The purpose of this study is to determine the safety of adding two drugs to the standard combination of chemotherapy drugs used to treat medulloblastoma and supratentorial primitive neuroectodermal tumor (PNET). The standard drugs include vincristine, etoposide, cisplatin, and cyclophosphamide. The two additional drugs are vorinostat and isotretinoin, which will be given during the initial (induction) phase of therapy and then later, during the “maintenance” stage of chemotherapy.
Vorinostat is approved for treating a form of lymphoma, but its use for medulloblastoma and PNET is considered investigational. It is a drug called a histone deacetylase inhibitor, which prevents cancer cells from reproducing by interfering with certain signaling pathways. Isotretinoin is a chemical cousin of vitamin A that is most often used to treat acne, but also has activity against brain and other cancers. Both drugs are taken orally (by mouth).
This study is being done as part of the Pediatric Brain Tumor Consortium, a group of eleven pediatric neuro-oncology centers in the United States dedicated to improving the treatment of childhood brain tumors.