Study of Amcenestrant (SAR439859) Versus Tamoxifen for Patients With Hormone Receptor-positive (HR+) Early Breast Cancer, Who Have Discontinued Adjuvant Aromatase Inhibitor Therapy Due to Treatment-related Toxicity

Investigating the Efficacy and Safety of an Investigational Medication Compared with Tamoxifen in Early Breast Cancer

Not Recruiting
18 years or above
All
Phase 3
3 participants needed

Study Overview

This was a phase III, randomized, double blind, multicenter, 2-arm study evaluating the efficacy and safety of amcenestrant compared with tamoxifen in participants with hormone receptor-positive early breast cancer who discontinued adjuvant aromatase inhibitor (AI) therapy due to treatment related toxicity. The primary objective was to demonstrate the superiority of amcenestrant versus tamoxifen on invasive breast cancer-free survival.

The treatment duration per participant was to be 5 years, followed with a subsequent 5-years follow-up period. For the treatment period, visits were scheduled at the start of treatment, then at 4 weeks and 12 weeks after treatment start, and then every 12 weeks for the first 2 years and every 24 weeks for year 3 to 5. For the follow-up period, visits were scheduled 30 days after last treatment and then every 12 months. Three periods were planned:

  • A screening period of up to 28 days,
  • A treatment period of up to 5 years,
  • A follow-up period of up to 5 years.

Study Details

Study duration per participant was to be approximately 10 years.

Eligibility Criteria

You may be eligible for this study if you meet the following criteria:

  • Conditions: Breast Cancer
  • Age: 18 years or above
  • Gender: All

Inclusion Criteria:

  • Adult participants with histologically confirmed diagnosis of adenocarcinoma of the breast with documentation of hormone receptor-positive status, irrespective of human epidermal growth factor receptor 2 (HER2) status NOTE: Participants with HER2-positive breast cancer were eligible only if they had completed their adjuvant anti-HER2 treatment and chemotherapy.
  • With Stage IIB or Stage III (invasive breast cancer) who had undergone breast surgery and adjuvant radiation (if indicated) for the current malignancy.
  • Who had received prior aromatase inhibitors (AIs) (letrozole, anastrozole or exemestane or any sequence thereof) per the following:
        Adjuvant AI therapy was discontinued due to AI treatment-related toxicity; Minimum of 6
        months duration and maximum of 30 months duration (from initiation of first AI if there was
        a switch between AIs) of AI therapy was required.
          -  Absence of locoregional and/or advanced/metastatic disease
          -  Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1
          -  Capable of giving signed informed consent.
        Exclusion Criteria:
          -  Medical history or ongoing gastrointestinal disorders potentially affecting the
             absorption of amcenestrant and/or tamoxifen. Participants unable to swallow normally
             or unable to take tablets and capsules. Predictable poor compliance to oral treatment.
             Active inflammatory bowel disease or chronic diarrhea, active hepatitis A/B/C, hepatic
             cirrhosis, short bowel syndrome, or any upper gastrointestinal surgery including
             gastric resection or banding procedures.
          -  History of prior breast cancer treated with AI.
          -  Any other solid tumor or lymphoma diagnosis was not allowed except if the participant
             had been free from disease for equal to greater than (=>5) years.
          -  Pregnant or nursing women, or women of child-bearing potential without a negative
             pregnancy test prior to randomization.
          -  Participants with unrecovered acute toxic effects of prior AI therapy or surgical
             procedures.
          -  Uncontrolled intercurrent illness, including psychiatric conditions that would have
             limited compliance with study requirements.
          -  Treatment with any selective estrogen receptor degrader (SERD), tamoxifen or
             toremifene were not allowed as prior adjuvant therapy but could have been used as
             neoadjuvant therapy for a total duration of 3 months. Participants who were treated
             with a SERD, tamoxifen or toremifene in the neoadjuvant setting and who experienced
             disease progression were not allowed. Prior treatment with raloxifene or tamoxifen for
             bone health, risk reduction, or a prior breast cancer was allowed provided this was
             discontinued at least 3 years before diagnosis of current breast cancer.
          -  Ongoing treatment with HER2 directed therapy. Appropriate wash out between the last
             dose of HER2 directed therapy and randomization should have been at least 4 weeks.
        The above information was not intended to contain all considerations relevant to a
        potential participation in a clinical trial.

Updated on 13 Dec 2024. Study ID: NCT05128773

This study investigates the effectiveness and safety of an investigational medication compared with tamoxifen in adults with hormone receptor-positive early breast cancer. This type of breast cancer grows in response to hormones like estrogen. The study focuses on participants who stopped using a type of medication called an aromatase inhibitor due to side effects. The main goal is to see if the investigational medication can improve the time participants remain free from invasive breast cancer compared to tamoxifen.

Participants will be randomly assigned to one of two study arms: one receiving the investigational medication and the other receiving tamoxifen. Both groups will take their assigned medication for up to 5 years. Visits will be scheduled at the start of treatment, then at specific intervals to monitor the participants' health and any side effects. A follow-up period is planned after the treatment phase to continue monitoring participants' health.

  • Who can participate: Adults with hormone receptor-positive breast cancer who have stopped aromatase inhibitor therapy due to side effects can participate. They should have Stage IIB or Stage III cancer and a good performance status.
  • Study details: Participants will take either the investigational medication or tamoxifen for up to 5 years. The study will monitor participants' health and any side effects.
  • Study timelines and visits: The study will last 10 years. The study requires 24 visits.