Note 8 - Stockholders' Equity (Tables)

9 Months Ended

Mar. 31, 2018

Notes Tables

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

	Weighted Average, March 31, 2018			Range, March 31, 2018					Weighted Average, March 31, 2017			Range, March 31, 2017
Volatility		74	%		68%	-	75	%		79	%		78%	-	86	%
Dividend yield		-				-				-				-
Risk-free interest rate		2.44	%		1.75%	-	2.64	%		1.14	%		0.82%	-	1.17	%
Expected term (years)		5			3	-	6			4			3	-	4

Share-based Compensation, Stock Options, Activity [Table Text Block]

	Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at July 1, 2017		4,545,037		$	1.42		2.9	$	176,575
Granted		2,647,500			0.76
Exercised		-			-
Forfeited		-			-
Expired		(365,312	)		-
Outstanding at March 31, 2018		6,827,225		$	1.11		4.0	$	-
Exercisable at March 31, 2018		6,827,225		$	1.11		4.0	$	-

Schedule of Nonvested Share Activity [Table Text Block]

	Options			Weighted Average Grant-Date Fair Value
Nonvested at July 1, 2017		25,000		$	0.46
Granted		2,647,500			0.52
Vested		(2,672,500	)		0.51
Nonvested at March 31, 2018		-		$	-

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Three months ended March 31, 2018		Three months ended March 31, 2017		Nine months ended March 31, 2018		Nine months ended March 31, 2017
General and administrative:
Fair value of stock/warrant bonuses expensed	$	1,500	$	-	$	8,723	$	6,830
Change in fair value from modification of option terms		-		-		243,761		166,031
Change in fair value from modification of warrant terms		7,091		-		163,956		-
Fair value of stock options expensed		682,485		6,134		782,135		112,699
Total	$	691,076	$	6,134	$	1,198,575	$	285,560
Research and development:
Fair value of stock bonus expensed	$	-	$	-	$	15,098	$	7,954
Change in fair value from modification of option terms		-		-		105,895		11,440
Change in fair value from modification of warrant terms		219		-		132,896		-
Fair value of stock options expensed		587,215		-		587,215		23,251
Total	$	587,434	$	-	$	841,104	$	42,645