Trial Outcomes & Findings for 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 (NCT NCT05128773)
NCT ID: NCT05128773
Last Updated: 2025-09-16
Results Overview
IBCFS was defined according to standardized definitions for efficacy outcome measure in adjuvant breast cancer trials (STEEP) criteria version 2.0 as the time interval from the date of randomization to the date of the first occurrence of one of the following events: ipsilateral invasive breast tumor recurrence (IIBTR): invasive breast cancer involving the same breast parenchyma as the original primary; local-regional invasive breast cancer recurrence: invasive breast cancer in the axilla, regional lymph nodes, chest wall, and skin of the ipsilateral breast; distant recurrence: metastatic disease-breast cancer that has either been biopsy confirmed or clinically diagnosed as recurrent invasive breast cancer, invasive contralateral breast cancer; death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause.
TERMINATED
PHASE3
3 participants
From randomization to the date of first occurrence of IBCFS event (maximum exposure duration: 155 days)
2025-09-16
Participant Flow
The study was conducted at 2 active centers in Chile and China. A total of 6 participants were screened between 17 February 2022 and 11 August 2022, of which 3 participants were randomized and exposed to study treatment.
Randomization stratified by prior exposure to (neo)adjuvant aromatase inhibitor therapy, (neo)adjuvant chemotherapy \& HER2 status, CDK4/6 inhibitor (Yes/No), geographic regions, men' or peri-/pre-menopausal women vs. post-menopausal women. Study was initially planned with two treatment arms (i.e. amcenestrant \& tamoxifen), however no participants were exposed to tamoxifen arm due to premature discontinuation \& study closure by sponsor thus none of the participants were enrolled in tamoxifen arm.
Participant milestones
| Measure |
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
Participants received amcenestrant 200 mg along with tamoxifen-matching placebo orally (PO), once a day (QD) from Day 1 to Day 28 of each 28-day treatment cycle and were followed-up until diagnosis of disease recurrence per invasive breast cancer-free survival (IBCFS) definition (recurrence of one of following: Ipsilateral invasive breast tumor recurrence (IIBTR); local-regional invasive breast cancer recurrence; distant recurrence, invasive contralateral breast cancer, death) or any other withdrawal criterion whichever occurs first (maximum exposure duration: 155 days).
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Overall Study
STARTED
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3
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Overall Study
COMPLETED
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0
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Overall Study
NOT COMPLETED
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3
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Reasons for withdrawal
| Measure |
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
Participants received amcenestrant 200 mg along with tamoxifen-matching placebo orally (PO), once a day (QD) from Day 1 to Day 28 of each 28-day treatment cycle and were followed-up until diagnosis of disease recurrence per invasive breast cancer-free survival (IBCFS) definition (recurrence of one of following: Ipsilateral invasive breast tumor recurrence (IIBTR); local-regional invasive breast cancer recurrence; distant recurrence, invasive contralateral breast cancer, death) or any other withdrawal criterion whichever occurs first (maximum exposure duration: 155 days).
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Overall Study
Sponsor decision to terminate study
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3
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Baseline Characteristics
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
Baseline characteristics by cohort
| Measure |
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
n=3 Participants
Participants received amcenestrant 200 mg along with tamoxifen-matching placebo orally PO, QD from Day 1 to Day 28 of each 28-day treatment cycle and were followed-up until diagnosis of disease recurrence per IBCFS definition (recurrence of one of following: IIBTR; local-regional invasive breast cancer recurrence; distant recurrence, invasive contralateral breast cancer, death) or any other withdrawal criterion whichever occurs first (maximum exposure duration: 155 days).
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Age, Continuous
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59.7 years
STANDARD_DEVIATION 5.0 • n=3 Participants
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Sex: Female, Male
Female
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3 Participants
n=3 Participants
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Sex: Female, Male
Male
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0 Participants
n=3 Participants
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Race (NIH/OMB)
American Indian or Alaska Native
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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Race (NIH/OMB)
Asian
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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Race (NIH/OMB)
Black or African American
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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Race (NIH/OMB)
White
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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Race (NIH/OMB)
More than one race
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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Race (NIH/OMB)
Unknown or Not Reported
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0 Participants
Race data was collected for 1 participant only; and was not presented in order to protect participant confidentiality.
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PRIMARY outcome
Timeframe: From randomization to the date of first occurrence of IBCFS event (maximum exposure duration: 155 days)Population: No invasive breast cancer event data was collected because of the early termination of the study by the Sponsor and thus IBCFS was not analyzed. Therefore, no data is reported for this outcome measure.
IBCFS was defined according to standardized definitions for efficacy outcome measure in adjuvant breast cancer trials (STEEP) criteria version 2.0 as the time interval from the date of randomization to the date of the first occurrence of one of the following events: ipsilateral invasive breast tumor recurrence (IIBTR): invasive breast cancer involving the same breast parenchyma as the original primary; local-regional invasive breast cancer recurrence: invasive breast cancer in the axilla, regional lymph nodes, chest wall, and skin of the ipsilateral breast; distant recurrence: metastatic disease-breast cancer that has either been biopsy confirmed or clinically diagnosed as recurrent invasive breast cancer, invasive contralateral breast cancer; death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: From randomization to the date of first occurrence of IDFS event (maximum exposure duration: 155 days)Population: No Invasive disease event data was collected because of the early termination of the study by the Sponsor and thus IDFS was not analyzed. Therefore, no data is reported for this outcome measure.
IDFS according to STEEP criteria version 2.0 was defined as the time interval from the date of randomization to the date of the first occurrence of one of the following events: IIBTR: invasive breast cancer involving the same breast parenchyma as the original primary; local-regional invasive breast cancer recurrence: invasive breast cancer in the axilla, regional lymph nodes, chest wall, and skin of the ipsilateral breast; distant recurrence: metastatic disease-breast cancer that has either been biopsy confirmed or clinically diagnosed as recurrent invasive breast cancer; invasive contralateral breast cancer; second non-breast primary invasive cancer; death attributable to any cause, including breast cancer, non-breast cancer, or unknown cause.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: From randomization to the date of the first occurrence of distant recurrence or death due to any cause, whichever occurs first (maximum exposure duration: 155 days)Population: No distant recurrence event data was collected because of the early termination of the study by the Sponsor and thus DRFS was not analyzed. Therefore, no data is reported for this outcome measure.
DRFS according to STEEP criteria version 2.0 was defined as the time interval from the date of randomization to the date of the first occurrence of one of the following events: distant recurrence or death attributable to any cause (including breast cancer, non-breast cancer, or unknown cause).
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: From randomization to the date of the first occurrence of local/regional ipsilateral recurrence or breast cancer or death due to any cause, whichever occurs first (maximum exposure duration: 155 days)Population: No locoregional recurrences event data was collected because of the early termination of the study by the Sponsor and thus LRRFS was not analyzed. Therefore, no data is reported for this outcome measure.
LRRFS was defined as the time interval from the date of randomization to the date of the first occurrence of one of the following events: local/regional ipsilateral recurrence, invasive contralateral breast cancer or death attributable to any cause (including breast cancer, non-breast cancer, or unknown cause).
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: From randomization to the date of death due to any cause (maximum exposure duration: 155 days)Population: Analysis was performed on randomized population.
Overall survival was defined as the time interval from the date of randomization to the date of documented death (due to any cause).
Outcome measures
| Measure |
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
n=3 Participants
Participants received amcenestrant 200 mg along with tamoxifen-matching placebo orally PO, QD from Day 1 to Day 28 of each 28-day treatment cycle and were followed-up until diagnosis of disease recurrence per IBCFS definition (recurrence of one of following: IIBTR; local-regional invasive breast cancer recurrence; distant recurrence, invasive contralateral breast cancer, death) or any other withdrawal criterion whichever occurs first (maximum exposure duration: 155 days).
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Overall Survival (OS)
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NA months
Median, upper and lower limit of 95% confidence interval (CI) was not estimable as no event was collected.
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SECONDARY outcome
Timeframe: From randomization to the date of death due to breast cancer (maximum exposure duration: 155 days)Population: Analysis was performed on randomized population.
BCSS was defined as the time interval from the date of randomization to the date of documented death attributable to breast cancer cause.
Outcome measures
| Measure |
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
n=3 Participants
Participants received amcenestrant 200 mg along with tamoxifen-matching placebo orally PO, QD from Day 1 to Day 28 of each 28-day treatment cycle and were followed-up until diagnosis of disease recurrence per IBCFS definition (recurrence of one of following: IIBTR; local-regional invasive breast cancer recurrence; distant recurrence, invasive contralateral breast cancer, death) or any other withdrawal criterion whichever occurs first (maximum exposure duration: 155 days).
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Breast Cancer-specific Survival (BCSS)
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NA months
Median, upper and lower limit of 95% CI was not estimable as no event was collected.
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SECONDARY outcome
Timeframe: Baseline, Cycle 3, 4, 5, 6, 7, 10, 13, 16, 19, 22, 25, 28, 34, 40, 46, 52, & 58 and at end of treatment (maximum exposure: any day up to 155 days)Population: Evaluable data was collected for 2 participants only; and thus, was not presented to protect participant confidentiality.
FACT-GP5 is a single-item from the Functional Assessment of Cancer Therapy-General (FACT-G) scale in which participants report their bother by side effects of treatment response. Responses were given on a 5- point Likert-type scale with score range from 0 (not at all bothered by side effect) to 4 (very much bothered by side effects). Higher scores indicate a higher degree of side effect bother. End of treatment (EOT) visit was 30 days after the last IMP administration.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: Baseline, Cycle 2, 4, 7, 10, 13, 16, 19, 22, 25, 28, 34, 40, 46, 52, & 58 and at end of treatment (maximum exposure: any day up to 155 days)Population: Evaluable data was collected for 1 participant only; and was not presented to protect participant confidentiality.
QLQ-BR23: 23-item disease-specific participant reported outcome measure of disease-related symptoms, treatment-related symptoms, and functioning relevant to participants with breast cancer. It consisted of 4 functional scales (body image, sexual enjoyment, sexual functioning, future perspective) and 4 symptoms scales (systemic therapy side effects, upset by hair loss, arm symptoms, breast symptom). Systemic therapy side effects scale consisted of 7 items \& each item was rated on a 4-point scale with responses as: 1= not at all, 2= a little, 3= quite a bit, 4= very much. A linear transformation was applied to raw scores so that all transformed scores are within 0 to 100. A higher score denotes worse symptoms for the systemic therapy side effects symptom scale. Negative change from baseline= improvement of side effects, positive change = deterioration. EOT visit was 30 days after last IMP administration.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: Baseline, Cycle 2, 4, 7, 10, 13, 16, 19, 22, 25, 28, 34, 40, 46, 52, & 58 and at end of treatment (maximum exposure: any day up to 155 days)Population: Evaluable data was collected for 1 participant only; and was not presented to protect participant confidentiality.
EORTC-QLQ-C30: cancer-specific instrument with 30 questions for evaluation of new chemotherapy \& assessment of participant reported outcome. EORTC QLQ-C30 included global health status/quality of life (GHS/QOL), functional scales (physical, role, cognitive, emotional, social), symptom scales (fatigue, pain, nausea/vomiting), and 6 single items (dyspnea, appetite loss, insomnia, constipation, diarrhea, financial difficulties). Most questions from QLQ-C30 were rated on a 4-point scale (1/Not at All to 4/Very Much), except Items 29-30, which comprise GHS scale and were rated on a 7-point scale (1/Very Poor to 7/Excellent). All scales were transformed from raw scores to linear scales ranging 0 to 100. A high score represented a favorable outcome with a best quality of life for participant. EOT visit was 30 days after last IMP administration.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: Pre-dose on Cycle 2 Day 1, Cycle 7 Day 1, Cycle 13 Day 1 and Cycle 25 Day 1Population: Data was not collected and analyzed for this outcome measure due to the early termination of the study by the Sponsor.
Outcome measures
Outcome data not reported
Adverse Events
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Amcenestrant 200 mg + Tamoxifen-Matching Placebo
n=3 participants at risk
Participants received amcenestrant 200 mg along with tamoxifen-matching placebo orally PO, QD from Day 1 to Day 28 of each 28-day treatment cycle and were followed-up until diagnosis of disease recurrence per IBCFS definition (recurrence of one of following: IIBTR; local-regional invasive breast cancer recurrence; distant recurrence, invasive contralateral breast cancer, death) or any other withdrawal criterion whichever occurs first (maximum exposure duration: 155 days).
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Gastrointestinal disorders
Dry Mouth
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33.3%
1/3 • Number of events 1 • Adverse Events (AE) data was collected from first dose of study drug administration up to 30 days after the last treatment administration (maximum exposure duration:155 days)
Analysis was performed on all randomized population.
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Infections and infestations
Nail Infection
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33.3%
1/3 • Number of events 1 • Adverse Events (AE) data was collected from first dose of study drug administration up to 30 days after the last treatment administration (maximum exposure duration:155 days)
Analysis was performed on all randomized population.
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Metabolism and nutrition disorders
Anorexia
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33.3%
1/3 • Number of events 1 • Adverse Events (AE) data was collected from first dose of study drug administration up to 30 days after the last treatment administration (maximum exposure duration:155 days)
Analysis was performed on all randomized population.
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Metabolism and nutrition disorders
Glucose Intolerance
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33.3%
1/3 • Number of events 1 • Adverse Events (AE) data was collected from first dose of study drug administration up to 30 days after the last treatment administration (maximum exposure duration:155 days)
Analysis was performed on all randomized population.
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Musculoskeletal and connective tissue disorders
Myalgia
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33.3%
1/3 • Number of events 1 • Adverse Events (AE) data was collected from first dose of study drug administration up to 30 days after the last treatment administration (maximum exposure duration:155 days)
Analysis was performed on all randomized population.
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Nervous system disorders
Headache
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33.3%
1/3 • Number of events 1 • Adverse Events (AE) data was collected from first dose of study drug administration up to 30 days after the last treatment administration (maximum exposure duration:155 days)
Analysis was performed on all randomized population.
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Additional Information
Trial Transparency Team
Sanofi aventis recherche & développement
Results disclosure agreements
- Principal investigator is a sponsor employee The Sponsor supports publication of clinical trial results but may request that investigators temporarily delay or alter publications in order to protect proprietary information. The Sponsor may also require that the results of multicenter studies be published only in their entirety and not as individual site data.
- Publication restrictions are in place
Restriction type: OTHER