Correlation of immunity-related adverse events with survival and response to anti-PD-1 treatment in patients with metastatic melanoma.

Abstract

e15164 Background: Immunotherapy has become a standard treatment option for metastatic melanoma patients, and the use of anti-programmed cell death-1 monoclonal antibodies (anti-PD-1) has significantly improved the outcomes of this group of patients. Immune related adverse events (irAEs) during anti-PD-1 treatment may present a significant problem. However, irAEs' relationship with overall survival although suggested in single studies was not confirmed in real world data. Methods: Consecutive patients starting treatment between March 2016 and April 2019 with fist line anti-PD-1 (nivolumab or pembrolizumab) for unresectable or metastatic melanoma in 6 comprehensive cancer centers in Poland were enrolled in the study. Baseline patients characteristics and irAEs development during treatment were evaluated to identify predictors of progression-free (PFS) and overall (OS) survival in Cox model. PFS and OS were assessed using Kaplan–Meier method. Results: Overall, 410 patients were included in the present analysis and 107 patients experienced irAEs. Response rate (RR) and disease control rate (DCR) were 36% (148 pts) and 65% (267 pts) respectively. Median PFS and OS were 7.6 (2.8–21.6) and 21.6 (6.7–38.2) months, respectively. In univariate analysis normal LDH level, no brain metastases, ECOG 0 or 1, ≤ 2 number of metastases locations were positive prognostic factors for both OS and PFS. At the same time irAEs occurrence was correlated with longer PFS, OS, RR and DCR (all p < 0.001); moreover high LDH level correlated with irAEs (p = 0.027) development. There was no correlation between irAEs and the number of cycles of anti-PD-1 patients received. Conclusions: Our study showed an association between irAEs and longer survival on anti-PD1 therapy in patients with advanced or metastatic melanoma. An association with irAEs and response to therapy has also been demonstrated.