XML 42 R20.htm IDEA: XBRL DOCUMENT v3.24.0.1
Stockholders' Equity
 12 Months Ended
Dec. 31, 2023
Stockholders' Equity Note [Abstract]  
Stockholders' Equity Stockholders’ Equity
Preferred Stock
   Shares Outstanding as of
December 31,
 Shares AuthorizedShares Issued20232022
Series C Preferred Stock, par $0.001
1,091 1,091 9 9 

The holder of a share or shares of Series C preferred stock has the right at any time, at such holder’s option, to convert all or any lesser portion of such holder’s shares of the preferred stock into fully paid and non-assessable shares of common stock. As of December 31, 2021, the conversion value was $326.40 per share, such that the outstanding shares of Series C preferred stock were convertible into an aggregate of 275 shares of common stock.
Issuances of Common Stock
On November 9, 2021, the Company entered into an ATM Equity OfferingSM Sales Agreement (the “2021 Sales Agreement”) with outside sales agents (collectively, the “Sales Agents”) for the offer and sale of its common stock for an aggregate offering price of up to $300.0 million. The 2021 Sales Agreement provides that the Sales Agents will be entitled to compensation in an amount equal to up to 3.0% of the gross sales proceeds of any common stock sold through the Sales Agents under the 2021 Sales Agreement. During the years ended December 31, 2023 and 2022, the Company sold 875,305 and 2,870,478 shares, respectively, of its common stock under the 2021 Sales Agreement. The sales were made at a weighted average price of $6.33 and $29.34 per share, respectively, resulting in aggregate net proceeds of $5.5 million and $83.0 million, respectively. As of December 31, 2023 there was $161.8 million of remaining capacity under the 2021 Sales Agreement.
During the three months ended March 31, 2023, the Company issued 760,083 shares of common stock pursuant to the securities class action settlement, as described in Note 11.
Stock Options and Restricted Stock Units
The Company's Board of Directors adopted the 2023 Omnibus Incentive Plan (the “2023 Plan”) on March 24, 2023, pursuant to which the Company may grant stock options, restricted stock awards, RSUs and other stock-based awards or short-term cash incentive awards to employees, directors and consultants.
The 2023 Plan was approved by stockholders on May 16, 2023. The aggregate number of shares of the Company’s common stock that may be issued under the 2023 Plan will not exceed the sum of 1,166,666 shares plus any shares that may return from time to time from the 2016 Omnibus Incentive Plan (as amended, the “2016 Plan”) as a result of expirations, terminations or forfeitures of awards outstanding under the 2016 Plan as of May 16, 2023. At December 31, 2023, the Company had 1,334,012 shares of common stock available for future grant under the 2023 Plan, 1,875 shares underlying outstanding but unvested RSUs and 3,150 shares underlying options outstanding to purchase common stock under the 2023 Plan. The awards granted and available for future grant under the 2023 Plan generally vest over three years and have a maximum contractual term of ten years. The 2023 Plan terminates by its terms on March 24, 2033.
At December 31, 2023, the Company had 262,641 shares underlying outstanding but unvested RSU and options outstanding to purchase 961,499 shares of common stock under the 2016 Plan. The outstanding awards granted under the 2016 Plan generally vest over three years and have a maximum contractual term of ten years. Following adoption of the 2023 Plan, no further awards may be made under the 2016 Plan, but outstanding awards continue to be governed by their existing terms.
On June 24, 2022, the Company's board of directors adopted a stock-based incentive plan (the "2022 Inducement Plan"), which provides for the discretionary grant of nonstatutory stock options, stock appreciation rights, restricted stock awards, RSU awards, performance awards, and other awards to individuals as a material inducement to entering into employment with the Company. The aggregate number of shares of the Company’s common stock that may be issued under the 2022 Inducement Plan will not exceed 166,666 shares. At December 31, 2023 the Company had 125,575 shares of common stock available for future grant under the 2022 Inducement Plan, 10,278 shares underlying outstanding but unvested RSUs and options outstanding to purchase 27,759 shares of common stock under the 2022 Inducement Plan. The 2022 Inducement Plan can be terminated by the Company's board of directors at any time.
The Amended and Restated 2007 Omnibus Incentive Plan (the "2007 Incentive Plan") was adopted on March 31, 2007 and terminated by its terms on March 31, 2017. At December 31, 2023, the Company had options outstanding to purchase 136,456 shares of common stock under the 2007 Incentive Plan. The awards granted under the 2007 Incentive Plan generally vest over three years and have a maximum contractual term of ten years.
Total employee and director stock-based compensation expense recognized in the consolidated statements of operations for the years ended December 31, 2023, 2022 and 2021 was $10.4 million, $22.2 million and $25.0 million, respectively, of which $4.5 million, $8.8 million and $13.4 million was included in research and development expenses and $5.9 million, $13.4 million and $11.6 million was included in general and administrative expenses, respectively.
At December 31, 2023 and 2022, there was $4.3 million and $10.5 million, respectively, of total unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average period of 1.3 years and 1.6 years, respectively.
At December 31, 2023 and 2022, there was $3.5 million and $7.2 million, respectively, of total unrecognized compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 1.5 years and 1.7 years, respectively.
The fair value of stock options granted to non-employees was estimated using the Black-Scholes pricing model. Total stock-based compensation expense for stock options and RSUs granted to non-employees for the years ended December 31, 2023, 2022 and 2021 was $669,000, $1.3 million and $1.4 million, respectively. As of December 31, 2023, options to purchase 61,808 shares of common stock granted to non-employees remained outstanding.
The following table summarizes total stock options outstanding at December 31, 2023:
 
 Options OutstandingOptions Exercisable
Exercise PriceShares Underlying Options
Outstanding		Weighted-Average
Remaining
Contractual Life
(in Years)		Weighted
Average
Exercise Price		Shares Underlying Options
Exercisable		Weighted Average
Exercise Price
$4.32-$18.00
283,472 9.2$14.11 66,918 $14.45 
$18.01-$39.00
264,108 7.3$35.69 141,600 $34.99 
$39.01-$52.00
156,505 4.5$44.93 156,271 $44.93 
$52.01-$90.00
129,681 4.2$76.82 121,124 $77.75 
$90.01-$130.00
136,716 4.2$100.15 131,640 $100.00 
$130.01-$233.28
158,382 5.4$140.27 129,250 $141.78 
1,128,864 6.4$58.76 746,803 $72.11 

At December 31, 2023, the aggregate intrinsic value of options outstanding was $2,000, the aggregate intrinsic value of options exercisable was $1,000, and the weighted average remaining contractual term of options exercisable was 5.5 years.
At December 31, 2023, the aggregate intrinsic value of unvested RSUs was $1.7 million and the aggregate intrinsic value of RSUs which vested during the year ended December 31, 2023 was $1.3 million.
At December 31, 2023, options to purchase 1,128,864 shares of common stock and 274,794 RSUs were expected to vest.
Stock option activity under the Company’s equity incentive plans during the year ended December 31, 2023 was as follows:
Number of
Shares		Weighted-Average
Exercise Price
Balance, December 31, 20221,018,095 $75.32 
Granted339,019 14.23 
Exercised— — 
Cancelled(228,250)66.47 
Balance, December 31, 20231,128,864 $58.76 

Restricted stock unit activity under the Company’s equity incentive plans during the year ended December 31, 2023 was as follows:
Number of
Shares
Balance, December 31, 2022212,964 
Granted194,747 
Vested(99,420)
Cancelled(33,497)
Balance, December 31, 2023274,794 

The weighted average exercise price per share was $38.86 for the 9,357 options which expired during the year ended December 31, 2023, $101.64 for the 6,437 options which expired during the year ended December 31, 2022 and $54.72 for the 583 options which expired during the year ended December 31, 2021.
The weighted average grant date fair value per share was $11.19, $28.08 and $91.32 for options granted during the years ended December 31, 2023, 2022 and 2021, respectively.
The weighted average grant date fair value was $10.34, $37.44 and $124.44 per share for RSUs granted during the years ended December 31, 2023, 2022 and 2021, respectively.
No stock options were exercised during the year ended December 31, 2023. The Company received $283,000 and $6.7 million in proceeds from the exercise of stock options during the years ended December 31, 2022 and 2021, respectively. The aggregate intrinsic value of options exercised was $81,000 and $7.0 million during the years ended December 31, 2022 and 2021, respectively.