{"entity":{"id":"nct04915755","kind":"trial","name":"Efficacy and Safety Comparison of Niraparib to Placebo in Participants With Human Epidermal Growth Factor 2 Negative (HER2-) Breast Cancer Susceptibility Gene Mutation (BRCAmut) or Triple-Negative Breast Cancer (TNBC) With Molecular Disease","aka":["ZEST"],"tldr":"This study tests a PARP inhibitor; the registry reports that it is active not recruiting.","summary":"The registry lists NCT04915755 as active not recruiting, last updated 2025-07-16. Enrolment is 40 actual participants. Interventions: Niraparib, Placebo. Primary measures include Number of Participants With Treatment Emergent Adverse Event (TEAEs), Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs); Number of Participants With TEAEs Leading to Death. Results are posted in the registry.","status":"active","asOf":"2026-10-06","links":[{"label":"ClinicalTrials.gov NCT04915755","url":"https://clinicaltrials.gov/study/NCT04915755"}],"tags":["pipeline","ctgov-ingest"],"related":[],"cancers":["tnbc","tnbc-early"],"sections":[],"technologies":["parp-inhibitor","mrd-testing"],"targets":["parp"],"drugs":["niraparib"],"companies":["gsk"],"institutions":[],"pathways":[],"terms":["ctdna","gbrca-mutation","tnbc-residual-disease-decision"],"trials":["c-trak-tn","bre12-158","olympia"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["ZEST (NCT04915755, GlaxoSmithKline): randomised double-blind phase 3 of niraparib versus placebo for HER2-negative BRCA-mutated or triple-negative breast cancer with ctDNA detected after definitive therapy; the registry records only 40 participants randomised (actual) against the design, primary completion June 2024 and results posted July 2025 as safety outcomes, because too few screened patients were ctDNA-positive and free of recurrence at detection, the same problem c-TRAK TN met in the UK. Twelve UK sites (Bath, Brighton, Cardiff, Coventry, Edinburgh, Leeds, London, Maidstone, Manchester, Sutton, Wigan) took part."],"nct":"NCT04915755","phase":"3","setting":"A Randomized Phase 3 Double-Blinded Study Comparing the Efficacy and Safety of Niraparib to Placebo in Participants With Either HER2-Negative BRCA-Mutated or Triple-Negative Breast Cancer With Molecular Disease Based on Presence of Circulating Tumor DNA After Definitive Therapy (ZEST)","sponsor":"GlaxoSmithKline","participation":[{"nct":"NCT04915755","source":"https://clinicaltrials.gov/study/NCT04915755","fetchedAt":"2026-10-07T16:53:30.019Z","studySha256":"d60e8677aa355c1173259bfb0ad823337d3d845ac06c817a812e8c4cb8178f58","overallStatus":"ACTIVE_NOT_RECRUITING","lastUpdatePosted":"2025-07-16","leadSponsor":"GlaxoSmithKline","collaboratorCount":0,"minimumAge":"18 Years","sex":"ALL","healthyVolunteers":false,"hasEligibility":true,"enrolment":40,"enrolmentType":"ACTUAL","siteCount":198,"recruitingSiteCount":0,"countries":["Argentina","Australia","Austria","Belgium","Brazil","Canada","Chile","Finland","France","Germany","Hungary","Ireland","Israel","Italy","Japan","Mexico","Netherlands","Norway","Poland","Portugal","Romania","Russia","South Africa","Spain","Switzerland","United Kingdom","United States"]}],"started":"2021-06-28","startedType":"actual","enrolled":40,"enrolledBasis":"registry","outcomes":[{"endpoint":"Number of Participants With TEAEs Leading to Death","primary":true,"unit":"participants","arms":[{"name":"Niraparib","n":18,"value":0,"note":"Figures from the ClinicalTrials.gov results section (first posted 2025-07-16), not from a publication"},{"name":"Placebo","n":22,"value":0}],"source":"https://clinicaltrials.gov/study/NCT04915755?tab=results"}]},"route":"/trials/nct04915755/","neighbours":{"cancer":[{"id":"tnbc-early","kind":"cancer","name":"Early triple-negative breast cancer","route":"/cancers/tnbc-early/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"technology":[{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"},{"id":"parp-inhibitor","kind":"technology","name":"PARP inhibitors","route":"/technologies/parp-inhibitor/"}],"target":[{"id":"parp","kind":"target","name":"PARP","route":"/targets/parp/"}],"drug":[{"id":"niraparib","kind":"drug","name":"Niraparib","route":"/drugs/niraparib/"}],"company":[{"id":"gsk","kind":"company","name":"GSK","route":"/companies/gsk/"}],"term":[{"id":"ctdna","kind":"term","name":"Circulating tumour DNA (ctDNA)","route":"/terms/ctdna/"},{"id":"gbrca-mutation","kind":"term","name":"Germline BRCA mutation (gBRCA)","route":"/terms/gbrca-mutation/"},{"id":"tnbc-residual-disease-decision","kind":"term","name":"Residual disease after neoadjuvant therapy in triple-negative breast cancer: the decision point","route":"/terms/tnbc-residual-disease-decision/"}],"trial":[{"id":"bre12-158","kind":"trial","name":"BRE12-158 (Hoosier Oncology Group)","route":"/trials/bre12-158/"},{"id":"c-trak-tn","kind":"trial","name":"c-TRAK TN","route":"/trials/c-trak-tn/"},{"id":"olympia","kind":"trial","name":"OlympiA","route":"/trials/olympia/"}]}}