Study of ZD1839 Combined With Irinotecan and Vincristine in Pediatric Patients With Refractory Solid Tumors

Objectives of this study are:

• To determine the dose-limiting toxicities (DLT) of the combination of irinotecan and ZD1839 when given on this schedule.
• To characterize the pharmacokinetics and pharmacodynamics of gefitinib alone and in combination with irinotecan and vincristine.
• To estimate the maximum tolerated dose (MTD) of gefitinib in combination with escalating intravenous irinotecan by using selective intestinal decontamination with oral cefixime or cefpodoxime to prevent diarrhea.
• To estimate the MTD of vincristine (MTD) in combination with gefitinib and irinotecan.

Details of Treatment Interventions

First Cohort:

Standard dose escalation, starting at ZD1839 150 mg/m2/day for 21 days in combination with irinotecan 15mg/m2/day on a daily x 5 for two consecutive week schedule. Dose-limiting diarrhea was seen in this cohort. ZD scheduled was reduced to 12 days. The first dose level (1a) consisted of ZD1839 112.5mg/m2/day for 12 days + irinotecan 15mg/m2/day daily x 5 x 2 and was found to be the MTD in this cohort.

Second Cohort:

Cefixime then added at 4 additional subjects were enrolled at dose level 1c, consisting of ZD1839 at 112mg/m2/day + irinotecan 20mg/m2/day + cefixime 8 mg/kg/day administered once daily, beginning on day -1, and continued to day 14.

Third Cohort:

Irinotecan/ZD1839/Vincristine/Cefixime- Cefixime 8 mg/kg/day administered once daily, beginning on day -1, and continued to day 14, with a maximum dose of 400 mg daily + gefitinib 112.5 mg/m2 orally, daily for 12 days and irinotecan at 15 mg/m2 daily x 5 x 2 +1 mg/m2 (maximum 2mg/dose) on days 1 and 8 with escalating dose of VCR as tolerated.

Inclusion criteria

• Younger than 22 years of age.
• Histologic verification of solid tumor malignancy at original diagnosis.
• Has disease considered refractory to conventional therapy or no conventional therapy exists.
• Adequate performance status, bone marrow, liver and kidney function.
• Patients must not have had any previous allergic reactions to penicillin or cephalosporins

Exclusion criteria

• Known severe hypersensitivity to ZD1839 or any of the excipients of this product
• Concomitant use of phenytoin, carbamazepine, barbiturates, rifampicin, phenobarbital, or St John's Wort, and CYP3A4 inhibitors
• Treatment with a non-approved or investigational drug within 30 days before Day 1 of trial treatment.
• Incomplete healing from previous oncologic or other major surgery
• Pregnant or breast-feeding
• Patients who have an uncontrolled infection
• Any evidence of clinically active interstitial lung disease (patients with chronic stable radiographic changes who are asymptomatic need not be excluded).
• As judged by the investigator, any evidence of uncontrolled systemic disease (e.g., unstable or uncompensated respiratory, cardiac, hepatic, or renal disease).
• Evidence of any other significant clinical disorder or laboratory finding that makes is undesirable for the subject to participate in the trial.