Washington, D.C. — December 8, 2025 — Leads & Copy — Kite, a Gilead Company, and Arcellx announced new positive data today from the pivotal iMMagine-1 Phase 2 study of anitocabtagene autoleucel (anito-cel), an investigational agent, which continues to show clinically meaningful deep and durable efficacy with predictable and manageable safety observed to date in relapsed or refractory multiple myeloma (RRMM) patients who had received at least three prior lines of therapy. The findings from the ongoing study were shared in an oral presentation (Abstract #256) during the 67th American Society of Hematology (ASH) Annual Meeting and Exposition.
Dr. Krina Patel, lead investigator and Associate Professor in the Department of Lymphoma/Myeloma, Division of Cancer Medicine, at The University of Texas MD Anderson Cancer Center, stated the data are compelling and an important advancement for patients living with multiple myeloma. She added that she is encouraged by the depth of responses in the iMMagine-1 study and that clinicians rely on therapies that deliver continued meaningful efficacy, a predictable safety profile, and reliable manufacturing. She noted that anito-cel demonstrates that it could become a significant new treatment option in efforts to improve outcomes for patients with multiple myeloma.
Data from an October 7, 2025, cutoff date, including 117 patients treated with anito-cel, who were followed for a median of 15.9 months, showed an independent review committee (IRC)-assessed overall response rate (ORR) of 96%, with 74% achieving a stringent complete response or complete response (sCR or CR) per International Myeloma Working Group (IMWG) criteria. According to the data, 102 of 117 patients (87%) were triple refractory, 48 of 117 patients (41%) were penta refractory, 21 of 117 patients (18%) had extramedullary disease, and 47 of 117 patients (40%) had high risk cytogenetics.
For many in this heavily pre-treated population, responses began quickly, often within one month. Median time to best response was 4.8 months and median time to sCR or CR was 3.2 months. Of the 96 patients evaluable for minimal residual disease (MRD) testing, 91 (95%) achieved MRD negativity at a median time of 1 month, meaning no cancer cells could be detected even with highly sensitive tests (≤10-5 sensitivity).
The progression-free survival (PFS) rates were 82.1% at 12 months, 67.4% at 18 months and 61.7% at 24 months, meaning many patients were still alive and free from cancer progression at those timepoints. The overall survival (OS) rates showed that a significant majority of patients remained alive, with 94% at 12 months, 88% at 18 months and 83% at 24 months. According to the release, the median PFS and OS have not yet been reached, suggesting sustained and ongoing benefit for a majority of patients.
The release notes that no delayed (non-ICANS) neurotoxicities, including no Parkinsonism, no cranial nerve palsies, no Guillain-Barré syndrome, and no immune effector cell-associated enterocolitis, have been observed to date, with all patients dosed at least 12 months prior to the cutoff. An exploratory study sponsored by Kite (Abstract #503) showed characterization of CD4+ CAR T cell subtypes provide further mechanistic hypotheses supporting the neurologic tolerability profile of anito-cel.
Cindy Perettie, Executive Vice President, Kite, stated that effective options are critical as resistance to treatment grows for multiple myeloma patients in advanced treatment stages. Perettie added that the deep, durable responses seen with iMMagine-1, combined with a predictable and manageable safety profile and rapid and reliable manufacturing, highlight anito-cel’s potential to redefine care. Together with Arcellx, the goal is to deliver a differentiated, one-time treatment option in 2026 that may reduce patient burden and improve access, including in outpatient and community oncology settings.
Observed side effects were generally consistent with past readouts. Cytokine release syndrome (CRS) was observed in 86% of patients but was generally mild and manageable. According to the release, 83% of patients in the study experienced no CRS or Grade 1 CRS (fever only). Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 8% of patients, with only one Grade 3 case and all other cases Grade 2 or lower.
The most common hematologic adverse events noted during treatment were low white blood cell counts (neutropenia) in 71% of patients, low red blood cells (anemia) in 28%, and low platelets (thrombocytopenia) in 26%. Grade 3 or higher infections occurred in 9% of patients.
Preclinical research (Abstract #7644) shows that anito-cel’s D-Domain binder interacts with BCMA by binding and releasing quickly. Relative to a comparator CAR T-cell therapy in preclinical models, this transient interaction with cancer cells may be associated with decreased inflammation while maintaining the ability to effectively kill cancer cells. Additionally, the abstract shows anito-cel retains its ability to target cancer cells with altered BCMA expression after previous treatments, demonstrating the potential for anito-cel to maintain efficacy in patients previously exposed to BCMA-targeting therapies. Further research, including crystallography and epitope mapping, is ongoing to provide more detail on this mechanism.
Anitocabtagene autoleucel (anito-cel, previously ddBCMA) is the first BCMA-directed CAR T-cell therapy to be investigated in multiple myeloma that utilizes Arcellx’s novel and compact binder known as the D-Domain. Anito-cel has been granted Fast Track, Orphan Drug, and Regenerative Medicine Advanced Therapy Designations by the U.S. Food and Drug Administration.
Multiple myeloma (MM) is a type of hematological cancer in which diseased plasma cells proliferate and accumulate in the bone marrow, crowding out healthy blood cells and causing bone lesions, loss of bone density, and bone fractures. The median age of patients at diagnosis is 69 years with one-third of patients diagnosed at an age of at least 75 years. Because MM tends to afflict patients at an advanced stage of life, patients often have multiple comorbidities and toxicities that can quickly escalate and become life-endangering.
iMMagine-1 is a Phase 2 registrational, pivotal open-label study of anito-cel in patients with relapsed or refractory multiple myeloma (RRMM) who have received at least three prior regimens of systemic therapy including proteasome inhibitor, immunomodulatory drugs (IMiD) and anti-CD38 antibody and are refractory to the last line of therapy.
The trial assessed both safety and efficacy in 117 patients receiving a single infusion of anito-cel (target dose of 115×106 CAR+ viable T cells). Efficacy was assessed monthly for the first 6 months, then quarterly up to 2 years, or upon patient relapse. Long-term safety data will be collected under a separate long-term follow-up study for up to 15 years. The primary endpoint is overall response rate (ORR) per International Myeloma Working Group (IMWG) criteria, as assessed by an independent review committee. Secondary endpoints include complete response rate (CR/sCR), progression-free survival, overall survival, duration of response, minimal residual disease negativity and safety.
Cindy Perettie, Executive Vice President, Kite
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Source: Gilead Company
