compensation programs, our compensation committee ultimately makes its own decision about these matters. In the future, we expect that our compensation committee will continue to engage independent compensation consultants to provide additional guidance on our executive compensation programs and to conduct further competitive benchmarking against a peer group of publicly traded companies.
Base Salary
We use base salaries to recognize the experience, skills, knowledge and responsibilities required of all our employees, including our named executive officers. None of our named executive officers is currently party to an employment agreement or other agreement or arrangement that provides for automatic or scheduled increases in base salary.
In January 2023, we set the 2023 base salaries for Drs. Hicklin and Isaacs and Mr. Trost at $583,440, $474,000 and $447,000, respectively.
Annual Bonus
The employment agreements for Drs. Hicklin and Isaacs and Mr. Trost provide that they will be eligible for annual bonuses up to a specified percentage of their salary, based upon the assessment of the board of directors (or a committee thereof), in its sole discretion, of the officer’s performance and our Company’s performance during the applicable fiscal year. These annual bonuses are calculated as a percentage of base salary and are designed to motivate our employees to achieve annual goals based on our strategic, financial and operating performance objectives. From time to time, our board of directors or our compensation committee may approve discretionary annual cash bonuses to our named executive officers.
The target annual bonus percentage for the 2023 bonuses was 50% for Dr. Hicklin and 40% for each of Dr. Isaacs and Mr. Trost. With respect to 2023, we awarded bonuses of $332,561, $216,144 and $203,832 to Drs. Hicklin and Isaacs and Mr. Trost, respectively, based on our achievement of certain company goals and individual performance objectives as determined by the compensation committee.
Equity Incentives
Although we do not have a formal policy with respect to the grant of equity incentive awards to our executive officers, or any formal equity ownership guidelines applicable to them, we believe that equity grants provide our executive officers with a strong link to our long-term performance, create an ownership culture and help to align the interests of our executive officers and our stockholders. In addition, we believe that equity grants with a time-based vesting feature promote executive retention because this feature incentivizes our executive officers to remain in our employment during the vesting period. Accordingly, our board of directors periodically reviews the equity incentive compensation of our executive officers, including our named executive officers, and from time to time may grant equity incentive awards to them in the form of stock options.
On January 3, 2023, we granted stock option awards to purchase 295,500 shares, 103,300 shares and 102,800 shares of our common stock to Drs. Hicklin and Isaacs and Mr. Trost, respectively. These stock options vest in equal monthly installments over a four-year period beginning on February 1, 2023 and ending on January 1, 2027.
On January 6, 2022, we granted stock option awards to purchase 215,888 shares, 79,516 shares and 65,960 shares of our common stock to Drs. Hicklin and Isaacs and Mr. Trost, respectively. These stock options vest in equal monthly installments over a four-year period beginning on January 1, 2022 and ending on January 1, 2026.
On July 1, 2022, we granted performance-based stock option awards to purchase 274,670 shares, 101,447 shares and 101,447 shares of our common stock to Drs. Hicklin and Isaacs and Mr. Trost, respectively. These stock options would have vested only upon achievement of specified performance targets related to certain business objectives, with 60% vesting upon the achievement of one performance target and 40% vesting upon the achievement of a second performance target, in each case prior to December 31, 2023. These performance targets were not achieved, and accordingly these awards expired without vesting on December 31, 2023.
The vesting of the stock options granted to our named executive officers is subject to acceleration upon certain terminations of the officer’s employment with us, as described below under “Employment Agreements with our Named Executive Officers.”