Genmab said a late-stage head and neck squamous cell carcinoma trial met key endpoints with petosemtamab plus Merck’s Keytruda (pembrolizumab), cutting the risk of death by half versus Keytruda alone in patients whose tumors are PD-L1 positive. The company reported results from an early analysis and said the regimen also met targets on response rates and survival. The update adds to Genmab’s streak of positive late-stage readouts in recent weeks, reinforcing momentum ahead of patent expiries tied to its multiple myeloma franchise Darzalex. Genmab last year inherited petosemtamab via its acquisition of Merus, and it is positioning the bispecific antibody—targeting EGFR and LGR5—as a potential new standard in first-line head and neck cancer. Genmab plans to share more detailed findings with global regulators and present at a future medical meeting. Analysts highlighted the commercial importance of building sales beyond Darzalex exclusivity, with Genmab reliant on royalties from Johnson & Johnson’s commercial rights to Darzalex.