XML 35 R23.htm IDEA: XBRL DOCUMENT v3.24.1.u1
Stock-Based Compensation Plans (Tables)
3 Months Ended
Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]  
Schedule of Stock Option Activity
The following table summarizes stock option activity for the quarters ended March 31, 2024 and 2023, respectively, for the 2019 Plan:
OptionsWeighted-
Average
Exercise
Price
Weighted-
Average
Remaining
Contractual
Term (Years)
Aggregate
Intrinsic
Value
Outstanding as of January 1, 20246,196,140 $7.15 
Granted4,175,349 $1.21 
Exercised— $— 
Repricing Modification— $9.55 
Forfeited or expired(53,166)$5.25 
Outstanding as of March 31, 202410,318,323 $1.68 8.64$462,223 
Options vested and expected to vest as of March 31, 202410,318,323 $1.68 8.64$462,223 
Options exercisable as of March 31, 20243,224,039 $2.21 7.23$5,500 
OptionsWeighted-
Average
Exercise
Price
Weighted-
Average
Remaining
Contractual
Term (Years)
Aggregate
Intrinsic
Value
Outstanding as of January 1, 20233,791,688 $11.33 
Granted1,815,314 $1.41 
Exercised— $— 
Forfeited or expired(11,161)$13.29 
Outstanding as of March 31, 20235,595,841 $8.11 8.66$161,428 
Options vested and expected to vest as of March 31, 20235,595,841 $8.11 8.66$161,428 
Options exercisable as of March 31, 20231,888,367 $12.66 7.67$1,980 
Schedule of Valuation Assumptions Used The following are the underlying assumptions used in the Black-Scholes option pricing model to determine the fair value of stock options granted to employees and to non-employees under this stock plan:
Three Months Ended March 31,
20242023
Risk-free interest rate4.05%3.97%
Expected dividend yield0%0%
Expected volatility100.0%102.0%
Expected term of options (years)6.026.02
Schedule of Stock-based Compensation Expense for Stock Awards Recognized
Total stock-based compensation expense for all stock awards recognized in the accompanying unaudited condensed consolidated statements of operations is as follows:
 Three Months
 Ended March 31,
 20242023
Research and development$1,163,000 $903,000 
General and administrative1,587,000 1,076,000 
Total$2,750,000 $1,979,000