Rechallenge with checkpoint inhibitors in metastatic melanoma.

To date, there have been only few studies investigating rechallenge with checkpoint inhibitors in melanoma patients. Herein, we present the first review of all internationally published, English-language articles. A total of 570 patients were included in our analysis, divided into four groups: 1) rechallenge with anti-PD1 following disease progression on anti-PD1 therapy; 2) rechallenge with anti-PD1 and anti-CTLA4 following disease progression on anti-PD1 therapy; 3) rechallenge with anti-CLTA-4 following disease progression on anti-CTLA-4 therapy; and 4) rechallenge following toxicity-related treatment discontinuation. In the first group (85 patients), the mean disease control rate (DCR) was 45.8 %, with a mean overall response rate (ORR) of 15.5 %. The second group (114 patients) showed a mean DCR of 40.6 % and an ORR of 20 %. In the third group (182 patients), the mean DCR was 50.9 %, with an ORR of 20.4 %. Thus, even patients with a history of disease progression on initial checkpoint inhibitor therapy may benefit from rechallenge. Patients in the fourth group (189 patients) showed a mean DCR of 89.5 % and an ORR of 70.2 %. Of these individuals, 18 % saw recurrence of the same toxicity; 23 % were affected by adverse events different from the ones previously experienced.