Genmab A/S said its investigational petosemtamab and chemotherapy combination produced objective tumor responses in patients with first- and second-line metastatic colorectal cancer, while two Phase 3 trials continue to enroll.
In an Oct. 25 release, Genmab reported confirmed and unconfirmed responses in both treatment groups, including first-line patients with left-sided tumors. The company did not state the response-evaluable group sizes.
The analysis used a May 15 data cutoff and included 79 patients who received the combination: 45 in first-line treatment and 34 in second-line treatment. Median follow-up was 5.9 months and 7.1 months, respectively. Among patients with liver metastases, Genmab reported objective response rates of 76% in first-line treatment and 67% in second-line treatment, with disease control rates of 95% and 93%.
The ongoing Phase 2 study is open-label and single-arm. Patients receive petosemtamab with FOLFOX or FOLFIRI; Genmab describes the investigational antibody as targeting EGFR and LGR5. With no comparison group, the study cannot establish whether the combination performed better than another treatment.
Genmab said petosemtamab-related treatment-emergent adverse events led to treatment discontinuation in two of 42 patients receiving it with mFOLFOX6 and one of 37 receiving it with FOLFIRI. The company reported no treatment-emergent adverse events leading to death.
Genmab said its Phase 3 trials in first- and second-line metastatic colorectal cancer are enrolling. Separately, Genmab and Incyte said Saturday they plan a Phase 1/2 study in first-line patients with KRAS G12D-mutated disease, combining petosemtamab, Incyte’s investigational inhibitor INCB161734 and standard chemotherapy.
Genmab scheduled an investor update for Wednesday, Oct. 28, at noon EDT.
