Phase I Trial and Pharmacokinetic Study of Arsenic Trioxide in Pediatric Patients With Refractory Leukemia or Lymphoma

OBJECTIVES:

• Determine the toxic effects of arsenic trioxide in pediatric patients with refractory leukemia or lymphoma.
• Determine the maximum tolerated dose of this drug in this patient population.
• Determine the plasma pharmacokinetics of this drug in these patients.

OUTLINE: This is a dose-escalation, multicenter study. Patients are stratified according to disease (acute promyelocytic leukemia [APL] vs non-APL).

• Stratum I (APL patients): Patients receive standard-dose arsenic trioxide IV over 2 hours daily 5 days a week for 4 weeks. Treatment continues every 6 weeks for up to 3 courses in the absence of disease progression or unacceptable toxicity.
• Stratum II (Non-APL patients): Cohorts of 3-6 patients receive escalating doses of arsenic trioxide (according to the stratum 1 schedule above) until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which at least 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. Once the MTD is determined, additional patients are accrued to receive treatment with arsenic trioxide at the recommended phase II dose.

Leukemia patients in both strata without progressive disease who have not achieved complete remission after the first 20 doses may continue to receive arsenic trioxide for 2 additional weeks.