Preliminary results using the rhelise kit to measure tamoxifen and metabolite concentrations in blood

Preliminary Results Using a Kit to Measure Tamoxifen and Metabolites Concentrations in Capillary Blood Samples from Women with Breast Cancer

In a joint venture between Karolinska Institutet and redhot diagnostics a new technique for Therapeutic Drug Monitoring (TDM) has been evaluated. To facilitate TDM and home testing redhot diagnostic has developed a blood sampling kit that can be used by a layperson. Women with estrogen sensitive breast cancer receives tamoxifen as adjuvant, tamoxifen gives rise to severe side effects if the pharmaceutical if the dose is too high. Many women therefor stop taking tamoxifen. 

This problem could be solved by regularly analyze the blood levels of tamoxifen and its metabolites and the patient together with the treating oncologist could adjust the intake of tamoxifen.

The challenges consist of 1) the western world’s high laboratory costs for regular blood sampling as part of the follow-up among cancer patients – and thus the challenge of developing countries that do not have the same well-developed laboratories and logistics, and 2) patients’ compliance with prescribed cancer medication that significantly reduces the risk of death. 

Therapeutic drug monitoring of tamoxifen using an innovative kit and capillary blood sampling is feasible. Preliminary data from this study will aid in developing a multicenter randomized clinical trial of personalized tamoxifen drug monitoring and adjustments, with the goal of enhancing quality of life and outcomes in patients with breast cancer.

TDM analysis is a prerequisite for individual drug treatment. The purpose of TDM is to improve the individual benefit of treatment and reduce the number of patients at risk of insufficient clinical effect, or side effects due to excessive concentrations. Although there are major individual differences in the way drugs are metabolized in different patients, routine TDM is used for relatively few drugs in health care.

A new study on 40 women is scheduled to March 2022, where the blood samples will be taken at the hospital as well as in home environment by the women themselves.  

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