Pazopanib Hydrochloride in Treating Young Patients With Solid Tumors That Have Relapsed or Not Responded to Treatment

OBJECTIVES:

Primary

- Estimate the maximum-tolerated dose and/or recommended phase II dose of pazopanib
hydrochloride in pediatric patients with relapsed or refractory solid tumors.

- Define and describe the toxicities of this regimen in these patients.

- Characterize the pharmacokinetics of pazopanib hydrochloride in these patients.

Secondary

- Preliminarily define the antitumor activity of pazopanib hydrochloride within the
confines of a phase I study.

- Evaluate changes in tumor vascular permeability following initiation of pazopanib
hydrochloride and correlate these changes with clinical outcome by dynamic
contrast-enhanced MRI.

OUTLINE: This is a multicenter study dose-escalation study.

Patients receive oral pazopanib hydrochloride once daily on days 1-28. Courses repeat every
28 days for up to 24 courses in the absence of disease progression or unacceptable toxicity.
Patients accrued after the maximum-tolerated dose (MTD) of pazopanib hydrochloride has been
determined receive pazopanib hydrochloride as an oral suspension.

Some patients undergo dynamic contrast-enhanced MRI at baseline and periodically during
study.

Blood samples are collected at baseline and periodically during study for pharmacokinetic
studies.