The primary purpose of this study is to find the highest dose of the investigational drug LEE011 that can be safely given in children and adolescents with malignant rhabdoid tumors and neuroblastoma that persist despite prior treatment. LEE011 has been evaluated in adults; this is the first study assessing its use in children. The drug is taken orally (by mouth).
LEE011 blocks the activity of two enzymes called cyclin D kinases 4 and 6 (CDK4/6). These enzymes are part of a pathway known to regulate cell growth. Blocking the activity of CDK 4/6 prevents some cancer cells from being able to make a new copy of their DNA. As a result, they cannot divide and may enter into a process called programmed cell death. Researchers hope LEE011 will slow the growth of cancer cells and lead to their death.