Genmab’s petosemtamab in combination with pembrolizumab (Keytruda) posted a clinically meaningful reduction in risk of death in a late-stage readout for PD-L1–positive head and neck squamous cell carcinoma, driving shares to record highs. In an early analysis, the regimen cut the risk of death by about half versus Keytruda alone as a first-line treatment, while also meeting dual main objectives on response rates and survival. The company said it will share detailed results with global regulators and present at a future medical meeting. Petosemtamab is an EGFR/LGR5 bispecific antibody that Genmab inherited through its acquisition of Merus. The program had previously shown positive phase 2 results, and the latest win marks a third consecutive late-stage positive readout for the company in recent weeks. Genmab’s momentum matters as it prepares for patent expiry pressure on Darzalex and works to establish new revenue drivers ahead of that transition; Johnson & Johnson holds commercial rights to Darzalex, while Genmab receives royalties.