Genmab said its bispecific antibody petosemtamab, when combined with Merck’s Keytruda, met primary endpoints in a late-stage study of first-line head and neck squamous cell carcinoma in patients with PD-L1 positivity. An early analysis showed the regimen cut the risk of death by half versus Keytruda alone, alongside improvements on response rate and survival objectives. The readout extends Genmab’s run of recent late-stage wins, with the company pointing to a broader strategy to replace revenue exposure as patents approach for its Darzalex franchise. Genmab inherited petosemtamab through its acquisition of Merus last year, and the antibody had previously generated positive Phase 2 results. Genmab said it will share detailed data with global regulators and present findings at an upcoming medical meeting. TD Cowen analyst Yaron Werber cited the trial as positioning petosemtamab for potential inclusion in a new standard-of-care pathway for PD-L1-positive disease. Market reaction underscored the momentum: the company’s shares surged to record highs, adding more than $7 billion in market value on the news and pushing its worth above $35 billion.