Share-Based Payments (Tables)

3 Months Ended

Jul. 31, 2018

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

Allocation of Share Based Compensation Expense

Stock-based compensation expense was recognized as follows (table in thousands):

	Three Months Ended July 31,
	2018		2017
General and administrative	$	60	$	423
Sales and marketing	7		34
Research and development	4		80
Cost of oncology solutions	12		27
Total stock-based compensation expense	$	83	$	564

Valuation Assumptions for Stock Options

Black-Scholes assumptions used to calculate the fair value of options granted during the three months ended July 31, 2018 and 2017 were as follows:

	Three Months Ended July 31,
	2018	2017
Expected term in years	6	6
Risk-free interest rates	2.82%	1.98%
Volatility	84.4%	87.1%
Dividend yield	—%	—%

Summary of Stock Option Activity

The Company’s stock options activity for the three months ended July 31, 2018 was as follows:

	Non- Employees	Directors and Employees		Total		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2018	50,000	2,655,845		2,705,845		$	2.85	5.9	$	5,265,000
Granted	—	1,250		1,250		7.17		9.9	1,000
Exercised	—	(20,000	)	(20,000	)	2.10
Forfeited	—	—		—		—
Canceled	—	—		—		—
Expired	—	—		—		—
Outstanding, July 31, 2018	50,000	2,637,095		2,687,095		2.85		5.8	$	14,401,000
Vested and expected to vest as of July 31, 2018	50,000	2,637,095		2,687,095		2.69		5.8	$	14,401,000
Exercisable as of July 31, 2018	25,836	2,454,721		2,480,557		2.63		5.5	$	13,473,000

Summary of Warrant Activity

Activity related to these warrants, which expire at various dates through March 2020, is summarized as follows:

	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding, May 1, 2018	2,004,284	$	5.57	1.8	$	—
Granted	—	—		—	—
Exercised	—	—		—	—
Expired	—	—		—	—
Outstanding, July 31, 2018	2,004,284	$	5.57	1.6	$	—