Prognostic Factors and Treatment Outcomes in Merkel Cell Carcinoma

2.9%) as third-line treatment.ORR was 43.6% in the group treated with avelumab in first-line and 38.5% in second line.Patients who received IO in third-line had PD as best response.In the CHT cohort, ORR in the first-line treatment was 33.3%.In the IO cohort, at 12 months since palliative systemic treatment start, the probability of being dead due to MCC progression was 32.1%, and the probability of being dead due to other reasons was 10.8%.At 24 months, those probabilities were 51.4% and 15.9%, respectively.In the CHT cohort, at 12 months, the probability of being dead due to MCC progression was 59%, and the probability of being dead due to other reasons was 0%.The Hazard Ratio of death due to progression of MCC was 0.42 (0.23 -0.74) when IO was administered.Conclusions: The retrospective analysis supports the clinical benefit of avelumab, compared with the results of treatment with classic chemotherapy.The IO therapy decreased the rate of death due to progression of MCC.