Characterization and Outcomes of Disease Progression in 52 Patients Treated with BRAF-V600 + MEK Inhibitors for Advanced Melanoma.

Background: Combined treatment with BRAF-V600 and MEK inhibitors has significantly improved progression-free and overall survival of patients with BRAF-mutated melanoma. Pattern of disease progression and outcomes in patients have not been fully characterized.

Methods: We conducted a single-center, retrospective, descriptive analysis of a cohort of 52 patients treated with BRAF-V600 + MEK inhibitors for advanced melanoma over a 12-month period. The aim of this study was to characterize disease progression, defined as metastatic pattern, disease kinetics, and response to subsequent therapies, in melanoma patients treated with BRAF-V600 + MEK inhibitors.

Results: Disease progression was observed in 31/52 (59.6%) patients treated with BRAF-V600 + MEK inhibitors. Relapse of melanoma involved the CNS for 22/31 (70.9%) patients with disease progression, including 18/31 (58%) patients who had exclusive intracranial metastases. Sixteen patients died from disease progression. Among the 31 patients who had disease progression, the median time until a relapse was 8 months, and the median survival time after disease progression was 2 months.

Conclusion: Our study shows that, for patients treated with BRAF-V600 + MEK inhibitors who lose response, disease progression was aggressive and had poor outcomes. Most patients had CNS metastases and low rates of therapeutic response to any subsequent therapy.