Genmab Reports 50% Reduction in Risk of Death in Phase 3 Trial of Head and Neck Cancer Treatment
Key Facts
Genmab announced on October 28 that adding experimental drug petosemtamab to pembrolizumab delivered a statistically significant and clinically meaningful improvement in overall survival, reducing the risk of death by 50% in the first interim analysis of the Phase 3 LiGeR-HN1 trial. The trial compared the combination with pembrolizumab alone in first-line patients with PD-L1-positive recurrent or metastatic head and neck squamous cell carcinoma. The company said objective response rate also improved statistically, though its announcement summary did not provide a figure for that rate in Phase 3. It said the reduction in risk of death was seen regardless of human papillomavirus status. The result puts the experimental drug to an advanced test within this treatment program, while the announced reading is based on a first interim analysis.
The new results follow separate Phase 2 data presented by Genmab on October 26, and do not represent results from LiGeR-HN1 or its patient group. In the combination arm of that study, median overall survival was 28.2 months among 43 patients evaluable for efficacy, and the response rate was 63%. Median progression-free survival was 9.0 months, while the overall survival rate at 12 months was 79%. These figures were based on an efficacy analysis group smaller than the total number of patients who received treatment in the combination arm, which was 45. The follow-up cutoff reading on May 15, 2026 showed a median follow-up of 25.5 months, while the company estimated that 55% of responders would maintain their response at 24 months.
The Phase 2 data also included safety information, with the most common treatment-related adverse events being asthenia, acneiform dermatitis and rash. Asthenia was reported in 51% of patients, acneiform dermatitis in 51%, and rash in 49%, according to Genmab. Infusion reactions affected 38% of patients. No grade 5 adverse events or treatment-related deaths were reported in those data. These figures relate to the separate Phase 2 trial, and the LiGeR-HN1 results summary does not provide similar Phase 3 safety details.
Genmab described petosemtamab as an experimental bispecific antibody targeting EGFR and LGR5. The U.S. Food and Drug Administration granted the drug Fast Track designation for recurrent or metastatic head and neck cancer, and Breakthrough Therapy designation for first-line PD-L1-positive patients and for second-line and later treatment. These are prior regulatory designations, not marketing approval. The drug program includes 4 Phase 3 LiGeR trials, comprising two in head and neck cancer and two in colorectal cancer across different treatment lines. These trials provide the broader framework for developing the drug in more than one type of cancer, while the result announced on October 28 focuses on LiGeR-HN1.
In the first half of 2026, Genmab revenue rose 25% to 2,051 million dollars, compared with 1,640 million dollars in the same period of 2025. The company attributed the increase mainly to higher royalties from Darzalex and Kesimpta and increased sales of Epkinly. Research and development expenses reached 899 million dollars, compared with 723 million a year earlier, an increase of 24%. The company said the rise was mainly linked to higher clinical development costs to support ongoing trials of petosemtamab and Rina-S, as well as an increase in headcount. Separately from the LiGeR-HN1 results, Genmab announced on October 26 that it would hold an investor update on October 28 at 5:00 p.m. Central European Time, corresponding to 12:00 noon Eastern Time.
Genmab shares closed at 44.67 dollars on October 27, a day before the LiGeR-HN1 results announcement. That price does not reflect post-announcement trading, as the data provided do not include a later price to measure the stock's response. The company's shares had risen by as much as 13% on October 26, but that followed Phase 2 data for colorectal cancer, not the head and neck trial results. JPMorgan also raised its rating on the stock on October 27 from Neutral to Overweight, and increased its price target to 3,500 Danish kroner from 2,050 kroner. That assessment came before the LiGeR-HN1 announcement and does not represent a reaction to its results.
Genmab said it would engage with global regulatory authorities about the results and present the full data at a future medical meeting for which it did not specify a date. This follows the announcement of improvements in overall survival and objective response in the first interim analysis. The announcement summary did not provide a figure for the Phase 3 response rate or specify when the full results would be presented. The Phase 2 results announced in October remain separate in design and patient group from LiGeR-HN1. Regulatory engagement and presentation of the full data are the next two steps announced by the company.