Vikram Gota1,2, Manjunath Nookala1,2, Avinash Bonda2,3, Ashwin Karanam1,4, Bharati Shriyan1, Yogesh Kembhavi3, Murari Gurjar1, Anand Patil1, Ashish Singh3, Navin Goyal5, Sudeep Gupta2,3. 1. Department of Clinical Pharmacology, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi Mumbai, India. 2. Homi Bhabha National Institute, Mumbai, India. 3. Department of Medical Oncology, Tata Memorial Centre, Mumbai, India. 4. Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA. 5. Clinical Pharmacology, GlaxoSmithKline, Pennsylvania, PA, USA.
Abstract
BACKGROUND: Paclitaxel is dosed according to body surface area (BSA) but there is scant information on actual drug exposure in overweight and obese patients. METHODS: Early breast cancer patients receiving paclitaxel at 175 mg/m2 every 3 weeks, in two BMI groups (normal, 18-24.9 kg/m2 and overweight/obese, ≥25 kg/m2 , respectively), matched for age, serum albumin and bilirubin levels using minimization technique, were included. Sparse pharmacokinetic (PK) sampling was performed at 7 time points from 0 h until 24 h of starting paclitaxel in cycle 1. Paclitaxel concentration was measured using a validated LCMS/MS method. Covariate effect on paclitaxel PK was evaluated by population PK analysis using NONMEM software. RESULTS: Eighteen female patients each were enrolled in normal and overweight groups with mean BMI of 21.62 ± 2.06 and 28.16 ± 2.31 kg/m2 , mean BSA of 1.44 ± 0.11 and 1.69 ± 0.14 m2 and mean paclitaxel dose of 250 ± 18 and 293 ± 21 mg, respectively. Model predicted AUC and dose normalized AUC (mean ±SD) in the normal BMI versus overweight obese groups were 23 ± 11.0 µmol*h/L versus 25.7 ± 13.7 µmol*h/L (two-sample t-test p > 0.05) and 0.08 ± 0.04 (µmol*h/L)/ µmol versus 0.08 ± 0.04 (µmol*h/L)/ µmol (2-sample t-test p > 0.05), respectively. No significant correlation was observed between BMI and standardized dose normalized AUC (Pearson's correlation coefficient, -0.009; p > 0.05). CONCLUSION: When dosed according to BSA calculated using actual body weight there is no significant difference in paclitaxel exposure between normal and overweight women. Using alternative descriptors of weight to calculate BSA could lead to under-dosing of this drug. TRIAL REGISTRATION: This study is registered in the Clinical Trials Registry of India CTRI/2015/09/006193.
BACKGROUND:Paclitaxel is dosed according to body surface area (BSA) but there is scant information on actual drug exposure in overweight and obesepatients. METHODS: Early breast cancerpatients receiving paclitaxel at 175 mg/m2 every 3 weeks, in two BMI groups (normal, 18-24.9 kg/m2 and overweight/obese, ≥25 kg/m2 , respectively), matched for age, serum albumin and bilirubin levels using minimization technique, were included. Sparse pharmacokinetic (PK) sampling was performed at 7 time points from 0 h until 24 h of starting paclitaxel in cycle 1. Paclitaxel concentration was measured using a validated LCMS/MS method. Covariate effect on paclitaxel PK was evaluated by population PK analysis using NONMEM software. RESULTS: Eighteen female patients each were enrolled in normal and overweight groups with mean BMI of 21.62 ± 2.06 and 28.16 ± 2.31 kg/m2 , mean BSA of 1.44 ± 0.11 and 1.69 ± 0.14 m2 and mean paclitaxel dose of 250 ± 18 and 293 ± 21 mg, respectively. Model predicted AUC and dose normalized AUC (mean ±SD) in the normal BMI versus overweight obese groups were 23 ± 11.0 µmol*h/L versus 25.7 ± 13.7 µmol*h/L (two-sample t-test p > 0.05) and 0.08 ± 0.04 (µmol*h/L)/ µmol versus 0.08 ± 0.04 (µmol*h/L)/ µmol (2-sample t-test p > 0.05), respectively. No significant correlation was observed between BMI and standardized dose normalized AUC (Pearson's correlation coefficient, -0.009; p > 0.05). CONCLUSION: When dosed according to BSA calculated using actual body weight there is no significant difference in paclitaxel exposure between normal and overweight women. Using alternative descriptors of weight to calculate BSA could lead to under-dosing of this drug. TRIAL REGISTRATION: This study is registered in the Clinical Trials Registry of India CTRI/2015/09/006193.
Authors: Lishi Lin; Marcel Soesan; Dorieke E M van Balen; Jos H Beijnen; Alwin D R Huitema Journal: Breast Cancer Res Treat Date: 2022-08-16 Impact factor: 4.624