Background Outcome of low-grade glioma (LGG, WHO grade II) is highly variable reflecting molecular heterogeneity of the disease. We compared two different single modality treatment strategies: standard radiotherapy (RT) versus primary temozolomide (TMZ) chemotherapy with the aim of tailoring treatment and identifying predictive molecular factors. Methods 477 patients (2005 – 2012, median FU 48 months) with a low-grade glioma (astrocytoma, oligoastrocytoma, oligodendroglioma, WHO grade II) with at least one high-risk feature (age > 40 years, progressive disease, tumor > 5 cm or crossing the midline, neurological symptoms (e.g. focal or mental deficits, increased intracranial pressure or intractable seizures)) were, after stratification by chromosome 1p-status, randomized to either conformal RT (50.4 Gy/28 fractions) or dose-dense TMZ (75 mg/m2 daily × 21 days, q28 days, max. 12 cycles). Random treatment allocation was performed online using a minimization technique. A planned analysis was performed after 246 progression events. All analyses are intent to treat. Primary clinical endpoint was progression-free survival (PFS), correlative analyses included molecular markers (1p/19q co-deletion, MGMT methylation status, IDH1+2 mutations). The trial has been registered at the European Trials Registry (EudraCT 2004-002714-11) and at ClinicalTrials.gov (NCT00182819). Findings Four hundred seventy-seven patients were randomized. Severe hematological toxicity occurred in 14% of TMZ-treated patients, infections in 3% of TMZ-treated patients, and 1% of RT-treated patients. Moderate to severe fatigue was recorded in 3% of patients in the RT group and 7% in the TMZ group. At a median follow-up of 48 months (IQR:31–56), median PFS was 39 months (IQR:16–46) in the TMZ arm and 46 months (IQR:19–48) in the RT group (hazard ratio 1.16, 95% CI, 0.9–1.5; p=0.22). Median OS has not been reached. Exploratory analyses identified treatment-dependent variation in outcome of molecular LGG subgroups (n=318). Interpretation There was no significant difference in outcome of the overall patient population treated with either radiotherapy alone or TMZ chemotherapy alone. Further data maturation is needed for overall survival analyses and evaluation of the full predictive impact of the molecular subtypes for individualized treatment choices. Funding Merck & Co, Swiss-Bridge Award 2011, Swiss Cancer League.

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.