Trial · NCT04191382

Phase 2 Window Study of SAR439859 (Amcenestrant) Versus Letrozole in Post-menopausal Patients With ER+, HER2- Pre-operative Post-menopausal Primary Breast Cancer

NCT04191382, Phase 2, Terminated, Sanofi; results first posted 2022-06-29

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Phase 2 Window Study of SAR439859 (Amcenestrant) Versus Letrozole in Post-menopausal Patients With ER+, HER2- Pre-operative Post-menopausal Primary Breast Cancer. Trials, record NCT04191382. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT04191382

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Phase 2 Window Study of SAR439859 (Amcenestrant) Versus Letrozole in Post-menopausal Patients With ER+, HER2- Pre-operative Post-menopausal Primary Breast Cancer
NCT number: NCT04191382
Status: Terminated
Phases: Phase 2
Enrollment: 105 participants, actual
Lead sponsor: Sanofi
Conditions: Breast Cancer
Interventions: Amcenestrant (SAR439859), Letrozole
First posted: 2019-12-09
Last updated: 2025-09-18
Other registries' IDs: eudract:2019-002015-26
Results first posted: 2022-06-29
Limitations and caveats: The study recruitment discontinued early based on strategic sponsor decision that was not driven by any safety concerns. No inferential statistical analysis was performed due to early termination.

Source ClinicalTrials.gov

Registered outcomes5

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Percent Change From Baseline in Ki67 Level at Day 15	Baseline, Day 15	Tumor tissue collected through a core-cut biopsy at Baseline and Day 15 was used to determine Ki67 expression. Ki67 expression was defined as the percentage of positive tumor cells assessed by central reading. Ki67 percent change from Baseline for a given participant was defined as 100\*(Ki67pre - Ki67post) / Ki67pre, where Ki67pre and Ki67post were pre-treatment and post-treatment Ki67 value of the participant. Adjusted geometric least square (LS) means and 95 percentage (%) confidence interval (CI) for the percent change were obtained from analysis of covariance (ANCOVA) model of the log proportional change i.e., log (Ki67post/ki67pre) with treatment and log-Ki67pre as fixed effect and converted by antilog transformation.
Secondary	Percentage of Participants With Percent Change From Baseline in Ki67 Greater Than or Equal to (>=) 50 Percent at Day 15	Baseline, Day 15	Tumor tissue collected through a core-cut biopsy at Baseline and Day 15 was used to determine Ki67 expression. Ki67 expression was defined as the percentage of positive tumor cells assessed by central reading. Ki67 percent change from Baseline for a given participant was defined as 100\*(Ki67pre - Ki67post) / Ki67pre, where Ki67pre and Ki67post were pre-treatment and post-treatment Ki67 value of the participant.
Secondary	Change From Baseline in Estrogen Receptor (ER) Expression as Measured by H-Score at Day 15	Baseline, Day 15	Change from Baseline in ER expression was measured by H-Score. The H-score was calculated as the sum of the percent of cells staining positive (0 to 100) multiplied staining intensity level from 0 to 3 (0=none, 1=low, 2=moderate, 3=high). Total ER expression H-score ranged from 0 to 300, where higher score indicated stronger ER expression. Change from Baseline in H-Score equals H-scorepost minus H-scorepre; where H-scorepost and H-scorepre denoted post-treatment and pre-treatment H-scores, respectively. LS-means and 95% CI were obtained from an ANCOVA model for change from baseline with treatment and baseline as fixed effect.
Secondary	Number of Participants With Abnormalities: Hematological Parameters	From first dose of study drug up to Day 14	Hematology parameters covered by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) and included: Hemoglobin, Lymphocyte, Neutrophils, Leukocytes (white blood cells), Anemia, Platelets, Eosinophils, and international normalized ratio (INR). An NCI-CTCAE Grades 1 to 5 were described as: Grade 1-Mild; asymptomatic/mild symptoms; Grade 2-Moderate; minimal, local or noninvasive intervention indicated; limiting age appropriate instrumental daily activities. Grade 3-Severe/medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; Grade 4-Life-threatening consequences; Grade 5-Death. Data for 'All Grades' were reported in this outcome measure.
Secondary	Number of Participants With Abnormalities: Clinical Chemistry	From first dose of study drug up to Day 14	Clinical chemistry laboratory parameters covered by NCI-CTCAE and included: Glucose, Potassium, Sodium, Creatinine. An NCI-CTCAE Grades 1 to 5 were described as: Grade 1-Mild; asymptomatic or mild symptoms; Grade 2- Moderate; minimal, local or noninvasive intervention indicated; limiting age appropriate instrumental daily activities; Grade 3-Severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; Grade 4-Life-threatening consequences; Grade 5-Death. Data for 'All Grades' were reported in this outcome measure.

Source ClinicalTrials.gov

Outcomes5

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Percent Change From Baseline in Ki67 Level at Day 15	Baseline, Day 15	Analysis was performed on modified intent-to-treat (mITT) population that included all enrolled participants for whom there was a confirmation of successful allocation of a randomization number by IRT, who had taken at least one study drug, and who had both Baseline and post treatment available biopsies with Ki67 values.	percent change	GEOMETRIC_LEAST_SQUARES_MEAN
SECONDARY	Percentage of Participants With Percent Change From Baseline in Ki67 Greater Than or Equal to (>=) 50 Percent at Day 15	Baseline, Day 15	Analysis was performed on mITT population.	percentage of participants	NUMBER
SECONDARY	Change From Baseline in Estrogen Receptor (ER) Expression as Measured by H-Score at Day 15	Baseline, Day 15	Analysis was performed on mITT population. Here, 'overall number of participants analyzed' signifies participants with available data for this outcome measure.	score on a scale	LEAST_SQUARES_MEAN
SECONDARY	Number of Participants With Abnormalities: Hematological Parameters	From first dose of study drug up to Day 14	Analysis was performed on safety population that included all participants who were randomly assigned to study drug and who took at least 1 dose of study drug. Here, 'Number analyzed' signifies participants with available data for each specified category for this outcome measure.	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Number of Participants With Abnormalities: Clinical Chemistry	From first dose of study drug up to Day 14	Analysis was performed on safety population. Here, 'Number analyzed' signifies participants with available data for each specified category for this outcome measure.	Participants	COUNT_OF_PARTICIPANTS

Source ClinicalTrials.gov

Results by group51

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Spread	Units
Percent Change From Baseline in Ki67 Level at Day 15	Amcenestrant 400 mg		75.9	95% Confidence Interval 67.9 to 81.9	percent change
Percent Change From Baseline in Ki67 Level at Day 15	Amcenestrant 200 mg		68.2	95% Confidence Interval 58.4 to 75.7	percent change
Percent Change From Baseline in Ki67 Level at Day 15	Letrozole 2.5 mg		77.7	95% Confidence Interval 70.0 to 83.4	percent change
Percentage of Participants With Percent Change From Baseline in Ki67 Greater Than or Equal to (>=) 50 Percent at Day 15	Amcenestrant 400 mg		74.2	95% Confidence Interval 55.4 to 88.1	percentage of participants
Percentage of Participants With Percent Change From Baseline in Ki67 Greater Than or Equal to (>=) 50 Percent at Day 15	Amcenestrant 200 mg		68.6	95% Confidence Interval 50.7 to 83.1	percentage of participants
Percentage of Participants With Percent Change From Baseline in Ki67 Greater Than or Equal to (>=) 50 Percent at Day 15	Letrozole 2.5 mg		89.7	95% Confidence Interval 72.6 to 97.8	percentage of participants
Change From Baseline in Estrogen Receptor (ER) Expression as Measured by H-Score at Day 15	Amcenestrant 400 mg		-176.7	95% Confidence Interval -201.4 to -152.0	score on a scale
Change From Baseline in Estrogen Receptor (ER) Expression as Measured by H-Score at Day 15	Amcenestrant 200 mg		-202.9	95% Confidence Interval -226.1 to -179.7	score on a scale
Change From Baseline in Estrogen Receptor (ER) Expression as Measured by H-Score at Day 15	Letrozole 2.5 mg		-32.5	95% Confidence Interval -57.2 to -7.7	score on a scale
Number of Participants With Abnormalities: Hematological Parameters	Amcenestrant 400 mg	White blood cell decreased	5		Participants

1 to 10 of 51Source ClinicalTrials.gov

See all 51 results by group

Participant flow12

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Amcenestrant 400 mg	34
Overall Study	STARTED	Amcenestrant 200 mg	36
Overall Study	STARTED	Letrozole 2.5 mg	35
Overall Study	Treated	Amcenestrant 400 mg	33
Overall Study	Treated	Amcenestrant 200 mg	36
Overall Study	Treated	Letrozole 2.5 mg	35
Overall Study	COMPLETED	Amcenestrant 400 mg	33
Overall Study	COMPLETED	Amcenestrant 200 mg	36
Overall Study	COMPLETED	Letrozole 2.5 mg	35
Overall Study	NOT COMPLETED	Amcenestrant 400 mg	1

1 to 10 of 12Source ClinicalTrials.gov

See all 12 participant flow

Adverse events48

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Constipation	Gastrointestinal disorders	Amcenestrant 400 mg	1	33	1
other	Constipation	Gastrointestinal disorders	Amcenestrant 200 mg	2	36	2
other	Constipation	Gastrointestinal disorders	Letrozole 2.5 mg	1	35	1
other	Diarrhoea	Gastrointestinal disorders	Amcenestrant 400 mg	0	33	0
other	Diarrhoea	Gastrointestinal disorders	Amcenestrant 200 mg	3	36	3
other	Diarrhoea	Gastrointestinal disorders	Letrozole 2.5 mg	3	35	3
other	Asthenia	General disorders	Amcenestrant 400 mg	2	33	2
other	Asthenia	General disorders	Amcenestrant 200 mg	2	36	2
other	Asthenia	General disorders	Letrozole 2.5 mg	0	35	0
other	Fatigue	General disorders	Amcenestrant 400 mg	2	33	2

1 to 10 of 48Source ClinicalTrials.gov

See all 48 adverse events

Adverse event totals9

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Amcenestrant 400 mg	0	33
Total, all-cause mortality	Amcenestrant 200 mg	0	36
Total, all-cause mortality	Letrozole 2.5 mg	0	35
Total, other adverse events	Amcenestrant 400 mg	11	33
Total, other adverse events	Amcenestrant 200 mg	12	36
Total, other adverse events	Letrozole 2.5 mg	14	35
Total, serious adverse events	Amcenestrant 400 mg	0	33
Total, serious adverse events	Amcenestrant 200 mg	2	36
Total, serious adverse events	Letrozole 2.5 mg	0	35

Source ClinicalTrials.gov

Papers1

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as
37950338	DERIVED

Source PubMed

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons0

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

None in this release.

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT04191382

GET https://conductscience.org/api/trials/v1/NCT04191382/results?page=2

API reference For AI assistants