Comparing CNS Efficacy of First-Line Regimens in EGFR-Mutant NSCLC With Brain Metastases

Dr. Rodriguez walks through the central nervous system (CNS) efficacy data for the three first-line options. She notes that MARIPOSA was specifically designed for close intracranial monitoring: patients with baseline brain metastases were imaged every 8 weeks, and patients without baseline brain metastases were also followed closely, which she cites as a reason for its National Comprehensive Cancer Network (NCCN) Category 1 recommendation. With amivantamab plus lazertinib, intracranial progression-free survival (PFS) at 3 years was 36% versus 18% with osimertinib monotherapy, intracranial overall response rate (ORR) was 78%, and intracranial duration of response (DOR) was approximately 35.7 months. Dr. Rodriguez contrasts these durations with the pre-targeted-therapy era, when CNS outcomes were typically measured in shorter timeframes.

FLAURA2 also includes drugs active in the brain (osimertinib plus carboplatin and pemetrexed), with CNS PFS of approximately 24.9 months. However, FLAURA2 only closely imaged patients with brain metastases at baseline; patients without baseline CNS involvement were imaged only if symptomatic, so the CNS picture is less granular. Among patients with baseline brain metastases in FLAURA2, the 36-month overall survival (OS) was 57% with the combination versus 40% with osimertinib monotherapy.

Dr. Rodriguez acknowledges that the two trials used different endpoints, imaging schedules, and patient populations, both were open-label, and no head-to-head data exist. Both combinations have shown improved CNS efficacy compared with osimertinib monotherapy in their respective trials. For a patient like Mr. Smith who presents with symptomatic brain metastases, Dr. Rodriguez considers MARIPOSA’s CNS data the most directly informative given its intracranial monitoring design, consistent with NCCN preference, and frames the first decision point as selecting a combination regimen over monotherapy.

In the next episode, “Overall Survival and Systemic Efficacy of First-Line Regimens in EGFR-Mutant NSCLC,” Dr. Rodriguez compares the overall survival data from MARIPOSA and FLAURA2.