The board of directors of CARsgen Therapeutics Holdings Limited announced that at the 2023 American Society of Hematology Annual Meeting, the Company presented one poster with study results for zevorcabtagene autoleucel ("zevor-cel", R&D code: CT053, an autologous CAR T-cell therapy candidate against BCMA), which include the 3-year follow-up on efficacy and safety results from the Phase I portion of Phase I/II registrational study in China (LUMMICAR-1, NCT03975907). Poster #4845: Three-Year Follow-up on Efficacy and Safety Results from Phase I Lummicar Study 1 of Zevorcabtagene Autoleucel in Chinese Patients with Relapsed or Refractory Multiple Myeloma Zevor-cel is a fully human autologous chimeric antigen receptor (CAR) T-cell therapy product with a B-cell maturation antigen (BCMA) which is being developed for the treatment of patients with relapsed or refractory multiple myeloma (R/R MM). The LUMMICAR STUDY 1 trial is a multi-center, open-label Phase I/II clinical trial ongoing in China.

The New Drug Application (NDA) in China for zevor-cel is based on the Phase I/II data from LUMMICAR STUDY 1 and is currently under review. Herein, the Company presented the updated results with 3 years of follow-up after the last patient was infused with zevor-cel in the Phase I portion of the study. Responses were assessed by investigator per the International Myeloma Working Group (IMWG) 2016 criteria.

As of July 17, 2023, 14 participants with R/R MM, who had received at least 3 prior regimens including a proteasome inhibitor and an immunomodulatory drug (IMiD) with a median of 6 prior regimens (range: 3-11), received zevor-cel infusion. A single infusion of zevor-cel was administered 1-2 days after the completion of lymphodepletion. Three participants received 1.0×108 CAR+ T cells, and 11 participants received 1.5×108 CAR+ T cells.

The median age of the cohort was 54 years (range: 34-62 years); 50.0% (7/14) of the participants had high-risk cytogenetic abnormalities, 14.3% (2/14) had extramedullary disease (EMD), and 14.3% (2/14) of the participants had Stage III disease based on International Staging System (ISS). Safety Overall, the safety profile of zevor-cel was manageable. There were no Grade 3 cytokine release syndrome (CRS) events.

There were no immune effector cell-associated neurotoxicity syndrome (ICANS) events of any grade. Three treatment-related Grade 3 infections were observed. Three patients experienced serious adverse events (SAE) including 2 patients who had treatment-related SAEs which were pulmonary infection and tumor lysis syndrome.

There were overall 2 deaths on the study; neither was related to zevor-cel. Efficacy As of July 17, 2023, the median follow-up duration was 37.7 months (range:14.8-44.2 months). The overall response rate (ORR) was 100% (14/14) with 78.6% (11/14) patients achieving a complete response (CR) or a stringent complete response (sCR); minimal residual disease (MRD) negativity was attained in all patients achieving either a CR or sCR.

The median duration of response (mDOR) was 24.1 months in all patients and 26.0 months in those achieving CR or sCR. The median progression-free survival (mPFS) was 25.0 months. A total of 7 (50%) patients were in remission lasting longer than 24 months.

The median overall survival (OS) was not reached, and 92.9% (13/14) of patients were still alive at month 36. Conclusion At 3-year follow up of Phase I portion of LUMMICAR-1 study in heavily pre-treated R/R MM population, zevor-cel demonstrated an encouraging safety profile with deep and durable responses consistent with the initial results.