) | $ / shares	$ 142.50
Options outstanding, number (in shares) | shares	1,182,629
Options outstanding, weighted-average exercise price (in dollars per share) | $ / shares	$ 14.91
Options outstanding, weighted-average remaining contractual life (Year)	9 years
Options outstanding, aggregate intrinsic value | $
Exercisable (in shares) | shares	560,524
Exercisable, weighted-average exercise price (in dollars per share) | $ / shares	$ 30.60
Exercisable, weighted-average remaining contractual life (Year)	8 years 73 days
Exercisable, aggregate intrinsic value | $

Note 6 - Stock-based Compensa_6

Note 6 - Stock-based Compensation - Fair Value Assumptions (Details)	3 Months Ended
	Mar. 31, 2020
Expected term (Year)	5 years 255 days
Risk-free interest rate	1.70%
Expected volatility	113.70%
Dividend yield

Note 7 - Commitments and Cont_3

Note 7 - Commitments and Contingencies (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Jan. 01, 2019
Operating Lease, Remaining Lease Term (Year)			2 years 109 days
Operating Lease, Liability, Current	$ 111,970		$ 111,477	$ 100,000
Operating Lease, Liability, Noncurrent	$ 111,787		$ 135,566	$ 200,000
Lessee, Operating Lease, Discount Rate	10.00%
Lessee, Operating Lease, Renewal Term (Year)	5 years
Operating Lease, Expense	$ 30,000	$ 20,000
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	90.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	4.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 17,000	$ 18,000

Note 7 - Commitments and Cont_4

Note 7 - Commitments and Contingencies - Future Minimum Rental Payments (Details)	Mar. 31, 2020USD ($)
2020 (remaining)	$ 87,691
2021	118,519
2022	39,735
Total	245,945
Less: imputed interest	(22,188)
Current and noncurrent operating lease liability	$ 223,757

Note 8 - Subsequent Events (Det

Note 8 - Subsequent Events (Details Textual) - USD ($)	May 08, 2020	May 08, 2020	Mar. 31, 2020	Mar. 31, 2019
Class of Warrant or Right, Exercised (in shares)			1,124,071
Proceeds from Warrant Exercises			$ 393,425
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 0.35
Subsequent Event [Member]
Class of Warrant or Right, Exercised (in shares)		6,385,496
Proceeds from Warrant Exercises		$ 2,500,000
Proceeds from Warrant Exercises, and Issuance of New Warrants	$ 2,400,000
Subsequent Event [Member] | Warrants Issued Prior to the Exchange on May 8, 2020 [Member]
Class of Warrant or Right, Exercised (in shares)	5,000,000
Subsequent Event [Member] | New Warrants Issued May 8, 2020 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	5,000,000	5,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.5263	$ 0.5263
Warrants and Rights Outstanding, Term (Year)	5 years 182 days	5 years 182 days
Subsequent Event [Member] | The May 2020 PA Warrants [Member] | H.C Wainwright & Co., LLC [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	250,000	250,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.5938	$ 0.5938
Warrants and Rights Outstanding, Term (Year)	5 years 182 days	5 years 182 days