Phase I study of temozolomide and irinotecan for recurrent malignant gliomas in patients receiving enzyme-inducing antiepileptic drugs: a north american brain tumor consortium study.
OBJECTIVE
To determine the maximum tolerated dose of irinotecan when administrated with temozolomide every 28 days, in patients with recurrent malignant glioma who were also receiving CYP450 enzyme-inducing antiepileptic drugs (EIAED), and to characterize the pharmacokinetics of irinotecan and its metabolites. The study was also intended to assess whether temozolomide affects the conversion of irinotecan to SN-38.


METHODS
Patients with recurrent malignant glioma received a fixed dose of temozolomide (150 mg/m(2)) daily for 5 days from days 1 to 5 every 28 days, and an i.v. infusion of irinotecan on days 1 and 15 of each cycle. The starting dose of irinotecan was 350 mg/m(2), which was escalated to 550 mg/m(2) in 50-mg/m(2) increments. The plasma pharmacokinetics of irinotecan and its active metabolite, SN-38, were determined during the infusion of irinotecan on cycle 1, day 1.


RESULTS
Thirty-three patients were enrolled into the study and treated. Thirty-one patients were evaluable for both tumor response and toxicity and two patients were evaluable for toxicity only. Common toxicities included neutropenia and thrombocytopenia, nausea, vomiting, and diarrhea. Dose-limiting toxicities were grade 3 diarrhea and nausea/vomiting. The maximum tolerated dose for irinotecan was determined to be 500 mg/m(2).


CONCLUSIONS
The recommended phase II dose of irinotecan in combination with temozolomide for patients receiving EIAEDs is 500 mg/m(2), administrated every 15 days on a 28-day schedule. This study also confirmed that concomitant administration of EIAEDs increases irinotecan clearance and influences SN-38 disposition. No pharmacokinetic interaction was observed between temozolomide and irinotecan.
Loghin
Monica E
ME
Department of Neuro-Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Prados
Michael D
MD
Wen
Patrick
P
Junck
Larry
L
Lieberman
Frank
F
Fine
Howard
H
Fink
Karen L
KL
Metha
Minesh
M
Kuhn
John
J
Lamborn
Kathleen
K
Chang
Susan M
SM
Cloughesy
Timothy
T
DeAngelis
Lisa M
LM
Robins
Ian H
IH
Aldape
Kenneth D
KD
Yung
W K Alfred
WK
D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects* / Q000493:pharmacokinetics; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D002166:Camptothecin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D003606:Dacarbazine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004790:Enzyme Induction; D005260:Female; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D000077146:Irinotecan; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000378:metabolism; D000077204:Temozolomide
D000927:Anticonvulsants; D000077146:Irinotecan; D003606:Dacarbazine; D002166:Camptothecin; D000077204:Temozolomide