Note 8 - Stockholders' Equity (Tables)

6 Months Ended

Dec. 31, 2019

Notes Tables

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

	Weighted Average, December 31, 2019			Range, December 31, 2019			Weighted Average, December 31, 2018			Range, December 31, 2018
Volatility		68	%	68	-	70%		70	%	63%	-	76%
Dividend yield		—			—			—			—
Risk-free interest rate		1.75	%	1.74	–	1.75%		2.73	%	2.68%	-	2.78%
Expected term (years)		5.0		5.0	to	5.2		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		390,000		0.60
Exercised		-		-
Forfeited		-		-
Expired		-		-
Outstanding at December 31, 2019		7,801,600	$	1.06		2.8	$	-
Exercisable at December 31, 2019		7,801,600	$	1.06		2.8	$	-

Schedule of Nonvested Share Activity [Table Text Block]

	Options			Weighted Average Grant-Date Fair Value
Nonvested at July 1, 2019		-		$	-
Granted		390,000			0.26
Vested		(390,000	)		0.26
Nonvested at December 31, 2019		—		$	—

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

	Three months ended December 31, 2019		Three months ended December 31, 2018		Six months ended December 31, 2019		Six months ended December 31, 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		92,000		22,500		92,000		92,125
Total	$	92,000	$	22,500	$	92,000	$	421,543
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		7,500		-		7,500		25,875
Total	$	7,500	$	-	$	7,500	$	81,783