CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013
Operating activities:
Net loss	$ (7,406)	$ (6,330)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,807	2,376
Net foreign currency remeasurement loss	124	0
Depreciation expense	213	203
Change in fair value of warrant liability	965	74
Changes in operating assets and liabilities:
Accounts receivable	(825)	84
Grant receivable	0	0
Prepaid expenses, deposits and other	(68)	(110)
Restricted cash	27	(42)
Accounts payable	(223)	(472)
Accrued liabilities	(24)	(14)
Deferred revenue	977	(71)
Net cash used in operating activities	(3,433)	(4,302)
Investing activities:
Purchase of property and equipment	(234)	(57)
Net cash used in investing activities	(234)	(57)
Financing activities:
Private placement of common shares and warrants	0	9,141
Proceeds from exercise of options and warrants	21	0
Net cash provided by financing activities	21	9,141
Exchange rate effect on cash and cash equivalents	(24)	25
Increase (decrease) in cash and cash equivalents	(3,670)	4,807
Cash and cash equivalents, beginning of year	9,561	4,754
Cash and cash equivalents, end of year	$ 5,891	$ 9,561