Confirmatory win could vindicate Imdelltra and the FDA

Amgen's controversial anti-DLL3 T-ell engager Imdelltra might have just got its biggest endorsement to date. After Imdelltra faced questions over toxicity, the protocol deviations revealed in its FDA review, and the lack of dose response in its registrational Dellphi-301 trial, its confirmatory phase 3 Dellphi-304 study was toplined on Friday as having scored a statistically significant and clinically meaningful improvement in overall survival versus standard of care, its primary endpoint. The drug, first approved a year ago for second-line SCLC, on an accelerated basis backed by the uncontrolled third-line-plus Dellphi-301 study, now looks set to have this converted to a full green light. Depending on how strong the Dellphi-304 data are – nothing beyond the topline hit has yet been revealed – the win could vindicate the FDA, which in spite of numerous doubts and inconsistencies had approved Imdelltra without convening an adcom, and without implementing a risk evaluation and mitigation strategy. That last point remains contentious, as even though Imdelltra now has a survival benefit under its belt Dellphi-304 is said to have shown safety "consistent with its known profile".

Selected Imdelltra trials

Source: OncologyPipeline.