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Evaluating Response to Atezolizumab and Bevacizumab Treatment in Patients with Gastrointestinal Cancers and Minimal Residual Disease using ctDNA

Trial Status: active

This phase III trial evaluates response to atezolizumab and bevacizumab in treating patients with gastrointestinal (GI) cancer (colorectal, gastric, hepatobiliary or pancreatic) who have evidence of a small number of cancer cells left in the body after treatment (minimal residual disease [MRD]), as identified through a positive circulating tumor deoxyribonucleic acid (DNA) (ctDNA) test. To date, the standard of care approach after curative-intent treatment for select GI cancers is to pursue active surveillance with frequent routine imaging, diagnostic procedures, labs, and blood-based tumor markers (proteins in the blood expressed or released by cancer cells) to monitor for disease return. Patients and physicians often have to wait until the cancer has grown enough to be measurable on imaging or biopsy before confirming that the cancer has come back (relapse) and before restarting therapy. Even if imaging and diagnostics do not show evidence of disease, there is the possibility that microscopic levels of cancer that cannot be detected on imaging and will manifest as disease relapse as they grow. Many cancers recur as wide-spread disease, at which point prognosis is worse and treatment consists of limited systemic options. Blood tests can be used to help detect microscopic levels of cancer before it has grown enough to be identified on imaging or other lab tests. These blood tests of interest detect microscopic levels of DNA specifically released from cancer cells and signal the ongoing presence of cancer in the body. Identifying patients very early in relapse and initiating treatment before cancer has significantly grown could eradicate microscopic disease and improve outcomes. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Bevacizumab is in a class of medications called antiangiogenic agents. It works by stopping the formation of blood vessels that bring oxygen and nutrients to the tumor. This may slow the growth and spread of tumor. Early therapeutic intervention with combination atezolizumab and bevacizumab in the MRD setting along with serial ctDNA monitoring to assess drug activity may improve cancer outcomes.