Genmab A/S (NASDAQ:GMAB) just gave investors a lot to chew on. Over the weekend and into Monday, the biotech rolled out a trio of updates for its investigational bispecific antibody petosemtamab at the European Society for Medical Oncology Congress 2026, covering two major solid tumor types. And it threw in a new clinical partnership with Incyte Corporation (NASDAQ:INCY) for good measure.

Head And Neck Cancer: Survival That Turns Heads

In first-line recurrent or metastatic head and neck squamous cell carcinoma, Genmab on Monday presented updated Phase 2 data testing petosemtamab in combination with pembrolizumab.

The numbers are hard to ignore. The regimen produced a median overall survival of 28.2 months and an overall response rate of 63%, with 19% of evaluable patients achieving a complete response.

Patients recorded a median progression-free survival of 9.0 months, and an estimated 55% of responders kept their clinical response at 24 months. Investigators saw consistent antitumor activity across PD-L1 expression levels and p16 subgroups. Importantly, the study recorded no Grade 5 adverse events or treatment-related deaths.

Genmab is pressing ahead with a global Phase 3 trial in this setting, with topline data expected later this year.

Colorectal Cancer: Response Rates That Pop

On Sunday, Genmab reported updated Phase 2 findings evaluating petosemtamab alongside standard FOLFOX or FOLFIRI chemotherapy regimens in patients with metastatic colorectal cancer.

The combinations produced objective response rates of 75% in first-line treatment and 67% in second-line therapy. Among first-line patients with left-sided tumors, that response rate climbed to 81%.

Subgroup analyses showed robust activity in difficult-to-treat patients with liver metastases, generating response rates of 76% in first-line and 67% in second-line settings. Disease control rates reached 95% and 93%, respectively.

On the safety side, adverse events prompted treatment discontinuation in only 5% of mFOLFOX6 patients and 3% of FOLFIRI patients, with zero therapy-related fatalities.

Incyte Joins The Party With A KRAS-Targeted Combo

Expanding petosemtamab's clinical reach, Genmab on Friday announced a clinical trial collaboration with Incyte to target first-line metastatic colorectal cancer bearing KRAS G12D mutations.

Under the agreement, Genmab will run a Phase 1/2 trial evaluating petosemtamab alongside standard chemotherapy and Incyte's selective KRAS G12D candidate, INCB161734. Incyte will co-fund the clinical study and provide investigational drug supplies.

GMAB Price Action: Genmab shares were up 1.56% at $44.93 at the time of publication on Monday. The stock is trading at a new 52-week high, according to market data.