Spotlight on Patritumab Deruxtecan (HER3-DXd) from HERTHENA Lung01. Is a Median PFS of 5.5 Months Enough in Light of FLAURA-2 and MARIPOSA?

On December 22, 2023, the US Food and Drug Administration (FDA) approved the biologics license application for patritumab deruxtecan (HER3-DXd) for priority review. This treatment is aimed at adult patients with locally advanced or metastatic NSCLC with EGFR mutations, who have received at least two prior systemic therapies. Approval of patritumab deruxtecan would mark it as the first HER3 targeted therapy in the United States. This prioritization by the FDA is grounded in compelling results from the global Phase II HERTHENA-Lung01 trial, wherein HER3-DXd exhibited clinically meaningful efficacy, achieving a median progression-free survival (mPFS) of 5.5 months in patients with heavily treated EGFR-mutated NSCLC. A pivotal question remains: Is a mPFS of 5.5 months sufficient in the context of the evolving first-line landscape observed in the FLAURA-2 and MARIPOSA trials?