Phase II Trial of Continuous Dose-Intense Temozolomide in Recurrent Malignant Glioma: RESCUE Study

PURPOSE Concomitant temozolomide (TMZ)/radiotherapy followed by adjuvant TMZ has increased survival in patients with glioblastoma multiforme (GBM). However, few options are effective for patients who experience treatment failure. We conducted a multicenter, phase II study to assess the efficacy and safety of continuous dose-intense TMZ for recurrent GBM. PATIENTS AND METHODS Patients with malignant glioma at progression after standard TMZ 150 to 200 mg/m(2) x 5 days in a 28-day cycle for three or more cycles were stratified by tumor type (anaplastic glioma group A, GBM, group B). Ninety-one patients with GBM were prospectively divided into three groups (early B1, extended B2, and rechallenge B3) according to the timing of progression during adjuvant therapy. All patients received continuous dose-intense TMZ 50 mg/m(2)/d for up to 1 year or until progression occurred. Response was assessed by using RECIST (Response Evaluation Criteria in Solid Tumors). Results A total of 116 of 120 patients were evaluable for efficacy. For patients with GBM, 6-month progression-free survival (PFS) was 23.9% (B1, 27.3%; B2, 7.4%; B3, 35.7%). One-year survival from time of study entry was 27.3%, 14.8%, and 28.6% for the B1, B2 and B3 groups, respectively. For patients with anaplastic glioma, 6-month PFS was 35.7%; 1-year survival was 60.7%. The most common grades 3 and 4 nonhematologic toxicities were nausea/vomiting (6.7%) and fatigue (5.8%). Grades 3 and 4 hematologic toxicities were uncommon. CONCLUSION Rechallenge with continuous dose-intense TMZ 50 mg/m(2)/d is a valuable therapeutic option for patients with recurrent GBM. Patients who experience progression during the first six cycles of conventional adjuvant TMZ therapy or after a treatment-free interval get the most benefit from therapy.