PURPOSE: This Phase II study was designed to determine the median survival time 
of adults with supratentorial glioblastoma treated with a combination of 
temozolomide (TMZ) and 13-cis-retinoic acid (cRA) given daily with conventional 
radiation therapy (XRT).
METHODS AND MATERIALS: This was a single arm, open-labeled, Phase II study. 
Patients were treated with XRT in conjunction with cRA and TMZ. Both drugs were 
administered starting on Day 1 of XRT, and chemotherapy cycles continued after 
the completion of XRT to a maximum of 1 year.
RESULTS: Sixty-one patients were enrolled in the study. Time to progression was 
known for 55 patients and 6 were censored. The estimated 6-month 
progression-free survival was 38% and the estimated 1-year progression-free 
survival was 15%. Median time to progression was estimated as 21 weeks. The 
estimated 1-year survival was 57%. The median survival was 57 weeks.
CONCLUSIONS: The combined therapy was relatively well tolerated, but there was 
no survival advantage compared with historical studies using XRT either with 
adjuvant nitrosourea chemotherapy, with TMZ alone, or with the combination of 
TMZ and thalidomide. Based on this study, cRA does not seem to add a significant 
synergistic effect to TMZ and XRT.