License and Collaborations	12 Months Ended
Dec. 31, 2021
Licenses And Collaborations [Abstract]
License and Collaborations	12. 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 issued to Ares a non-refundable license issue fee of 22,171,553 shares of Series C redeemable convertible preferred stock resulting in Ares becoming a related party to the Company. The Series C redeemable convertible preferred stock had a deemed issuance price of $0.5918 per share, or $13.1 million in the aggregate. In December 2020, the Company paid Ares $25.0 million in milestone payments upon delivery and initiation of the transfer of specified information and materials. 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 and up to $515.0 million upon the achievement of specified commercial milestones. The non-refundable license issue fee of $13.1 million and milestone payments of $25.0 million were recorded to research and development expense. Ares is performing manufacturing technology and know-how transfer to the Company over a period not to exceed two years from the effective date of the Ares Agreement. The Company recorded related party expense of $1.7 million to Ares for these services during the year ended December 31, 2021. 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 is 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. 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 has recognized a $2.0 million contingent milestone obligation that is probable of achievement as an assumed liability related to the asset purchase. The transaction was treated as an asset acquisition as the assets acquired did not meet the definition of a business. ASC 805-10-55 states that if substantially all the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the set is not considered a business. Since the gross assets acquired are concentrated on a single identifiable asset, MAU868, the transaction was accounted for as an asset acquisition. In accordance with accounting guidance, costs incurred in obtaining technology licenses are charged to research and development expense if the technology licensed has not reached technological feasibility and has no alternative future use. The assets purchased from Amplyx require substantial completion of research and development, regulatory and marketing approval efforts in order to reach technological feasibility. Accordingly, the acquisition cost of $7.0 million was recorded as research and development expense in the statement of operations for the year ended December 31, 2021. 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 Agreement, 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 totaling up to approximately $76.0 million, contingent upon the achievement of various clinical development and regulatory milestones. Of this total, the Company has recognized $2.0 million of future milestone payments to Novartis as assumed liabilities upon acquisition. In the event that MAU868 is commercialized, the Company is obligated to pay to Amplyx and Novartis royalties based on net sales by country and by product.

License and Collaborations

12 Months Ended

Dec. 31, 2021

Licenses And Collaborations [Abstract]

12. 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 issued to Ares a non-refundable license issue fee of 22,171,553 shares of Series C redeemable convertible preferred stock resulting in Ares becoming a related party to the Company. The Series C redeemable convertible preferred stock had a deemed issuance price of $0.5918 per share, or $13.1 million in the aggregate.

In December 2020, the Company paid Ares $25.0 million in milestone payments upon delivery and initiation of the transfer of specified information and materials. 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 and up to $515.0 million upon the achievement of specified commercial milestones.

The non-refundable license issue fee of $13.1 million and milestone payments of $25.0 million were recorded to research and development expense.

Ares is performing manufacturing technology and know-how transfer to the Company over a period not to exceed two years from the effective date of the Ares Agreement. The Company recorded related party expense of $1.7 million to Ares for these services during the year ended December 31, 2021.

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 is 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. 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 has recognized a $2.0 million contingent milestone obligation that is probable of achievement as an assumed liability related to the asset purchase.

The transaction was treated as an asset acquisition as the assets acquired did not meet the definition of a business. ASC 805-10-55 states that if substantially all the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the set is not considered a business. Since the gross assets acquired are concentrated on a single identifiable asset, MAU868, the transaction was accounted for as an asset acquisition. In accordance with accounting guidance, costs incurred in obtaining technology licenses are charged to research and development expense if the technology licensed has not reached technological feasibility and has no alternative future use. The assets purchased from Amplyx require substantial completion of research and development, regulatory and marketing approval efforts in order to reach technological feasibility. Accordingly, the acquisition cost of $7.0 million was recorded as research and development expense in the statement of operations for the year ended December 31, 2021.

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 Agreement, 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 totaling up to approximately $76.0 million, contingent upon the achievement of various clinical development and regulatory milestones. Of this total, the Company has recognized $2.0 million of future milestone payments to Novartis as assumed liabilities upon acquisition. In the event that MAU868 is commercialized, the Company is obligated to pay to Amplyx and Novartis royalties based on net sales by country and by product.