7. EQUITY COMPENSATION PLANS (Tables)

6 Months Ended

Oct. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of stock option transaction activity

Stock Options	Shares			Weighted Average Exercisable Price
Outstanding, May 1, 2015		20,708,672		$	1.54
Granted		3,731,035		$	1.30
Exercised		(165,266	)	$	0.80
Canceled or expired		(650,840	)	$	1.76
Outstanding, October 31, 2015		23,623,601		$	1.50

Share-based compensation expense

	Three Months Ended October 31,				Six Months Ended October 31,
	2015		2014		2015		2014
Cost of contract manufacturing	$	9,000	$	8,000	$	22,000	$	32,000
Research and development		569,000		860,000		1,040,000		1,603,000
Selling, general and administrative		696,000		1,020,000		1,395,000		2,029,000
Total	$	1,274,000	$	1,888,000	$	2,457,000	$	3,664,000
Share-based compensation from:
Stock options	$	1,223,000	$	1,828,000	$	2,347,000	$	3,525,000
ESPP		51,000		60,000		110,000		139,000
	$	1,274,000	$	1,888,000	$	2,457,000	$	3,664,000