A Study in Advanced or Metastatic Gastrointestinal Cancers Exploring Treatment Combinations With Pelareorep and Atezolizumab

This trial is testing combinations of two drugs — pelareorep (a cancer-fighting virus) and atezolizumab (an immunotherapy) — in people with advanced gastrointestinal cancers including colorectal, pancreatic, stomach, and biliary cancers. **You may be eligible if...** - You have advanced or metastatic gastrointestinal cancer - You are in good physical condition (ECOG 0 or 1) - You have measurable disease on scan - Your blood, kidney, and liver function are adequate - You have recovered from side effects of previous treatments - You are willing to use contraception if applicable **You may NOT be eligible if...** - You received chemotherapy, radiation, or surgery within the past 4 weeks - You have already been treated with immune checkpoint inhibitors (such as PD-1/PD-L1 drugs) - You have symptomatic brain metastases - You have active autoimmune disease requiring treatment - You have active, uncontrolled infections or serious heart disease - You have active interstitial lung disease - You are pregnant or breastfeeding - You have received a vaccine within 28 days before starting treatment Talk to your doctor to see if this trial is right for you.