Pembrolizumab and XL888 in Patients With Advanced Gastrointestinal Cancer

This phase Ib trial studies the side effects and best dose of Hsp90 inhibitor XL888 when given together with pembrolizumab in treating patients with advanced gastrointestinal cancer that has spread to other places in the body. XL888 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Monoclonal antibodies, such as pembrolizumab, may block tumor growth in different ways by targeting certain cells. Giving XL888 with pembrolizumab may work better in treating patients with gastrointestinal cancer.