Petosemtamab

Dive Brief:An experimental drug that Genmab gained in an $8 billion buyout succeeded in a late-stage trial in a form of head and neck cancer, sending shares of the Danish drugmaker soaring to an all-time high.At an early analysis, a combination of Genmabs drug petosemtamab and the immunotherapy Keytruda, cut the risk of death by half compared to Keytruda alone when used as a first-line treatment in people whose head and neck squamous cell carcinoma is positive for the protein PD-L1. The regimen met dual main objectives on response rates and survival.The latest finding represents the third consecutive positive late-stage readout in a few weeks for Genmab, providing an important boost ahead of the patent expiry for the multiple myeloma drug Darzalex. The company will share detailed results with global regulatory authorities and present them at a future medical meeting. Genmabs market value swelled by more than $7 billion on the news, pushing its worth past $35 billion.Dive Insight:Petosemtamab is one of a few drugs Genmab is betting on to grow sales as it braces for the loss of Darzalexs exclusivity. Though Johnson & Johnson owns commercial rights to Darzalex, Genmab derives royalties that heavily contributed to the roughly $3.7 billion in revenue the company booked in 2025.Genmab inherited petosemtamab when it acquired the Dutch biotechnology company Meruslast year. The drug a bispecific antibody targeting the proteins EGFR and LGR5 had already produced positive results in a Phase 2 trial. Genmab predicted the antibody could become a blockbuster by 2029, should those results be replicated in a late-stage study.Ahead of those findings, Genmab scored two other wins that have lifted its revenue potential. Earlier this month, the company and partner AbbVie announced the blood cancer drug Epkinly succeeded in a Phase 3 trial in frontline lymphoma. Wall Street analysts claimed the results have positioned Epkinly to become a new treatment standard in people with newly diagnosed, diffuse large B-cell lymphoma.The company continued its streak last week when an antibody-drug conjugate dubbed rinatabart sesutecan hit its goal in a late-stage study in ovarian cancer. Genmab picked up that therapy in a 2024 buyout of startup ProfoundBio.Wednesdays result positions petosemtamab to become part of a new treatment standard in first-line head and neck squamous cell carcinoma, wrote TD Cowen analyst Yaron Werber. The findings should support a broad label enabling access regardless of whether patients tumors are driven by HPV infections, he wrote.The trio of successes show Genmab has delivered on the late-stage catalysts that define the companys longer-term growth story, wrote William Blair analyst Matt Phipps, in a Thursday client note. The company is now on the path to surpassing $10 billion in annual revenue, with pending launches that can more than offset the impending loss of Darzalex royalties, Phipps added.Petosemtamab is being tested in multiple other Phase 3 trials, among them studies in second- and third-line recurrent head and neck cancer, and a trial in colorectal cancer. '

Capping off a busy few days in Spain, Genmab reported results from the first interim analysis of a phase 3 trial showing that adding its bispecific antibody petosemtamab to Merck & Co.'s Keytruda cut the risk of death by 50% compared with Keytruda alone in patients with PD-L1-positive recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). The results, announced Wednesday, came a day after the European Society for Medical Oncology (ESMO) congress concluded in Madrid. The late-stage LiGeR-HN1 study met both primary endpoints, demonstrating statistically significant improvements in overall survival and objective response rate with the combination compared with Keytruda alone. Genmab acquired the immunoglobulin G1 bispecific antibody through its $8 billion acquisition of Merus last year. Petosemtamab binds both epidermal growth factor receptor (EGFR) and leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), the latter of which is a novel oncology target. The overall survival benefit was reflected in a hazard ratio of 0.50, while the odds of achieving an objective response were 3.17 times higher with the combination than with Keytruda alone. Genmab reported that the combination's safety profile was consistent with previous findings for the individual drugs, with no new safety signals identified. "These topline phase 3 results represent a defining milestone for Genmab and further strengthen our conviction in petosemtamab as a potential first-in-class treatment option for patients with this difficult-to-treat cancer," Genmab CEO Jan van de Winkel, Ph.D., said in a release. Genmab plans to discuss the results with global regulators and submit the full dataset for presentation at a future medical meeting. Earlier this week , the company disclosed data from a midstage trial in recurrent or metastatic HNSCC showing an objective response rate of 63% among 43 evaluable patients and median progression-free survival of nine months with petosemtamab plus Keytruda. In a note this week, William Blair analysts projected $4 billion in peak sales for petosemtamab in HNSCC alone. Genmab is also evaluating the drug in second- and third-line recurrent or metastatic HNSCC, as well as colorectal cancer, across three additional phase 3 studies. And petosemtamab isn't Genmab's only recent success. The company also reported a phase 3 win for its antibody-drug conjugate rinatabart sesutecan in platinum-resistant ovarian cancer during the ESMO congress.