Safety, Pharmacokinetics, and Efficacy of CPX-1 Liposome Injection in Patients with Advanced Solid Tumors
Purpose: CPX-1 is a novel, liposome-encapsulated formulation of irinotecan and floxuridine designed to prolong in vitro optimized synergistic molar ratios of both drugs postinfusion. This open-label, single-arm, dose-escalating phase I study was designed to determine the maximum tolerated dose and p...
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Published in | Clinical cancer research Vol. 15; no. 2; pp. 692 - 700 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Philadelphia, PA
American Association for Cancer Research
15.01.2009
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Subjects | |
Online Access | Get full text |
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Summary: | Purpose: CPX-1 is a novel, liposome-encapsulated formulation of irinotecan and floxuridine designed to prolong in vitro optimized synergistic molar ratios of both drugs postinfusion. This open-label, single-arm, dose-escalating phase I study
was designed to determine the maximum tolerated dose and pharmacokinetics of CPX-1 in patients with advanced solid tumors.
Experimental Design: Patients received CPX-1 at 30, 60, 100, 150, 210, or 270 units/m 2 (1 unit = 1 mg irinotecan + 0.36 mg floxuridine) infused over 90 minutes every 14 days in 28-day cycles. Pharmacokinetic
samples were collected on days 1 and 15 of cycle 1.
Results: Thirty-three patients were enrolled, treated, and evaluated for safety; 30 patients were evaluated for response. A 1:1 plasma
irinotecan to floxuridine molar ratio was maintained for 8 to 12 hours. Grade 3/4 toxicities included diarrhea (24.2%), neutropenia
(12.1%), and hypokalemia (12.1%); 1 patient (270 units/m 2 ) died of persistent diarrhea, which led to dehydration and renal failure (grade 5). Partial response occurred in 3 (12%)
of the 25 subjects evaluated through Response Evaluation Criteria in Solid Tumors. Progression-free survival lasting >6 months
occurred in 9 patients, 6 with colorectal cancer. Among 15 colorectal cancer patients (10 with prior irinotecan), the calculated
median progression-free survival was 5.4 months; 11 patients (72.7%) achieved disease control and 2 patients (13%) had partial
response.
Conclusions: Outpatient CPX-1 was well tolerated and antitumor activity was shown in patients with advanced solid tumors. The recommended
dose for future studies is 210 units/m 2 . This is the first clinical evaluation of fixed drug ratio dosing designed to maintain synergistic molar ratios for enhanced
therapeutic benefit. |
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ISSN: | 1078-0432 1557-3265 |
DOI: | 10.1158/1078-0432.CCR-08-0515 |