Phase 3 BATTMAN Trial in mCRC Begins Enrollment

The first patient has been enrolled in the global BATTMAN (CCTG CO.33) Phase 3 trial, a randomized study in refractory, unresectable MSS or pMMR metastatic colorectal cancer evaluating botensilimab plus balstilimab versus a control described as best supportive care.

Eligible participants are described as having chemo-refractory, unresectable colorectal adenocarcinoma with microsatellite-stable or mismatch repair–proficient disease. Investigators are comparing botensilimab plus balstilimab with best supportive care, with the stated aim of determining whether treated patients live longer. Beyond survival, researchers are exploring patient-reported quality of life, measures of tumor response and tumor growth, and biomarkers in tumor tissue or blood for their ability to predict benefit.

Investigators plan to enroll approximately 830 patients, with participation across more than 100 sites in Canada, France, Australia, and New Zealand. The program is an international cooperative-group study led by the Canadian Cancer Trials Group, with partner networks in Australia and France.

The company characterizes botensilimab as an Fc-enhanced anti–CTLA-4 antibody and balstilimab as a PD-1 inhibitor, describing the pair as a complementary immunotherapy combination. Botensilimab is portrayed as enhancing immune activation, while balstilimab is described as blocking PD-1 signaling to reduce inhibitory constraints on T-cell activity.