Ontology highlight
ABSTRACT: Background
Paclitaxel is widely used for the treatment of metastatic breast cancer (MBC). However, it has a low oral bioavailability due to gut extrusion caused by P-glycoprotein (P-gp). Oral paclitaxel (oPAC) may be more convenient, less resource-intensive, and more tolerable than its intravenous form. Encequidar (E) is a first-in-class, minimally absorbed, gut-specific oral P-gp inhibitor that facilitates the oral absorption of paclitaxel.Objectives
To investigate the pharmacokinetics (PK), overall response rate (ORR), and safety of weekly oral paclitaxel with encequidar (oPAC + E) in patients with advanced breast cancer.Design
This is a multicenter, single-arm, open-label study in six medical centers in Taiwan.Methods
Patients with advanced breast cancer were administered 205 mg/m2 oPAC and 12.9 mg E for 3 consecutive days weekly for up to 16 weeks. Plasma samples were collected at weeks 1 and 4. PK, ORR, and safety were evaluated.Results
In all, 28 patients were enrolled; 27 had MBC; 23 had prior chemotherapy; and 14 had ⩾2 lines of prior chemotherapy. PK were evaluable in 25 patients. Plasma paclitaxel area under the curve (AUC)(0-52 h) at week 1 (3419 ± 1475 ng h/ml) and week 4 (3224 ± 1150 ng h/ml) were equivalent. Best overall response in 28 evaluable patients was partial response (PR) in 11 (39.3%), 13 (46.4%) stable disease (SD), and 1 (3.6%) with progressive disease (PD). No patient achieved complete response (CR). The clinical benefit rate (CR + PR + SD) was 85.7%. Major adverse events among the 28 treated patients were grade 3 neutropenia (25%), grade 4 neutropenia (18%), with febrile neutropenia in 4%, and grade 3 diarrhea (4%). No treatment-related deaths occurred. Grade 2 peripheral neuropathy occurred in 1 (4%) patient and grade 3 peripheral neuropathy in 1 (4%) patient.Conclusions
oPAC + E produced a consistent therapeutic plasma paclitaxel exposure during treatment. There was a high rate of radiologically assessed clinical benefit, and a low rate of neurotoxicity which may provide advantages over IV paclitaxel.Registration
ClinicalTrials.gov Identifier: NCT03165955.
SUBMITTER: Dai MS
PROVIDER: S-EPMC10363869 | biostudies-literature | 2023
REPOSITORIES: biostudies-literature
Dai Ming-Shen MS Chao Ta-Chung TC Chiu Chang-Fang CF Lu Yen-Shen YS Shiah Her-Shyong HS Jackson Christopher G C A CGCA Hung Noelyn N Zhi Jianguo J Cutler David L DL Kwan Rudolf R Kramer Douglas D Chan Wing-Kai WK Qin Albert A Tseng Kuan-Chiao KC Hung Cheung Tak CT Chao Tsu-Yi TY
Therapeutic advances in medical oncology 20230721
<h4>Background</h4>Paclitaxel is widely used for the treatment of metastatic breast cancer (MBC). However, it has a low oral bioavailability due to gut extrusion caused by P-glycoprotein (P-gp). Oral paclitaxel (oPAC) may be more convenient, less resource-intensive, and more tolerable than its intravenous form. Encequidar (E) is a first-in-class, minimally absorbed, gut-specific oral P-gp inhibitor that facilitates the oral absorption of paclitaxel.<h4>Objectives</h4>To investigate the pharmacok ...[more]