Extracorporeal photopheresis for cancer immunotherapy-related gastrointestinal toxicity: emerging clinical evidence

Immune-mediated gastrointestinal toxicities of cancer immunotherapy can be severe, corticosteroid-refractory, and treatment-limiting. Extracorporeal photopheresis (ECP) may provide immunomodulation with less systemic immunosuppression. To evaluate the role of ECP in immune-mediated gastrointestinal toxicity, we searched MEDLINE, Embase and Scopus from inception through July 2026 for human studies in which ECP was used to treat gastrointestinal toxicity associated with immune-checkpoint inhibitors or immune-effector-cell therapies. Study characteristics, treatment regimens, clinical response, corticosteroid use, mucosal healing, recurrence, and safety were narratively synthesized. Among 1423 records, seven publications were identified: three case reports, two uncontrolled cohorts, one prospective non-randomized comparative study, and one CAR T-cell enterocolitis series containing a single ECP-treated patient. Across reports of immune-checkpoint-inhibitor-associated colitis, ECP was followed by clinical improvement, corticosteroid exposure reduction, and, where assessed, endoscopic or histological improvement. In the PRIA ECP study, complete resolution occurred in 11/12 ECP-treated colitis events and 13/16 colitis events treated with systemic immunosuppression (91% vs 81%; p=0.61). Across all organ toxicities, ECP was associated with lower cumulative corticosteroid exposure and fewer worsening events. No serious ECP-attributable adverse events were reported. ECP is a promising rescue or corticosteroid-sparing option for selected refractory gastrointestinal toxicities; however, efficacy remains unproven because evidence is limited, heterogeneous, and predominantly uncontrolled. Randomized controlled trials evaluating standardized clinical and endoscopic outcomes, corticosteroid-free remission, safety, and treatment burden are required.