Survival of Patients with Metastatic Melanoma Treated with Ipilimumab after PD-1 Inhibitors: A Single-Center Real-World Study

Background: When monotherapy with PD-1 inhibitors in metastatic melanoma fails, there are currently no standard second-line choices. In case of the unavailability of clinical trials, ipilimumab represents a possible alternative treatment. Methods: We collected data of 44 patients who received ipilimumab after the failure of PD-1 inhibitors from July 2017 to May 2023 at our Institute. Overall survival (OS), progression-free survival (PFS), and post-progression survival (PPS) based on BRAF or NRAS mutation status, sex, and the presence of brain metastases were estimated using the Kaplan–Meier method. Cox regression was used to evaluate independence in multivariate analysis. The objective response rate (ORR) was estimated based on RECIST 1.1. Results: Among the 44 patients enrolled in this study, 28 BRAF-wildtype, 9 BRAF-mutated, and 7 NRAS-mutated patients were identified. OS analysis showed a significant difference between wildtype and BRAF- or NRAS-mutated patients: 23.2 months vs 5.3 and 4.59, respectively, p = 0.017. The presence of brain metastases and BRAF or NRAS mutation were independent factors for mortality in multivariate analysis. Conclusions: In case of failure to enroll patients in innovative clinical trials, second-line ipilimumab still represents an effective therapy in patients with metastatic wildtype melanoma and in the absence of brain metastases.