A Pilot Study of Varying Doses of Tamoxifen in the Setting of Genetic Polymorphisms of CYP2D6
Recruitment status was Recruiting
The investigators plan to examine endoxifen and 4-OH-Tam as a function of the tamoxifen dose in patients with a genetic CYP2D6 polymorphism. The investigators also plan to investigate other genetic variations in the metabolism of tamoxifen.
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Pilot Study of Varying Doses of Tamoxifen in the Setting of Genetic Polymorphisms of CYP2D6|
- Specific human 2D6 variants measurement(s) or observation(s) [ Time Frame: every two weeks ] [ Designated as safety issue: No ]
|Study Start Date:||January 2009|
|Estimated Study Completion Date:||January 2010|
|Estimated Primary Completion Date:||January 2010 (Final data collection date for primary outcome measure)|
Endocrine therapy has proven to be an extremely effective therapy in breast cancer. For women with hormone-receptor-positive tumors, tamoxifen given for as little as two years results in a statistically significant recurrence and survival benefit. The benefits increase as the duration of treatment increase, up to 5 years, so that among women treated for five years, tamoxifen can result in up to a 46 percent annual reduction in the recurrence rate and up to a 28 percent annual reduction in the death rate. This means that about half of the recurrences and more than one fourth of the deaths each year are prevented by tamoxifen treatment. However, despite initial successful responses, many patients on tamoxifen relapse and die from progressive disease. Consequently, tamoxifen resistance remains a major clinical problem in the management of breast cancer.
Tamoxifen is metabolized by cytochrome P450 2D6 (CYP2D6) to the more potent metabolites 4-hydroxy-tamoxifen (4-OH-TAM) and 4-hydroxy-N-desmethyltamoxifen (endoxifen). Variations in the metabolic capacity of this enzyme have shown to be an independent predictor of breast cancer relapse and death. To date, studies have not correlated tamoxifen doses to CYP2D6 genotype status or associated tamoxifen doses to endoxifen and 4-OH-tamoxifen.
We plan to examine endoxifen and 4-OH-Tam as a function of the tamoxifen dose in patients with a genetic CYP2D6 polymorphism. We also plan to investigate other genetic variations in the metabolism of tamoxifen. The possible identification of gene variants that alter tamoxifen's metabolism may improve initial dose selection and therefore optimize treatment outcome in the future.
In addition to examining polymorphisms in CYP2D6, we will examine other genes that may influence the metabolism of medications.
|Contact: Annie Zuo, MScfirstname.lastname@example.org|
|Contact: Marisa Cortese||212-824-7319|
|United States, New York|
|Mount Sinai School of Medicine||Recruiting|
|New York, New York, United States, 10029|
|Principal Investigator:||Myra Barginear, MD||Mount Sinai School of Medicine|