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

Trial number:
Trial phase:
Study type:
Targeted therapy, Hormonal therapy
Overall status:

Study start date

October, 2020

Scientific title

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


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.

Inclusion criteria :

Adult participants with loco-regional recurrent or metastatic disease not amenable to curative treatment.Confirmed diagnosis of ER+/HER2- breast cancer. No prior systemic treatment for loco-regional recurrent or metastatic disease. Measurable disease evaluable per Response Evaluation Criterion in Solid Tumors (RECIST) v.1.1 or non-measurable bone-only disease. Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Participants should be willing to provide tumor tissue. Capable of giving informed consent.

Exclusion criteria:

Known active brain metastases.Prior neo (adjuvant) treatment with any selective estrogen receptor degrader (SERD). Inadequate organ and marrow function. Disease recurrence while on, or within 12 months of completion of (neo)adjuvant endocrine therapy. Pregnant, breastfeeding, or woman of childbearing potential unwilling to use recommended contraception methods. Male participants who disagree to follow contraception. Participants with advanced, symptomatic visceral spread, that are at risk of life-threatening complications in the short term. Participants with significant concomitant illness.

The above information was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.

Study design

Primary purpose: Treatment, Allocation: Randomized, Intervention model: Parallel Assignment, Masking: Quadruple, Subject masked: Yes, Caregiver masked: Yes, Investigator masked: Yes, Outcomes assessor masked: Yes,


Breast Cancer

Other study ID numbers

EFC15935; 2020-001824-33; U1111-1233-0486

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