Anitocabtagene autoleucel

If approved, anito-cel would be the third BCMA-directed CAR T cell therapy for multiple myeloma in the United States, after Abecma (idecabtagene vicleucel) and Carvykti (ciltacabtagene autoleucel). Its proposed place is the same as theirs at launch: people whose myeloma has come back after at least 3 prior lines of treatment covering the 3 main drug classes. There is no head-to-head trial against either product. The points Kite and Arcellx emphasize are the response depth in iMMagine-1 and the absence so far of the delayed movement and nerve problems that have been reported with other BCMA CAR T therapies. Trials of anito-cel in earlier lines of treatment are under way.

CAR T cell therapy turns a patient's own immune cells into a targeted treatment. T cells are collected from the blood, engineered in a lab to carry a receptor that recognizes BCMA, a protein on the surface of nearly all myeloma cells, multiplied, and returned as a single infusion. The engineered cells then hunt down and destroy myeloma cells wherever they are. Anito-cel's receptor uses a small synthetic binder called a D-Domain instead of the antibody fragment used in earlier CAR T products. According to Kite and Arcellx, the D-Domain binds BCMA and lets go quickly, which in laboratory studies was associated with less inflammation while still killing myeloma cells, and the binder is stable enough to allow high receptor expression without the cells firing on their own. Those design choices are the company's explanation for the lower rate of severe immune side effects seen so far.

Side effects in iMMagine-1 followed the pattern of other CAR T therapies. Cytokine release syndrome, the fever-and-low-blood-pressure reaction that follows CAR T infusion, occurred in 86% of patients but was mostly mild: 83% of patients had either no CRS or grade 1 CRS, meaning fever only. Immune effector cell-associated neurotoxicity syndrome (ICANS), which causes confusion or difficulty speaking, occurred in 8%, with 1 grade 3 case and all others grade 2 or lower. The most common blood-count effects were low neutrophils in 71% of patients, anemia in 28% and low platelets in 26%, and grade 3 or higher infections occurred in 9%. Kite and Arcellx reported no delayed neurotoxicities such as Parkinsonism, cranial nerve palsies or Guillain-Barre syndrome, and no immune effector cell-associated enterocolitis, across the Phase 1 and Phase 2 studies, with every patient dosed at least 12 months before the data cutoff. Those delayed effects have been reported with other BCMA CAR T products and are the reason this finding is watched closely. There is no US label yet, so the boxed warning and monitoring requirements are not known; the approved BCMA CAR T therapies carry boxed warnings for CRS, neurologic toxicity, prolonged low blood counts and secondary blood cancers, and patients are typically required to stay near the treatment center for several weeks after infusion.

iMMagine-1 (NCT05396885) is the pivotal Phase 2 study, open label and single arm, in 117 treated patients with relapsed or refractory myeloma who had received at least 3 prior lines of therapy including a proteasome inhibitor, an immunomodulatory drug and an anti-CD38 antibody, and whose disease had stopped responding to their last treatment; 87% were triple refractory and 41% penta refractory. At the October 7, 2025 data cutoff, after a median follow-up of 15.9 months, the overall response rate by independent review was 96%, 74% reached a stringent complete response or complete response, and 95% of the 96 patients tested for minimal residual disease had none detectable at a sensitivity of 1 in 100,000 cells. Progression-free survival was 82.1% at 12 months, 67.4% at 18 months and 61.7% at 24 months; overall survival was 94%, 88% and 83% at the same points, and the medians had not been reached. A Phase 1 study (NCT04155749) preceded it. Ongoing studies include the Phase 3 iMMagine-3 trial in people with at least 1 prior therapy and the Phase 2 GEM-AnitoFIRST study in newly diagnosed myeloma.

Anito-cel was developed by Arcellx, which partnered with Kite, Gilead's cell therapy unit, to co-develop and co-commercialize it. The FDA granted Fast Track, Orphan Drug and Regenerative Medicine Advanced Therapy designations. Updated iMMagine-1 results were presented at the American Society of Hematology meeting on December 6, 2025. The FDA accepted the biologics license application for fourth-line relapsed or refractory myeloma with a target action date of December 23, 2026. On February 23, 2026 Gilead announced it would acquire Arcellx outright for $115 per share plus a contingent value right of $5 per share tied to anito-cel sales, an implied equity value of about $7.8 billion, and the acquisition closed on April 28, 2026.