Combination Chemotherapy and Peripheral Stem Cell Transplantation in Treating Patients With Recurrent or Refractory Solid Tumors

OBJECTIVES:

- Determine the maximum tolerated dose of thiotepa in combination with carboplatin and
topotecan with peripheral blood stem cell transplantation in patients with recurrent or
refractory pediatric solid tumors.

- Determine the toxicity of this regimen in these patients.

OUTLINE: This is a dose escalation study of thiotepa.

Patients may receive 2 courses of mobilization comprising cyclophosphamide and etoposide with
filgrastim (G-CSF) support and peripheral blood stem cell (PBSC) collection.

Patients receive thiotepa IV over 2 hours on days 0 and 1; topotecan IV over 30 minutes on
days 0-4; and carboplatin IV over 2 hours on days 2 and 3. Patients also receive G-CSF
beginning on day 5, 24-36 hours following the last dose of topotecan. PBSC are reinfused on
day 6 (36-48 hours following the last dose of topotecan) of each course of therapy. Patients
receive 3 courses of therapy.

Cohorts of 3-6 patients receive escalating doses of thiotepa until the maximum tolerated dose
(MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients
experience dose-limiting toxicity.

Patients are followed at 1 and 2 years.

PROJECTED ACCRUAL: A maximum of 24 patients will be accrued into this study.

DISEASE CHARACTERISTICS:

- Histologically proven recurrent or refractory pediatric solid tumor

- Bone marrow metastases allowed

PATIENT CHARACTERISTICS:

Age:

- 1 to 30

Performance status:

- 0-2

Life expectancy:

- At least 2 months

Hematopoietic:

- Absolute neutrophil count at least 1,000/mm3

- Platelet count at least 100,000/mm3 (transfusion independent)

- Hemoglobin at least 10 g/dL (RBC transfusion allowed)

Hepatic:

- Bilirubin no greater than 1.5 times normal

- SGOT no greater than 2.5 times normal

Renal:

- Adequate renal function as defined by one of the following:

- GFR by creatinine clearance

- Radioisotope GFR

- Iothalamate at least 70 mL/min

Cardiovascular:

- Adequate cardiac function as defined by one of the following:

- Ejection fraction at least 55% by MUGA

- Fractional shortening at least 28% by echocardiogram

Neurologic:

- Adequate CNS function as defined by:

- Seizure disorder, if present, controlled by anticonvulsants

- CNS toxicity no greater than grade 2

Other:

- No uncontrolled infections

- Not pregnant or nursing

- No allergy to platinum compounds

- No history of allergy to etoposide (unless mobilization phase not required)

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Recovered from prior immunotherapy

- At least 1 week since prior cytokines

- At least 3 months since prior bone marrow or peripheral blood stem cell
transplantation

- No concurrent immunomodulator

- No concurrent cytokines

Chemotherapy:

- At least 3 weeks (6 for nitrosourea) since prior chemotherapy and recovered

- No prior thiotepa

- No other concurrent chemotherapy

Endocrine therapy:

- Not specified

Radiotherapy:

- Recovered from prior radiotherapy

- At least 6 months since prior total body irradiation conditioning

- No concurrent radiotherapy to greater than 10% of total liver, lung, or bone marrow

Surgery:

- Not specified