Temozolomide versus procarbazine, lomustine, and vincristine in recurrent high-grade glioma

Temozolomide (TMZ) is an alkylating agent licensed for treatment of high-grade glioma (HGG). No prospective comparison with nitrosourea-based chemotherapy exists. We report, to our knowledge, the first randomized trial of procarbazine, lomustine, and vincristine (PCV) versus TMZ in chemotherapy-naive patients with recurrent HGG.

Four hundred forty-seven patients were randomly assigned to PCV (224 patients) or TMZ (sub-random assignment: TMZ-5 [200 mg/m(2) for 5 days, 112 patients] or TMZ-21 [100 mg/m(2) for 21 days, 111 patients]) for up to 9 months or until progression. The primary outcomes were survival (PCV v TMZ) and 12-week progression-free survival (PFS; TMZ-5 v TMZ-21). This study is registered as ISRCTN83176944.

Percentages of patients completing 9 months of treatment in the PCV, TMZ-5, and TMZ-21 arms were 17%, 26%, and 13%, respectively. Major toxicity was similar across all three groups. With a median follow-up time of 12 months and 382 deaths, there was no clear survival benefit when comparing PCV with TMZ (hazard ratio [HR], 0.91; 95% CI, 0.74 to 1.11; P = .350). For TMZ-5 versus TMZ-21, 12-week PFS rates were similar (63.6% and 65.7%, respectively; P = .745), but TMZ-5 improved overall PFS (HR, 1.38; 95% CI, 1.05 to 1.82; P = .023), survival (HR, 1.32; 95% CI, 0.99 to 1.75; P = .056), and global quality of life (49% v 19% improved > 10 points at 6 months, respectively; P = .005).

Although TMZ (both arms combined) did not show a clear benefit compared with PCV, comparison of the TMZ schedules demonstrated that the 21-day schedule was inferior to the 5-day schedule in this setting. This challenges the current understanding of increasing TMZ dose-intensity by prolonged scheduling.