Equity-Method Investment and Other Investments	3 Months Ended
Mar. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity-Method Investment and Other Investments	8. Equity-Method Investment and Other Investments On July 30, 2021, the Company finalized a transaction in which the Company, Cellex and BXLS established AvenCell, a joint venture and privately held company. In exchange for contributing an exclusive license to the joint venture, the Company entered into a Preferred Stock Purchase Agreement with AvenCell for a 33.33% equity interest in AvenCell at the time of the initial closing. Cellex and BXLS each equally owned the remaining 66.67% at that time. The Company has significant influence over, but does not control, AvenCell through its noncontrolling representation on AvenCell’s board of directors and the Company’s equity interest in AvenCell. The Company has determined that the preferred stock it owns is in-substance common stock. The Company is not the primary beneficiary as it does not have the power to direct the activities of AvenCell that most significantly impact AvenCell’s economic performance. Accordingly, the Company does not consolidate the financial statements of AvenCell and accounts for its investment using the equity method of accounting. The Company recorded the initial investment in AvenCell of $62.9 million in “Equity method investments” on its condensed consolidated balance sheet. Due to the timing and availability of AvenCell’s financial information, the Company is recording its share of losses from AvenCell on a quarterly basis on a one-quarter lag. During the first quarter of 2023, the Company recorded its share of the three months of AvenCell’s losses generated in the fourth quarter of 2022 in the Company’s operating results and other comprehensive loss, resulting in a reduction of the Company’s investment by $1.3 million for the three months ended March 31, 2023. The elimination of the intra-entity profit component of $2.8 million (see Note 7) in the three months ended March 31, 2023 resulted in a further reduction in the balance of the investment in AvenCell, bringing the carrying value of the investment to $28.4 million as of March 31, 2023. The Company is not aware of any material events or transactions during the quarter ended March 31, 2023 that would warrant additional disclosure or recognition in the financial statements. At March 31, 2023, the maximum exposure to loss is limited to the Company’s equity investment in the joint venture. SparingVision SAS In connection with the SparingVision LCA (see Note 7), the Company received 83,316 shares of SparingVision Series A2 Preferred Stock (“Series A2”). Attached to each share of Series A2, the Company received three warrants for the right to purchase additional Series A2 shares at designated prices that are subject to certain vesting conditions (collectively referred to as the “SparingVision investments”). The Company accounts for the SparingVision investments using the measurement alternative as SparingVision is a private company and there is no readily observable transaction price. The Company recorded the initial investment in SparingVision of $14.8 million in “Investments and other assets” on its condensed consolidated balance sheet. There was no change in the observable price or impairment of the SparingVision investment as of March 31, 2023. Kyverna Therapeutics, Inc. In connection with the Kyverna LCA (see Note 7), the Company received 3,739,515 shares of Kyverna Series B Preferred Stock (“Series B”) with a fair value of $7.0 million. The Company separately made an additional investment in Kyverna, purchasing 1,602,649 shares of Series B in exchange for $3.0 million in cash (collectively referred to as the “Kyverna investments”). The Company accounts for the Kyverna investments using the measurement alternative as Kyverna is a private company and there is no readily observable transaction price. The Company recorded the initial investment in Kyverna of $10.0 million in “Investments and other assets” on its condensed consolidated balance sheet. There was no change in the observable price or impairment of the Kyverna investment as of March 31, 2023.

Equity-Method Investment and Other Investments

3 Months Ended

Mar. 31, 2023

Equity Method Investments and Joint Ventures [Abstract]

Equity-Method Investment and Other Investments

8. Equity-Method Investment and Other Investments

On July 30, 2021, the Company finalized a transaction in which the Company, Cellex and BXLS established AvenCell, a joint venture and privately held company. In exchange for contributing an exclusive license to the joint venture, the Company entered into a Preferred Stock Purchase Agreement with AvenCell for a 33.33% equity interest in AvenCell at the time of the initial closing. Cellex and BXLS each equally owned the remaining 66.67% at that time.

The Company has significant influence over, but does not control, AvenCell through its noncontrolling representation on AvenCell’s board of directors and the Company’s equity interest in AvenCell. The Company has determined that the preferred stock it owns is in-substance common stock. The Company is not the primary beneficiary as it does not have the power to direct the activities of AvenCell that most significantly impact AvenCell’s economic performance. Accordingly, the Company does not consolidate the financial statements of AvenCell and accounts for its investment using the equity method of accounting.

The Company recorded the initial investment in AvenCell of $62.9 million in “Equity method investments” on its condensed consolidated balance sheet. Due to the timing and availability of AvenCell’s financial information, the Company is recording its share of losses from AvenCell on a quarterly basis on a one-quarter lag. During the first quarter of 2023, the Company recorded its share of the three months of AvenCell’s losses generated in the fourth quarter of 2022 in the Company’s operating results and other comprehensive loss, resulting in a reduction of the Company’s investment by $1.3 million for the three months ended March 31, 2023. The elimination of the intra-entity profit component of $2.8 million (see Note 7) in the three months ended March 31, 2023 resulted in a further reduction in the balance of the investment in AvenCell, bringing the carrying value of the investment to $28.4 million as of March 31, 2023. The Company is not aware of any material events or transactions during the quarter ended March 31, 2023 that would warrant additional disclosure or recognition in the financial statements.

At March 31, 2023, the maximum exposure to loss is limited to the Company’s equity investment in the joint venture.

SparingVision SAS

In connection with the SparingVision LCA (see Note 7), the Company received 83,316 shares of SparingVision Series A2 Preferred Stock (“Series A2”). Attached to each share of Series A2, the Company received three warrants for the right to purchase additional Series A2 shares at designated prices that are subject to certain vesting conditions (collectively referred to as the “SparingVision investments”). The Company accounts for the SparingVision investments using the measurement alternative as SparingVision is a private company and there is no readily observable transaction price. The Company recorded the initial

investment in SparingVision of $14.8 million in “Investments and other assets” on its condensed consolidated balance sheet. There was no change in the observable price or impairment of the SparingVision investment as of March 31, 2023.

Kyverna Therapeutics, Inc.

In connection with the Kyverna LCA (see Note 7), the Company received 3,739,515 shares of Kyverna Series B Preferred Stock (“Series B”) with a fair value of $7.0 million. The Company separately made an additional investment in Kyverna, purchasing 1,602,649 shares of Series B in exchange for $3.0 million in cash (collectively referred to as the “Kyverna investments”). The Company accounts for the Kyverna investments using the measurement alternative as Kyverna is a private company and there is no readily observable transaction price. The Company recorded the initial investment in Kyverna of $10.0 million in “Investments and other assets” on its condensed consolidated balance sheet. There was no change in the observable price or impairment of the Kyverna investment as of March 31, 2023.