NCT04478266

Amcenestrant (SAR439859) Plus Palbociclib as First Line Therapy for Patients With ER (+) HER2(-) Advanced Breast Cancer

A Randomized, Multicenter, Double-blind Phase 3 Study of Amcenestrant (SAR439859) Plus Palbociclib Versus Letrozole Plus Palbociclib for the Treatment of Patients With ER (+), HER2 (-) Breast Cancer Who Have Not Received Prior Systemic Anti-cancer Treatment for Advanced Disease

• Status: Terminated
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 1,068 (actual)
• Sponsor: Sanofi · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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.

Detailed description

Study duration per participant was approximately 59 months, which includes a 33- month treatment period.

Conditions

• Breast Cancer

Interventions

Type	Name	Description
DRUG	Amcenestrant-matching placebo	Pharmaceutical form: Tablets Route of Administration: Oral
DRUG	SAR439859	Pharmaceutical form: Tablets Route of Administration: Oral
DRUG	Palbociclib	Pharmaceutical form: Capsules/Tablets Route of Administration: Oral
DRUG	Letrozole	Pharmaceutical form: Capsules Route of Administration: Orally
DRUG	Goserelin	Pharmaceutical form: Depot Injection Route of Administration: Subcutaneous
DRUG	Letrozole-matching placebo	Pharmaceutical form: Capsules Route of Administration: Orally

Timeline

• Start date: 2020-10-14
• Primary completion: 2022-06-28
• Completion: 2023-05-26
• First posted: 2020-07-20
• Last updated: 2025-09-11
• Results posted: 2023-07-06

Locations

249 sites across 30 countries: United States, Argentina, Australia, Austria, Belgium, Brazil, Bulgaria, Canada, Chile, China, Czechia, Finland, France, Georgia, Germany, Hungary, Italy, Japan, Netherlands, Poland, Portugal, Russia, Singapore, South Africa, South Korea, Spain, Taiwan, Turkey (Türkiye), Ukraine, United Kingdom

Regulatory

• FDA-regulated drug study