MARIPOSA vs. FLAURA2: CNS Efficacy Head-to-Head Debate

The debate centered on CNS efficacy comparisons between MARIPOSA and FLAURA2, with the key distinction being that MARIPOSA mandated serial brain MRIs for all patients, enabling full intracranial PFS analysis across all 429 participants, whereas FLAURA2 only required serial imaging in patients with baseline CNS metastases, limiting the robustness of its CNS data. Team Thriller countered that FLAURA2's more flexible imaging schedule better reflects real-world practice, and that catching a brain metastasis earlier via more frequent scanning does not necessarily translate to improved survival, particularly in light of ASCO 2026 data showing no survival difference between early and delayed brain radiation. Both teams ultimately agreed that neither regimen has clearly demonstrated CNS superiority over the other in a true apples-to-apples comparison, and that brain metastasis status alone should not be the deciding factor in choosing between the two intensification strategies.