Combination of Osimertinib and Brigatinib in the Treatment of EGFR Triple-Mutated Lung Adenocarcinoma: A Case Report

Osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is widely used in treating patients with EGFR-mutated non-small-cell lung cancers (NSCLCs), especially in cases with secondary resistance mutations. However, tertiary resistance mutations often arise, and there is currently no established standard of care for NSCLC harboring triple EGFR mutations. In recent years, brigatinib, an anaplastic lymphoma kinase (ALK) TKI, has shown effectiveness in treating EGFR triple-mutated NSCLC. Despite this, the combined use of osimertinib and brigatinib remains largely unstudied. This case report describes a 51-year-old woman with EGFR-mutated NSCLC who was initially treated with first- and second-generation EGFR TKIs, then switched to osimertinib upon development of an exon 20 T790M mutation. When an exon 20 C797S mutation emerged, the decision was made to add brigatinib to the osimertinib regimen. The combined treatment of osimertinib and brigatinib offers a promising new approach. Nonetheless, it is important to consider the potential risk of off-target toxicities.