ECP for Immune-related Adverse Events After Checkpoint Inhibitor Treatment

Preliminary data demonstrate that irAEs induced by immune checkpoint blockade can be successfully treated with ECP (Apostolova et al. NEJM 2020). Therefore this retrospective analysis is launched to validate the finding made with the individual patient in a larger patient cohort. The analysis will include the evaluation of safety of ECP treatment in patients with irAEs and collect data on the efficacy of ECP as a treatment for immune-related adverse events and its effect on tumor progression.

Immune checkpoint inhibitors (ICI) have improved the long-term survival of patients with metastatic tumors. However, approximately 50% of the patients treated with ICI develop serious immune-related adverse events (irAE). A recent study reported that grade 3 or higher irAE occurred in 49 of 124 patients (39.5%) who received nivolumab/ipilimumab and in 41 of 123 patients (33.3%) who received nivolumab alone. Other studies report an overall frequency of grade 3-5 irAE in 24% - 59% of patients treated with nivolumab 1 mg/kg body weight and ipilimumab 3 mg/kg body weight. An incidence of 33.3% was reported when patients were treated with nivolumab 3 mg/kg body weight and ipilimumab 1 mg/kg body weight. The most common events reported during combined ICI treatment are diarrhea, rash, pruritus, hepatitis, hypothyroidism, neurological disease and pneumonitis. These numbers show that irAE are a particularly frequent complication of ICI and limit their use. This retrospective analysis is launched to validate the finding made with the individual patient in a larger patient cohort. The analysis will include the evaluation of safety of ECP treatment in patients with irAEs and collect data on the efficacy of ECP as a treatment for immune-related adverse events and its effect on tumor progression.