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. There was no preferred stock outstanding as of December 31, 2022, 2021, or 2020.

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 of $24.0 million, were $274.1 million.

On July 2, 2021, the Company entered into a sales agreement (the 2021 Sales Agreement) with Cowen and Company, LLC (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 2021 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). During the years ended December 31, 2022 and 2021, the Company sold 7,771,812 and 780,549 shares of its common stock, respectively, pursuant to the 2021 Sales Agreement and received net proceeds of $121.1 million and $19.6 million, respectively, after deducting offering-related transaction costs and commissions of $3.7 million and $0.7 million, respectively.

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 of $10.5 million. The shares sold in the offering were registered pursuant to the Company’s Shelf Registration Statement.

On November 8, 2022, the Company entered into a sales agreement (the 2022 Sales Agreement) with the Sales Agent, with substantially similar terms as the 2021 Sales Agreement. Under the 2022 Sales Agreement, the Company may, from time to time, sell shares of its common stock having an aggregate offering price of up to $200.0 million through the Sales Agent. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Sales Agent. The Company is not obligated to sell, and the Sales Agent is not obligated to buy or sell, any shares of common stock under the 2022 Sales Agreement. Upon entry into the 2022 Sales Agreement, the 2021 Sales Agreement was terminated. See Note 10 (Subsequent Events) for information on additional shares sold after December 31, 2022.

On December 15, 2022, the Company completed a public offering of 13,800,000 shares of its common stock at a public offering price of $17.25 per share. The net proceeds from the offering were $223.8 million, after deducting underwriting discounts, commissions and offering costs of $14.3 million. The shares sold in the offering were registered pursuant to the Company’s Shelf Registration Statement.

Through December 2019, the company issued an aggregate of 37,267,331 shares of convertible preferred stock and issued an additional 537,232 shares of convertible preferred stock in January 2020. In connection with the completion of the IPO in June 2020, all of the outstanding shares of convertible preferred stock were converted into 17,921,069 shares of the Company’s common stock.

The Company's board of directors adopted, and the company's shareholders approved, the 2013 Equity Incentive Plan (the 2013 Plan) and the 2020 Incentive Award Plan (the 2020 Plan). Under the plans, 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-

A total of 3,900,000 shares of common stock were initially reserved for issuance under the 2020 Plan. 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. Through December 31, 2022, 4,266,161 additional shares were reserved for issuance under the 2020 Plan.

In December 2022, the Company’s board of directors adopted the 2022 Employment Inducement Incentive Award Plan (the Inducement Plan). Under the Inducement Plan, the Company may grant non-qualified stock options, restricted stock, restricted stock units, stock appreciation rights, and other stock or cash-based awards to an employee in connection with his or her commencement of employment with the Company or an affiliate. A total of 1,500,000 shares of common stock were reserved for issuance under the Inducement Plan.

Options granted from the 2013 Plan, 2020 Plan, and the Inducement 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.


	Shares Available for Grant	Number of Outstanding Options	Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Balance at December 31, 2021	2,575	5,778	$	14.49
Additional shares authorized under 2020 Plan	2,387	—
Shares authorized under Inducement Plan	1,500	—
Granted	(4,450)	4,450	15.42
Exercised	—	(351)	1.34
Forfeited/expired	525	(525)	17.05
Balance at December 31, 2022	2,537	9,352	$	15.28	8.34	$	72,280
Vested and expected to vest at December 31, 2022		9,352	$	15.28	8.34	$	72,280
Exercisable at December 31, 2022		3,659	$	13.42	7.64	$	36,120

The aggregate intrinsic values presented in the table above were calculated as the difference between the closing price of the Company’s common stock at December 31, 2022 and the exercise price of stock options that had strike prices below the closing price.


	Year Ended December 31,
	2022		2021		2020
Cash received from options exercised	$	470	$	930	$	53
Intrinsic value of options exercised	$	6,724	$	3,436	$	516
Weighted-average grant date fair value per share	$	11.11	$	16.78	$	11.63

The total intrinsic values of options exercised were calculated as the difference between the fair value of the Company’s common stock at the time of the option exercise and the exercise price of that stock option.

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 offering 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 issued 90,535, 33,147, and 28,979 shares of common stock under the ESPP during the years ended December 31, 2022, 2021, and 2020, respectively. The Company had an outstanding liability of $78 thousand at December 31, 2022, which is included in accounts payable and accrued liabilities on the balance sheet, for employee contributions to the ESPP for shares pending issuance at the end of the current offering period. As of December 31, 2022, 548,028 shares of common stock were available for issuance under the ESPP.


	Options			ESPP
	Year Ended December 31,			Year Ended December 31,
	2022	2021	2020	2022	2021	2020
Risk-free interest rate	1.5% - 4.2%	0.5% - 1.3%	0.3% - 1.5%	2.2% - 4.7%	0.1%	0.1% - 0.2%
Expected volatility	85%	86% - 88%	88% - 92%	78% - 79%	69% - 75%	75% - 96%
Expected term (in years)	5.5 - 6.1	5.5 - 6.1	5.4 - 6.1	0.5	0.5	0.5
Expected dividend yield	—%	—%	—%	—%	—%	—%

Risk-Free Interest Rate. The Company bases the risk-free interest rate assumption for equity awards on the rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued.

Expected Volatility. Due to the limited trading history of the Company’s common stock, the expected volatility assumption is based on volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology industry. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available.

Expected Term. The Company's limited option exercise history does not provide a reasonable basis for estimating expected term, therefore the Company has estimated the expected life of its stock options using the simplified method, whereby the expected life equals the average of the vesting term and the original contractual term of the option. The expected life assumption for employee stock purchases under the ESPP is six months to conform with the six-month ESPP offering period.


	Year Ended December 31,
	2022		2021		2020
Research and development expense	$	15,222	$	9,228	$	1,895
General and administrative expense	11,917		7,828		2,415
Total stock-based compensation expense	$	27,139	$	17,056	$	4,310

As of December 31, 2022, the unrecognized compensation cost related to outstanding time-based options was $65.1 million, which is expected to be recognized over a weighted-average period of 2.6 years. As of December 31, 2022, the unrecognized compensation cost related to stock purchase rights under the ESPP was $0.4 million, which is expected to be recognized over a weighted-average period of 0.5 years.