Summary of Significant Accounting Policies (Tables)

9 Months Ended

12 Months Ended

Jan. 31, 2015

Apr. 30, 2014

Accounting Policies [Abstract]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

The following table presents information about our warrants liability, which was our only financial instrument measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of January 31, 2015 and April 30, 2014 (in thousands):

Balance, May 1, 2014	$	(2,011)
Transfers to (from) Level 3		-
Total (gains) losses included in earnings		1,401
Purchases, issuances and settlements, net		-
Balance, January 31, 2015	$	(610)

The following table presents information about our warrant liability, which was our only financial instrument measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of April 30 (dollars in thousands):

	2014		2013
Balance beginning of year	$	(1,046)	$	(555)
Transfers to (from) Level 3		-		-
Total gains (losses) included in earnings		(965)		(74)
Issuances		-		(417)
Balance end of year	$	(2,011)	$	(1,046)

Public Utility Property, Plant, and Equipment [Table Text Block]

Property and equipment is recorded at cost and primarily consists of laboratory equipment, furniture and fixtures, and computer hardware and software. Depreciation is calculated on a straight-line basis over the estimated useful lives of the various assets ranging from three to seven years. Property and equipment consisted of the following (in thousands):

	April 30,
	2014		2013
Furniture and fixtures	$	69	$	59
Computer equipment and software		655		549
Laboratory equipment		296		179
Leasehold improvements		2		2
Total property and equipment		1,022		789
Less: Accumulated depreciation		(588)		(375)
Property and equipment, net	$	434	$	414

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

The following table reflects the total potential share-based instruments outstanding at January 31, 2015 and 2014 that could have an effect on the future computation of dilution per common share:

	January 31,
	2015		2014
Stock options		23,990,008		22,633,955
Warrants		3,126,667		3,276,667
Total common stock equivalents		27,116,675		25,910,622

The following table reflects the total potential share-based instruments outstanding at April 30, 2014 and 2013, that could have an effect on the future computation of dilution per common share:

	Year Ended April 30,
	2014		2013
Stock options		23,351,037		13,890,205
Warrants		3,276,667		3,276,667
Restricted stock		-		50,000
Total common stock equivalents		26,627,704		17,216,872