Stock-Based Compensation

3 Months Ended

Mar. 31, 2021

Share-based Payment Arrangement [Abstract]

Stock-based compensation expense has been reported in the Company’s condensed statements of operations for the three months ended March 31, 2021 and 2020 as follows (in thousands):


	Three Months Ended March 31,
	2021		2020
General and administrative	$	475	$	340
Research and development	195		131
Total stock-based compensation	$	670	$	471

As of March 31, 2021, the total unrecognized compensation expense related to unvested employee and non-employee stock options was $5.9 million, which is expected to be recognized in expense over a weighted-average period of approximately 2.6 years.

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.

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 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 and zero for the three months ended March 31, 2021 and 2020, respectively. As of March 31, 2021, 62,063 shares of common stock had been issued under the ESPP.

As of March 31, 2021, 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 1.1 years.