Evaluation of Lasofoxifene Versus Fulvestrant in Advanced or Metastatic ER+/HER2- Breast Cancer With an ESR1 Mutation
Public ClinicalTrials.gov record NCT03781063. 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
An Open-Label, Randomized, Multicenter Study Evaluating the Activity of Lasofoxifene Relative to Fulvestrant for the Treatment of Pre- and Postmenopausal Women With Locally Advanced or Metastatic ER+/HER2- Breast Cancer With an ESR1 Mutation
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This is an open label, randomized, multicenter study evaluating the activity of lasofoxifene relative to fulvestrant for the treatment of pre- and postmenopausal women with locally advanced or metastatic ER+/HER2- breast cancer with an acquired ESR1 mutation and who have disease progression on an aromatase inhibitor (AI) in combination with a cyclin dependent kinase (CDK) 4/6 inhibitor. The primary objective is to evaluate the progression free survival (PFS) of 5 mg lasofoxifene relative to fulvestrant for the treatment of pre- and postmenopausal women with locally advanced or metastatic estrogen receptor positive (ER+)/human epidermal growth factor 2 negative (HER2-) breast cancer with an estrogen receptor 1 (ESR1) mutation. The secondary objectives are to evaluate: 1. Clinical benefit rate (CBR) and Objective Response Rate (ORR) 2. Duration of response 3. Time to response 4. Overall Survival (OS) 5. Pharmacokinetics of lasofoxifene 6. Quality of life (QoL): Quality of Life (QoL): vaginal assessment scale (VAS) and vulvar assessment scale (VuAS) questionnaires 7. Safety of lasofoxifene 8. Response to various ESR1 mutation (Y537S, Y537C, D538G, E380Q, S463P, V534E, P535H, L536H, L536P, L536R, L536Q, or Y537N).
Study identification
- NCT ID
- NCT03781063
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 100 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years and older
- Sex
- Female
- 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
- Sep 20, 2019 (Actual)
- Primary completion
- May 8, 2025 (Actual)
- Completion
- May 8, 2025 (Actual)
- Last update posted
- Jan 28, 2026
2019 – 2025
United States locations
- U.S. sites
- 42
- U.S. states
- 24
- U.S. cities
- 39
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Mayo Clinic Arizona | Phoenix | Arizona | 85054 | — |
| Yuma Regional Medical Center (JIT) | Yuma | Arizona | 85364 | — |
| City of Hope Comprehensive Cancer | Duarte | California | 91010 | — |
| Compassionate Care Research Group | Fountain Valley | California | 92708 | — |
| UCSF Cancer Center | San Francisco | California | 94115 | — |
| Rocky Mountain Cancer Centers | Longmont | Colorado | 80501 | — |
| Mayo Clinic Florida | Jacksonville | Florida | 32224 | — |
| Miami Cancer Institute | Miami | Florida | 33176 | — |
| Ocala Oncology Center (JIT) | Oscala | Florida | 34474 | — |
| Florida Cancer Specialists | Tallahassee | Florida | 32308 | — |
| The Bond Clinic Cancer & Research Center. | Winter Haven | Florida | 33880 | — |
| Emory University | Atlanta | Georgia | 30322 | — |
| Hawaii Cancer Care (JIT) | Honolulu | Hawaii | 96813 | — |
| Robert H. Lurie Comprehensive Cancer Center of Northwestern University | Chicago | Illinois | 60611 | — |
| University of Chicago | Chicago | Illinois | 60637 | — |
| Illinois Cancer Care (JIT) | Peoria | Illinois | 61615 | — |
| Carle Cancer Center | Urbana | Illinois | 61801 | — |
| Beacon Health (JIT) | South Bend | Indiana | 46601 | — |
| University of Louisville / James Graham Brown Cancer Center | Louisville | Kentucky | 40202 | — |
| FMH James M Stockman Cancer Institute (JIT) | Frederick | Maryland | 21702 | — |
| Mayo Clinic | Rochester | Minnesota | 55902 | — |
| Hattiesburg Clinic Hematology/Oncology | Hattiesburg | Mississippi | 39401 | — |
| Saint Luke's Cancer Institute | Kansas City | Missouri | 64111 | — |
| HCA Midwest Health | Kansas City | Missouri | 64132 | — |
| Washington University School of Medicine | St Louis | Missouri | 63110 | — |
| Comprehensive Cancer Centers of Nevada (JIT) | Las Vegas | Nevada | 89128 | — |
| New Jersey Cancer Care and Blood Disorders (JIT) | Belleville | New Jersey | 07203 | — |
| Summit Medical Group (JIT) | Florham Park | New Jersey | 07932 | — |
| Roswell Park Comprehensive Cancer Center | Buffalo | New York | 14263 | — |
| Duke University Medical Center | Durham | North Carolina | 27710 | — |
| TriHealth Cancer Institute | Cincinnati | Ohio | 45220 | — |
| The Ohio State University - Comprehensive Cancer Center | Columbus | Ohio | 43210 | — |
| Ohio Health (JIT) | Columbus | Ohio | 43221 | — |
| UPMC Hillman Cancer Center | Pittsburgh | Pennsylvania | 15232 | — |
| Sanford Cancer Center (JIT) | Sioux Falls | South Dakota | 57104 | — |
| Tennessee Oncology Chattanooga | Chattanooga | Tennessee | 37404 | — |
| West Cancer Center | Germantown | Tennessee | 38138 | — |
| Tennessee Oncology/SCRI | Nashville | Tennessee | 37203 | — |
| Mary Crowley Cancer Research (JIT) | Dallas | Texas | 75230 | — |
| Oncology Consultants (JIT) | Houston | Texas | 77024 | — |
| Utah Cancer Specialists (JIT) | Salt Lake City | Utah | 84102 | — |
| Peninsula Cancer Institute | Newport News | Virginia | 23601 | — |
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 9 non-U.S. sites.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT03781063, 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 Jan 28, 2026 · Synced Oct 23, 2026
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Open the official record
The complete public registry record, listed eligibility criteria, and available contact information for NCT03781063 live on ClinicalTrials.gov.