REG-Genmab Announces Updated Follow-Up Analyses from Phase 2 Study of Petosemtamab Demonstrate Meaningful Objective Response Rates in Patients with Metastatic Colorectal Cancer
Key Highlights
- ➤1L mCRC ORR reached 75% after median 5.9-month follow-up
- ➤2L mCRC ORR reached 67% after median 7.1-month follow-up
- ➤Left-sided 1L tumors achieved an 81% objective response rate
- ➤Phase 3 mCRC trials are actively enrolling patients globally
- ➤Petosemtamab discontinuation from treatment-related TEAEs was 5% with FOLFOX, 3% with FOLFIRI
Expert Statements
Ruth Vera, Medical Oncology Department, Hospital Universitario de Navarra, and study investigator
“Despite advances in the treatment of metastatic colorectal cancer, outcomes remain poor for many patients once disease has spread, including those with RAS/BRAF wild-type disease who may face limited options after standard chemotherapy and targeted therapy.”
Ruth Vera, Medical Oncology Department, Hospital Universitario de Navarra, and study investigator
“The encouraging response rates observed in both the first- and second-line settings, along with the maturation of the dataset over time, suggest that treatment with petosemtamab plus chemotherapy may offer a potential new approach for these patients.”
Tahamtan Ahmadi, Executive Vice President and Chief Medical Officer, Head of Experimental Medicines, Genmab
“These updated Phase 2 results presented at ESMO continue to build on the encouraging clinical efficacy of petosemtamab.”
Tahamtan Ahmadi, Executive Vice President and Chief Medical Officer, Head of Experimental Medicines, Genmab
“The confirmation of previously unconfirmed responses with longer follow-up further reinforces the durability of responses observed across treatment lines and strengthens our confidence in petosemtamab.”
Tahamtan Ahmadi, Executive Vice President and Chief Medical Officer, Head of Experimental Medicines, Genmab
“The data provide a compelling rationale for our ongoing global Phase 3 trials, where we aim to establish the potential benefit for patients in 1L and 2L settings.”
COPENHAGEN, Denmark; October 25, 2026 * Petosemtamab demonstrates encouraging objective response rates (ORRs), with promising depth and durability of response, in first- and second-line metastatic colorectal cancer (mCRC) * Data reinforces the ongoing global Phase 3 trials of petosemtamab in mCRC, which are actively enrolling patients Genmab A/S (Nasdaq: GMAB) today announced updated follow-up analyses from a Phase 2 trial evaluating petosemtamab, an investigational IgG1-bispecific antibody targeting the epidermal growth factor receptor (EGFR) and leucine-rich repeat containing G-protein-coupled receptor 5 (LGR5), in combination with FOLFOX or FOLFIRI in patients with metastatic colorectal cancer (mCRC). At a median follow-up of 5.9 months in the first-line (1L) setting and 7.1 months in the second-line (2L) setting, confirmed and unconfirmed objective response rates (ORRs) were 75% and 67%, respectively, with an ORR of 81% observed among 1L patients with left-sided tumors. With longer follow-up, most of the previously unconfirmed objective responses were subsequently confirmed, reinforcing the consistency of the clinical activity observed across treatment settings. The updated analyses reinforce the depth and durability of responses observed in both 1L and 2L treatment settings and support the ongoing global Phase 3 development program. The findings were presented at the European Society for Medical Oncology (ESMO) Congress 2026, held in Madrid, Spain.
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