Stock-Based Compensation | Stock-Based Compensation The Company recognized total stock-based compensation expense during the three and nine months ended September 30, 2021 and 2020 as follows (table in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Service-based awards: Restricted stock units $ 81 $ 9 $ 263 $ 243 Stock option awards 315 243 1,050 1,019 396 252 1,313 1,262 Performance-based awards: Restricted stock awards — — (391) — Restricted stock units — (123) — (1,148) Stock option awards (35) 121 (364) (390) (35) (2) (755) (1,538) Total $ 361 $ 250 $ 558 $ (276) Restricted Stock A summary of the Company’s restricted stock awards during the nine months ended September 30, 2021 is as follows: Number of Shares Weighted Average Unvested at January 1, 2021 146,800 $ 5.70 Forfeited (68,500) $ 5.70 Unvested at September 30, 2021 78,300 $ 5.70 A summary of the Company’s restricted stock awards during the nine months ended September 30, 2020 is as follows: Number of Shares Weighted Average Unvested at January 1, 2020 146,800 $ 5.70 Unvested at September 30, 2020 146,800 $ 5.70 The fair value of restricted stock awards are measured based on their fair value on the date of grant and amortized over the vesting period of 20 months. As of September 30, 2021, unvested restricted stock awards of 78,300 were related to performance-based awards. The forfeited performance-based restricted stock awards of 68,500 was due to the termination of the Company's former Chief Science Officer on January 19, 2021. These forfeited awards reduced stock-based compensation expense by $0.4 million. Service-Based Restricted Stock Units A summary of the Company’s service-based restricted stock units during the nine months ended September 30, 2021 is as follows: Number of Shares Weighted Average Unvested at January 1, 2021 265,494 $ 2.60 Granted 310,050 0.90 Vested (221,474) 2.38 Forfeited (11,799) 4.81 Unvested at September 30, 2021 342,271 $ 1.17 A summary of the Company’s service-based restricted stock units during the nine months ended September 30, 2020 is as follows: Number of Shares Weighted Average Unvested at January 1, 2020 463,786 $ 4.26 Granted 188,904 2.09 Vested (247,561) 4.30 Forfeited (159,724) 4.26 Unvested at September 30, 2020 245,405 $ 2.72 The fair value of service based restricted stock units are measured based on their fair value on the date of grant and amortized over the vesting period. The vesting periods range from 1 to 3 years. Stock-based compensation expense of $0.1 million and $0.3 million was recognized for the three and nine months ended September 30, 2021, respectively. Stock-based compensation expense of nil and $0.2 million was recognized for the three and nine months ended September 30, 2020, respectively. As of September 30, 2021, the unrecognized stock-based compensation expense was $0.2 million, which is expected to be recognized over an estimated weighted average remaining term of less than 1 year. Performance-Based Restricted Stock Units As of September 30, 2021, there were no outstanding performance-based restricted stock units. A summary of the Company’s performance-based restricted stock units during the nine months ended September 30, 2020 is as follows: Number of Shares Weighted Average Unvested at January 1, 2020 988,958 $ 4.48 Forfeited (988,958) 4.48 Unvested at Unvested at September 30, 2020 — $ — Service-Based Stock Options The fair value of the service-based stock options granted for the nine months ended September 30, 2021 were based on the following assumptions: September 30, Exercise price $0.61 - $1.73 Expected stock price volatility 75.8% - 77.7% Risk-free interest rate 0.47% - 1.06% Term (years) 5.5 - 6 A summary of the Company’s service-based stock option activity for the nine months ended September 30, 2021 is as follows: Shares Weighted Weighted Aggregate Outstanding at January 1, 2021 5,717,956 $ 4.55 6.6 $ — Granted 1,872,162 0.89 6.0 — Forfeited (385,278) 2.30 — — Expired (1,333,220) 7.16 — — Outstanding at September 30, 2021 5,871,620 $ 2.95 7.7 $ — Exercisable at September 30, 2021 2,539,438 $ 4.96 5.8 $ — A summary of the Company’s service-based stock option activity for the nine months ended September 30, 2020 is as follows: Shares Weighted Weighted Aggregate Outstanding at January 1, 2020 8,210,024 $ 7.06 5.1 $ 107,000 Granted 2,252,344 1.95 5.9 — Forfeited (440,026) 3.96 — — Expired (4,090,150) 8.24 — — Outstanding at September 30, 2020 5,932,192 $ 4.54 6.7 $ — Exercisable at September 30, 2020 2,889,218 $ 6.95 3.8 $ — The aggregate intrinsic value in the table above is calculated as the difference between the closing price of the Company's common stock and the exercise price of the stock options that had strike prices below the closing price. During the nine months ended September 30, 2021, the Company granted stock options to purchase up to 1,872,162 shares of common stock to certain employees. During the nine months ended September 30, 2021, 385,278 shares were forfeited and 1,333,220 shares expired. Forfeitures are recorded in the period of occurrence; compensation expense is adjusted accordingly. Stock-based compensation expense recognized for service-based stock options was $0.3 million and $1.0 million for the three and nine months ended September 30, 2021, respectively. Stock-based compensation expense recognized for service-based stock options was $0.2 million and $1.0 million for the three and nine months ended September 30, 2020, respectively. As of September 30, 2021, total stock-based compensation expense related to unvested options not yet recognized totaled approximately $1.7 million, which is expected to be recognized over an estimated weighted average remaining term of 3.0 years. Performance-Based Stock Options A summary of the performance-based stock options for the nine months ended September 30, 2021 is as follows: Number of Shares Weighted Average Outstanding at January 1, 2021 750,000 $ 2.20 Expired (750,000) 2.20 Outstanding at September 30, 2021 — $ — Exercisable at September 30, 2021 — $ — A summary of the performance-based stock options for the nine months ended September 30, 2020 is as follows: Number of Shares Weighted Average Outstanding at January 1, 2020 388,125 $ 4.70 Granted 750,000 $ 2.20 Forfeited (388,125) $ 4.70 Outstanding at September 30, 2020 750,000 $ 2.20 Exercisable at September 30, 2020 — $ — Stock-based compensation expense recognized for performance-based stock options was nil and $(0.4) million for the three and nine months ended September 30, 2021, respectively. Stock-based compensation expense recognized for performance-based stock options was $0.1 million and $(0.4) million for the three and nine months ended September 30, 2020, respectively. The increase in expired performance-based stock options and reduction in stock-based compensation expense was due to the performance criteria of certain performance-based options granted to officers of the Company becoming non-probable as of September 30, 2021. As of September 30, 2021, there was no unrecognized stock-based compensation expense related to unvested performance-based stock options. |