Anito-cel has shown no signs of delayed neurotoxicity at around 9 months of follow-up, hinting at a safety profile that could set it apart from J&J and Legend’s Carvykti.
Gilead Sciences and Arcellx on Sunday unveiled new data from the pivotal Phase II iMMagine-1 trial of their CAR T therapy anitocabtagene autoleucel in relapsed or refractory multiple myeloma, touting an encouraging safety profile that could set the investigational treatment apart in an increasingly crowded CAR T space.
At a median follow-up of 9.5 months, the partners reported no delayed neurotoxicities such as cranial nerve palsies, Guillain-Barré syndrome or Parkinsonism.
In a Monday note, BMO Capital Markets analysts said that safety “is a key focus for commercialization to overcome Carvykti’s lead” in relapsed or refractory multiple myeloma (RRMM), adding that Gilead and Arcellx’s data “support the potential for this differentiation on safety.”
According to BMO, Gilead explained the neurotoxicity advantage of anitocabtagene autoleucel—also called anito-cel—is thanks to its D-domain binder, which helps the therapy “quickly release from the BCMA target, and could help the product eliminate MM cells without severe immunotoxicity,” the analysts wrote.
Aside from neurotoxicity, iMMagine-1 found that 86% of patients with evaluable data developed cytokine release syndrome of at most grade 1 in severity. There were three deaths in the study, though it remains unclear how many were deemed related to anito-cel.
In terms of efficacy, anito-cel resulted in a 97% overall response rate, with a complete response or stringent complete response rate of 62%. Median progression-free survival (PFS) and overall survival (OS) were not reached at the time of the analysis. Six-month PFS and OS rates were 93.3% and 96.5%, respectively, with the former dropping to 78.5% by 12 months, while the latter stayed constant.
According to the BMO analysts, anito-cel’s efficacy benefit remains “incremental” compared to Carvykti. Nevertheless, Sunday’s readout “only serves to bolster the highly competitive profile” of Arcellx and Gilead’s CAR-T therapy candidate, they wrote.
Anito-cel is a developmental CAR T therapy designed to target BCMA, a cell surface protein highly expressed on malignant plasma cells. Last month, Gilead and Arcellx touted the best-in-class potential of anito-cel in a data preview, disclosing a 95% overall response rate and a 92% minimal residual disease rate.
At the time, William Blair analysts said that the preview findings “support best-in-class profile” for anito-cel, pointing to its “superior benefit” versus Carvykti. In comments to Endpoints News, however, J&J insisted that comparing the two therapies is “flawed given the stark differences in sample size, populations and follow-ups prior to the data being published.”
Gilead and Arcellx have kicked off the Phase III iMMagine-3 study for anito-cel. The trial has an enrollment target of around 450 adult patients. As per the BMO note on Monday, the partners hope to launch anito-cel by 2026, targeting a second-line CAR T opportunity in RRMM that could top 12 billion.
