Evaluating Novel Therapies in ctDNA Positive GI Cancers

This study is a non-randomized, open-label, multi-cohort, multi-site, pilot feasibility therapeutic trial. The study will enroll 20 patients across 4 cohorts (CRC, gastric, PDAC, and HCC/intra-hepatic-/extra-hepatic-, gall bladder adenocarcinomas) diagnosed with histologically confirmed GI cancers. These patients will have already completed all Standard of Care (SOC) treatments (including neoadjuvant, surgery, local therapies, and/or adjuvant therapy as applicable), as defined by the treating primary physician or research team, with curative intent but have a positive SignateraTM tumor-informed ctDNA test and NED radiographically by standard imaging within 28 days prior to enrollment and within 1 year of completing all curative-intent therapy. All patients will be treated with intravenous (IV) atezolizumab 1200 mg IV and bevacizumab 15 mg/kg on Day 1 of 21-day cycles until disease recurrence, ctDNA POD, unacceptable toxicity, or subject withdrawal of consent with a maximum 12 month total duration of study therapy. Atezolizumab and bevacizumab drug will be provided.