Stock-Based Compensation

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

2014 Employee Stock Purchase Plan

The Company’s 2014 Employee Stock Purchase Plan, or the ESPP, became effective in April 2014, but no offering period has been initiated thereunder since January 2017. There was no stock-based compensation related to the ESPP for the three months ended March 31, 2022 or March 31, 2021.

Amended and Restated 2014 Stock Incentive Plan

The Company maintains the Amended and Restated 2014 Stock Incentive Plan, or the Amended 2014 Plan, which provides for the grant of options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards to employees, officers and directors, and consultants and advisors. There were 2,046,885 shares of common stock authorized for issuance under the Amended 2014 Plan when it was approved by the Company's stockholders in July 2018. The number of authorized shares increases annually on the first day of each fiscal year until, and including, the fiscal year ending December 31, 2024 by the least of (i) 2,000,000, (ii) 4% of the number of outstanding shares of common stock on such date, or (iii) an amount determined by the Company’s board of directors. On January 1, 2022, the number of authorized shares increased by 2,000,000 to 2,201,855.

Summary of Stock Option Activity

The table below summarizes stock option activity under the Amended 2014 Plan and related information for the three months ended March 31, 2022. The exercise price of all options granted during the three months ended March 31, 2022 was equal to the market value of the Company’s common stock on the date of grant. As of March 31, 2022, unamortized stock-based compensation expense of approximately $5.3 million will be amortized over a weighted average period of 2.98 years. At March 31, 2022, 642,175 shares of common stock were available for future awards granted under the Amended 2014 Plan.


	Number of Shares	Weighted Average Exercise Price
Outstanding at December 31, 2021	4,717,602	$	1.65
Granted	1,759,692	1.59
Exercised	—	—
Canceled/forfeited	(200,012)	1.96
Expired	—	—
Outstanding at March 31, 2022	6,277,282	$	1.63
Exercisable at March 31, 2022	2,597,775	$	1.45

Compensation Expense

Total stock-based compensation expense related to stock options granted to employees and directors recognized in the condensed consolidated statements of operations is as follows:


	Three Months Ended March 31,
	2022		2021
Research and development	$	174,613	$	115,625
General and administrative	$	357,796	$	250,286
Total	$	532,409	$	365,911

The assumptions used in the Black-Scholes option-pricing model for stock options granted to employees and to directors in respect of board services during the three months ended March 31, 2022 are as follows:


						Three Months Ended March 31, 2022
Expected life in years						6.02
Risk-free interest rate						1.65%
Expected volatility						122%
Forfeiture rate						0.0%
Dividend yield						0.0%
Weighted-average fair value of options granted						$1.38