On March 5, 2015, the Company’s Board adopted and the Company’s stockholders approved, the Company’s 2015 Equity Incentive Plan (the “2015 Plan”). Awards under the 2015 Plan may include, but need not be limited to, one or more of the following: options, stock appreciation rights, restricted stock, performance grants, stock bonuses, and any other type of award deemed by the administrator to be consistent with the purposes of the 2015 Plan. The exercise price of all options awarded under the 2015 Plan must be no less than 100% of the fair market value of the Company common stock as determined on the date of the grant and have a term of no greater than ten years from the date of grant. In February 2018, the 2015 Plan was amended making available 12.5% of shares of common stock issued and outstanding. As of March 31, 2021, there were 2,485,717 shares available for grant under the 2015 Plan.

On August 23, 2018 the stockholders approved the Amended and Restated 2016 Stock Option Plan for Non-Employee Directors (the “2016 Director Plan”), which: (i) increased the total number of shares of Common Stock authorized and reserved for issuance under the 2016 Director Plan by 2,000,000 shares to 2,750,000 shares: (ii) made “Initial Grants” upon a director’s initial appointment to the Board consisting of an immediate stock option grant of 100,000 shares at fair market value; and (iii) made “Annual Grants” for members who continue in service as members of the Board subsequent to each annual meeting of stockholders occurring subsequent to an Initial Grant, an annual stock option grant of 50,000 shares at fair market value. The Initial Grants and Annual Grants have a ten year term, subject to applicable termination or forfeiture provisions, and vest in equal quarterly increments over a one-year period from the date of grant. As of March 31, 2021, there were 889,167 shares available for grant under the 2016 Director Plan.

As of March 31, 2021, and 2020, there was approximately $3.6 million and $4.2 million, respectively, of total unrecognized compensation related to non-vested stock options. The cost is expected to be recognized over the remaining weighted average remaining amortization period of 2.8 years. During the years ended March 31, 2021 and 2020, the Company had stock compensation expense of $3.5 million and $6.1 million, respectively. For the year ended March 31, 2021, stock compensation expense is recognized as $2.1 million in general and administrative expense, $1.4 million in research and development expense. For the year ended March 31, 2020, stock compensation expense recognized was $3.6 million in general and administrative expense and $2.5 million in research and development expense.

The Company uses the Black-Scholes option pricing model to determine the fair value of stock options granted. For employees and non-employees, the compensation expense is amortized on a straight-line basis over the requisite service period, which approximates the vesting period. The Company accounts for forfeitures as they occur, rather than estimating forfeitures as of an award’s grant date.

The expected volatility of options granted has been determined using the method described under ASC 718 using a blend of the Company’s expected volatility and those of similar companies. The expected term of options granted to employees, non-employees and consultants in the current fiscal period has been based on the term by using the simplified “plain-vanilla” method as allowed under SAB No. 110 and ASU 2018-7.

The assumptions utilized to estimate the fair value of stock options granted are presented in the following table:

	Year Ended
	March 31,
	2021	2020
Risk free interest rate	0.174% - 0.527%	0.304% - 2.38%
Expected volatility	88.02% - 101.67%	71.65% - 78.95%
Expected term	2.8 - 6.1 years	2.5 - 6 years
Dividend yield	0.0%	0.0%

The following is a summary of the activity of the Company’s stock options under the 2015 Plan and 2016 Director Plan as of March 31, 2021:

	Number of Options			Weighted Average Exercise Price
Outstanding at March 31, 2020		11,815,982		$	3.43
Granted		5,568,000			1.24
Exercised		(2,028,203	)		2.64
Cancelled/Forfeited		(2,767,711	)		1.93
Outstanding at March 31, 2021		12,588,068			2.92
Options exercisable at March 31, 2021		8,232,897		$	3.77

Weighted-average grant date fair value of options granted during the years ended March 31, 2021 and 2020 was $0.89 and $0.96, respectively.

During the year ended March 31, 2021, holders of options issued under the equity incentive plans exercised their rights to acquire an aggregate of 2,028,203 shares of common stock at a weighted average exercise price of $2.64. The total proceeds to the Company from these option exercises were $5.4 million. There were no option exercises during the year ended March 31, 2020.

Stock Options Outstanding

Stock Options Vested

Range of

Exercise

Price

Number

Outstanding

at March 31,

2021

Weighted

Average

Exercise

Price

Weighted

Average

Remaining

Life (Years)

Aggregate

Intrinsic

Value

Number

Vested at

March 31,

2021

Weighted

Average

Exercise

Price

Weighted

Average

Remaining

Life (Years)

Aggregate

Intrinsic

Value

$0.95 - $8.75

12,588,068

2.92

7.33

3,295,837

8,232,897

3.77

6.46

1,002,042

The intrinsic value calculated as the excess of the market value as of March 31, 2021 over the exercise price of the options is $3.3 million. The market value as of March 31, 2021 was $1.78 as reported by the NASDAQ Capital Market. The total intrinsic value of options exercised during the year ended March 31, 2021 was $1.7 million.

	Options			Weighted Average Grant Date Fair Value Per Share
Non-vested options at March 31, 2020		3,591,507		$	1.36
Granted		5,568,000			0.89
Vested		(2,920,332	)		1.27
Cancelled/Forfeited		(1,884,004	)		1.13
Non-vested options at March 31, 2021		4,355,171		$	0.91

The fair value of options vested during the years ended March 31, 2021 and 2020 was $3.7 million and $6.0 million, respectively.