RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. Drugs such as motexafin gadolinium may make the tumor cells more sensitive to radiation therapy.

PURPOSE: Phase I trial to study the effectiveness of motexafin gadolinium plus radiation therapy in treating children who have newly diagnosed brain stem glioma.

OBJECTIVES:

• Determine the maximum tolerated dose (MTD) and schedule of motexafin gadolinium administered prior to radiotherapy in children with newly diagnosed diffuse intrinsic pontine glioma.
• Determine the toxic effects of this drug given at the MTD in these patients.
• Determine the intratumor and brain distribution of this drug by MRI in these patients.

OUTLINE: This is a dose-escalation study of motexafin gadolinium.

Approximately 2-5 hours before radiotherapy, patients receive motexafin gadolinium IV over 5 minutes. Patients undergo radiotherapy 5 days a week for 6 weeks.

Cohorts of 3-6 patients receive escalating doses of motexafin gadolinium until the maximum tolerated dose (MTD) is determined. The first cohort receives motexafin gadolinium 5 days a week for 3 weeks; the second cohort receives motexafin gadolinium 3 days a week for 6 weeks; and subsequent cohorts receive motexafin gadolinium 5 days a week for 6 weeks. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity.

Patients are followed every 3 months for up to 3 years.

PROJECTED ACCRUAL: A maximum of 24 patients will be accrued for this study within 2 years.

• Drug: motexafin gadolinium
• Radiation: radiation therapy

DISEASE CHARACTERISTICS:

• Clinically and radiographically (MRI) proven newly diagnosed diffuse intrinsic brainstem glioma

  • Greater than 50% intra-axial involvement of the pons, pons and medulla, pons and midbrain, or entire brainstem
  • Contiguous involvement of the thalamus or upper cervical cord allowed

PATIENT CHARACTERISTICS:

Age:

• 21 and under

Performance status:

• ECOG 0-2

Life expectancy:

• More than 2 months

Hematopoietic:

• Absolute neutrophil count at least 1,000/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 10.0 g/dL (transfusion allowed)
• No glucose 6 phosphate dehydrogenase deficiency

Hepatic:

• Bilirubin no greater than 1.5 times normal
• SGOT or SGPT less than 1.5 times normal

Renal:

• Creatinine no greater than 1.5 times normal OR
• Creatinine clearance or radioisotope glomerular filtration rate at least 70 mL/min

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent immunomodulating agents

Chemotherapy:

• No other concurrent chemotherapy

Endocrine therapy:

• Concurrent corticosteroid therapy allowed for increased intracranial pressure only

Radiotherapy:

• No prior cranial radiotherapy

Surgery:

• Not specified

Other:

• No prior motexafin gadolinium
• No other concurrent experimental agents