Real-world treatment patterns and clinical outcomes of advanced melanoma patients following disease progression on anti-PD-1-based therapy.

Abstract

e22036 Background: Despite the success of anti-programmed cell death-1 (PD-1) based therapies that prolong survival in advanced melanoma, some patients experience disease progression. Real-world treatment patterns and outcomes after progression on anti-PD-1 based regimens are unknown. Methods: Adults with advanced melanoma and a record of disease progression on anti-PD-1 treatment (alone or in combination) between 1 Sept 2014–31 Jan 2019 were selected from the Flatiron Health Oncology electronic medical record (EMR) database for this retrospective study. Index progression date was defined as an event where the treating clinician concluded in the patient record that there had been disease progression. The first subsequent therapy received was identified. Kaplan-Meier methods estimated overall survival (OS) with 95% confidence interval (CI) after the progression date. Analyses were run separately for BRAF mutant (mt) and wild type (wt). Results: Among 2,169 patients with advanced melanoma treated with an anti-PD-1, 213 BRAFmt and 302 BRAFwt had a record of progression following anti-PD-1 initiation and were included; an additional 82 BRAFmt and 138 BRAFwt were excluded due to death without a record of progression. Median age was 64 and 71 years, respectively; 27.7% and 9.9% had >1 line of therapy prior to the anti-PD-1. Among the BRAFmt patients who progressed on anti-PD-1, 94 (44.1%) received no subsequent therapy, 80 (37.6%) BRAF±MEK (± IO), and 16 (7.5%) anti-CTLA4 alone or with anti-PD-1 after progression on the initial anti-PD-1; 11% received other treatments with no clear pattern of care. Median (95% CI) OS from the index progression date for BRAFmt was 11.9 (8.2–16.9) months. In a subgroup of these BRAFmt patients with BRAF treatment prior to or during the first anti-PD-1 line (N = 65), 52.3% had no subsequent therapy and a median OS of 4.0 (2.7–7.5) months. Among the BRAFwt patients who progressed on anti-PD-1, 186 (61.6%) received no subsequent therapy, 46 (15.2%) received anti-CTLA4 alone or with anti-PD-1, 26 (8.6%) switched anti-PD-1s, and 15% received other treatments. Median (95% CI) OS for BRAFwt was 10.1 (8.8–12.5) months. Conclusions: In this real-world retrospective study, > 40% of BRAFmt and > 60% of BRAFwt patients did not initiate a new regimen after progression on anti-PD-1 therapy. Median OS after progression was < 1 year. This may be overestimated, as it excluded patients who died before progression was recorded in the EMR. These findings highlight a need for more effective treatments for advanced melanoma.