Phase I Trial of Temodar Plus O6-Benzylguanine (O6-BG) (NSC 637037) in the Treatment of Patients With Newly Diagnosed (Part 1) or Recurrent/Progressive (Parts 1 and 2) Cerebral Anaplastic Gliomas

OBJECTIVES:

• Determine the dose of O6-benzylguanine (O6-BG) effective in producing complete suppression of tumor O6-alkylguanine-DNA alkyltransferase activity in patients with newly diagnosed (closed to accrual 12/19/2000) or recurrent or progressive cerebral anaplastic glioma.
• Determine the maximum tolerated dose of temozolomide administered after O6-BG in these patients.
• Determine the toxicity of this regimen in these patients.
• Determine the anti-tumor response in patients treated with this regimen.

OUTLINE: This is a dose-escalation, multicenter study.

• Part I: Patients receive escalating doses of O6-benzylguanine (O6-BG) IV continuously for 49 hours until the dose that produces the target depletion of tumor O6-alkylguanine-DNA alkyltransferase (AGT) is determined. Patients undergo a craniotomy after completion of the O6-BG infusion. (closed to accrual 12/19/2000)
• Part II: After determination of the O6-BG dose in Part I, patients with recurrent malignant gliomas receive O6-BG IV continuously for 49 hours beginning on day 1. Patients also receive oral temozolomide on day 1. Treatment repeats every 28 days in the absence of disease progression or unacceptable toxicity.

Cohorts of 3-6 patients receive escalating doses of temozolomide until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which no more than 1 of 6 patients experiences dose-limiting toxicity.