A phase I and pharmacokinetic study of pemetrexed plus irinotecan in patients with advanced solid malignancies.
OBJECTIVE
The main objectives of this phase I and pharmacokinetic, open-label study were to characterize the principal toxicities and determine the maximum tolerated dose of the multitargeted antifolate pemetrexed administered in combination with irinotecan. The study also sought to detect major pharmacokinetic drug-drug interactions between these agents and preliminary evidence of antitumor activity in patients with advanced solid malignancies.


METHODS
Pemetrexed was administered as a 10-min i.v. infusion followed by irinotecan given i.v. over 90 min every 3 weeks to patients with advanced solid malignancies. The study objectives were first pursued in heavily pretreated patients and then in lightly pretreated patients who also received vitamin supplementation.


RESULTS
Twenty-three heavily pretreated patients enrolled in the first stage of the study, and the maximum tolerated dose level of pemetrexed/irinotecan without vitamin supplementation was 400/250 mg/m(2); further dose escalation was precluded by severe neutropenia that was protracted and/or associated with fever. In the second stage of the study, 28 lightly pretreated patients were administered pemetrexed/irinotecan with vitamin supplementation; these patients tolerated pemetrexed/irinotecan at a dose level of 500/350 mg/m(2), which reflected clinically relevant single-agent doses of both agents. No major pharmacokinetic interactions between the agents were evident. Four patients, two patients each with colorectal cancer refractory to fluoropyrimidines and advanced mesothelioma, had partial responses.


CONCLUSIONS
The pemetrexed/irinotecan regimen is well tolerated in patients with advanced solid malignancies at clinically relevant single-agent doses. The recommended dose level of pemetrexed/irinotecan for subsequent disease-directed evaluations involving lightly pretreated patients is 500/350 mg/m(2) every 3 weeks with vitamin supplementation.
Rowinsky
Eric K
EK
Institute for Drug Development, Cancer Therapy, and Research Center, San Antonio, Texas, USA. erowinsky@oncodrugs.com
Beeram
Muralidhar
M
Hammond
Lisa A
LA
Schwartz
Garry
G
De Bono
Johann
J
Forouzesh
Baharam
B
Chu
Quincy
Q
Latz
Jane E
JE
Hong
Shengyan
S
John
William
W
Nguyen
Binh
B
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D015331:Cohort Studies; D019587:Dietary Supplements; D004347:Drug Interactions; D005260:Female; D005971:Glutamates / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D006801:Humans; D000077146:Irinotecan; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D000068437:Pemetrexed; D014815:Vitamins / Q000494:pharmacology
D000970:Antineoplastic Agents; D005971:Glutamates; D014815:Vitamins; D000068437:Pemetrexed; D006147:Guanine; D000077146:Irinotecan; D002166:Camptothecin