Hormone positive breast cancer
Conditions
Interventions
Trade Name: Tamoxifen
Product Name: Tamoxifen
Product Code: 30049048
Pharmaceutical Form: Tablet
Sponsors
Erasmus MC Cancer Institute
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: In order to be eligible to participate in this study, a subject must meet all of the following criteria: 1. Age = 18 years; 2. WHO Performance Status = 1 3. Patients with primary breast cancer, with a prescription for adjuvant tamoxifen treatment. 4. Willing to abstain from strong and moderate CYP3A4 or CYP2D6 inhibitors or inducers, according to: CYTOCHROME P450 DRUG INTERACTION TABLE - Drug Interactions (iu.edu); 5. Able and willing to sign the Informed Consent Form; 6. Able and willing to undergo blood sampling for PK analysis. Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range 50 F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range 50
Exclusion criteria
Exclusion criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: 1. Patients with known alcoholism, drug addiction and/or psychiatric or physiological condition which in the opinion of the investigator would impair treatment compliance; 2. > 2 weeks of tamoxifen treatment before inclusion 3. Patients who’s endoxifen levels have been used for therapeutic drug monitoring in the past. 4. Evidence of a neurological disorder which might affect cognitive functioning (only for cognition scan part)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Main Objective: The primary objective of this study is to determine the proportion of patients that reach an endoxifen level of 16 nmol/L or higher using MIPD.;Secondary Objective: 1.To determine the total success rate of the POP-PK model as well as in different groups, stratified by dosage as predicted by the POP-PK model. 2.To establish the predictive value of the POP-PK model for patients which will not reach the 16 nmol/L endoxifen threshold with the highest prescribed tamoxifen dose of 40 mg. 3.To test if an early blood sample (at baseline and 4-6 weeks after baseline) is indicative for the steady-state concentration; 4.To compare the incidence of side-effects and quality of life of breast cancer patients between baseline and the final assessment after 3 months; 5.To investigate change in cognitive functioningbbetween the start of tamoxifen treatment and two years after start of tamoxifen treatment. 6.To investigate the association between tamoxifen dose, tamoxifen plasma concentrations and endoxifen plasma concentrations and change in objective and subjective cognitive functioning. ;Primary end point(s): The primary endpoint is the proportion of patients that reach an endoxifen level of 16 nmol/L or higher after three months of tamoxifen treatment. The main study parameter is the endoxifen level at 3 months after baseline.;Timepoint(s) of evaluation of this end point: 3 months after inclusion | — |
Secondary
| Measure | Time frame |
|---|---|
| Secondary end point(s): 1. The total success rate of the POP-PK model as well as in different groups, stratified by dosage as predicted by the POP-PK model. 2. The predictive value of the POP-PK model for patients who do not reach the 16 nmol/L endoxifen threshold with the highest prescribed tamoxifen dose of 40 mg; 3. The correlation between the endoxifen values from an early blood sample (at baseline and 4-6 weeks after baseline) and the steady-state concentration of endoxifen; 4. The difference in incidence of side-effects and quality of life between baseline and 3 months after tamoxifen treatment as determined by FACT-ES questionnaires. 5. The intra-patient difference in cognitive test performance and self-reported cognition between baseline and after two years of tamoxifen treatment. 6. The association between tamoxifen, dose, plasma concentrations of tamoxifen and endoxifen and intra-patient differences in cognitive test performance and self-reported cognition. ;Timepoint(s) of evaluation of this end point: 3 months after inclusion | — |
Countries
Netherlands
Contacts
Public ContactS.M. Buijs
Erasmus MC
Outcome results
None listed