Anitocabtagene autoleucel (anito-cel), a CAR T-cell therapy, has demonstrated durable efficacy and a manageable safety profile in heavily pretreated patients with high-risk relapsed or refractory multiple myeloma. Data from the phase 2 iMMagine-1 study, presented at the ASH Annual Meeting and Exposition, reveal promising outcomes for patients with limited treatment options.
Promising Efficacy in Advanced Myeloma
The iMMagine-1 trial included patients with triple class-exposed relapsed or refractory multiple myeloma who had progressed after at least three prior lines of therapy. The results showed an investigator-assessed overall response rate (ORR) of 97%, with 62% of patients achieving complete response or stringent complete response. Furthermore, 81% achieved very good partial response or higher, according to International Myeloma Working Group criteria. Among patients evaluable for minimal residual disease (MRD), 93.1% achieved MRD negativity at a sensitivity threshold of 10-5.
"The data from the iMMagine-1 study demonstrate that this is a highly active product with impressive depth of responses achieved in patients with relapsed or refractory multiple myeloma," said Ciara Louise Freeman, MD, PhD, MSc, FRCPC, MRCP, assistant member of the department of blood and marrow transplant and cellular immunotherapy at Moffitt Cancer Center.
Manageable Safety Profile
In terms of safety, the emerging profile of anito-cel is encouraging. There were no reports of delayed neurotoxicities. Grade 2 cytokine release syndrome (CRS) occurred in 19% of patients, and one patient experienced a grade 5 CRS event. Immune effector cell-associated neurotoxicity syndrome (ICANS) developed in 9% of patients, with one grade 3 case, all of which resolved without lasting effects. The most common grade 3 or higher treatment-emergent adverse events included neutropenia (54%), anemia (22%), and thrombocytopenia (20%).
Survival Outcomes and Future Directions
Median progression-free survival (PFS) and overall survival (OS) had not been reached at the time of the analysis. However, estimated 6-month PFS was 93.3%, and 6-month OS was 96.5%. The 12-month PFS was 78.5%, and the 12-month OS was 96.5%.
Building on these encouraging results, a randomized phase 3 trial, iMMagine-3, is underway. This trial compares anito-cel with standard therapy in patients with relapsed or refractory multiple myeloma who have received one to three prior lines of therapy. The iMMagine-3 study could pave the way for anito-cel to become an approved treatment option for a broader range of patients with relapsed or refractory multiple myeloma.
Phase 1 Trial Results
In a phase 1 study, anito-cel demonstrated a 100% overall response rate and a 76% complete response/stringent complete response rate in patients who had received at least three prior lines of therapy. An estimated 56% of patients remained progression free at 24 months. These results further support the potential of anito-cel as a valuable treatment option for relapsed/refractory multiple myeloma, including high-risk patient subgroups.
