Study of the Bromodomain (BRD) and Extra-Terminal Domain (BET) Inhibitors BMS-986158 and BMS-986378 in Pediatric Cancer

This is a Phase I clinical trial, which tests the safety of an investigational drug and also tries to define the appropriate dose of the investigational drug to use for further studies. "Investigational" means that the drug is being studied. The FDA (the U.S. Food and Drug Administration) has not approved BMS-986158 or BMS-986378 as a treatment for any disease. BMS-986158 and BMS-986378 are currently still being studied in adults. This is the first time that BMS-986158 or BMS-986378 will be evaluated in younger children, though children 12-17 years of age may also be included in parts of adult studies of BMS-986158. Research in the laboratory has shown that BMS-986158 and BMS-986378 may have activity against cancer cells. These drugs belong to a group of drugs called Bromodomain (BRD) and Extra-Terminal Domain (BET) inhibitors. These drugs block proteins that are important in reading DNA, which is a process important for cancer cells.