O6-benzylguanine and Carmustine in Treating Children With Refractory CNS Tumors

Study Overview
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Brief Summary
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Phase I trial to study the effectiveness of O6-benzylguanine and carmustine in treating children who have refractory CNS tumors. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells.

Detailed Description
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OBJECTIVES: I. Determine the maximum tolerated dose and the dose limiting toxicity of carmustine administered after O6-benzylguanine in children with refractory primary CNS tumors. II. Determine a safe and tolerable dose of carmustine administered after O6-benzylguanine to be used in phase II studies. III. Determine the pharmacokinetics of O6-benzylguanine and its metabolite, O6-benzyl-8-oxoguanine, in these patients. IV. Seek preliminary evidence of antitumor activity of this regimen in these patients. V. Evaluate the acute and chronic toxicities, and describe cumulative toxicity, in patients treated with multiple courses of this regimen. OUTLINE: This is a dose escalation study of carmustine. Patients receive O6-benzylguanine IV over 1 hour, then, 1 hour later, carmustine IV is administered over 1 hour. Treatment is repeated every 6 weeks for up to 1 year in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients each receive escalating doses of carmustine until the maximum tolerated dose (MTD) is reached. The MTD is defined as the dose level at which fewer than 2 of 6 patients experience dose limiting toxicity (DLT). If myelosuppression is the DLT, stratum 1 is closed and patients are accrued to stratum 2. If neutropenia is the DLT in stratum 2, patients receive filgrastim (G-CSF) subcutaneously beginning on day 2 and continuing until blood counts recover. Patients are followed every 6 months for 4 years, then annually thereafter.

Official Title
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A Trial of 06-BG and BCNU in Children With CNS Tumors

Conditions
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Brain and Central Nervous System Tumors

Intervention / Treatment
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* Drug: O6-benzylguanine
* Drug: carmustine


Participation Criteria
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Eligibility Criteria
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DISEASE CHARACTERISTICS: Histologically or cytologically proven CNS tumor that is refractory to conventional therapy or for which no effective therapy is known Histological requirement may be waived for brainstem and optic gliomas Stratum 2: No bone marrow involvement PATIENT CHARACTERISTICS: Age: 21 and under Performance status: Karnofsky 50-100% OR Lansky 50-100% Life expectancy: At least 8 weeks Absolute neutrophil count at least 1500/mm3 Platelet count at least 100,000/mm3 (stratum 2: at least 125,000/mm3) Hemoglobin at least 8 g/dL Bilirubin less than 1.5 mg/dL SGOT/SGPT no greater than 2.5 times normal Creatinine or GFR normal for age If required, DLCO must be 80% of normal and patient old enough to cooperate for DLCO test Neurologic deficits must be stable for at least 2 weeks prior to study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for 6 months after study PRIOR CONCURRENT THERAPY: At least 7 days since prior biologic therapy or immunotherapy and recovered At least 6 months since prior bone marrow transplant (stratum 1 only) At least 7 days since prior growth factors No concurrent filgrastim (G-CSF) prophylaxis Stratum 2: No prior bone marrow transplantation At least 2 weeks since prior myelosuppressive chemotherapy (6 weeks for nitrosourea) and recovered Stratum 2: No greater than 2 prior chemotherapy regimens No prior nitrosourea therapy If receiving dexamethasone, must be on stable or decreasing dose for at least 2 weeks prior to study At least 2 weeks since prior local palliative radiotherapy (small port) At least 6 months since prior substantial bone marrow radiation, total body irradiation, hemipelvic radiotherapy, or total abdominal/pelvic/chest or mantle/Y ports radiotherapy Recovered from prior radiotherapy Stratum 2: No prior central axis radiation No other concurrent anticancer or investigational agents

Ages Eligible for Study
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Maximum Age: 21 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arm I<br>Patients receive O6-benzylguanine IV over 1 hour, then, 1 hour later, carmustine IV is administered over 1 hour. Treatment is repeated every 6 weeks for up to 1 year in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients each receive escalating doses of carmustine until the maximum tolerated dose (MTD) is reached. The MTD is defined as the dose level at which fewer than 2 of 6 patients experience dose limiting toxicity (DLT). If myelosuppression is the DLT, stratum 1 is closed and patients are accrued to stratum 2. If neutropenia is the DLT in stratum 2, patients receive filgrastim (G-CSF) subcutaneously beginning on day 2 and continuing until blood counts recover. | Drug: O6-benzylguanine<br> <br> Drug: carmustine<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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childhood craniopharyngioma, childhood central nervous system germ cell tumor, childhood oligodendroglioma, childhood choroid plexus tumor, recurrent childhood brain stem glioma, recurrent childhood supratentorial primitive neuroectodermal tumor, recurrent childhood visual pathway glioma, recurrent childhood cerebellar astrocytoma, recurrent childhood cerebral astrocytoma, recurrent childhood medulloblastoma, recurrent childhood ependymoma