Key Highlights

● Petosemtamab plus pembrolizumab met both trial endpoints.

● The combination significantly reduced the risk of death.

● Pembrolizumab is Merck's widely used immunotherapy Keytruda.

● Genmab's shares surged at a double-digit pace.

Genmab (NASDAQ:GMAB) soared after the Danish biotech said a Phase 3 trial in head and neck cancer met both of its primary endpoints, one of the biggest moves among large companies that day. The trial tested petosemtamab in combination with pembrolizumab against pembrolizumab alone, with the combination significantly reducing the risk of death compared with pembrolizumab on its own.

The US-listed shares surged at a double-digit pace, though reports differed on the exact size of the gain.

Why the Trial Matters

Primary endpoints are the main goals a trial is designed to test, and meeting both is a clear win. A meaningful reduction in the risk of death, known as an overall survival benefit, is one of the most persuasive results a cancer drug can show, because it demonstrates that patients actually live longer.

Pembrolizumab, sold by Merck as Keytruda, is already a standard treatment for many patients with head and neck cancer, so showing that adding petosemtamab improves survival on top of that standard could be significant for the combination, subject to regulatory review.

What Genmab Does

Genmab is a Copenhagen-based biotechnology company that specializes in antibody medicines, best known for its role in creating daratumumab, a multiple myeloma drug marketed by Johnson & Johnson that has generated substantial royalties for Genmab over the years.

The company has been working to build its own portfolio of wholly owned drugs to reduce its reliance on those royalties, and petosemtamab, which came to Genmab through its acquisition of Merus, is a central part of that strategy.