STOCK-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Schedule of Stock Options Valuation Assumptions

The assumptions that the Company used to determine the grant-date fair value of options granted were as follows, presented on a weighted-average basis:

	December 31,
	2021		2020
Risk-free interest rate	0.93	%	0.91	%
Expected term (in years)	5.6		6.1
Expected volatility	76.0	%	63.8	%
Expected dividend yield	0	%	0	%

Schedule of Stock Option Activity

The following table summarizes the stock option activity under the Company’s equity awards plans:

	Options	Weighted Average Exercise Price		Weighted Average Remaining Life (in Years)	Intrinsic Value (in thousands)
Outstanding December 31, 2020	3,752,744	$	15.71	9.0	$	62,842
Granted	1,996,644	$	21.61
Exercised	(110,621)	$	6.02
Cancelled or forfeited	(734,928)	$	22.24
Outstanding December 31, 2021	4,903,839	$	17.38	7.6	$	847
Options vested or expected to vest at December 31, 2021	4,903,839	$	17.38	7.6	$	847
Options exercisable at December 31, 2021	1,791,964	$	14.27	6.4	$	583

Schedule of Restricted Stock Activity

The following table summarizes restricted stock activity since January 1, 2020:

	Number of shares	Weighted average grant date fair value
Unvested restricted common stock as of January 1, 2020	—	$	—
Granted	61,000	$	29.65
Vested	(6,664)	$	30.00
Unvested restricted common stock as of December 31, 2020	54,336	$	29.68
Granted	10,000	$	28.69
Vested	(27,002)	$	26.46
Cancelled or forfeited	(6,667)	$	1.21
Unvested restricted common stock as of December 31, 2021	30,667	$	29.53

Schedule of Stock-Based Compensation

The Company recorded stock-based compensation expense in the following award type categories included within its consolidated statements of operations and comprehensive loss:

	December 31,
	2021		2020
Stock options	$	12,964	$	7,344
Restricted stock units	812		404
Employee Stock Purchase Plan and Other	261		17
	$	14,037	$	7,765

The Company recorded stock-based compensation expense related to stock options and restricted stock units in the following expense categories of its consolidated statements of operations and comprehensive loss:

	December 31,
	2021		2020
Research and development	$	6,324	$	3,607
General and administrative	7,713		4,158
	$	14,037	$	7,765