Outcomes of retreatment with anti-PD-1 monotherapy after response to first course in patients with cutaneous melanoma

To determine outcomes of retreatment with anti-PD-1 monotherapy for melanoma. This retrospective study included adults with unresectable cutaneous melanoma who achieved stable disease (SD) or better after anti-PD-1 monotherapy and were retreated with anti-PD-1 monotherapy after ≥90-day gap. We determined overall survival and real-world tumor response. For 21 eligible patients, from retreatment initiation, median follow-up was 14.4 months (range, 2.6–34.5); median overall survival was 30.0 months (95% CI: 14.4–not reached); 1-year survival was 100% (95% CI: 100–100%); 2-year survival was 83% (48–96%). Of 16 patients with recorded best real-world tumor response, ten (63%) responded (complete/partial response); three achieved SD; three had progressive disease. Patients with advanced melanoma achieving SD/better after first-course anti-PD-1 monotherapy may benefit from retreatment.