Combination Chemotherapy Followed By Peripheral Stem Cell Transplant in Treating Young Patients With Newly Diagnosed Supratentorial Primitive Neuroectodermal Tumors or High-Risk Medulloblastoma

A Phase III Randomized Trial for the Treatment of Newly Diagnosed Supratentorial PNET and High Risk Medulloblastoma in Children < 36 Months Old With Intensive Induction Chemotherapy With Methotrexate Followed by Consolidation With Stem Cell Rescue vs. the Same Therapy Without Methotrexate

This randomized phase III trial is studying two different combination chemotherapy regimens to compare how well they work in treating young patients with newly diagnosed supratentorial primitive neuroectodermal tumors or high-risk medulloblastoma when given before additional intense chemotherapy followed by peripheral blood stem cell rescue. It is not yet known which combination chemotherapy regimen is more effective when given before a peripheral stem cell transplant in treating supratentorial primitive neuroectodermal tumors or medulloblastoma.

PRIMARY OBJECTIVES:

I. To determine if treatment of infants with high risk primitive neuroectodermal tumors (PNET) central nervous system (CNS) tumors with intensive chemotherapy plus high-dose methotrexate and peripheral blood stem cell rescue results in a higher complete response rate then the same regimen without methotrexate.

SECONDARY OBJECTIVES:

I. To determine whether biologic characterization of these tumors will refine therapeutic stratification separating atypical teratoid rhabdoid tumors (AT/RT) from primitive neuroectodermal tumors (PNETs) and possibly identifying other markers of value for stratification within the group of PNETs.

II. To determine if event free survival (EFS) and patterns of failure differ between the methotrexate arm versus the arm without methotrexate.

III. To compare the acute, chronic and late effects of these two very intensive regimens, especially as to the tolerance of the same consolidation regimen following the differing induction regimens.

IV. To compare the gastrointestinal and nutritional toxicities of these intense regimens.

V. To describe and compare the quality of life outcomes and neuropsychological effects of these intense systemic therapies.

OUTLINE: Patients are randomized to 1 of 2 treatment arms

INDUCTION THERAPY:

ARM I: Patients receive vincristine IV over 1 minute on days 1, 8, and 15; etoposide IV over 1 hour on days 1-3; cyclophosphamide IV over 1 hour on days 1 and 2; cisplatin IV over 6 hours on day 3; and filgrastim (G-CSF) IV or subcutaneously (SC) beginning on day 4 and continuing until blood counts recover. Treatment repeats every 3 weeks for 3 courses in the absence of disease progression or unacceptable toxicity.

ARM II: Patients receive vincristine IV over 1 minute on days 1, 8, and 15; high-dose methotrexate IV over 4 hours on day 1; and leucovorin calcium IV or orally (PO) every 6 hours beginning on day 2 and continuing until methotrexate levels are in a safe range. Once methotrexate levels are in a safe range, patients then receive etoposide IV over 1 hour on approximately days 4, 5, and 6, cyclophosphamide IV over 1 hour on approximately days 4 and 5, and cisplatin IV over 6 hours on approximately day 6. Patients also receive G-CSF IV or SC beginning 24 hours after the completion of chemotherapy and continuing until blood counts recover. Treatment repeats every 3 weeks for 3 courses in the absence of disease progression or unacceptable toxicity.

In both arms, patients with stable disease or partial response after induction therapy proceed to second-look surgery followed by consolidation therapy. Patients with a complete response after induction therapy proceed directly to consolidation therapy.

CONSOLIDATION THERAPY: Beginning no more than 6 weeks after completion of induction therapy, patients receive consolidation therapy comprising carboplatin IV over 2 hours and thiotepa IV over 2 hours on days 1 and 2 and G-CSF IV or SC beginning on day 5 and continuing until blood counts recover. Patients also receive autologous peripheral blood stem cells (PBSC) IV on day 4. Treatment repeats every 4 weeks for 3 courses in the absence of disease progression or unacceptable toxicity.

After completion of study therapy, patients are followed up periodically for 4 years and then annually thereafter.

Inclusion Criteria:

• High-risk medulloblastoma defined by any of the following:

  • > 1.5 cm^2 residual disease for any medulloblastoma histology, or
  • Lumbar cerebral spinal fluid (CSF) cytology positive for tumor cells by analysis of fluid collected either before definitive surgery or at least 10 days after definitive surgery unless contraindicated, or
  • Magnetic resonance imaging (MRI) evidence of M2 or M3 metastatic disease, or
  • M4 disease

• Supratentorial primitive neuroectodermal tumor (PNET) (any M-stage) will be eligible for study entry

• Children less than 8 months of age at the time of definitive surgery with or without measurable radiographic residual tumor with M0 stage medulloblastoma will be eligible for study entry

• Patients with anaplastic medulloblastoma are eligible regardless of M-stage or residual tumor

• Patients with M0 classic, non-desmoplastic medulloblastoma (R1) with radiographically measurable residual disease < 1.5 cm^2 are eligible

• Cranial MRI (with and without gadolinium) must be done pre-operatively; post-operatively, cranial MRI (with and without gadolinium) must be done, preferably within 48 hours of surgery; entire spinal MRI must be obtained either pre-operatively (with gadolinium) or post-operatively (at least 10 days following surgery) prior to study enrollment (with and without gadolinium); patients with MRI evidence of spinal disease are eligible for this study

• Evaluation of lumbar CSF cytology (cytospin preparation for microscopic evaluation) must be performed either pre-operatively or at least 10 days after definitive surgery unless contraindicated

• Patient must have a life expectancy > 8 weeks

• Patient must have received no prior radiation therapy or chemotherapy other than corticosteroids; corticosteroids are allowable for all patients

• Creatinine clearance or radioisotope glomerular filtration rate >= 60 mL/min

• Total bilirubin =< 1.5 x upper limit of normal (ULN) for age, and

• Serum glutamic oxaloacetic transaminase (SGOT) (aspartate aminotransferase [AST]) and serum glutamic pyruvic transaminase (SGPT) (alanine transaminase [ALT]) < 2 x ULN for age

• Shortening fraction >= 27% by echocardiogram, or

• Ejection fraction >= 47% by radionuclide angiogram

• No evidence of dyspnea at rest

• Pulse oximetry > 94% on room air

• Peripheral absolute neutrophil count (ANC) > 1,000/uL

• Platelet count > 100,000/uL (transfusion independent)

• Hemoglobin greater than 8 g/dL (may have received red blood cell [RBC] transfusions allowed)

• Hold trimethoprim/sulfamethoxazole (Bactrim) on the day of high-dose methotrexate (HDMTX) infusion and continue to hold until the methotrexate level is less than 0.1 micromolar (1 x 10-7 M)

• Avoid probenecid, penicillins, cephalosporins, aspirin, proton pump inhibitors and nonsteroidal anti-inflammatory drug (NSAIDS) on the day of methotrexate and continue until the methotrexate level is less than 0.1 micromolar (1 x 10-7 M) as renal excretion of methotrexate is inhibited by these agents

• Avoid IV contrast media, urinary acidifiers, phenytoin, and fosphenytoin on the day of methotrexate and until the methotrexate level is less than 0.1 micromolar (1 x 10-7 M)

• Concurrent use of enzyme inducing anticonvulsants (e.g. phenytoin, phenobarbital, and carbamazepine) should be avoided

• Clinically significant drug interactions have been reported when using vincristine with strong cytochrome P450 (CYP450) family 3 subfamily A member 4 (3A4) inhibitors and inducers; selected strong inhibitors of cytochrome P450 3A4 include azole antifungals, such as fluconazole, voriconazole, itraconazole, ketoconazole, and strong inducers include drugs such as rifampin, phenytoin, phenobarbitol, carbamazepine, and St. John's wort; the use of these drugs should be avoided with vincristine

• All patients and/or their parents or legal guardians must sign a written informed consent

• All institutional, Food and Drug administration (FDA), and National Cancer Institute (NCI) requirements for human studies must be met