This is a Phase II Study of Tarceva plus Temodar during and following radiation therapy in patients with newly diagnosed glioblastoma multiforme and gliosarcoma. The efficacy and safety profile of Tarceva in combination with radiation therapy plus Temodar will be studied. In addition, correlations between response to treatment and epidermal growth factor receptor (EGFR) status as well as other molecular markers of tumor prior to treatment will be explored. Patients will be stratified according to enzyme inducing anti epileptic drug (EIAED) use. Group A (not on EIAEDs) will take 100 milligrams (mg) Tarceva/day during radiotherapy and start with a dose of 150 mg Tarceva/day two weeks after radiotherapy. Group B (on EIAEDs) will take 200mg Tarceva/day during radiotherapy and start with a dose of 300 mg Tarceva/day two weeks after radiotherapy. Both groups will take 75 mg/m^2 Temodar/day during radiotherapy and 200 mg/m^2 Temodar/day x 5 two weeks after radiotherapy. Intrapatient Tarceva dose escalation may occur every two weeks after radiotherapy until the appearance of a particular rash severity. The maximum dose allowed is 200 mg for group A and 500 mg for group B.
The patients eligible for this study are those diagnosed with glioblastoma or gliosarcoma who have recently undergone surgery and who have not been treated with radiation therapy or chemotherapy. This is called a phase II study. The purpose of the phase II study is to determine how effective Tarceva plus Temodar plus radiation is in controlling the growth of glioblastoma and gliosarcoma. All patients will receive radiation and Temodar plus Tarceva. There is no placebo drug.