Testing the Effectiveness of the Anti-cancer Drug Pidnarulex (CX-5461), in Combination With Another Anti-cancer Drug Cemiplimab (REGN2810), in Treating Refractory Microsatellite Stable Colorectal Cancer

This phase I/II trial studies the side effects and best dose of pidnarulex when given together with cemiplimab and to see how well it works in treating patients with microsatellite stable (MSS) colorectal cancer (CRC) that does not respond to treatment (refractory). Pidnarulex may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Immunotherapy with monoclonal antibodies, such as cemiplimab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving pidnarulex with cemiplimab may be safe, tolerable and/or effective in treating patients with refractory MSS CRC.