{"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":"A phase 3 trial of Niraparib in triple-negative breast cancer, run by GlaxoSmithKline, active and no longer recruiting.","summary":"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 is a phase 3 interventional study registered as NCT04915755 by GlaxoSmithKline, with 40 participants enrolled, started 2021-06-28 and due to reach its primary completion in 2024-06-28. Interventions recorded: Niraparib and Placebo. Results have been posted on the registry.","status":"active","asOf":"2026-09-22","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":[],"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","started":"2021-06-28","startedType":"actual","yearReported":2025,"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/"}],"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/"}]}}