Botensilimab, Balstilimab, and SBRT in Colorectal Cancer

Starting on Day 1 participants will have 2-4 treatments per week for about 2 weeks, with no more than 2 days in a row. This is expected to last about 2 weeks but could last up to 3 weeks.

Administered once every 6 weeks by intravenous infusion over about 30 minutes, on Day 1 of Cycles 1-4 (six-week cycles). Administered 30 minutes after balstilimab.

Administered once every 2 weeks by intravenous infusion over about 30 minutes, starting on Day 1 of Cycle 1 and continuing for 4 six-week cycles (with botensilimab) followed by up to 14 six-week cycles of balstilimab alone. Participants will receive balstilimab for a total of 18 six-week cycles.