Phase I/II Evaluation of Temozolomide and ZARNESTRA (R115777) for Recurrent and Progressive Glioblastoma Multiforme

Temozolomide works by killing cancer cells. R115777 is a new drug that may slow down the growth of cancer cells. Used in combination, the two drugs may control the growth of brain tumors. Before treatment starts, patients will have a complete exam, including measurement of height and weight. Blood tests (less than 2 tablespoons of blood) will be performed. A MRI scan will be done. Women who are able have children must have a negative blood pregnancy test. Temozolomide and R115777 will both be taken by mouth. Participants in this study will take temozolomide once a day for 7 days every other week (Days 1-7 and 15-21). This will be repeated every 28 days (1 course). Patients must not eat for 1 hour before and after taking the drug; drinking water is allowed. All treatment may be given on an outpatient basis. During the alternate weeks (Days 8-14 and 22-28), participants will take R115777 tablets by mouth in the morning and evening with food. At the beginning of the study, groups of 3 participants each will take increasing doses of both R115777 and temozolomide until the highest safe dose of each drug, when given in combination, is found. Participants entering the study after the highest safe dose is found will receive that dosage. If tumors do not grow and serious side effects do not occur, participants may keep on taking temozolomide and R115777 for up to 2 year. If your physician thinks it is advisable, treatment may continue with R115777 alone after that time. In this case, routine blood tests for counts, liver and kidney function (less than 2 tablespoons) will be repeated every 4 weeks and MRI scans, physical, and neurological exams will be done every 8 weeks. Participants may not receive any other treatment for cancer (including surgery) while taking part in this study. Participants will come to the clinic to have a complete physical and neurological exam and blood tests (less than 2 tablespoons of blood) before each course. Blood tests will be repeated once a week for the first 2 courses of treatment and then on Days 14 and 28 of each later course. A MRI scan will be done before the odd-numbered (3, 5, 7, etc.) courses of treatment or at any time clinically indicated. At the end of the study, participants will have another complete physical exam. Blood tests (less than 2 tablespoons of blood) will be performed. A MRI scan will be done. This is an investigational study. Temozolomide is approved by the FDA for the treatment of some brain tumors and is commercially available. R115777 is approved for research use only in the treatment of brain tumors. The use of these two drugs together is experimental.