Older melanoma patients aged 75 and above retain responsiveness to anti-PD1 therapy: results of a retrospective single-institution cohort study

Introduction: The utility of immunotherapy in elderly melanoma patients is debated. We aimed in this study to evaluate the efficacy and tolerability of immunotherapy among elderly patients. Method: This is a retrospective single-institution cohort study. Patients aged 75 years and above who had been treated with nivolumab, pembrolizumab or ipilimumab for advanced or metastatic melanoma, were included. Patients and disease characteristics were collected using electronic medical records. Objective response was determined according to the immune-related response criteria. Drug-related toxicities (DRT) were graded according to the CTCAE v4.03. Results: 99 patients were included with a mean age of 80 years (SD = 4). One patient received nivolumab and ipilimumab combination, but died because of drug-related diverticulitis. Median PFS on pembrolizumab, nivolumab or ipilimumab were equal to 11.9 (95% CI 5.4–18.4), 1.4 (95% CI 0.01–2.8), and 2.8 months (95% CI 2.6-3), respectively, while objective response rates were equal to 51.6, 12.5, and 17.3%, respectively. Median OS was not reached in patients who received only pembrolizumab, 8.7 months in the ipilimumab only group, and 23 months in patients receiving several immune therapies sequentially. Pembrolizumab, nivolumab, and ipilimumab grade 3–4 DRT rates were equal to 24.2, 62.5, and 32.7% respectively, while discontinuation rates were equal to 43.5, 62.5, and 28.8%, respectively. Conclusions: Our study suggests that immunotherapy is effective and well tolerated in the elderly. The PFS on pembrolizumab was greater than expected, a finding that needs to be investigated further.