Stock-Based Compensation

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Stock-based compensation expense has been reported in the Company’s condensed statements of operations as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
General and administrative	$	500	$	510	$	943	$	984
Research and development	215		219		369		414
Total stock-based compensation	$	715	$	729	$	1,312	$	1,398

As of June 30, 2022, the total unrecognized compensation expense related to unvested employee and non-employee stock option awards was $4.4 million, which is expected to be recognized in expense over a weighted-average period of 2.6 years. As of June 30, 2022, the total unrecognized compensation expense related to unvested employee and non-employee restricted stock units was $0.3 million, which is expected to be recognized in expense over a weighted-average period of 2.6 years. These amounts include grants of stock options and restricted stock units made under the 2018 Equity Incentive Plan and the 2022 Inducement Plan, which was established on January 14, 2022.

In October 2018, the Company's board of directors and stockholders approved the ESPP, which became effective on October 17, 2018. The ESPP is intended to qualify as an "employee stock purchase plan" within the meaning of Section 423 of the Internal Revenue Code for U.S. employees.

Under the ESPP, eligible employees are granted rights to purchase shares of common stock, which are funded through payroll deductions that cannot exceed 15% of each employee’s compensation. The ESPP generally provides for a 24-month offering period, which includes four six-month purchase periods. At the end of each purchase period, eligible employees are permitted to purchase shares of the Company's common stock at 85% of the lower of fair market value at the beginning of the offering period or fair market value at the end of the purchase period. The ESPP is considered a compensatory plan, and the Company recorded stock-based compensation expense of $0.1 million for the three months ended June 30, 2022 and 2021 and $0.2 million and $0.1 million for the six months ended June 30, 2022 and 2021, respectively. As of June 30, 2022, the Company issued 513,864 shares of common stock under the ESPP.

As of June 30, 2022, the total unrecognized compensation expense related to the ESPP was $0.5 million, which is expected to be recognized over a weighted-average period of approximately 1.3 years.