CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) (USD $)	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
REVENUES:
Contract manufacturing revenue	$ 6,061,000	$ 4,154,000	$ 10,196,000	$ 9,593,000
License revenue	78,000	78,000	194,000	294,000
Total revenues	6,139,000	4,232,000	10,390,000	9,887,000
COSTS AND EXPENSES:
Cost of contract manufacturing	3,703,000	3,718,000	5,727,000	6,735,000
Research and development	6,053,000	9,818,000	13,034,000	17,578,000
Selling, general and administrative	3,440,000	2,732,000	6,357,000	5,661,000
Total costs and expenses	13,196,000	16,268,000	25,118,000	29,974,000
LOSS FROM OPERATIONS	(7,057,000)	(12,036,000)	(14,728,000)	(20,087,000)
OTHER INCOME (EXPENSE):
Interest and other income	44,000	9,000	52,000	22,000
Interest and other expense	(44,000)	(28,000)	(45,000)	(82,000)
Loss on early extinguishment of debt	(1,696,000)	0	(1,696,000)	0
NET LOSS	(8,753,000)	(12,055,000)	(16,417,000)	(20,147,000)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING Basic and Diluted (in Shares)	109,405,778	77,523,005	106,344,857	74,089,786
BASIC AND DILUTED LOSS PER COMMON SHARE (in Dollars per share)	$ (0.08)	$ (0.16)	$ (0.15)	$ (0.27)
COMPREHENSIVE LOSS	$ (8,753,000)	$ (12,055,000)	$ (16,417,000)	$ (20,147,000)