Genmab shares hit record high after head and neck cancer drug shows strong survival benefit

Genmab A/S shares hit a record high on October 28, 2026, surging as much as 30% on Nasdaq after the Danish biotech announced that its experimental drug petosemtamab, combined with Merck's Keytruda, improved overall survival in patients with a common form of head and neck cancer — capping a week in which the company delivered positive late-stage trial results across three different cancers.

The stock closed at $57.29, up $12.62 or 28.25%, with more than 29 million shares traded. That close established a new 52-week high of $59.97 reached intraday, lifting Genmab's market capitalisation to approximately $34.47 billion, according to Stock Analysis.

The catalyst was topline results from the global Phase 3 LiGeR-HN1 trial, in which petosemtamab combined with pembrolizumab — sold as Keytruda — was tested against pembrolizumab alone as a first-line treatment for PD-L1-positive recurrent or metastatic head and neck squamous cell carcinoma. The trial met both primary endpoints, delivering a statistically significant and clinically meaningful improvement in overall survival and objective response rate, according to the company's announcement from Copenhagen.

Genmab scores a 'hat trick' with positive data for its experimental cancer drug, petosemtamab.— Jefferies

The head and neck result was the third major positive readout in less than a week, and JPMorgan — which had upgraded Genmab to 'overweight' from 'neutral' on Tuesday and raised its Copenhagen-listed price target to 3,500 Danish kroner from 2,050 kroner — had specifically flagged this trial as the next key catalyst, saying it expected positive results in November from interim data covering roughly 300 of 500 planned patients. The results arrived ahead of that timeline.

The rally had begun the previous week with results from RAINFOL-02, a late-stage trial of Rina-S, an antibody-drug conjugate for platinum-resistant ovarian cancer. That study, which enrolled 584 patients and compared Rina-S with physician's choice of chemotherapy, showed Rina-S reduced the risk of disease progression or death by 71% and cut the risk of death by 57%, according to ibtimes.com.au. Genmab shares jumped roughly 13% on Monday after the company then presented updated mid-stage data for petosemtamab in metastatic colorectal cancer at the European Society for Medical Oncology Congress in Madrid, showing response rates of 75% in first-line patients and 67% in second-line patients among 79 treated patients.

The magnitude of the benefit exceeds investor expectations and sets a high bar for future competition in ovarian cancer.— William Blair analysts

The data establish Rina-S as a potential new standard of care across broad PROC.— Truist Securities analysts

Analysts at Leerink Partners expect Genmab to file for regulatory approval of Rina-S in early 2027, with a possible U.S. launch late that year. JPMorgan raised its peak sales forecast for petosemtamab to $5 billion from $2.5 billion, and set peak sales targets of $4 billion for Rina-S and $2.5 billion for Epkinly in first-line lymphoma.

Epkinly — the brand name for epcoritamab, developed with partner AbbVie — also contributed to the week's positive news. A late-stage trial showed epcoritamab plus standard chemotherapy significantly improved progression-free survival in newly diagnosed diffuse large B-cell lymphoma, potentially expanding the drug's use into earlier treatment.

Both petosemtamab and Rina-S came to Genmab through acquisitions — petosemtamab via the purchase of Merus, and Rina-S through the earlier acquisition of ProfoundBio. Analysts say the recent data suggest those deals are beginning to pay off as Genmab works to build a portfolio of wholly owned drugs, reducing its longstanding dependence on royalties from Darzalex, the multiple myeloma blockbuster sold by Johnson & Johnson whose patents will eventually expire.

Genmab also announced a collaboration with Incyte to evaluate Incyte's investigational KRAS G12D inhibitor, INCB161734, in combination with petosemtamab and chemotherapy in patients with metastatic colorectal cancer. The company raised its 2026 financial outlook in August after revenue jumped approximately 25% in the first half of the year. Full Phase 3 results from the LiGeR-HN1 head and neck trial are expected to be presented at a future medical meeting. Genmab's next earnings date is November 5, 2026.

JPMorgan cautioned that a failure of the head and neck trial — now resolved positively — and faster-than-expected competition were the key risks it had identified. With that trial now cleared, investor attention turns to regulatory filings, the pace of potential 2027 launches, and third-quarter financial results.

Why it matters — Three positive Phase 3 cancer trial results in a single week — covering ovarian, colorectal, head and neck, and lymphoma — give Genmab a credible path to multiple drug launches starting in 2027, potentially transforming it from a royalty-dependent company into a fully independent cancer drug developer.

Reported by bloomberg.com, benzinga.com, stockanalysis.com, ibtimes.com.au