Restructuring	9 Months Ended
Sep. 30, 2023
Restructuring and Related Activities [Abstract]
Restructuring	11. Restructuring In November 2021, the Board approved a restructuring of its business based on its decision to stop the clinical development of MarzAA and focus solely on its complement programs and protease medicines platform. The restructuring included a reduction-in-force whereby approximately 35% of employees were terminated. In March 2022, the Board approved a further reduction of its workforce as part of its restructuring plan whereby 22 full-time employees were terminated. Following this reduction, the Company had five full-time employees remaining. During the quarter ended March 31, 2022, the Company recorded additional charges of $1.0 million for severance and other costs related to the reduction-in-force, recognized as an operating expense within the condensed consolidated statements of operations and comprehensive income (loss), which the Company paid during the second quarter of 2022. Sale of Assets During the quarter ended June 30, 2022, the Company entered into sales agreements with Dren Bio, Inc. and Copia Scientific, LLC, pursuant to which the Company sold various lab equipment, consumables, and furniture and fixtures for a total consideration of $0.4 million. The Company recorded a loss on disposal of $0.2 million during the nine months ended September 30, 2022, which is included in gain on disposal of assets, net in the condensed consolidated statements of operations and comprehensive income (loss). In May 2022, the Company entered into an asset purchase agreement with Vertex, pursuant to which Vertex purchased the Company’s complement portfolio, including CB 2782-PEG and CB 4332, as well as its complement-related intellectual property including the ProTUNETM and ImmunoTUNETM platforms for $60.0 million in cash consideration. Cash of $55.0 million was received upfront in May 2022 and the remaining $5.0 million was received in May 2023 upon satisfaction of certain post-closing indemnification obligations. The hold-back amount was initially recorded within accounts and other receivables on the condensed consolidated balance sheet. In June 2023, the Company distributed $3.5 million, which reflected the hold-back amount received from Vertex less expenses and a reserve for potential tax liabilities, to the CVR Holders pursuant to the CVR Agreement. In August 2023, the Company distributed the remaining $1.5 million initially withheld as a reserve for potential tax liabilities to the CVR Holders pursuant to the CVR Agreement, see Note 8, Commitments and Contingencies. There were no carrying amounts associated with the intellectual property sold to Vertex, and, therefore, the Company recorded a gain of $57.4 million related to the disposal, net of $2.6 million of transaction costs during the second quarter of 2022. In February 2023, Catalyst entered into an asset purchase agreement with GCBP, pursuant to which GCBP acquired the Company’s legacy rare bleeding disorders programs, including MarzAA, DalcA and CB-2679d-GT, for $6.0 million in cash consideration. Cash of $1.0 million was received upfront in February 2023 and the remaining $5.0 million will be paid two years after the closing upon satisfaction of certain post-closing indemnification obligations. The hold-back amount is recorded as a long-term receivable on the condensed consolidated balance sheet. In March 2023, the Company distributed the net cash proceeds received upfront of $0.2 million to the CVR Holders. Once received, the remaining net proceeds, net of expenses, from the hold-back amount will be distributed to the CVR Holders pursuant to the CVR Agreement, see Note 8, Commitments and Contingencies. There were no carrying amounts associated with the intellectual property sold to GCBP, and, therefore, Catalyst recorded a gain of $4.7 million related to the disposal, net of $0.8 million of transaction costs, which is included in gain on disposal of assets, net in the condensed consolidated statements of operations and comprehensive income (loss) for the nine months ended September 30, 2023.

Restructuring

9 Months Ended

Sep. 30, 2023

Restructuring and Related Activities [Abstract]

11.

Restructuring

In November 2021, the Board approved a restructuring of its business based on its decision to stop the clinical development of MarzAA and focus solely on its complement programs and protease medicines platform. The restructuring included a reduction-in-force whereby approximately 35% of employees were terminated.

In March 2022, the Board approved a further reduction of its workforce as part of its restructuring plan whereby 22 full-time employees were terminated. Following this reduction, the Company had five full-time employees remaining. During the quarter ended March 31, 2022, the Company recorded additional charges of $1.0 million for severance and other costs related to the

reduction-in-force, recognized as an operating expense within the condensed consolidated statements of operations and comprehensive income (loss), which the Company paid during the second quarter of 2022.

Sale of Assets

During the quarter ended June 30, 2022, the Company entered into sales agreements with Dren Bio, Inc. and Copia Scientific, LLC, pursuant to which the Company sold various lab equipment, consumables, and furniture and fixtures for a total consideration of $0.4 million. The Company recorded a loss on disposal of $0.2 million during the nine months ended September 30, 2022, which is included in gain on disposal of assets, net in the condensed consolidated statements of operations and comprehensive income (loss).

In May 2022, the Company entered into an asset purchase agreement with Vertex, pursuant to which Vertex purchased the Company’s complement portfolio, including CB 2782-PEG and CB 4332, as well as its complement-related intellectual property including the ProTUNETM and ImmunoTUNETM platforms for $60.0 million in cash consideration. Cash of $55.0 million was received upfront in May 2022 and the remaining $5.0 million was received in May 2023 upon satisfaction of certain post-closing indemnification obligations. The hold-back amount was initially recorded within accounts and other receivables on the condensed consolidated balance sheet. In June 2023, the Company distributed $3.5 million, which reflected the hold-back amount received from Vertex less expenses and a reserve for potential tax liabilities, to the CVR Holders pursuant to the CVR Agreement. In August 2023, the Company distributed the remaining $1.5 million initially withheld as a reserve for potential tax liabilities to the CVR Holders pursuant to the CVR Agreement, see Note 8, Commitments and Contingencies. There were no carrying amounts associated with the intellectual property sold to Vertex, and, therefore, the Company recorded a gain of $57.4 million related to the disposal, net of $2.6 million of transaction costs during the second quarter of 2022.

In February 2023, Catalyst entered into an asset purchase agreement with GCBP, pursuant to which GCBP acquired the Company’s legacy rare bleeding disorders programs, including MarzAA, DalcA and CB-2679d-GT, for $6.0 million in cash consideration. Cash of $1.0 million was received upfront in February 2023 and the remaining $5.0 million will be paid two years after the closing upon satisfaction of certain post-closing indemnification obligations. The hold-back amount is recorded as a long-term receivable on the condensed consolidated balance sheet. In March 2023, the Company distributed the net cash proceeds received upfront of $0.2 million to the CVR Holders. Once received, the remaining net proceeds, net of expenses, from the hold-back amount will be distributed to the CVR Holders pursuant to the CVR Agreement, see Note 8, Commitments and Contingencies. There were no carrying amounts associated with the intellectual property sold to GCBP, and, therefore, Catalyst recorded a gain of $4.7 million related to the disposal, net of $0.8 million of transaction costs, which is included in gain on disposal of assets, net in the condensed consolidated statements of operations and comprehensive income (loss) for the nine months ended September 30, 2023.