Fusion as Resistance Mechanism to Osimertinib in -Mutated NSCLC: A Case Report and Review of Literature.

Despite the efficacy of osimertinib in the first-line treatment of advanced -mutated NSCLC, the development of resistance is nearly inevitable. mutations and fusions are reported in 1% to 3% of patients with -mutated NSCLC receiving osimertinib and represent potential targetable alterations. In this case report, we discuss the rationale for EGFR-MEK co-inhibition in a patient with -mutated NSCLC treated with osimertinib that developed a fusion at progression. In addition, we provide a brief overview of the current evidence of fusions as an acquired resistance mechanism to osimertinib and potential treatment strategies.