A Study to Evaluate the Efficacy of Osimertinib With Early Intervention SRS Treatment Compared to the Continuation of Osimertinib Alone, in Patients With EGFR Mutated NSCLC and Asymptomatic Brain Metastases

This study involves patients with EGFR-mutated NSCLC and asymptomatic brain metastases. This is an open-label, randomized study, comparing the continuation of Osimertinib treatment alone to Osimertinib treatment combined with early intervention stereotactic radiosurgery (SRS). The current first line of care for EGFR-mutated NSCLC is administration of Osimertinib, a small molecule that penetrates the blood brain barrier (BBB) well and controls majority, but not all, of the brain metastases. We hypothesize that relatively early intervention with SRS to brain metastases that are still visualized by MRI 2 months-post initiation of Osimertinib treatment, LUNG- will improve long term brain control, cognitive abilities and potentially overall survival. Patients with EGFR-mutated NSCLC and asymptomatic brain metastases will be treated with Osimertinib for 2 months. Brain MRI scans will be collected pre-Osimertinib and 2 months after treatment start. Patients with asymptomatic brain metastases present after 2 months of Osimertinib will be randomized into one of two study arms. Arm A patients will be treated with SRS while continuing Osimertinib, while arm B patients will continue with Osimertinib alone. Patients will be assessed based on brain and whole body progression by RECIST. Patients will also be assessed for CNS-PFS and body-PFS, cognitive function, Quality of life and overall survival status via routine follow-up tests.