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
Public ClinicalTrials.gov record NCT04915755. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
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)
Study identification
- NCT ID
- NCT04915755
- Recruitment status
- Active, not recruiting
- Study type
- Interventional
- Phase
- Phase 3
- Lead sponsor
- GlaxoSmithKline
- Industry
- Enrollment
- 40 participants
Conditions and interventions
Conditions
Interventions
- Niraparib Drug
- Placebo Drug
Drug
Eligibility (public fields only)
- Age range
- 18 Years and older
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jun 27, 2021
- Primary completion
- Jun 27, 2024
- Completion
- Dec 30, 2025
- Last update posted
- Jul 15, 2025
2021 – 2025
United States locations
- U.S. sites
- 24
- U.S. states
- 12
- U.S. cities
- 23
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| GSK Investigational Site | Burbank | California | 91505 | — |
| GSK Investigational Site | Duarte | California | 91010 | — |
| GSK Investigational Site | Palo Alto | California | 94304 | — |
| GSK Investigational Site | San Francisco | California | 94158 | — |
| GSK Investigational Site | Aurora | Colorado | 80045 | — |
| GSK Investigational Site | Highlands Ranch | Colorado | 80045 | — |
| GSK Investigational Site | Chicago | Illinois | 60612 | — |
| GSK Investigational Site | Skokie | Illinois | 60076 | — |
| GSK Investigational Site | Ann Arbor | Michigan | 48109 | — |
| GSK Investigational Site | Albuquerque | New Mexico | 87106 | — |
| GSK Investigational Site | New York | New York | 10032 | — |
| GSK Investigational Site | Fargo | North Dakota | 58122 | — |
| GSK Investigational Site | Philadelphia | Pennsylvania | 19111 | — |
| GSK Investigational Site | Pittsburgh | Pennsylvania | 15213 | — |
| GSK Investigational Site | Sioux Falls | South Dakota | 57104 | — |
| GSK Investigational Site | Austin | Texas | 78731 | — |
| GSK Investigational Site | Dallas | Texas | 75231 | — |
| GSK Investigational Site | Dallas | Texas | 75246 | — |
| GSK Investigational Site | Fort Worth | Texas | 76104 | — |
| GSK Investigational Site | Houston | Texas | 77024 | — |
| GSK Investigational Site | San Antonio | Texas | 78240 | — |
| GSK Investigational Site | Tyler | Texas | 75702 | — |
| GSK Investigational Site | Norfolk | Virginia | 23502 | — |
| GSK Investigational Site | Everett | Washington | 98201 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
Non-U.S. locations
This page focuses on the U.S. directory. The official record also lists 174 non-U.S. sites.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04915755, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Jul 15, 2025 · Synced Jul 22, 2026
Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.
Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04915755 live on ClinicalTrials.gov.