A previous placebo-controlled trial has shown that biodegradable 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) wafers (Gliadel wafers) prolong survival in patients with recurrent glioblastoma multiforme. A previously completed phase 3 trial, also placebo controlled, in 32 patients with newly diagnosed malignant glioma also demonstrated a survival benefit in those patients treated with BCNU wafers.