7. EQUITY COMPENSATION PLANS

9 Months Ended

Jan. 31, 2015

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

7. EQUITY COMPENSATION PLANS

Stock Incentive Plans

As of January 31, 2015, we had an aggregate of 25,002,996 shares of common stock reserved for issuance under our stock incentive plans, of which, 20,679,394 shares were subject to outstanding options and 4,323,602 shares were available for future grants of share-based awards.

The following summarizes our stock option transaction activity for the nine months ended January 31, 2015:

Stock Options	Shares			Weighted Average Exercisable Price
Outstanding, May 1, 2014		17,165,333		$1.58
Granted		4,336,296		$1.74
Exercised		(294,878	)	$0.95
Cancelled or expired		(527,357	)	$3.51
Outstanding, January 31, 2015		20,679,394		$1.57

Employee Stock Purchase Plan

We have reserved a total of 5,000,000 shares of common stock to be purchased under our 2010 Employee Stock Purchase Plan (the “ESPP”), of which 2,714,717 shares of common stock remain available for purchase as of January 31, 2015. The ESPP allows eligible employees on a voluntary basis to purchase shares of our common stock directly from the Company. Under the ESPP, we sell shares to participants at a price equal to the lesser of 85% of the fair market value of our common stock at the (i) beginning of a six-month offering period, or (ii) at the end of the six-month offering period. The ESPP provides for two six-month offering periods each year; the first offering period begins on the first trading day on or after each November 1; the second offering period begins on the first trading day on or after each May 1. During the nine months ended January 31, 2015, 225,792 shares of our common stock were purchased under the ESPP at a purchase price of $1.36 per share.

Share-Based Compensation

Total share-based compensation expense is included in the accompanying interim unaudited condensed consolidated statements of operations as follows:

	Three Months Ended January 31,				Nine Months Ended January 31,
	2015		2014		2015		2014
Cost of contract manufacturing	$	16,000	$	18,000	$	48,000	$	58,000
Research and development		685,000		769,000		2,288,000		2,231,000
Selling, general and administrative		915,000		814,000		2,944,000		2,625,000
Total	$	1,616,000	$	1,601,000	$	5,280,000	$	4,914,000

Share-based compensation from:
Stock options	$	1,561,000	$	1,540,000	$	5,086,000	$	4,549,000
Restricted stock awards		–		–		–		139,000
Employee stock purchase plan		55,000		61,000		194,000		226,000
	$	1,616,000	$	1,601,000	$	5,280,000	$	4,914,000

As of January 31, 2015, the total estimated unrecognized compensation cost related to non-vested stock options was $4,575,000. This cost is expected to be recognized over a weighted average vesting period of 1.24 years based on current assumptions.