Response to the Combination of Osimertinib, Dabrafenib, and Trametinib in Leptomeningitis From EGFR-Mutant NSCLC With Acquired BRAF V600E Mutation: A Case Report

Molecular sequencing after highly potent targeted gene inhibitors have suggested resistant tumors can display substantial heterogeneity. Among these various mechanisms of resistance, secondary mutations on targetable oncogenes have been identified. BRAF V600E, as a bypass mechanism on disease progression while receiving osimertinib therapy, has been reported in 3% of EGFR-mutated patients. Few case reports described the efficacy of the association of osimertinib and dabrafenib plus trametinib. Here, we report, for the first time, a case of a patient treated with this association, with a prolonged response on leptomeningeal metastasis. We also provide a comprehensive overview of the available literature on the efficacy and tolerance of this association.