XML 36 R25.htm IDEA: XBRL DOCUMENT

Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Option Activity Under Company's Equity Incentive Plans

The following table summarizes stock option activity under the Company’s 2018 Plan and related information:

	Number of Shares Underlying Outstanding Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)
Outstanding — December 31, 2021		2,603,630		$	7.70		7.46
Options granted ⁽¹⁾		10,270,911		$	1.34
Options forfeited and cancelled ⁽¹⁾		(3,920,511	)	$	5.16
Options expired		(47,319	)	$	13.27
Outstanding — September 30, 2022		8,906,711		$	1.42		7.78
Exercisable — September 30, 2022		4,331,100		$	2.38

(1)

Includes options that were cancelled and re-granted as part of the option modification from the special cash dividend, as further discussed above.

Summary of Weighted Average Valuation Assumptions Used to Estimate Fair Value of Employee Stock Options

The fair value of employee stock options was estimated using the following weighted-average assumptions:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2022			2021			2022			2021
Employee Stock Options:
Risk-free rate		3.02	%		0.91	%		2.25	%		0.76	%
Expected term (in years)		6.1			6.0			6.0			6.0
Dividend yield	—			—			—			—
Volatility		91.61	%		90.95	%		91.63	%		93.34	%
Weighted-average fair value of stock options granted	$	1.34		$	3.23		$	0.58		$	4.31

Summary of Stock-Based Compensation Expense Recognized

Total stock-based compensation expense recognized was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Research and development	$	78	$	158	$	289	$	921
General and administrative⁽¹⁾		146		555		796		1,801
Total stock-based compensation expense	$	224	$	713	$	1,085	$	2,722

(1)

Included in general and administrative stock-based compensation for the nine months ended September 30, 2022 is stock-based compensation expense related to 32,684 shares of common stock issued to certain board members in lieu of their cash compensation. No shares of common stock were issued to board members for the three months ended September 30, 2022.