On June 16, 2020, the Company’s certificate of incorporation was amended and restated to authorize 400,000,000 shares of common stock and 40,000,000 shares of undesignated preferred stock, each with a par value of $0.0001 per share.

On June 16, 2020, the Company completed its IPO in which it sold 16,560,000 shares of common stock at an offering price of $18.00 per share. Proceeds from the IPO, net of underwriting discounts, commissions and offering costs, were $274.1 million.

On July 2, 2021, the Company entered into the Sales Agreement with the Sales Agent, under which the Company may, from time to time, sell shares of its common stock having an aggregate offering price of up to $150.0 million through the Sales Agent. Sales of the Company’s common stock made pursuant to the Sales Agreement are made under the Company’s shelf registration statement on Form S-3, which became automatically effective upon filing on July 2, 2021 (the Shelf Registration Statement). In addition, the Sales Agreement may be terminated by the Company or the Sales Agent at any time upon ten days’ notice to the other party, or by the Sales Agent, with respect to itself, at any time in certain circumstances, including the occurrence of a material adverse change. During the three months ended March 31, 2022, the Company sold 1,519,941 shares of its common stock pursuant to the Sales Agreement and received net proceeds of $24.1

million, after deducting offering-related transaction costs and commissions. Through March 31, 2022, the Company has sold 2,300,490 shares of its common stock pursuant to the Sales Agreement and received net proceeds of $43.7 million, after deducting offering-related transaction costs and commissions.

On August 6, 2021, the Company completed a public offering of 9,200,000 shares of its common stock at a public offering price of $18.00 per share. The net proceeds from the offering were $155.1 million, after deducting underwriting discounts, commissions and offering costs. The shares sold in the offering were registered pursuant to the Company’s Shelf Registration Statement.

In January 2013, the Company adopted the 2013 Equity Incentive Plan (the 2013 Plan). The 2013 Plan provided for the issuance of incentive units to employees and nonemployees of the Company and non‑statutory unit options, restricted unit awards, unit appreciation rights, and unit bonuses to directors, employees and consultants of the Company. Under the 2013 Plan, 2,127,013 units were initially reserved for issuance. Upon the conversion of the Company to a C corporation, the 2013 Plan continued on the same terms and conditions. In 2019, the number of shares reserved under the 2013 Plan was increased to 4,771,615 shares.

In June 2020, the Company’s board of directors adopted, and the Company’s stockholders approved, the 2020 Incentive Award Plan (the 2020 Plan), which became effective in connection with the IPO. Pursuant to the 2020 Plan, the Company ceased granting awards under the 2013 Plan. Under the 2020 Plan, the Company may grant stock options, restricted stock, dividend equivalents, restricted stock units, stock appreciation rights, and other stock or cash-based awards to individuals who are then employees, officers, non-employee directors or consultants of the Company. A total of 3,900,000 shares of common stock were initially reserved for issuance under the 2020 Plan. In addition, the number of shares of common stock available for issuance under the 2020 Plan will be increased annually on the first day of each fiscal year during the term of the 2020 Plan, beginning with the 2021 fiscal year, by an amount equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year or (b) such smaller number of shares as determined by the Company’s board of directors. At March 31, 2022, 2,449,129 shares remain available for issuance under the 2020 Plan.

Options granted from the 2013 Plan and 2020 Plan are exercisable at various dates and will expire no more than ten years from their date of grant. Options generally vest over a four-year period. Prior to the IPO, the exercise price of options was determined by the Company’s board of directors. Following the IPO, the Company grants options with an exercise price equal to the fair market value of the Company’s stock on the date of the option grant.

Stock option activity for employee and nonemployee awards and related information is as follows (in thousands, except per share data):

	Number of Options			Weighted- Average Exercise Price Per Share
Outstanding at December 31, 2021		5,778		$	14.49
Granted		2,655			14.95
Exercised		(7	)		1.48
Forfeited/expired		(142	)		22.26
Outstanding at March 31, 2022		8,284		$	14.51

The weighted-average grant date fair value of options granted during the three months ended March 31, 2022 and 2021 were $10.71 and $16.89 per share, respectively.

In June 2020, the Company adopted the ESPP, which permits participants to contribute up to 15% of their eligible compensation during defined rolling six-month periods to purchase the Company’s common stock. The purchase price of the shares will be 85% of the lower of the fair market value of the Company’s common stock on the first day of trading of the offering period or on the applicable purchase date. The Company did not issue any shares of common stock under the ESPP during the three months ended March 31, 2022 and 2021, respectively. The Company had an outstanding liability of

$0.4 million at March 31, 2022, which is included in accounts payable and accrued liabilities on the condensed balance sheet, for employee contributions to the ESPP for shares pending issuance at the end of the offering period. As of March 31, 2022, 638,563 shares of common stock were available for issuance under the ESPP.

The assumptions used in the Black-Scholes model to determine the fair value of stock option grants and shares purchasable under the ESPP were as follows:

	Three Months Ended March 31,
Stock Option Grants	2022	2021
Risk-free interest rate	1.5% - 1.9%	0.5% - 1.1%
Expected volatility	85%	88%
Expected term (in years)	6.0 - 6.1	5.8 - 6.1
Expected dividend yield	—%	—%

	Three Months Ended March 31,
ESPP	2022	2021
Risk-free interest rate	N/A	N/A
Expected volatility	N/A	N/A
Expected term (in years)	N/A	N/A
Expected dividend yield	N/A	N/A

For the three months ended March 31, 2022 and 2021, the Company did not commence any new ESPP offerings that required valuation.

The allocation of stock-based compensation expense was as follows (in thousands):

	Three Months Ended March 31,
	2022		2021
Research and development expense	$	3,266	$	2,010
General and administrative expense		2,972		1,691
Total stock-based compensation expense	$	6,238	$	3,701

As of March 31, 2022, the unrecognized compensation cost related to outstanding time-based options was $68.4 million, which is expected to be recognized over a weighted-average period of 3.0 years. As of March 31, 2022, the unrecognized compensation cost related to stock purchase rights under the ESPP was $0.1 million, which is expected to be recognized over a weighted-average period of 0.2 years.