Ph. I Temozolomide + O6-BG + Irinotecan in Treatment of Pts w Recurrent / Progressive Cerebral Anaplastic Gliomas

Objectives of study: to determine maximum tolerated dose of CPT-11 when administered following Temodar + O6-benzylguanine (O6-BG); to characterize any toxicity associated w combo of CPT-11 + Temodar + O6-BG; to observe pts for clinical antitumor response when treated w combo of CPT-11 + Temodar plus O6-BG. Pts have histologically confirmed diagnosis of recurrent primary malignant glioma. 2 separate strata accrued independently of each other: Stratum 1-pts receiving Dilantin, Tegretol/phenobarbital. Stratum 2-pts on anti-convulsants other than Dilantin, Tegretol/phenobarbital/pts not on any anti-convulsants. Each strata will be treated \& escalated independent of each other. Pre-chemo, O6-BG administered intravenously at 120 mg/m2, over 1hr, prior to administration of Temodar on day 1 of 21-day cycle. Post-chemo, O6-BG administered intravenously at 30 mg/m2/day, over 48hrs, immediately after completion of the CPT-11 infusion on day 1 of 21-day cycle. Temodar administered orally at 355 mg/m2, in fasting state, within 60 minutes of the end of 1hr O6-BG infusion. Treatment cycles may be repeated every 3 weeks following dose of Temozolomide from previous cycle. CPT-11 will be administered intravenously in fasting state over 90min. CPT-11 infusion will begin 1hr after Temozolomide administration. Initial doses 60 mg/m2 for stratum 1 \& 40 mg/m2 for stratum 2. Treatment cycles may be repeated every 3 wks following dose of CPT-11 from previous cycle. Major toxicities associated w CPT- 11 are myelosuppression \& diarrhea. Temozolomide has been well tolerated by both adults \& children w most common toxicity being mild myelosuppression. Other, less likely, potential toxicities include nausea \& vomiting, constipation, headache, alopecia, rash, burning sensation of skin, esophagitis, pain, diarrhea, lethargy, \& hepatotoxicity. Hypersensitivity reactions have not yet been noted w Temozolomide. As is case w many anti-cancer drugs, Temozolomide may be carcinogenic. O6-BG toxicities include transient lymphopenia has been seen w O6-BG as single agent. O6-BG in combo w other agents could cause exacerbation of any adverse event currently known to be caused by other agent,/ combo may result in events never previously associated w either agent. Animal studies indicated that agitation, lethargy, convulsions, nausea, vomiting, rapid heart rate, elevated liver functions, leukopenia, lymphopenia could be seen.