Medical Information Only. Always consult your healthcare provider before enrolling in any clinical trial.
NCT04478266 · ClinicalTrials.gov registry record · Phase 3
Amcenestrant (SAR439859) Plus Palbociclib as First Line Therapy for Patients With ER (+) HER2(-) Advanced Breast Cancer
A Phase 3 study, sponsored by Sanofi.
- Terminated
- Registry status
- Phase 3
- Development phase
- 1,068
- Enrollment target
NCT04478266: Clinical Trial Phase 3 study, sponsored by Sanofi.
NCT04478266 is a Phase 3 study that was terminated before completion, run by Sanofi. The registered enrollment target is 1,068 participants, above the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (38% higher). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT04478266, a Phase 3 study, was terminated before completion, sponsored by Sanofi.
- TERMINATED
- Registry status
- Phase 3
- Development phase
- 1,068 participants
- Enrollment target
Study Summary
Primary Objective: To determine whether Amcenestrant (SAR439859) in combination with palbociclib improves progression free survival (PFS) when compared with letrozole in combination with palbociclib in participants with estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer who have not received any prior systemic anticancer therapies for advanced disease. Secondary Objective: * To compare the overall survival in both treatment arms. * To evaluate the objective response rate in both treatment arms. * To evaluate the duration of response in both treatment arms. * To evaluate the clinical benefit rate in both treatment arms. * To evaluate progression-free survival on next line of therapy. * To evaluate the pharmacokinetics of amcenestrant, and palbociclib. * To evaluate health-related quality of life in both treatment arms. * To evaluate the time to first chemotherapy in both treatment arms. * To evaluate safety in both treatment arms.
Primary Outcome
PFS was defined as the time interval (in months) from the date of randomization to the date of first documented tumor progression as per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) assessed by local radiologist or investigator, or death (due to any cause), whichever comes first. Progressive Disease (PD) as per RECIST 1.1: at least a 20 percent (%) increase in sum of diameters of target lesions, unequivocal progression of existing non-target lesions. Analysis was performed by Kaplan
Interventions
- DRUG Letrozole
- DRUG Palbociclib
- DRUG Goserelin
- DRUG Amcenestrant-matching placebo
- DRUG SAR439859
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 1,068 participants |
| Start Date | 2020-10-14 |
| Est. Completion | 2023-05-26 |
| Phase | Phase 3 |
Why NCT04478266 stopped before completion
NCT04478266 is an interventional study that assigns participants to a tested intervention. Its 1,068 participants enrollment target places it among the larger protocols in the corpus, above the 772-participant average among 15,282 other Phase 3 trials with a reported enrollment target (38% higher).
The record links to 0 conditions, and to 5 interventions - of which Letrozole is the first listed.
NCT04478266 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT04478266 about?
NCT04478266 is a clinical study titled "Amcenestrant (SAR439859) Plus Palbociclib as First Line Therapy for Patients With ER (+) HER2(-) Advanced Breast Cancer". Primary Objective: To determine whether Amcenestrant (SAR439859) in combination with palbociclib improves progression free survival (PFS) when compared with letrozole in combination with palbociclib in participants with estrogen receptor positive (ER+), human epidermal growth factor receptor 2 nega...
What is the current status of trial NCT04478266?
This trial is currently terminated. It is a Phase 3 study. The enrollment target is 1,068 participants. The study started on 2020-10-14. Estimated completion is 2023-05-26.
What interventions are being tested in trial NCT04478266?
The interventions under investigation include: Letrozole (DRUG), Palbociclib (DRUG), Goserelin (DRUG), Amcenestrant-matching placebo (DRUG), SAR439859 (DRUG).
Who is sponsoring clinical trial NCT04478266?
This trial is sponsored by Sanofi, which has 713 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT04478266's enrollment target sits among peer trials
1,068 272nd of 2000 higher than 1,727 of 2,000 other Phase 3 trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other Phase 3 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
Nationwide trials with similar profiles
Cross-condition peers matched on enrollment target and registry start date, not the same-condition list above.
Similar enrollment target
- NCT04165798 · 1,065 participants
KEYMAKER-U01 Umbrella Master Study: Studies of Investigational Agents With Either Pembrolizumab (MK-3475) Alone or With Pembrolizumab PLUS Chemotherapy in Participants With Non-small Cell Lung Cancer (NSCLC) (MK-3475-U01/KEYMAKER-U01)
- NCT06751043 · 1,072 participants · NA
Preoperative Fasting vs. Not Fasting in Critically Ill Patients
- NCT06159673 · 1,074 participants · Phase 2
ACP-204 in Adults With Alzheimer's Disease Psychosis
- NCT06658808 · 1,075 participants · NA
Efficacy-Implementation Study for PC CARES in Rural Alaska
Similar registry start date
- NCT05962346 · started 2026-12 · NA
Fetal Endoscopic Tracheal Occlusion for Congenital Diaphragmatic Hernia
- NCT07125183 · started 2026-12 · Phase 2
Study on Efficacy and Tolerability of Weekly Doxorubicin in Elderly Patients With Advanced or Metastatic Leiomyosarcoma
- NCT07292298 · started 2026-11 · Phase 2
Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinoma After Total Neoadjuvant Therapy to Improve Organ Preservation Rates
- NCT04263285 · started 2026-10 · NA
Treatment of Depression Post-SCI