Phase I trial of two schedules of vincristine, oral irinotecan, and temozolomide (VOIT) for children with relapsed or refractory solid tumors: a Children's Oncology Group phase I consortium study.
BACKGROUND
In preclinical models, temozolomide, and vincristine are additive or synergistic with irinotecan. We examined this three-drug combination in children with relapsed solid tumors. Patients received orally administered irinotecan together with temozolomide and vincristine on two different schedules, using cefixime to reduce irinotecan-associated diarrhea.


METHODS
Oral irinotecan was given daily on days 1-5 and 8-12 (Schedule A), or on days 1-5 (Schedule B). Temozolomide was given on days 1-5, with vincristine 1.5 mg/m(2) administered on days 1 and 8 (Schedule A) or day 1 (Schedule B) in 21-day courses.


RESULTS
On Schedule A, the maximum tolerated dose of oral irinotecan was 35 mg/m(2)/day combined with temozolomide 100 mg/m(2)/day and vincristine on days 1 and 8. Dose-limiting toxicities in 4 of 12 patients included hepatotoxicity, abdominal pain, anorexia, hypokalemia, and thrombocytopenia at 50 mg/m(2)/day. Using Schedule B, 0 of 6 patients experienced dose-limiting toxicity (DLT) at the highest doses studied of oral irinotecan 90 mg/m(2)/day, temozolomide 150 mg/m(2)/day x 5, and vincristine on day 1. First-course and cumulative toxicity was greater with Schedule A. UGT1A1*28 genotype did not correlate with DLT. At the irinotecan dose of 90 mg/m(2)/day, the mean SN-38 AUC(inf) was 63 ng/ml hr. Activity was seen in sarcoma patients, and overall eight patients received >or=6 courses.


CONCLUSIONS
The 5-day schedule of VOIT was well tolerated and provided SN-38 exposures similar to those achieved with intravenous IRN. Activity on this and prior studies suggests a potential role for VOIT in a spectrum of childhood solid tumors.
Wagner
Lars M
LM
Division of Hematology/Oncology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA. lars.wagner@cchmc.org
Perentesis
John P
JP
Reid
Joel M
JM
Ames
Matthew M
MM
Safgren
Stephanie L
SL
Nelson
Marvin D
MD
Ingle
Ashish M
AM
Blaney
Susan M
SM
Adamson
Peter C
PC
D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000493:pharmacokinetics / Q000627:therapeutic use*; D019540:Area Under Curve; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D002648:Child; D002675:Child, Preschool; D003606:Dacarbazine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007223:Infant; D000077146:Irinotecan; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy*; D009369:Neoplasms / Q000188:drug therapy*; D000077204:Temozolomide; D014750:Vincristine / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D055815:Young Adult
D014750:Vincristine; D000077146:Irinotecan; D003606:Dacarbazine; D002166:Camptothecin; D000077204:Temozolomide