Stock-Based Compensation | Stock-Based Compensation The Company recognized total stock-based compensation expense during the three and six months ended June 30, 2021 and 2020 as follows (table in thousands): Three Months Ended Six Months Ended 2021 2020 2021 2020 Service-based awards: Restricted stock units $ 78 $ (4) $ 182 $ 234 Stock option awards 344 336 735 776 422 332 917 1,010 Performance-based awards: Restricted stock awards — — (390) — Restricted stock units — (1,197) — (1,025) Stock option awards 11 (596) (330) (511) 11 (1,793) (720) (1,536) Total $ 433 $ (1,461) $ 197 $ (526) Restricted Stock A summary of the Company’s restricted stock awards during the six months ended June 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 June 30, 2021 78,300 $ 5.70 A summary of the Company’s restricted stock awards during the six months ended June 30, 2020 is as follows: Number of Shares Weighted Average Unvested at January 1, 2020 146,800 $ 5.70 Unvested at June 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 June 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 six months ended June 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 (11,466) 4.81 Unvested at June 30, 2021 342,604 $ 1.17 A summary of the Company’s service-based restricted stock units during the six months ended June 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 (104,168) 4.66 Forfeited (128,460) 4.30 Unvested at June 30, 2020 420,062 $ 3.27 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 $0.2 million was recognized for the three and six months ended June 30, 2021, respectively. Stock-based compensation expense of nil and $0.2 million was recognized for the three and six months ended June 30, 2020, respectively. As of June 30, 2021, the unrecognized stock-based compensation expense was $0.3 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 June 30, 2021, there were no outstanding performance-based restricted stock units. A summary of the Company’s performance-based restricted stock units during the six months ended June 30, 2020 is as follows: Number of Shares Weighted Average Unvested at January 1, 2020 988,958 $ 4.48 Forfeited (905,625) 4.61 Unvested at June 30, 2020 83,333 $ 3.09 Service-Based Stock Options The fair value of the service-based stock options granted for the six months ended June 30, 2021 were based on the following assumptions: June 30, Exercise price $0.90 - $0.94 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 six months ended June 30, 2021 is as follows: Shares Weighted Weighted Aggregate Outstanding at January 1, 2021 5,717,956 $ 4.55 6.6 $ — Granted 1,522,162 0.96 6.0 — Forfeited (277,764) 2.52 — — Expired (1,266,553) 7.35 — — Outstanding at June 30, 2021 5,695,801 $ 3.07 7.8 $ 5,000 Exercisable at June 30, 2021 2,387,440 $ 5.25 5.8 $ — A summary of the Company’s service-based stock option activity for the six months ended June 30, 2020 is as follows: Shares Weighted Weighted Aggregate Outstanding at January 1, 2020 8,210,024 $ 7.06 5.1 $ 107,000 Granted 1,610,344 2.24 5.9 — Forfeited (211,471) 4.41 — — Expired (3,983,335) 8.30 — — Outstanding at June 30, 2020 5,625,562 $ 4.90 6.7 $ 1,000 Exercisable at June 30, 2020 2,809,954 $ 7.09 4.3 $ — 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 six months ended June 30, 2021, the Company granted stock options to purchase up to 1,522,162 shares of common stock to certain employees. During the six months ended June 30, 2021, 277,764 shares were forfeited and 1,266,553 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 $0.7 million for the three and six months ended June 30, 2021, respectively. Stock-based compensation expense recognized for service-based stock options was $0.3 million and $0.8 million for the three and six months ended June 30, 2020, respectively. As of June 30, 2021, total stock-based compensation expense related to unvested options not yet recognized totaled approximately $2.0 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 six months ended June 30, 2021 is as follows: Number of Shares Weighted Average Outstanding at January 1, 2021 750,000 $ 2.20 Expired (375,000) 2.20 Outstanding at June 30, 2021 375,000 $ 2.20 Exercisable at June 30, 2021 — $ — A summary of the performance-based stock options for the six months ended June 30, 2020 is as follows: Number of Shares Weighted Average Outstanding at January 1, 2020 388,125 $ 4.70 Granted 600,000 $ 2.45 Forfeited (388,125) $ 4.70 Outstanding at June 30, 2020 600,000 $ 2.45 Exercisable at June 30, 2020 — $ — Stock-based compensation expense recognized for performance-based stock options was nil and $(0.3) million for the three and six months ended June 30, 2021, respectively. Stock-based compensation expense recognized for performance-based stock options was $(0.6) million and $(0.5) million for the three and six months ended June 30, 2020, respectively. The 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 March 31, 2021. The Company will continue to assess the probability of the performance criteria until such time the criteria becomes probable and the performance-based stock option vests or continues to be non-probable and the performance-based stock option expires. As of June 30, 2021, there was no unrecognized stock-based compensation expense related to unvested performance-based stock options. |