Gossypol in Treating Patients With Progressive or Recurrent Glioblastoma Multiforme

PRIMARY OBJECTIVES: I. To estimate the overall survival rate associated with AT-101 in treating adult patients with recurrent glioblastoma multiforme. SECONDARY OBJECTIVES: I. To assess and estimate the acute and late toxicities. II. Tumor response rate. III. To estimate 6-month progression free survival. IV. To explore associations of the clinical outcome (overall survival) among the changes of potential serum biomarkers, baseline tumor protein expression and gene methylation status. OUTLINE: This is a multicenter study. Patients receive oral R-(-)-gossypol once daily on days 1-21. Treatment repeats every 28 days in the absence of disease progression or unacceptable toxicity. Patients undergo tumor tissue and blood sample collection at baseline and periodically during study for biomarker correlative studies. Archived tumor tissue samples, if available, are analyzed for Bcl-2 family protein expression (e.g., Bcl-2, Bcl-xL, MCl-1, Bax, Bak, and BH3 domain for BH3 members only) and 06-methylguanine-DNA-methyltransferase (MGMT) gene methylation status. Blood samples are analyzed for apoptotic protein levels (Bcl-2) by enzyme-linked immunosorbent assay. After completion of study therapy, patients are followed every 2 months.