Genmab reports 50% lower death risk with petosemtamab in Phase 3 trial
The combination beat pembrolizumab alone on survival and tumour response in first-line PD-L1-positive head-and-neck cancer.
Adrian Kessler
Survival improved against pembrolizumab alone as Genmab A/S NASDAQGMAB reported on Wednesday that its petosemtamab combination reduced the risk of death by 50 per cent in a Phase 3 head-and-neck cancer trial. The treatment met both primary endpoints in a study whose registry lists 699 enrolled patients.
The LiGeR-HN1 study tested petosemtamab plus pembrolizumab against pembrolizumab alone in previously untreated recurrent or metastatic disease expressing PD-L1. The ClinicalTrials.gov record, updated Sept. 25, describes randomized allocation. Genmab's release specifies a one-to-one ratio between the two arms.
Genmab is a Copenhagen-based commercial antibody developer with a large international cancer-drug business.
Its Nasdaq-listed American depositary shares rose 15.22 per cent to US$51.47 at 9:45 a.m. EDT on Wednesday, according to Google Finance's NASDAQGMAB page. Genmab plans discussions with global regulators, but the topline disclosure gives no application date.
Survival And Response Both Improved
The overall-survival hazard ratio was 0.50, with a 95 per cent confidence interval of 0.37 to 0.67. The p value was below 0.0001, and Genmab said the benefit applied regardless of human papillomavirus status.
The objective-response odds ratio was 3.17, with a 95 per cent confidence interval of 2.06 to 4.89. Its p value was also below 0.0001, meeting the other primary endpoint.
The odds ratio does not mean the response rate tripled. Genmab did not provide either arm's absolute response rate or median survival in the disclosed topline results, so the additional months of life remain unquantified.
The trial was open-label, meaning treatment assignments were known, while the registry specifies blinded independent central review for the response endpoint. The disclosed topline account provides no FDA assessment of the design; meeting trial endpoints does not itself authorize commercial use.
Genmab said the combination's safety profile was consistent with the individual agents and identified no new safety signals, but the topline account supplied no severe-event, discontinuation or treatment-related death rates. Those figures are needed to assess the additional treatment burden alongside the survival benefit.
"Based on these positive topline results, Genmab plans to engage global regulatory authorities and will submit the full results from LiGeR-HN1 for presentation at a future medical meeting," the company said in the release.
Response measures tumour shrinkage, while overall survival measures time to death. A randomized survival comparison supplies evidence that a response-only study cannot establish.
Read more: MacroGenics reports 25 per cent response in clear cell gynecologic cancer trial
The Comparator Is An Established Treatment
Merck & Co., Inc. NYSEMRK announced in June 2019 that Keytruda, its pembrolizumab brand, gained FDA approval as first-line monotherapy for recurrent or metastatic head-and-neck cancer with PD-L1 expression meeting the label's threshold. LiGeR-HN1 therefore tested the addition of petosemtamab to an established treatment.
For broader sector context, the iShares Biotechnology ETF closed at US$208.69 at 4 p.m. EDT on Oct. 26, according to Google Finance's NASDAQIBB page. That earlier close predates Wednesday's announcement.
The head-and-neck result is separate from Genmab's Oct. 25 colorectal disclosure. That single-arm Phase 2 study combined petosemtamab with chemotherapy and reported response rates including unconfirmed responses; it did not establish a randomized survival advantage.
Read more: Genmab reports 75 per cent first-line response in petosemtamab colorectal study
Genmab's Aug. 6 financial results reported operating profit of US$555 million for the first half of 2026. The company attributed higher spending partly to petosemtamab development and preparations for anticipated launches; the disclosed trial topline gives no cash-runway estimate.
The next scheduled checkpoint is Genmab's Oct. 28 investor update at noon EDT. The absolute survival benefit, detailed safety results and regulatory filing timetable remain the questions for that update.
