Therapeutic Drug Monitoring of Endoxifen for Tamoxifen Precision Dosing: Feasible in Patients with Hormone-Sensitive Breast Cancer.

ABSTRACT:

Background

Endoxifen is the most important active metabolite of tamoxifen. Several retrospective studies have suggested a minimal or threshold endoxifen systemic concentration of 14-16 nM is required for a lower recurrence rate. The aim of this study was to investigate the feasibility of reaching a predefined endoxifen level of ≥ 16 nM (5.97 ng/mL) over time using therapeutic drug monitoring (TDM).

Methods

This prospective open-label intervention study enrolled patients who started treatment with a standard dose of tamoxifen 20 mg once daily for early breast cancer. An outpatient visit was combined with a TDM sample at 3, 4.5, and 6 months after initiation of the tamoxifen treatment. The tamoxifen dose was escalated to a maximum of 40 mg if patients had an endoxifen concentr

SUBMITTER: Braal CL 

PROVIDER: S-EPMC8975771 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature