Share-Based Payments

The Company has in place a 2010 Equity Incentive Plan and a 2008 Equity Incentive Plan. In general, these plans provide for stock-based compensation in the form of (i) Non-statutory Stock Options; (ii) Restricted Stock Awards; and (iii) Stock Appreciation Rights to the Company’s employees, directors and non-employees. The plans also provide for limits on the aggregate number of shares that may be granted, the term of grants and the strike price of option awards.

Stock-based compensation in the amount of $88,000 and $148,000 was recognized for the three months ended October 31, 2018 and 2017, respectively. The decrease in 2018 is due to a $56,529 option modification charge that was included in 2017 stock-based compensation under general and administrative expenses. Stock-based compensation in the amount of $171,000 and $741,000 was recognized for the six months ended October 31, 2018 and 2017, respectively. Included in 2018 stock-based compensation expense for the six months ended October 31, 2018 and 2017 under general and administrative line item is $7,500 and $30,000 issuance of common stock as compensation for services performed, respectively. Stock-based compensation expense was recognized as follows (table in thousands):



	Three Months Ended October 31,				Six Months Ended October 31,
	2018		2017		2018		2017
General and administrative	$	23	$	96	$	83	$	549
Sales and marketing	40		7		47		41
Research and development	5		42		9		122
Cost of oncology solutions	20		3		32		29
Total stock-based compensation expense	$	88	$	148	$	171	$	741

On October 31, 2018, there was $1,244,698 in unrecognized stock based compensation which will be recognized as expense over 4.5 years.

Stock Option Grants

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



	Three Months Ended October 31,		Six Months Ended October 31,
	2018	2017	2018	2017
Expected term in years	6	—	6	6
Risk-free interest rates	2.78%	—%	2.78% - 2.82%	1.98%
Volatility	83.88%	—%	83.88% - 84.35%	87.10%
Dividend yield	—%	—%	—%	—%

The weighted average fair value of stock options granted during the three months ended October 31, 2018 and 2017 was $6.17 and $0.00, respectively, and $6.16 and $1.84 was recognized for the six months ended October 31, 2018. The Company’s stock options activity for the six months ended October 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	—	141,957		141,957		8.55		9.8
Exercised	—	(380,925	)	(380,925	)	2.16		4.8	2,782,000
Forfeited	—	—		—		—
Canceled	—	—		—		—
Expired	—	—		—		—

Outstanding, October 31, 2018	50,000	2,416,877		2,466,877		3.28		5.9	$	22,630,000

Vested and expected to vest as of October 31, 2018	50,000	2,416,877		2,466,877		3.11		5.9	$	22,630,000

Exercisable as of October 31, 2018	25,836	2,110,961		2,136,797		2.71		5.4	$	20,410,000

Stock Purchase Warrants

As of October 31, 2018 and April 30, 2018, the Company had warrants outstanding for the purchase of 1,878,219 and 2,004,284, respectively, shares of its common stock, all of which were exercisable. 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	(126,065	)	5.74		—	—
Expired	—		—		—	—

Outstanding, October 31, 2018	1,878,219		$	5.56	1.27	$	—