Note 8 - Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Notes Tables

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

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Research and development	$	174,932	$	78,289	$	601,260	$	197,871
General and administrative		215,425		63,119		520,730		176,118
Total stock-based compensation expense	$	390,357	$	141,408	$	1,121,990	$	373,989

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

	Number of Options			Weighted average exercise price per share		Weighted average remaining contractual life (in years)
Balance at January 1, 2016		1,495,615		$	3.92
RestorGenex options outstanding		301,156			40.13
Cancelled		(48,190	)		61.30
Granted		261,828			8.89
Outstanding at September 30, 2016		2,010,409		$	8.62		7.6
Exercisable at September 30, 2016		1,357,109		$	9.64		7.1
Vested and expected to vest at September 30, 2016		2,006,156		$	8.62		7.6

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

Grant date fair value	$7.30	-	$8.01
Exercise price	$8.75	-	$9.60
Expected term (in years)	5.77	-	7.48
Risk-free interest rate	1.2%	-	1.5%
Expected volatility	106.8%	-	124.0%
Dividend yield		0%