Clinical Research Directory
Browse clinical research sites, groups, and studies.
The POWER Trial: Personalised Dose Optimisation With Adjuvant Tamoxifen Therapy in Breast cancER
Sponsor: Karolinska Institutet
Summary
In Sweden, approximately 7000 women are diagnosed with hormone-sensitive breast cancer annually. According to international and national guidelines, most of these women are recommended anti-hormonal therapy for five to ten years to improve prognosis. Tamoxifen, one of the most widely used anti-hormonal agents globally, reduces the risk of recurrence by 40% and breast cancer mortality by 30%. Tamoxifen is a pro-drug that undergoes hepatic metabolism to form endoxifen and other active metabolites. Variability in metabolic capacity affects therapeutic efficacy: poor metabolisers produce insufficient endoxifen and other active metabolites, risking therapeutic failure, while ultrarapid metabolisers generate excessive amounts, leading to intolerable adverse effects. Today, 30-50% of patients discontinue treatment prematurely due to severe side effects, resulting in suboptimal outcomes. Currently, tamoxifen is uniformly prescribed at a daily dose of 20 mg, and so far, no clinical trials have tested whether individualised dosing could enhance adherence and improve survival outcomes. The primary objective is to evaluate whether individualised tamoxifen dosing reduces discontinuation rates and enhances patient outcomes in breast cancer treatment.
Official title: The POWER Trial: A Randomised, Two-armed Open Label Phase 3 Clinical Trial on Personalised Dose Optimisation With Adjuvant Tamoxifen Therapy After Breast Cancer to Investigate the Impact on Discontinuation and Efficacy Compared to Standard of Care
Key Details
Gender
FEMALE
Age Range
18 Years - Any
Study Type
INTERVENTIONAL
Enrollment
1100
Start Date
2026-03
Completion Date
2036-08
Last Updated
2026-03-31
Healthy Volunteers
No
Conditions
Interventions
Individual dose of tamoxifen
Each subject starts their treatment with the standard dose 20 mg tamoxifen daily by oral intake. During visits 2 (3 months), 3 (six months) and 4 (twelve months), the investigator will either let the patient remain on 20 mg tamoxifen or individualise the dose. The investigator may change the daily tamoxifen from 20 mg per day to: a halved dose to 10 mg, or a doubled dose to 40 mg. The recommendation for oral intake of tablet(s) tamoxifen for a daily dose of 10, 20 or 40 mg is accordingly: for 10 mg: one tablet (20 mg) every two days for 20 mg: one tablet (20 mg) every day for 40 mg: two tablets (20 mg) every day.
Standard adjuvant therapy of tamoxifen
The global standard dose for everyone is 20 mg orally once per day. Each subject undergoes treatment with the standard dose 20 mg daily by oral intake of one tablet, with no possibility of dose adjustment during the trial.
Locations (4)
S:a Älvsborgs Sjukhus
Borås, Sweden
Skaraborgs Sjukhus
Skövde, Sweden
Capio S:t Görans Sjukhus
Stockholm, Sweden
Södersjukhuset, Onkologiska kliniken
Stockholm, Sweden