Investment in Equity Securities	3 Months Ended
Mar. 31, 2025
Equity Method Investments and Joint Ventures [Abstract]
Investment in Equity Securities	. Investment in Equity Securities As part of the Merger, the Company obtained Homology's 20% equity interest in OXB (US) LLC, an AAV vector process development and manufacturing services company. At that time, the Company had significant influence over, but did not control, OXB (US) LLC through its noncontrolling representation on OXB (US) LLC’s board of directors and the Company’s equity interest in OXB (US) LLC. Accordingly, the Company did not consolidate the financial statements of OXB (US) LLC and accounted for its investment using the equity method of accounting. The Company recorded its equity method investment in OXB (US) LLC at fair value upon the effective date of the Merger. The fair value of the equity method investment was determined based on the market approach. This approach estimated the fair value of OXB (US) LLC based on the implied value for the entity, including the Options (as defined in Note 3 above), for a controlling interest in OXB (US) LLC at the entity’s formation. As part of its fair value analysis, the Company determined that the Options are embedded in the Company’s ownership units of OXB (US) LLC because the Options are not legally detachable or separately exercisable. Accordingly, the equity method investment and the Options represent one unit of account and the fair value recorded reflects the value of the equity interest and the Options (refer to Note 3 for more information for how the fair value was determined). As a result of transactions by OXB (US) LLC, the Company’s investment was diluted to a 10% equity interest in OXB (US) LLC on May 22, 2024, and the Company no longer has the ability to exert significant influence over the operating and financial policies of OXB (US) LLC. The Company discontinued the equity method of accounting for the investment in OXB (US) LLC on May 22, 2024 and determined the remaining investment to be an equity security accounted for in accordance with FASB ASC Topic 321, Investments—Equity Securities (“ASC 321”) at the date the investment no longer qualifies for the equity method of accounting. The Company recorded the equity instrument at fair value and applied the measurement alternative under ASC 321 such that the Company would not change the amount recorded for the equity instrument unless the Company identified observable price changes in orderly transactions for the identical or similar investment of the same issuer or the equity instrument was otherwise deemed to be impaired. At each reporting period, the Company is required to make a qualitative assessment considering impairment indicators to evaluate whether the investment is impaired. If deemed impaired, the Company is required to estimate the fair value of the investment and recognize an impairment loss equal to the difference between the fair value of the investment and its carry amount. On March 1, 2025, Oxford Biomedica (US), Inc. exercised its option to cause the Company to sell and transfer to Oxford Biomedica (US), Inc. all of the Company’s equity ownership interest in OXB (US) LLC. As of March 31, 2025, the Company performed an assessment to evaluate whether the investment is impaired and determined that the fair value of its investment in OXB (US) LLC was negatively impacted due to the projected payment to the Company as outlined in the call option exercise notice. The Company determined that the decline in value was deemed to be other than temporary and recorded an impairment charge of approximately $0.1 million to reduce its investment to fair value. The impairment charge is included in other income (expense), net in the Company's consolidated statements of operations. The Company and Oxford Biomedica (US), Inc. expect to finalize the transaction and pay the CVR holders by the end of the second quarter of 2025. Prior to May 22, 2024, the Company was recording its share of income or losses from OXB (US) LLC on a quarterly basis under the equity method of accounting. As of March 31, 2025, the carrying value of the equity investment was $2.5 million.

Investment in Equity Securities

3 Months Ended

Mar. 31, 2025

Equity Method Investments and Joint Ventures [Abstract]

. Investment in Equity Securities

As part of the Merger, the Company obtained Homology's 20% equity interest in OXB (US) LLC, an AAV vector process development and manufacturing services company. At that time, the Company had significant influence over, but did not control, OXB (US) LLC through its noncontrolling representation on OXB (US) LLC’s board of directors and the Company’s equity interest in OXB (US) LLC. Accordingly, the Company did not consolidate the financial statements of OXB (US) LLC and accounted for its investment using the equity method of accounting.

The Company recorded its equity method investment in OXB (US) LLC at fair value upon the effective date of the Merger. The fair value of the equity method investment was determined based on the market approach. This approach estimated the fair value of OXB (US) LLC based on the implied value for the entity, including the Options (as defined in Note 3 above), for a controlling interest in OXB (US) LLC at the entity’s formation. As part of its fair value analysis, the Company determined that the Options are embedded in the Company’s ownership units of OXB (US) LLC because the Options are not legally detachable or separately exercisable. Accordingly, the equity method investment and the Options represent one unit of account and the fair value recorded reflects the value of the equity interest and the Options (refer to Note 3 for more information for how the fair value was determined).

As a result of transactions by OXB (US) LLC, the Company’s investment was diluted to a 10% equity interest in OXB (US) LLC on May 22, 2024, and the Company no longer has the ability to exert significant influence over the operating and financial policies of OXB (US) LLC. The Company discontinued the equity method of accounting for the investment in OXB (US) LLC on May 22, 2024 and determined the remaining investment to be an equity security accounted for in accordance with FASB ASC Topic 321, Investments—Equity Securities (“ASC 321”) at the date the investment no longer qualifies for the equity method of accounting. The Company recorded the equity instrument at fair value and applied the measurement alternative under ASC 321 such that the Company would not change the amount recorded for the equity instrument unless the Company identified observable price changes in orderly transactions for the identical or similar investment of the same issuer or the equity instrument was otherwise deemed to be impaired. At each reporting period, the Company is required to make a qualitative assessment considering impairment indicators to evaluate whether the investment is impaired. If deemed impaired, the Company is required to estimate the fair value of the investment and recognize an impairment loss equal to the difference between the fair value of the investment and its carry amount.

On March 1, 2025, Oxford Biomedica (US), Inc. exercised its option to cause the Company to sell and transfer to Oxford Biomedica (US), Inc. all of the Company’s equity ownership interest in OXB (US) LLC. As of March 31, 2025, the Company performed an assessment to evaluate whether the investment is impaired and determined that the fair value of its investment in OXB (US) LLC was negatively impacted due to the projected payment to the Company as outlined in the call option exercise notice. The Company determined that the decline in value was deemed to be other than temporary and recorded an impairment charge of approximately $0.1 million to reduce its investment to fair value. The impairment charge is included in other income (expense), net in the Company's consolidated statements of operations. The Company and Oxford Biomedica (US), Inc. expect to finalize the transaction and pay the CVR holders by the end of the second quarter of 2025.

Prior to May 22, 2024, the Company was recording its share of income or losses from OXB (US) LLC on a quarterly basis under the equity method of accounting.

As of March 31, 2025, the carrying value of the equity investment was $2.5 million.