The study objective is to determine whether paclitaxel poliglumex and RT are likely to improve progression-free survival ("PFS") and overall survival ("OS") compared to TMZ and RT. This study will also evaluate neuro-cognitive function and toxicities of these therapies. If positive, results from the study could be used to plan a phase III study of paclitaxel poliglumex added to standard RT in this disease.About Glioblastoma According to the National Cancer Institute, glioblastoma is the most common and deadliest type of primary brain tumor in adults. It is estimated that there will be 10,000 new cases of GBM diagnosed in the US this year. The prognosis for the great majority of patients with glioblastoma is poor, with less than 25% of patients surviving two years with current therapies. About the Study The study is expected to enroll 60 patients. Patients in the paclitaxel poliglumex arm will receive paclitaxel poliglumex once every week plus RT for six weeks. Patients in the TMZ arm will receive daily oral TMZ plus RT for six weeks. After completion of initial therapy, both arms will receive TMZ on day 1-5 and then every 28 days for up to 12 cycles for a total of 48 weeks. Patients interested in participating in this study or wanting more information can call Sandra Johnston, PhD, RN at (206) 616-7117. About OPAXIO™ OPAXIO™ (paclitaxel poliglumex, CT-2103), which was formerly known as XYOTAX™, is an investigational, biologically enhanced, chemotherapeutic that links paclitaxel, the active ingredient in Taxol®, to a biodegradable polyglutamate polymer, which results in a new chemical entity. When bound to the polymer, the chemotherapy is rendered inactive, potentially sparing normal tissue's exposure to high levels of unbound, active chemotherapy and its associated toxicities. Blood vessels in tumor tissue, unlike blood vessels in normal tissue, are porous to molecules like polyglutamate. Based on preclinical studies, it appears that paclitaxel poliglumex is preferentially distributed to tumors due to their leaky blood vessels and trapped in the tumor bed, allowing significantly more of the dose of chemotherapy to localize in the tumor than with standard paclitaxel. Once inside the tumor cell, enzymes metabolize the protein polymer, releasing the paclitaxel chemotherapy. Paclitaxel poliglumex enhances the anti-tumor potency of radiation therapy in preclinical animal models and is being tested as a radiosensitizer in patients with esophageal cancer, brain cancer, and head and neck cancer.