In September 2021, the Company's Board of Directors adopted, and its stockholders approved, the 2021 Incentive Award Plan (the 2021 Plan). Upon the adoption of the 2021 Plan, the Company restricted the grant of future equity awards under the 2020 Equity Incentive Plan (the 2020 Plan).

The 2021 Plan provides for the grants of stock options and other equity-based awards to employees, non-employee directors, and consultants of the Company. A total of 5,570,000 shares of the Company’s common stock were initially reserved for issuance pursuant to the 2021 Plan. The number of shares reserved under the 2021 Plan also included 1,032,150 shares of the Company’s common stock that remained available for issuance under the 2020 Plan as of immediately prior to the effectiveness of the 2021 Plan. The 2021 Plan share reserve will be increased by the number of shares under the 2020 Plan that are repurchased, forfeited, expired or cancelled after the effective date of the 2021 Plan. In addition, the number of shares of the Company’s common stock available for issuance under the 2021 Plan will automatically increase on the first day of each fiscal year, beginning with the Company’s 2022 fiscal year, in an amount equal to the lesser of (1) 5% of the outstanding shares of the Company’s common stock on the last day of the immediately preceding fiscal year, or (2) such smaller amount as determined by the Company’s Board of Directors.

The options granted under the 2020 Plan and the 2021 Plan are exercisable at various dates as determined upon grant and will expire no more than ten years from their date of grant. The exercise price of each option shall be determined by the Company’s Board of Directors based on the fair market value of the Company’s stock on the date of the option grant. The exercise price shall not be less than 100% of the fair market value of the Company’s common stock at the time the option is granted. Most option grants generally vest 25% on the first anniversary of the original vesting commencement date, with the balance vesting monthly over the remaining three years and early exercise is permitted. The vesting period generally occurs over four years unless there is a specific performance vesting trigger at which time those shares will vest when the performance trigger is probable to occur.

A summary of the Company’s stock option activity for the period ended June 30, 2022 is as follows:


	Options			Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding at December 31, 2021		3,771,516		$	9.18		9.3	$	28,901
Granted		866,798		$	8.57
Exercised		(16,680	)	$	2.25
Forfeited		(116,376	)	$	14.66
Outstanding at June 30, 2022		4,505,258		$	8.79		8.7	$	11,748
Exercisable at June 30, 2022		1,184,526		$	7.45		7.5	$	4,154
Vested and expected to vest as of June 30, 2022		4,505,258		$	8.79		8.7	$	11,748

As of June 30, 2022, 98,879 performance-based stock options were both outstanding and unvested, with total unrecognized stock-based compensation expense of $0.5 million. The achievement of the performance conditions for these options was deemed probable to occur as of June 30, 2022, therefore the Company recognized $0.9 million in expense over the requisite service period related to these awards for the six months ended June 30, 2022.

The achievement of performance conditions for an additional 96,341 performance-based stock options were met during the three months ended June 30, 2022 and vested. The Company recognized $0.6 million of expense related to these awards for the three months ended June 30, 2022 and $1.2 million for the six months ended June 30, 2022.

The Company estimated the fair value of stock options using the Black-Scholes valuation model. The Company accounts for any forfeitures of options when they occur. Previously recognized compensation expense for an award is reversed in the period that the award is forfeited. The fair value of stock options was estimated using the following assumptions:


	Six Months Ended June 30,
	2022	2021
Stock Options:
Stock price	$5.38 - 12.31	$0.99 - 10.75
Risk-free rate of interest	1.6 - 3.6%	0.8 - 1.1%
Expected term (years)	5.1 - 6.1	5.0 - 6.1
Expected stock price volatility	86.4 - 90.4%	98.9 - 99.9%
Dividend yield	—	—


	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development expense	$	1,602	$	153	$	3,080	$	232
General and administrative expense		1,085		185		3,580		280
Total	$	2,687	$	338	$	6,660	$	512

The weighted-average grant date fair value of employee option grants for the six months ended June 30, 2022 and 2021 was $6.40 and $2.67 per share, respectively.

Forfeitures resulting in the reversal of compensation expense were immaterial for the three and six months ended June 30, 2022 and 2021.

As of June 30, 2022, the unrecognized compensation cost related to outstanding employee and nonemployee options was $21.8 million, and is expected to be recognized as expense over a weighted-average period of approximately 2.5 years.

In September 2021, the Company’s Board of Directors approved and adopted the 2021 Employee Stock Purchase Plan (ESPP). The ESPP became effective on the business day immediately prior to the effective date of the Company’s first registration statement. A total of 380,000 shares of the Company’s common stock were initially reserved for issuance pursuant to the ESPP. In addition, the number of shares of the Company’s common stock available for issuance under the ESPP will automatically increase on the first day of each fiscal year, beginning with the Company’s 2022 fiscal year, in an amount equal to the lesser of (1) 1% of the outstanding shares of the Company’s common stock on the last day of the immediately preceding fiscal year, or (2) such smaller amount as determined by the Company’s Board of Directors. The ESPP permits eligible employees who elect to participate in an offering under the ESPP to have up to 15% of their eligible earnings withheld, subject to certain limitations, to purchase shares of common stock pursuant to the ESPP. The price of common stock purchased under the ESPP is equal to 85% of the lower of the fair market value of the common stock at the commencement date of each offering period or the relevant date of purchase. Each offering period is six months, with new offering periods commencing every six months on or about the dates of March 15 and September 15 of each year. During the six months ended June 30, 2022, the Company issued 27,518 shares of common stock in connection with the ESPP.

Certain individuals were granted the ability to early exercise their stock options prior to the IPO. The shares of common stock issued from the early exercise of unvested stock options are restricted and continue to vest in accordance with the original vesting schedule. The Company has the option to repurchase any unvested shares at the original purchase price upon any voluntary or involuntary termination. The shares purchased by the employees and non-employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be outstanding until those shares vest. The cash received in exchange for exercised and unvested shares related to stock options granted is recorded as a liability for the early exercise of stock options on the accompanying balance sheets and will be transferred into common stock and additional paid-in capital as the shares vest. As of June 30, 2022 and December 31, 2021, 427,041 and 599,878 unvested shares issued under early exercise provisions were subject to repurchase by the Company, respectively. As of June 30, 2022 and December 31, 2021, the Company recorded $0.3 million and $0.4 million, respectively, associated with shares issued with repurchase rights in other long-term liabilities.