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Updated: Apr 18, 2026
Evaluation of Nanoparticle Uptake in Tumors in Real Time Using Intravital Imaging
Published on: June 21, 2011
Phase I study of nanoliposomal irinotecan (PEP02) in advanced solid tumor patients
T C Chang1, H S Shiah, C H Yang
1Department of Gynecology, Linkuo Chang-Gung Memorial Hospital, No.5, Fu-Hsing Street, Kuei-shan Hsiang, Taoyuan, 33305, Taiwan.
Purpose:
To define the dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and pharmacokinetics (PK) of PEP02, a novel liposome-encapsulated irinotecan, in patients with advanced refractory solid tumors.
Methods:
Patients were enrolled in cohorts of one to three to receive escalating dose of PEP02 in a phase I trial. PEP02, from 60 to 180 mg/m(2), was given as a 90-min intravenous infusion, every 3 weeks.
Results:
A total of 11 patients were enrolled into three dose levels: 60 (one patient), 120 (six patients) and 180 mg/m(2) (four patients). DLT was observed in three patients, one at 120 mg/m(2) (grade 3 catheter-related infection) and two at 180 mg/m(2) (grade 4 neutropenia lasting for >3 days in one, grade 4 hematological toxicities and grade 4 diarrhea in the other). MTD was determined as 120 mg/m(2). Comparing with those after free-form irinotecan in the literature, the dose-normalized PK of SN-38 (the active metabolite) after PEP02 was characterized by lower C max, prolonged terminal half-life and higher AUC but with significant inter-individual variation. One patient who died of treatment-related toxicity had significantly higher C max and AUC levels of SN-38 than those of the other three patients at 180 mg/m(2). Post hoc pharmacogenetic study showed that the patient had a combined heterozygosity genotype of UGT1A1*6/*28. Two patients had objective tumor response.
Conclusions:
PEP02 apparently modified the PK parameters of irinotecan and SN-38 by liposome encapsulation. The MTD of PEP02 monotherapy at 3-week interval is 120 mg/m(2), which will be the recommended dose for future studies.
