Note 8 - Stockholders' Equity (Tables)

3 Months Ended

Sep. 30, 2019

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Weighted Average, September 30, 2019			Range, September 30, 2019			Weighted Average, September 30, 2018			Range, September 30, 2018
Volatility		-	%		-	%		70	%	63%	-	76%
Dividend yield		—			—			—			—
Risk-free interest rate		-	%		-	%		2.73	%	2.68%	-	2.78%
Expected term (years)		-			-			3.9		3.4	to	4.3

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at July 1, 2019		7,411,600	$	1.08		3.1	$	20,375
Granted		-		-
Exercised		—		—
Forfeited		—		—
Expired		-		-
Outstanding at September 30, 2019		7,411,600	$	1.08		2.9	$	-
Exercisable at September 30, 2019		7,411,600	$	1.08		2.9	$	-

Schedule of Nonvested Share Activity [Table Text Block]

	Options		Weighted Average Grant-Date Fair Value
Nonvested at July 1, 2019		—	$	—
Granted		-		-
Vested		-		-
Nonvested at September 30, 2019		—	$	—

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three months ended September 30, 2019		Three months ended September 30, 2018
General and administrative:
Change in fair value from modification of option terms	$	-	$	211,185
Change in fair value from modification of warrant terms		-		118,233
Fair value of stock options expensed		-		69,625
Total	$	-	$	399,043
Research and development:
Change in fair value from modification of option terms	$	-	$	11,115
Change in fair value from modification of warrant terms		-		44,793
Fair value of stock options expensed		-		25,875
Total	$	-	$	81,783