Outcome and treatment-related adverse events of combined immune checkpoint inhibition with flipped dosing in a real-world cohort of 79 patients with metastasized melanoma.

Introduction: Combined immune checkpoint inhibition (ICI) with ipilimumab and nivolumab is a widely used treatment regimen for metastatic melanoma with non-resectable metastases. Nevertheless, the standard dose of ipilimumab 3 mg/kg bw and nivolumab 1 mg/kg bw is associated with a high rate of treatment-related adverse events (trAEs) (59% grade 3-4). In the CheckMate 511 study, it could be shown that flipped dosing with ipilimumab 1 mg/kg bw and nivolumab 3 mg/kg bw resulted in a significant reduction of trAE. Methods: We have also used this regimen in the clinical setting and report the trAE, progression-free survival, and overall survival for 79 patients with metastatic melanoma who started combined ICI in the flipped dosing between March 2019 and April 2020. Results: in total, 40 patients started first-line, 50% of whom had an elevated lactate dehydrogenase level at baseline. The disease control rate of these patients was 50%. The 2-year overall survival rate 67%. Moreover, 33% of the patients suffered grade 3 or 4 treatment related adverse events. Discussion: The results of our study correspond very well to the results of the CheckMate 511 study (2-year OS: 65%, grade 3-4 immune-related side effects: 35%). Combined ICI with ipilimumab 1 mg/kg bw and nivolumab 3 mg/kg bw seems to be an equally effective but better-tolerated therapy regimen for metastasized melanoma patients, also in a real-world cohort.