Licenses and Collaborations	12 Months Ended
Dec. 31, 2024
Licenses And Collaborations [Abstract]
Licenses and Collaborations	9. LICENSES AND COLLABORATIONS Ares Trading S.A. In October 2020, the Company entered into a license agreement with Ares (the Ares Agreement), pursuant to which the Company obtained an exclusive worldwide license to certain patents and related know-how to research, develop, manufacture, use and commercialize therapeutic products containing atacicept, a recombinant fusion protein used to inhibit B cell growth and differentiation, which could potentially treat some autoimmune diseases. As consideration for the Ares Agreement, the Company paid a non-refundable license issue fee to Ares in the form of shares of redeemable convertible preferred stock valued at $13.1 million, resulting in Ares becoming a related party to the Company. The redeemable convertible preferred stock subsequently converted into 1,913,501 shares of common stock in May 2021. In December 2020, the Company paid Ares a milestone payment of $25.0 million upon delivery and initiation of the transfer of specified information and materials. The non-refundable license issue fee and milestone payment were recorded to research and development expense in the period incurred. The Company is obligated to pay Ares aggregate milestone payments of up to $176.5 million upon the achievement of specified BLA filing or regulatory approval milestones, beginning with $15.0 million upon the first filing of an approval application and $20.0 million upon regulatory approval in the U.S., and up to $515.0 million upon the achievement of specified commercial milestones, beginning with $15.0 million if worldwide aggregate annual net sales reach $250.0 million and $50.0 million if worldwide aggregate annual net sales reach $500.0 million. Subsequent to the effective date of the Ares Agreement, Ares has performed transfer of manufacturing technology and know-how to the Company. The Company recorded related party expense of $0.3 million and $2.8 million to Ares for these services during the years ended December 31, 2024 and 2023, respectively. These amounts are included in research and development expenses on the statements of operations and comprehensive loss. Commencing on the first commercial sale of licensed products, the Company is obligated to pay Ares tiered royalties of low double-digit to mid-teen percentages on annual net sales of the licensed products covered by the license. The Company is obligated to pay royalties on a licensed product-by-licensed product and country-by-country basis from the first commercial sale of a product in a country until the latest of (i) 15 years after the first commercial sale of such licensed product in such country; (ii) the expiration of the last valid claim of a licensed patent that covers such licensed product in, or its use, importation or manufacture with respect to, such country; and (iii) expiration of all applicable regulatory exclusivity periods, including data exclusivity, in such country with respect to such product. If the Company were to sublicense its rights under the Ares Agreement, the Company would be obligated to pay Ares a percentage ranging from the mid-single-digit to the low double-digits of specified sublicensing income received. Amplyx Pharmaceuticals, Inc. In December 2021, the Company entered into an asset purchase agreement (the Amplyx Agreement) with Amplyx Pharmaceuticals, Inc. (Amplyx), a wholly owned subsidiary of Pfizer Inc. Pursuant to the terms of the Amplyx Agreement, the Company paid $5.0 million to Amplyx to purchase assets relating to an anti-BKV monoclonal antibody referred to as MAU868 for the treatment of BKV infection pursuant to a License Agreement between Amplyx and Novartis International Pharmaceutical AG (Novartis). In addition, the Company recognized a $2.0 million contingent milestone obligation as an assumed liability related to the asset purchase. The acquisition cost of $7.0 million was recorded as research and development expense in the statement of operations and comprehensive loss on the acquisition date. In connection with the Amplyx asset purchase, Amplyx assigned the Exclusive License Agreement between Amplyx and Novartis (the Novartis License) and Manufacturing and Supply Agreements to the Company. Under the Novartis License, the Company has exclusive worldwide rights from Novartis to develop, manufacture and commercialize MAU868. The Company will be solely responsible for all research, development, regulatory, manufacturing and commercialization activities of MAU868. Under the Amplyx Agreement, the Company is obligated to make future milestone payments to Amplyx and Novartis upon the achievement of specified development, regulatory and commercial milestones. In September 2022, the Company and Novartis entered into an amendment to the Novartis License to modify the terms of future milestone payments. Pursuant to this amendment, the Company issued 283,034 shares of Class A common stock to Novartis in exchange for a reduction of $7.0 million in contingent future development milestones, including the $2.0 million contingent milestone obligation accrued by the Company in December 2021. The value of the shares issued was $5.7 million based on the closing market value of the Company’s Class A common stock as of the effective date of the amendment. The Company is obligated to make future milestone payments of up to $7.0 million to Amplyx, contingent upon the achievement of certain regulatory milestones. The Company is also obligated to make future milestone payments of up to $62.0 million to Novartis, contingent upon the achievement of specified development, regulatory and commercial milestones. In the event that MAU868 is commercialized, the Company will be obligated to pay royalties to Amplyx and Novartis based on net sales by country and by product.

Licenses and Collaborations

12 Months Ended

Dec. 31, 2024

Licenses And Collaborations [Abstract]

9. LICENSES AND COLLABORATIONS

Ares Trading S.A.

In October 2020, the Company entered into a license agreement with Ares (the Ares Agreement), pursuant to which the Company obtained an exclusive worldwide license to certain patents and related know-how to research, develop, manufacture, use and

commercialize therapeutic products containing atacicept, a recombinant fusion protein used to inhibit B cell growth and differentiation, which could potentially treat some autoimmune diseases.

As consideration for the Ares Agreement, the Company paid a non-refundable license issue fee to Ares in the form of shares of redeemable convertible preferred stock valued at $13.1 million, resulting in Ares becoming a related party to the Company. The redeemable convertible preferred stock subsequently converted into 1,913,501 shares of common stock in May 2021.

In December 2020, the Company paid Ares a milestone payment of $25.0 million upon delivery and initiation of the transfer of specified information and materials. The non-refundable license issue fee and milestone payment were recorded to research and development expense in the period incurred. The Company is obligated to pay Ares aggregate milestone payments of up to $176.5 million upon the achievement of specified BLA filing or regulatory approval milestones, beginning with $15.0 million upon the first filing of an approval application and $20.0 million upon regulatory approval in the U.S., and up to $515.0 million upon the achievement of specified commercial milestones, beginning with $15.0 million if worldwide aggregate annual net sales reach $250.0 million and $50.0 million if worldwide aggregate annual net sales reach $500.0 million.

Subsequent to the effective date of the Ares Agreement, Ares has performed transfer of manufacturing technology and know-how to the Company. The Company recorded related party expense of $0.3 million and $2.8 million to Ares for these services during the years ended December 31, 2024 and 2023, respectively. These amounts are included in research and development expenses on the statements of operations and comprehensive loss.

Commencing on the first commercial sale of licensed products, the Company is obligated to pay Ares tiered royalties of low double-digit to mid-teen percentages on annual net sales of the licensed products covered by the license. The Company is obligated to pay royalties on a licensed product-by-licensed product and country-by-country basis from the first commercial sale of a product in a country until the latest of (i) 15 years after the first commercial sale of such licensed product in such country; (ii) the expiration of the last valid claim of a licensed patent that covers such licensed product in, or its use, importation or manufacture with respect to, such country; and (iii) expiration of all applicable regulatory exclusivity periods, including data exclusivity, in such country with respect to such product. If the Company were to sublicense its rights under the Ares Agreement, the Company would be obligated to pay Ares a percentage ranging from the mid-single-digit to the low double-digits of specified sublicensing income received.

Amplyx Pharmaceuticals, Inc.

In December 2021, the Company entered into an asset purchase agreement (the Amplyx Agreement) with Amplyx Pharmaceuticals, Inc. (Amplyx), a wholly owned subsidiary of Pfizer Inc. Pursuant to the terms of the Amplyx Agreement, the Company paid $5.0 million to Amplyx to purchase assets relating to an anti-BKV monoclonal antibody referred to as MAU868 for the treatment of BKV infection pursuant to a License Agreement between Amplyx and Novartis International Pharmaceutical AG (Novartis). In addition, the Company recognized a $2.0 million contingent milestone obligation as an assumed liability related to the asset purchase. The acquisition cost of $7.0 million was recorded as research and development expense in the statement of operations and comprehensive loss on the acquisition date.

In connection with the Amplyx asset purchase, Amplyx assigned the Exclusive License Agreement between Amplyx and Novartis (the Novartis License) and Manufacturing and Supply Agreements to the Company. Under the Novartis License, the Company has exclusive worldwide rights from Novartis to develop, manufacture and commercialize MAU868. The Company will be solely responsible for all research, development, regulatory, manufacturing and commercialization activities of MAU868.

Under the Amplyx Agreement, the Company is obligated to make future milestone payments to Amplyx and Novartis upon the achievement of specified development, regulatory and commercial milestones. In September 2022, the Company and Novartis entered into an amendment to the Novartis License to modify the terms of future milestone payments. Pursuant to this amendment, the Company issued 283,034 shares of Class A common stock to Novartis in exchange for a reduction of $7.0 million in contingent future development milestones, including the $2.0 million contingent milestone obligation accrued by the Company in December 2021. The value of the shares issued was $5.7 million based on the closing market value of the Company’s Class A common stock as of the effective date of the amendment.

The Company is obligated to make future milestone payments of up to $7.0 million to Amplyx, contingent upon the achievement of certain regulatory milestones. The Company is also obligated to make future milestone payments of up to $62.0 million to Novartis, contingent upon the achievement of specified development, regulatory and commercial milestones. In the event that MAU868 is commercialized, the Company will be obligated to pay royalties to Amplyx and Novartis based on net sales by country and by product.