[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100631602":3},{"organization":4,"armGroups":7,"interventions":20,"overallOfficials":31,"centralContacts":38,"locations":44,"responsibleParty":93,"collaborators":96,"id":109,"slug":110,"hasResults":111,"nctId":112,"briefTitle":113,"officialTitle":114,"acronym":115,"eligibilityCriteria":116,"healthyVolunteers":111,"sex":117,"minAge":118,"maxAge":26,"enrollmentInfo":119,"targetDuration":26,"studyType":122,"phases":123,"briefSummary":125,"conditions":126,"keywords":129,"overallStatus":136,"whyStopped":26,"lastUpdateSubmitDate":137,"lastUpdatePostDateStruct":138,"startDateStruct":141,"completionDateStruct":143,"leadSponsor":145,"locationsCount":146},{"fullName":5,"class":6},"Karolinska Institutet","OTHER",[8,14],{"label":9,"type":10,"description":11,"interventionNames":12},"Individualised care with tamoxifen dose adjustments.","EXPERIMENTAL","Patients randomised to individualised care will have their dose adjusted according to an algorithm based on patient reported side effects and the concentration of (z)-endoxifen in blood.",[13],"Drug: Individual dose of tamoxifen",{"label":15,"type":16,"description":17,"interventionNames":18},"Standard-of-care with the standard tamoxifen dose of 20 mg orally once per day.","ACTIVE_COMPARATOR","In the control arm, each subject undergoes treatment with the standard dose 20 mg tamoxifen daily by oral intake of one tablet, with no possibilty of dose adjustment during the trial.",[19],"Drug: Standard adjuvant therapy of tamoxifen",[21,27],{"type":22,"name":23,"description":24,"armGroupLabels":25,"otherNames":26},"DRUG","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.\n\nThe investigator may change the daily tamoxifen from 20 mg per day to:\n\na halved dose to 10 mg, or a doubled dose to 40 mg.\n\nThe recommendation for oral intake of tablet(s) tamoxifen for a daily dose of 10, 20 or 40 mg is accordingly:\n\nfor 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.",[9],null,{"type":22,"name":28,"description":29,"armGroupLabels":30,"otherNames":26},"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.",[15],[32,35],{"name":33,"affiliation":5,"role":34},"Marike Gabrielson, PhD","PRINCIPAL_INVESTIGATOR",{"name":36,"affiliation":5,"role":37},"Jenny Bergkvist, MD, PhD","STUDY_CHAIR",[39],{"name":40,"role":41,"phone":42,"phoneExt":26,"email":43},"Helena Aaröe, RN","CONTACT","+46852482267","powerstudien-meb@ki.se",[45,60,72,84],{"facility":46,"status":26,"city":47,"state":26,"zip":48,"country":49,"countryCode":50,"cosmosGeoPoint":51,"geoPoint":56,"contacts":57},"S:a Älvsborgs Sjukhus","Borås","501 82","Sweden","SE",{"type":52,"coordinates":53},"Point",[54,55],12.9401,57.72101,{"lat":55,"lon":54},[58],{"name":59,"role":34,"phone":26,"phoneExt":26,"email":26},"Rebecka Landin, MD PhD",{"facility":61,"status":26,"city":62,"state":26,"zip":63,"country":49,"countryCode":50,"cosmosGeoPoint":64,"geoPoint":68,"contacts":69},"Skaraborgs Sjukhus","Skövde","549 49",{"type":52,"coordinates":65},[66,67],13.84506,58.39118,{"lat":67,"lon":66},[70],{"name":71,"role":34,"phone":26,"phoneExt":26,"email":26},"Chaido Chamalidou, MD PhD",{"facility":73,"status":26,"city":74,"state":26,"zip":75,"country":49,"countryCode":50,"cosmosGeoPoint":76,"geoPoint":80,"contacts":81},"Capio S:t Görans Sjukhus","Stockholm","112 81",{"type":52,"coordinates":77},[78,79],18.06871,59.32938,{"lat":79,"lon":78},[82],{"name":83,"role":34,"phone":26,"phoneExt":26,"email":26},"Jenny Bergqvist, MD PhD",{"facility":85,"status":26,"city":74,"state":26,"zip":86,"country":49,"countryCode":50,"cosmosGeoPoint":87,"geoPoint":89,"contacts":90},"Södersjukhuset, Onkologiska kliniken","118 61",{"type":52,"coordinates":88},[78,79],{"lat":79,"lon":78},[91],{"name":92,"role":34,"phone":26,"phoneExt":26,"email":26},"Linda Thorén, MD PhD",{"type":34,"investigatorFullName":94,"investigatorTitle":95,"investigatorAffiliation":5,"oldNameTitle":26,"oldOrganization":26},"Marike Gabrielson","Sponsor representative and Chief Scientific Scientific Officer",[97,99,102,105,107],{"name":98,"class":6},"Swedish Cancer Society",{"name":100,"class":101},"Region Stockholm","OTHER_GOV",{"name":103,"class":104},"The Swedish Breast Cancer Association","UNKNOWN",{"name":106,"class":104},"The Sjöberg Foundation",{"name":108,"class":104},"The Cancer Research Foundations of Radiumhemmet","100631602","phase-3-the-power-trial-personalised-dose-optimisation-with-adjuvant-tamoxifen-therapy-in-breast-cancer-100631602",false,"NCT07502820","The POWER Trial: Personalised Dose Optimisation With Adjuvant Tamoxifen Therapy in Breast cancER","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","POWER","Inclusion Criteria:\n\n* Patients with primary breast cancer, recommended for adjuvant tamoxifen treatment with or without concomitant goserelin\n* Premenopausal or perimenopausal, defined according to SOC for therapy decision\n* Eastern Cooperative Oncology Group (ECOG) WHO Performance Scale 0 - 2\n* Participants must use non-hormonal contraception during the trial.\n\nExclusion Criteria:\n\n* Previous use of tamoxifen, endoxifen, or aromatase inhibitors.\n* Previous medical history of:\n\nDeep venous thrombosis or pulmonary embolism; bleeding disorder or coagulopathy; macular disorders, retinal disorders, severe cataract or glaucoma.\n\n* Current use of warfarin.\n* Not willing to abstain from strong and moderate CYP2D6 inhibitors or CYP3A4 inducers during the tamoxifen treatment\n* Current pregnancy, breastfeeding, or already at start of tamoxifen planning to become pregnant within the next two years\n* Use of systemic menopausal hormonal therapy (MHT).\n* Prior invasive malignancy during the last five years. Prior or current in situ cancers are allowed.","FEMALE","18 Years",{"count":120,"type":121},1100,"ESTIMATED","INTERVENTIONAL",[124],"PHASE3","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%.\n\nTamoxifen 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.\n\nCurrently, 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.",[127,128],"Breast Cancer","Adjuvant Drug Therapy",[130,131,132,133,134,135],"Early-stage breast cancer","Adjuvant","Endocrine therapy","Tamoxifen","Therapeutic drug monitoring TDM","Precision medicine","NOT_YET_RECRUITING","2026-03-27",{"date":139,"type":140},"2026-03-31","ACTUAL",{"date":142,"type":121},"2026-03",{"date":144,"type":121},"2036-08",{"name":5,"class":6},4]