Choosing Between MARIPOSA and FLAURA2: Efficacy Data Side by Side

Dr. Gumbleton compares MARIPOSA and FLAURA2 side by side, noting that no head-to-head data exist for amivantamab plus lazertinib versus osimertinib plus chemotherapy, so the two trials must be considered in parallel to inform the decision.

From MARIPOSA, the randomized phase 3 trial comparing amivantamab plus lazertinib with osimertinib monotherapy, he cites improved progression-free survival (PFS) of approximately 2 years with the combination, median overall survival (OS) not reached versus about 3 years with osimertinib alone, and a best current estimate that OS with the combination will exceed 4 years. Importantly for Mrs. Chen, a significant benefit was observed in the TP53 subgroup.

The FLAURA2 data look relatively similar on the face of it, with PFS close to 2 years versus about 16 months with osimertinib monotherapy and median OS of about 4 years with the combination versus about 3 years with monotherapy. Dr. Gumbleton notes that the shape of the curves appears slightly in favor of amivantamab plus lazertinib.

He adds a formulation-specific consideration: MARIPOSA was conducted with intravenous (IV) amivantamab, whereas the subcutaneous (SC) formulation is now available in practice. Taking efficacy and the logistical advantages of SC administration together, he leans modestly toward the amivantamab-plus-lazertinib combination for this patient, while acknowledging the decision is not clear-cut.

In the next episode, “CNS Protection and Risk of Brain Metastases”, Dr. Gumbleton reviews the intracranial data from both trials and why CNS outcomes matter for Mrs. Chen.