This study is designed to investigate the toxicity and pharmacokinetics (PK) of 2-weekly and 3-weekly docetaxel in metastatic hormone-sensitive prostate cancer (mHSPC). Also, a mechanism-based population pharmacokinetics/pharmacodynamics (PK/PD) model will be developed to provide a better understanding of the complex relationships between the drug exposure and toxicity profiles of docetaxel in mHSPC.
This pilot study is designed to investigate the toxicity and PK of 2-weekly and 3-weekly docetaxel in mHSPC. Furthermore, a mechanism-based population PK/ pharmacodynamics (PD) model will be developed to provide a better understanding of the complex relationships between the drug exposure and toxicity profiles of docetaxel in mHSPC. In addition, selected pro-inflammatory and macrophage-associated cytokines will be collected to assess the potential role of these cytokines as the early markers of docetaxel resistance in patients with mHSPC. (Cytokines: macrophage inhibitory cytokine 1 (MIC1), interleukin (IL)-1ra, IL-1β, IL-4, IL-6, IL-12, and IFNγ). Serological response, defined as a prostate-specific antigen (PSA) level of \<0.2 ng/mL at 12 months, and progression-free survival at 12 months are selected as the secondary clinical endpoints of the study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
50 mg/m2 of docetaxel will be given on day 1 every 14 days
75 mg/m2 of docetaxel will be given on day 1 every 21 days
University of Kentucky Markey Cancer Center
Lexington, Kentucky, United States
Comparison of the neutropenia toxicity rate over time between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
Toxicity rate in each arm will be estimated based on a one-sided 90% confidence interval. Assuming at most a 31% neutropenia rate, a sample of 16 patients per arm will provide a one-sided 90% confidence interval upper limit equal to 50%.
Time frame: Baseline; at each therapy cycle (a cycle is 2 weeks for the 2-weekly regimen, 3 weeks for the 3-weekly regimen); at 6-, 9-, and 12-months post treatment
Comparison of the pharmacokinetics (PK) parameter 'Cmax' (maximum concentration) between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
Individual docetaxel PK parameters will be estimated by non-compartmental method using Phoenix WinNonlin software (Certara Corporation, Princeton, NJ). Maximum concentration (Cmax) will be the observed value.
Time frame: 0, 0.25, 0.75, 3, 6.5, and 24 hours post first docetaxel infusion; and, at the end of docetaxel infusion of the last cycle (a cycle is 2 weeks for the 2-weekly regimen, 3 weeks for the 3-weekly regimen)
Comparison of the pharmacokinetics (PK) parameter 'Tmax' (time to Cmax) between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
Individual docetaxel PK parameters will be estimated by non-compartmental method using Phoenix WinNonlin software (Certara Corporation, Princeton, NJ). Time to Cmax (Tmax) will be the observed value.
Time frame: 0, 0.25, 0.75, 3, 6.5, and 24 hours post first docetaxel infusion; and, at the end of docetaxel infusion of the last cycle (a cycle is 2 weeks for the 2-weekly regimen, 3 weeks for the 3-weekly regimen)
Comparison of the pharmacokinetics (PK) parameter 'AUClast' between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
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Area under the plasma concentration-time curve from zero to last observed time (AUClast) will be estimated using the trapezoidal rule.
Time frame: 0, 0.25, 0.75, 3, 6.5, and 24 hours post first docetaxel infusion; and, at the end of docetaxel infusion of the last cycle (a cycle is 2 weeks for the 2-weekly regimen, 3 weeks for the 3-weekly regimen)
Comparison of the pharmacokinetics (PK) parameter 't1/2' (terminal half-life) between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
Terminal half-life (t1/2) will be calculated using the terminal linear portion of the log concentration-time curve.
Time frame: 0, 0.25, 0.75, 3, 6.5, and 24 hours post first docetaxel infusion; and, at the end of docetaxel infusion of the last cycle (a cycle is 2 weeks for the 2-weekly regimen, 3 weeks for the 3-weekly regimen)
Comparison of the pharmacokinetics (PK) parameter 'AUC0-inf' (area under the curve from zero to infinity)' between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
AUC from zero to infinity (AUC0-inf) will be determined using the following equation: AUC0-inf = AUClast + Cllast/Kel Where Clast is the observed concentration at the last time point and Kel is the slope of the terminal linear portion of the log concentration-time curve.
Time frame: 0, 0.25, 0.75, 3, 6.5, and 24 hours post first docetaxel infusion; and, at the end of docetaxel infusion of the last cycle (a cycle is 2 weeks for the 2-weekly regimen, 3 weeks for the 3-weekly regimen)
Comparison of all grades of neutropenia (including febrile neutropenia) and other toxicities between the 2-weekly docetaxel dosing regimen and the 3-weekly docetaxel dosing regimen in metastatic hormone-sensitive prostate cancer.
Adverse event data and corresponding toxicity grades during the days of treatment will be summarized for each docetaxel dosing arm. Neutropenia rates will be estimated along with exact 90% one-sided binomial confidence intervals. Incidence, frequency, severity, and attribution tables for other toxicities will be generated.
Time frame: up to 12 months after the first docetaxel dose
Development of a population system pharmacology model to describe the relationships between the PK (drug exposure) and PD (toxicity) of 2-weekly docetaxel in metastatic hormone-sensitive prostate cancer
The mechanism population PK/PD model will be developed using Monte-Carlo Expectation-Maximization algorithm implemented S-ADAPT software (version 1.57, BMSR, Log Angeles, CA).
Time frame: CBC with differential and platelet will be collected: 24-hour +/- 3hrs; and 7 days +/- 1day after the first administration of 2-weekly docetaxel in cycle 1 to support the development of population PK/PD model
Development of a population system pharmacology model to describe the relationships between the PK (drug exposure) and PD (toxicity) of 3-weekly docetaxel in metastatic hormone-sensitive prostate cancer
The mechanism population PK/PD model will be developed using Monte-Carlo Expectation-Maximization algorithm implemented S-ADAPT software (version 1.57, BMSR, Log Angeles, CA).
Time frame: CBC with differential and platelet will be collected: 24-hour +/- 3hrs; 7 days +/- 1day; and 14 days +/- 1day after the first administration of 3-weekly docetaxel in cycle 1 to support the development of population PK/PD model
Evaluation of the rate of complete serological response at 12 months
Defined as a prostate-specific antigen (PSA) level of less than 0.2 ng/mL
Time frame: 12 months post treatment
Evaluation of the cytokine profile before and after treatment at different docetaxel dosage regimens
Descriptive statistics will be calculated for each cytokine parameter measured at each time point for each docetaxel dosing regimen and comparison from pre vs post-treatment within each arm will be performed using paired t-test while comparisons of cytokine parameters between docetaxel dosing groups will likewise be performed using two-sample t-test. Several cytokine parameters are evaluated and we will employ the Holm's p-value adjustment method to account for multiple testing between dosing group arms.
Time frame: Baseline before chemotherapy; immediately prior to second dose (cycle length depends on dosing regimen) of chemotherapy; 30 minutes prior to chemotherapy at Week 7, and at Week 19; at Month 12 after start of first docetaxel dose.