9. EQUITY COMPENSATION PLANS

9 Months Ended

Jan. 31, 2013

Equity Compensation Plans

9. Equity Compensation Plans

Stock Incentive Plans

We currently maintain seven stock incentive plans referred to as the 2011 Plan, the 2010 Plan, the 2009 Plan, the 2005 Plan, the 2003 Plan, the 2002 Plan, and the 1996 Plan (collectively referred to as the “Stock Plans”). On October 18, 2012, our stockholders approved an amendment to our 2011 Plan to increase the number of shares of our common stock reserved for issuance from 3,500,000 to 11,500,000 shares.

As of January 31, 2013, we had an aggregate of 20,150,287 shares of common stock reserved for issuance under the Stock Plans, of which, 15,487,701 shares were subject to outstanding options and 4,662,586 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, 2013:

Stock Options	Shares			Weighted Average  Exercisable Price
Outstanding, May 1, 2012		7,531,651		$	2.90
Granted		8,556,862		$	0.87
Exercised		(92,497	)	$	0.86
Canceled or expired		(508,315	)	$	1.70
Outstanding, January 31, 2013		15,487,701		$	1.83

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 “2010 ESPP”), of which 3,889,004 shares of common stock remain available for purchase as of January 31, 2013. Under the 2010 ESPP, we will sell shares to participants at a price equal to the lesser of 85% of the fair market value of stock at the (i) beginning of a six-month offering period or (ii) at the end of the six-month offering period. The 2010 ESPP provides for two six-month offering periods each year; the first offering period will begin on the first trading day on or after each November 1; the second offering period will begin on the first trading day on or after each May 1. During the nine months ended January 31, 2013, 548,111 shares of common stock were purchased under the 2010 ESPP at a purchase price per share of $0.39.

Share-Based Compensation

Total share-based compensation expense for the three and nine-month periods ended January 31, 2013 and 2012 are included in the accompanying interim unaudited condensed consolidated statements of operations and comprehensive loss as follows:

	Three Months Ended   January 31,				Nine Months Ended January 31,
	2013		2012		2013		2012
Cost of contract manufacturing	$	37,000	$	5,000	$	55,000	$	10,000
Research and development		539,000		299,000		1,151,000		920,000
Selling, general and administrative		453,000		455,000		1,114,000		1,508,000
Total	$	1,029,000	$	759,000	$	2,320,000	$	2,438,000
Share-based compensation from:
Stock options	$	870,000	$	720,000	$	2,069,000	$	2,356,000
Employee stock purchase plan		159,000		39,000		251,000		82,000
	$	1,029,000	$	759,000	$	2,320,000	$	2,438,000

As of January 31, 2013, the total estimated unrecognized compensation cost related to non-vested stock options was $6,045,000. This cost is expected to be recognized over a weighted average vesting period of 1.64 years based on current assumptions.