Arcellx announces data from iMMagine-1 study of anitocabtagene autoleucel

Arcellx (ACLX) announced new data from its Phase 2 iMMagine-1 study of anitocabtagene autoleucel, in patients with relapsed or refractory multiple myeloma. These data will be presented during an oral presentation at the EHA2025 Congress in Milan on June 14, 2025. Anito-cel is partnered with Kite, a Gilead Company (GILD). The Phase 2 iMMagine-1 data are from a May 1, 2025 data cutoff date, including all 117 patients with a median follow-up of 12.6 months and a minimum follow-up of four months after treatment with anito-cel. All patients received a single infusion of anito-cel. 101 of 117 patients were triple refractory, and 48 of 117 patients were penta refractory. Patients received a median of three prior lines of therapy, with 60 of 117 patients having received three prior lines. Overall response rate was 97% with a complete response/stringent complete response rate of 68% and a very good partial response or higher rate of 85%, per International Myeloma Working Group criteria as investigator-assessed. Of those evaluable for minimal residual disease testing at the time of this data cut, 93.3% achieved MRD negativity at a minimum of 10-5 sensitivity. Six-month progression-free survival and overall survival rates were 91.9% and 96.6%, respectively, and 12-month PFS and OS rates were 78.8% and 95.2%, respectively. Median PFS and median OS have not been reached. No delayed or non-immune effector cell-associated neurotoxicity syndrome neurotoxicities, including no Parkinsonism, no cranial nerve palsies, and no Guillain-Barre syndrome, and no immune-mediated enterocolitis have been observed to date with anito-cel. No additional treatment- or therapy-related deaths or Grade greater than or equal to3 cytokine release syndrome or ICANS events have occurred since the previous data presentation in December 2024. Preliminary results from the Phase 2 iMMagine-1 study demonstrate deep and durable responses with a predictable and manageable safety profile in a fourth-line or higher RRMM population, including triple- and penta-class refractory disease. Notably, no delayed or non-ICANS neurotoxicities, including no Parkinsonism, no cranial nerve palsies, and no Guillain-Barre syndrome, and no immune-mediated enterocolitis have been observed with anito-cel to date.