At-the-Market Offering

In June 2020, the Company entered into a sales agreement (the "2020 ATM Sales Agreement") with SVB Securities LLC ("SVB Securities") under which the Company was able to issue and sell shares of its common stock, from time to time, having an aggregate offering price of up to $12.0 million. In May 2022, the Company and SVB Securities amended the 2020 ATM Sales Agreement to increase the maximum aggregate offering price of common stock that it was able to issue and sell from time to time under the 2020 ATM Sales Agreement by $50.0 million, from $12.0 million to up to $62.0 million.

Sales of common stock under the 2020 ATM Sales Agreement were able to be made by any method that was deemed an “at-the-market” offering as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended (the "Securities Act"). The Company was not obligated to make any sales of its common stock under the 2020 ATM Sales Agreement. The Company began making sales pursuant to the 2020 ATM Sales Agreement in July 2020. As of August 15, 2023, the date of termination of the 2020 ATM Sales Agreement, the Company had issued and sold an aggregate of 4,333,394 shares of common stock for gross proceeds of $12.7 million pursuant to the 2020 ATM Sales Agreement, before deducting estimated commissions and allocated fees of $1.0 million.

In June 2023, the Company filed with the SEC a universal shelf registration statement on Form S-3 (the “Shelf Registration Statement”), which allows the Company to offer and sell up to $200.0 million of common stock, preferred stock, debt securities, units and/or warrants from time to time pursuant to one or more offerings at prices and terms to be determined at the time of sale. The Shelf Registration Statement was filed to replace the Company’s prior universal shelf registration statement on Form S-3 and was declared effective on August 15, 2023. Further, in June 2023, the Company entered into a new at-the-market sales agreement with Leerink Partners, LLC (formerly SVB Securities) (the “2023 ATM Sales Agreement”), under which the Company may issue and sell shares of common stock, from time to time by any method that is deemed an “at-the-market” offering as defined in Rule 415(a)(4) under the Securities Act. The Company is not obligated to make any sales of its common stock under the 2023 ATM Sales Agreement. The Company filed a prospectus under the Shelf Registration Statement for the offer and sale of shares of the Company’s common stock having an aggregate offering price of up to $75.0 million pursuant to the 2023 ATM Sales Agreement. In accordance with the terms of the 2023 ATM Sales Agreement, the 2020 ATM Sales Agreement terminated upon effectiveness of the Shelf Registration Statement, at which point the Company was no longer able to issue and sell shares of its common stock under the 2020 ATM Sales Agreement. As of December 31, 2024, the Company had issued and sold 4,498,065 shares of common stock under the 2023 ATM Sales Agreement for gross proceeds of $14.6 million, before deducting estimated commissions and allocated fees of $0.5 million. No shares have been sold under the 2023 ATM Sales Agreement during the six months ended June 30, 2025. On June 2, 2025, the Company terminated the prospectus relating to the 2023 ATM Sales Agreement. The Company may not make any sales of its common stock pursuant to the 2023 ATM Sales Agreement unless and until a new prospectus or prospectus supplement relating to the shares of common stock to be issued and sold pursuant to the 2023 ATM Sales Agreement is filed. The 2023 ATM Sales Agreement otherwise remains in full force and effect.

Private Placements

On October 5, 2021, the Company issued and sold to an initial investor (the "Initial Private Placement Investor"), in a private placement priced at-the-market under Nasdaq rules, (i) 2,373,201 shares of the Company’s common stock and accompanying warrants to purchase an aggregate of 4,746,402 shares of the Company’s common stock, and (ii) pre-funded warrants to purchase up to an aggregate of 4,926,069 shares of the Company’s common stock and accompanying warrants to purchase an aggregate of 9,852,138 shares of the Company’s common stock. Each share of the Company’s common stock and accompanying common stock warrants were sold together at a combined price of $1.62, and each pre-funded warrant and accompanying common stock warrants were sold together at a combined price of $1.619, for gross proceeds of approximately $11.8 million. Each pre-funded warrant had an exercise price of $0.001 per share, became exercisable immediately upon issuance and was exercisable until exercised in full. The accompanying common stock warrants had an exercise price of $1.37 per share and became exercisable immediately upon issuance. Of the accompanying common stock warrants, warrants to purchase an aggregate of 7,299,270 shares had an expiration date of April 5, 2025, and warrants to purchase an aggregate of 7,299,270 shares had an expiration date of October 5, 2028. All of the pre-funded warrants and accompanying common stock warrants issued to the Initial Private Placement Investor have been exercised.

On October 18, 2021, the Company issued and sold to New Enterprise Associates 16, L.P., an existing stockholder of the Company (“NEA”) and related party, in a private placement, 1,851,852 shares of the Company’s common stock and accompanying warrants to purchase an aggregate of 3,703,704 shares of the Company’s common stock. Each share of the Company’s common stock and accompanying common stock warrants were sold together at a combined price of $1.62 for gross proceeds of approximately $3.0 million. The accompanying common stock warrants have an exercise price of $1.37 per share and became exercisable immediately upon issuance. Of the accompanying common stock warrants, warrants to purchase an aggregate of 1,851,852 shares of the Company’s common stock were scheduled to expire on April 18, 2025, and warrants to purchase an aggregate of 1,851,852 shares of the Company’s common stock will expire on October 18, 2028. On April 17, 2025, NEA exercised all of the warrants that would have expired on April 18, 2025. None of the accompanying common stock warrants issued to NEA in the private placement that expire on October 18, 2028 have been exercised.

Total net proceeds from the two October 2021 private placements were $13.7 million, after deducting issuance costs of $1.1 million and excluding any proceeds from the exercise of warrants that were issued and sold in such private placements.

On April 6, 2022, the Company entered into a securities purchase agreement with certain purchasers, pursuant to which the Company agreed to issue and sell to the purchasers, in a private placement priced at-the-market under Nasdaq rules, (i) 4,580,526 shares of the Company’s common stock at a purchase price of $1.90 per share, and (ii) pre-funded warrants to purchase up to an aggregate of 24,379,673 shares of common stock at a purchase price of $1.899 per warrant (the “April 2022 Private Placement”). Each pre-funded warrant has an exercise price of $0.001 per share, became exercisable immediately upon issuance and will be exercisable until the pre-funded warrant is exercised in full. The April 2022 Private Placement, which closed on April 11, 2022, resulted in gross proceeds to the Company of approximately $55.0 million. NEA, an existing stockholder of the Company and a related party, as well as an affiliate of NEA, participated in the offering.

Registered Offerings

On September 27, 2022, the Company issued and sold 14,252,670 shares of the Company’s common stock and, in lieu of common stock to certain investors, pre-funded warrants to purchase 14,247,330 shares of common stock in a public offering (the “September 2022 Offering”), at a public offering price of $1.93 per share of common stock and $1.929 per pre-funded warrant pursuant to an underwriting agreement with SVB Securities; Stifel, Nicolaus & Company, Incorporated; and Oppenheimer & Co. Inc., as representatives of the several underwriters. Each pre-funded warrant has an exercise price of $0.001 per share, became exercisable immediately upon issuance and will be exercisable until the pre-funded warrant is exercised in full. Under the terms of the underwriting agreement, the Company granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 4,275,000 shares of common stock, at the public offering price of $1.93 per share. The underwriters partially exercised the option to purchase 1,600,428 additional shares, which shares were issued and sold on October 25, 2022. The September 2022 Offering, including the initial closing on September 27, 2022 and the option closing on October 25, 2022, resulted in aggregate gross proceeds to the Company of approximately $58.1 million.

On December 17, 2024, the Company issued and sold 12,500,000 shares of the Company’s common stock to certain investors in an underwritten registered direct offering (the “December 2024 Offering”), at an offering price of $4.00 per share of common stock pursuant to an underwriting agreement with Leerink Partners LLC; Stifel, Nicolaus & Company, Incorporated; and Oppenheimer & Co. Inc, as representatives of the several underwriters. The December 2024 Offering resulted in aggregate gross proceeds to the Company of $50.0 million.

On June 5, 2025, the Company issued and sold 17,400,000 shares of the Company's common stock to the public in an underwritten offering, or (the “June 2025 Offering”), at an offering price of $5.75 per share of common stock pursuant to an underwriting agreement with Morgan Stanley & Co. LLC, Leerink Partners LLC, Stifel, Nicolaus & Company, Incorporated and Cantor Fitzgerald & Co., as representatives of the several underwriters. In connection with the offering, the Company also granted the underwriters a 30-day option to purchase up to an additional 2,610,000 shares of common stock at the price to the public, less underwriting discounts and commissions. The underwriters exercised the option in full and settled in cash, concurrent with the offering. The June 2025 Offering resulted in aggregate gross proceeds to the Company of approximately $115.1 million.

The pre-funded and common stock warrants are classified as equity in accordance with ASC 815 given that the pre-funded and common stock warrants are indexed to the Company’s own shares of common stock and meet the requirements to be classified in permanent equity.

Stock-Based Awards

The 2012 Stock Incentive Plan (the “2012 Plan”) was adopted by the Company’s board of directors and stockholders. The 2012 Plan provides for the issuance of stock-based awards to the Company’s employees, officers, directors, consultants and advisors. The Company’s board of directors administers the 2012 Plan. In April 2019, the Company’s board of directors adopted a resolution effective May 7, 2019, that no further equity-based awards may be granted under the 2012 Plan.

In April 2019, the Company’s board of directors adopted the 2019 Stock Incentive Plan (the “2019 Plan”), which became effective on May 7, 2019. The 2019 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The Company’s employees, officers, directors, consultants and advisors are eligible to receive awards under the 2019 Plan. The 2019 Plan is administered by the Company’s board of directors.

In April 2025, the Company’s board of directors approved, and the Company’s stockholders subsequently approved, an amendment to the 2019 Plan (the “Plan Amendment”), which (i) increased the number of shares authorized for issuance under the 2019 Plan by 6,000,000 shares to 16,490,422 shares and (ii) eliminated the evergreen provision of the 2019 Plan. Accordingly, the total number of shares of common stock that may be issued under both the 2019 Plan and the 2012 Plan was 16,768,840 as of June 30, 2025, of which 6,529,502 shares remained available for grant under the 2019 Plan.

Options granted under the 2019 Plan and the 2012 Plan have a maximum term of ten years. Options granted to employees, officers and non-employees generally vest over four years based on varying vesting schedules that primarily include: 25% vesting on the first anniversary date of grant and the balance ratably over the next 36 months or vesting in equal monthly or quarterly installments over four years. Options granted to directors generally vest over one to two years. The Company generally settles stock option exercises with newly issued shares of common stock. As of June 30, 2025 and December 31, 2024, respectively, options to purchase 9,960,920 shares and 7,555,310 shares of common stock were granted and outstanding, net of cancellations, under the 2019 Plan. As of June 30, 2025 and December 31, 2024, respectively, options to purchase 278,418 and 288,944 shares of common stock were granted and outstanding, net of cancellations, under the 2012 Plan.

In February 2024, the Company granted options to purchase 832,250 shares of common stock subject to performance-based vesting (“PSOs”) to employees of the Company. The PSOs were subject to vesting based on the timing and results of the Company’s clinical trials. As of June 30, 2025, the timing and results of the clinical trials had been determined, PSOs to purchase 642,160 shares had vested and the rest were cancelled.

In April 2019, the Company’s board of directors adopted the 2019 Employee Stock Purchase Plan (the “2019 ESPP”), which became effective on May 7, 2019. The 2019 ESPP is administered by the Company’s board of directors.

The total number of shares of common stock that may be issued under the 2019 ESPP was 1,116,075 as of June 30, 2025, all of which remain available for issuance. The number of shares of the Company’s common stock that have been approved to be issued under the 2019 ESPP is equal to the sum of i) 155,106 shares plus ii) an annual increase to be added on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2020 and continuing for each fiscal year until and including, the fiscal year ending December 31, 2029, equal to the least of (a) 526,315 shares of common stock, (b) 1% of the number of outstanding shares of the Company’s common stock on such date and (c) an amount determined by the Company’s board of directors. No annual increase was made on January 1, 2024 and 2025, respectively.