Key Highlights

● The trial showed a significant overall survival benefit.

● Petosemtamab is a bispecific antibody targeting two cancer-cell targets.

● The drug came to Genmab through its Merus acquisition.

● Shares surged at a double-digit pace.

Genmab (NASDAQ:GMAB) rocketed after its experimental drug petosemtamab delivered a survival benefit in a Phase 3 trial for head and neck cancer, turning the Danish biotech into one of the day's standout performers. In the trial, petosemtamab combined with pembrolizumab significantly cut the risk of death compared with pembrolizumab alone, and the study met both primary endpoints.

Genmab's US shares surged at a double-digit pace, with reports differing on the precise size of the move.

The Power of a Survival Result

In cancer drug development, overall survival is the gold standard. Many trials measure how long tumors stay in check or how many patients respond, but showing that patients actually live longer is the result regulators, doctors and investors value most.

A survival win on top of pembrolizumab, Merck's widely used immunotherapy sold as Keytruda, suggests petosemtamab could add real benefit to an existing standard of care rather than simply competing with it.

Inside the Drug

Petosemtamab is a bispecific antibody, meaning it is engineered to latch onto two different targets at once, an approach intended to work more effectively than hitting a single target. The drug joined Genmab's pipeline through the company's acquisition of Merus.

For Genmab, which has long relied on royalties from the multiple myeloma drug daratumumab, building a portfolio of its own products is a strategic priority, and a successful late-stage result for petosemtamab strengthens that effort.