Atezolizumab and bevacizumab are a type of drug called a monoclonal antibody. Antibodies are proteins that are naturally found in the blood stream that fight infections. A monoclonal antibody is a special kind of antibody that is created in a laboratory that seeks out specific proteins in the body that may be involved in cancers to stop tumor growth.~When tumor cells start to die, broken down pieces of the tumor's DNA gets released into the blood stream, called circulating tumor DNA (ctDNA). Looking at ctDNA may be useful in determining whether the cancer is responding to treatment.~The purpose of this research study is to see whether looking at tumor DNA circulating in the bloodstream can help to determine which patients may respond to atezolizumab and bevacizumab and whether this drug combination is useful, when given as a maintenance treatment for patients with TP53 mutant ovarian, fallopian tube, or primary peritoneal cancer.
This study is being done to look at the combination of the drugs atezolizumab and bevacizumab as a maintenance treatment (treatment given after the main treatment to keep the cancer from coming back or worsening) following standard therapy in patients with high grade ovarian, fallopian tube, or primary peritoneal cancer with a mutation (change) in a gene called TP53. Genes are molecules in the body that are made up of deoxyribonucleic acid (DNA) and control how the body's cells behave.