Yi Lin, MD, PhD, Hematologist/Oncologist at Mayo Clinic, discusses immune effector cell-associated enterocolitis (IEC-EC) in patients with relapsed/refractory multiple myeloma (R/R MM) treated with ciltacabtagene autoleucel (cilta-cel).
MM is a rare blood cancer characterized by the expansion of malignant plasma cells in the bone marrow associated with excessive production of monoclonal immunoglobulins in blood and urine. Individuals with multiple myeloma develop significant osteolytic bone lesions and have immunodeficiency that compromise their longevity and quality of life. The exact underlying cause of disease is currently unknown.
Cilta-cel is a B-cell maturation antigen-directed genetically modified autologous T cell immunotherapy. IEC-EC, an uncommon adverse reaction, is characterized by severe and persistent diarrhea, typically 1 to 3 months following CAR-T cell infusion. This study analyzed the incidence and features of IEC-EC in the CARTITUDE clinical studies of cilta-cel for RRMM.
A total of 483 patients across the CARTITUDE-1, -2, -4, and CARTIFAN-1 studies were evaluated for evidence of IEC-EC. Across these studies, six patients presented with IEC-EC, 12 to 214 days after receiving cilta-cel, and with a median onset 67 days post infusion.
Four patients experienced symptom resolution within 123 to 227 days, while two had persistent symptoms until death. Patients with IEC-EC had lower levels of B cells and higher levels of CAR+ T cells and inflammatory cytokines at onset compared to a GI symptom-free control group at comparable time. While all patients treated with cilta-cel experienced B cell depletion, patients with IEC-EC had more prolonged deficiency.
Histological analyses of GI biopsies from five patients with IEC-EC revealed the absence of plasma cells. CAR-T cells were detected and localized to the lamina propria and were not observed juxtaposed with epithelia. Histologic damage was greater in the small intestine (mainly the duodenum) than the colon.
Read the abstract presented at the 2026 Annual American Society of Clinical Oncology (ASCO) Meeting.
To learn more about MM and other rare cancers, visit https://checkrare.com/diseases/cancers/
