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TerminatedNCT03284957AMEERA-1Updated Nov 24, 2025Results posted

Phase 1/2 Study of Amcenestrant (SAR439859) Single Agent and in Combination With Other Anti-cancer Therapies in Postmenopausal Women With Estrogen Receptor Positive Advanced Breast Cancer

A Phase 1/2 interventional study of Amcenestrant and Palbociclib in Breast Cancer, sponsored by Sanofi. Terminated at 25 sites in 10 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-11-24.

Sponsored by Sanofi · Phase 1/2, Interventional, and Treatment

Why this study was terminated
Sponsor decision to prematurely stop the study, not linked to any safety concern.
Phase
Phase 1/2
Study type
Interventional
Enrollment
136
Allocation
Randomized
Ages
18 Years and older
Sex
Female
01

Study summary

Primary Objectives:

Dose Escalation:

  • To assess the incidence rate of dose-limiting toxicity (DLT) and to determine the maximum tolerated dose (MTD) as well as the recommended dose (RD) of amcenestrant administered as monotherapy and in combination with palbociclib
  • To assess the incidence rate of DLT and determine the RD of everolimus or abemaciclib in combination with the selected amcenestrant dose for the combination therapy

Safety Run-In:

- To confirm the RD of amcenestrant in combination with alpelisib

Dose Expansion:

  • Antitumor activity using objective response rate (ORR)
  • Overall safety profile of amcenestrant administered in combination with palbociclib, alpelisib, everolimus, and abemaciclib

Secondary Objectives:

  • Overall safety profile of amcenestrant monotherapy and in combination
  • Pharmacokinetic (PK) profile of amcenestrant administered as monotherapy or in combination and PK profile of palbociclib, alpelisib, everolimus and abemaciclib
  • Antitumor activity using ORR, the clinical benefit rate (CBR) and progression free survival (PFS)
  • Time to first tumor response
  • Residual ER availability with positron emission tomography (PET) scan [(18)F] fluoroestradiol (18F-FES) uptake with increasing doses of amcenestrant
  • Food effect on PK of amcenestrant
  • Potential induction/inhibition effect of amcenestrant on cytochrome P450 (CYP) 3A using 4b-OH cholesterol
Read the detailed description

Duration of the study, per participant, will include eligibility period (screening period) of up to 4 weeks (28 days), treatment period (at least 1 cycle [28 days] of study treatment), and end of treatment (EOT) visit at least 22 to 30 days (or until the participant receives another anticancer therapy, whichever is earlier) following the last study treatment administration. The expected enrollment period is approximately 60 months.

02

Conditions studied

  • Breast Cancer

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03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Inclusion criteria

  • Participants must be postmenopausal women
  • Histological diagnosis of breast adenocarcinoma
  • Locally advanced or metastatic disease
  • Either primary tumor or any metastatic site to be positive for Estrogen Receptors (ER+) and negative for HER2 (HER2-) receptor
  • Participants must have been previously treated with at least 6 months of endocrine therapy for advanced disease:
  • Dose Escalation study parts:

Arm #3 - Part F and Arm #5 - Part J: up to 2 prior lines of either single endocrine therapy and/or endocrine-based therapy Arm #4 -H: up to 2 prior lines of either single endocrine therapy and/or endocrine-based therapy (exemestane not allowed)

- Dose Expansion study parts: Arm #2: - Part D: no more than 2 prior lines of advanced endocrine therapy for advanced disease are allowed Arm #3, - Part G: patients must have received and progressed on the combination of Aromatase Inhibitors (AI) + CDK4/6 inhibitor as the first line (1L) treatment for advanced disease Arm #4 - Part I: participants must have received and progressed on the combination of Aromatase Inhibitors (AI) +CDK4/6 Inhibitor as the first line (1L) treatment for advanced disease (exemestane not allowed) Arm#5: - Part K: up to 1 prior line of a single endocrine therapy for advanced disease Note: Additional patients who relapsed while on previous adjuvant endocrine therapy that was initiated ≥24 months ago, or relapsed \< 12 months after completion of adjuvant endocrine therapy are also allowed for Arms #2, #3, #4, and #5 (Parts C, D, F, G, H, I, J and K).

  • Participants previously treated with chemotherapy for advanced disease: no more than 3 prior chemotherapeutic regimens in Arm #1 Part A, and no more than 1 prior chemotherapeutic regimen in Arms #1, #2, #3, #4, and #5 (Parts B, C, D, F, H and J respectively); prior chemotherapy for advanced disease is not allowed in dose expansion of Arms #3, #4, and #5 (Part G, I and K respectively).
  • Measurable lesion

Exclusion criteria

Exclusion criteria:

  • Medical history or ongoing gastrointestinal disorders that could affect absorption of oral study drugs (including difficulties with swallowing capsules)
  • Participants with any other cancer (except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer or any other cancer from which the participant has been disease free for >3 years)
  • Participants with known brain metastases
  • Treatment with anticancer agents (including investigational drugs) less than 2 weeks before first study treatment starts (less than 4 weeks if the anticancer agents were antibodies)
  • Prior treatment with another selective ER down-regulator (SERD)
  • Dose Escalation study parts (Parts F, H and J): SERDs are not allowed except for fulvestrant which will need a washout of at least 6 weeks prior to the first study drug administration
  • Dose Expansion study parts (Parts G, I and K): prior (last) treatment with any SERD including fulvestrant will not be allowed
  • Inadequate hematological and biochemical lab tests
  • Participants with Gilbert disease
  • Treatment with HIV-antiviral, antifungal and antioxidant agents less than 2 weeks before study treatment starts
  • Treatment with strong P450 (CYP) 3A inducers within 2 weeks before first study treatment
  • Treatment with OATP1B1/B3 sensitive substrates and which cannot be replaced
  • Arm#2 Treatment with strong CYP3A inhibitors within 2 weeks before first study treatment starts
  • More than one prior advanced cyclin-dependent kinase (CDK) 4/6 inhibitor-based therapy in Arm #1, Arm #2 (Part C), Arm #3 (Parts F and G), and Arm#4 (Part H).
  • Arm #2, #3, #4 and #5 (Parts C, D, F, G, H, I, J and K) only: participants with concurrent or history of pneumonitis
  • Arm #3, #4 and #5 (Parts F, G, H, I, J and K) only: prior treatment therapies that target the PI3K axis (mTOR inhibitors, AKT inhibitors, PI3K inhibitors)
  • Arm #3 and #4 (Parts F, G, H and I) only: participants with diabetes mellitus type-I or uncontrolled diabetes mellitus type-II: ie, fasting plasma glucose ≥ 140mg/dl (7.7 mmol/l) or HbA1C > 6.2%
  • Arm #3 and #4 (Parts F, G, H and I) only: history of severe cutaneous reaction (eg. Stevens-Johnson syndrome [SJS], erythema multiforme [EM]), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms [DRESS].
  • Arm #3 (Parts F and G) only: ongoing osteonecrosis of jaw
  • Arm #4 (Parts H and I) only: any active, untreated or uncontrolled infection (e.g. viral, bacterial, fungal etc.)
  • Arm #4 (Parts H and I) only: participants with active and uncontrolled stomatitis, angioedema due to concomitant treatment with ACE inhibitors, impaired wounds
  • Arm #4 (Parts H and I) only: uncontrolled hypercholesterolemia, hypertriglyceridemia and hyperglycemia in non-diabetic participants
  • Arm #4 (Parts H and I) only: treatment with strong or moderate CYP3A4 inhibitors, strong CYP3A4 inducers and/or P-gp inhibitors within 2 weeks before the first study treatment administration or 5 elimination half-lives, whichever is the longest
  • Arm #5 (Parts J and K) only: history or current (controlled/not controlled) venous thromboembolism (i.e. deep vein thrombosis (DVT), pulmonary embolism (PE), cerebral venous sinus thrombosis (CVST)

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

04

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
136 participants (actual)

Study arms

  • Experimental
    Amcenestrant Monotherapy: Arm #1 Part A Dose Escalation, Part B Dose Expansion

    Part A: Amcenestrant will be administered orally once daily (QD). Treatment will begin with an identified starting dose. Administration of higher doses to subsequent participants is based on occurrence of DLTs and evaluation of target saturation and PK parameters at initial and subsequent doses, until maximum administered dose (MAD) is reached. Drug will be administered in a 28-day cycle. Part B: When the dose escalation phase ends, the recommended dose will be administered for the expansion cohort. Drug will be administered in a 28-day cycle.

    Drug: Amcenestrant

  • Experimental
    Amcenestrant/Palbociclib: Arm #2 Part C Dose Escalation, Part D Dose Expansion

    Part C: Amcenestrant will be administered in combination with palbociclib: amcenestrant starting oral daily dose will be one dose level below monotherapy RD and palbociclib will be dosed at fixed standard dose. Administration of higher dose of amcenestrant (with standard palbociclib dose) to subsequent participants will be based on occurrence of DLTs at initial and subsequent doses, until MAD of amcenestrant is reached. Drugs will be administered in a 28-day cycle (palbociclib will be administered for 21 days of cycle). Part D: Based on the results in Part C, participants will be administered either: 1) a determined amcenestrant dose (RD) with standard dose of palbociclib in combination therapy, or 2) one of two randomized dose levels of amcenestrant with standard dose of palbociclib in combination therapy. Drugs will be administered in a 28-day cycle (palbociclib will be administered for 21 days of cycle).

    Drug: Amcenestrant · Drug: Palbociclib

  • Experimental
    Amcenestrant/Alpelisib: Arm #3 Part F Safety Run-In, Part G Dose Expansion

    Part F: Amcenestrant will be administered in combination with alpelisib at a fixed standard dose. Additional dose levels of amcenestrant with alpelisib could be explored if needed based on the safety and PK results. Lower dose of alpelisib could be explored based on the PK results and safety profile from the initial combination administration. Both amcenestrant and alpelisib will be administered in a 28-day cycle. Part G: Based on the conclusion in Part F, participants will be administered the determined RD of amcenestrant and alpelisib given in the combination in an expansion cohort. Both study drugs will be administered in a 28-day cycle.

    Drug: Amcenestrant · Drug: Alpelisib

  • Experimental
    Amcenestrant/Everolimus: Arm #4 Part H Dose Escalation, Part I Dose Expansion

    Part H: Amcenestrant will be administered at the determined RD in combination with 2 dose levels of everolimus. Additional dose levels of amcenestrant with everolimus could be explored if needed based on the safety and PK results. Both amcenestrant and everolimus will be administered in a 28-day cycle. Part I: Based on the conclusion in Part H, participants will be administered the determined RD of amcenestrant and RD of everolimus given in the combination in an expansion cohort. Both study drugs will be administered in a 28-day cycle.

    Drug: Amcenestrant · Drug: Everolimus

  • Experimental
    Amcenestrant/Abemaciclib: Arm #5 Part J Dose Escalation, Part K Dose Expansion

    Part J: Amcenestrant will be administered at the determined RD in combination with 2 dose levels of abemaciclib. Additional dose levels of amcenestrant with abemaciclib could be explored if needed based on the safety and PK results. Both amcenestrant and abemaciclib will be administered in a 28-day cycle. Part K: Based on the conclusion in Part J, participants will be administered the determined RD of amcenestrant and RD of abemaciclib given in the combination in an expansion cohort. Both study drugs will be administered in a 28-day cycle.

    Drug: Amcenestrant · Drug: Abemaciclib

Interventions

  • DrugAmcenestrant

    Pharmaceutical form: capsule Route of administration: oral

    Also known as: SAR439859

  • DrugPalbociclib

    Pharmaceutical form: capsule Route of administration: oral

    Also known as: Ibrance®

  • DrugAlpelisib

    Pharmaceutical form: tablet Route of administration: oral

    Also known as: Piqray®

  • DrugEverolimus

    Pharmaceutical form: tablet

  • DrugAbemaciclib

    Pharmaceutical form: tablet

    Also known as: Verzenio®

05

What researchers measure

Primary outcomes

  1. Parts A, C, F, H, J: Number of Participants With Study Treatment-Related Dose-Limiting Toxicities (DLTs)

    DLTs: any treatment-emergent adverse event(TEAE) related to study treatment per National Cancer Institute Common Terminology Criteria for AE scale version (v) 4.03:Grade(G)≥3 nonhematological toxicity except:G3 nausea/vomiting resolved to G≤1 in 48 hours(h),G3 diarrhea with therapy and lasting\<48h,G3 hyperglycemia resolved to G≤1 in 48h(Part H);G≥3 hematological toxicity except:G3 anemia,G4 neutropenia\<7days(d),G3 neutropenia without fever/infection,G3 thrombocytopenia without bleeding;elevated total serum bilirubin(BL)\>2xupper limit of normal(except Part F),Part F:G3 hyperglycemia not resolved to G≤2 in 7d after antidiabetic treatment,G2 hyperglycemia not resolved to G≤1 in 21d,G2 alanine aminotransferase(ALT) increase in conjunction with total blood BL G≥2 without liver metastases,G≥3 ALT/aspartate aminotransferase increase for\>4d,G3 rash/maculopapular rash not resolved to G≤1 in 7d;treatment related toxicity causing≥7d omission in Cycle 1 or \>2 weeks delay in Cycle 2 in Part C.

    Time frame: Cycle 1 Day 1 to Cycle 1 Day 28 (cycle duration=28 days)

  2. Part B: Objective Response Rate (ORR) as Determined by Independent Central Review (ICR)

    ORR was determined by dividing the number of participants who achieved confirmed complete response (CR) or partial response (PR) by the number of participants from the analysis population. ORR was assessed by ICR according to response evaluation criteria in solid tumors (RECIST) v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 millimeters (mm). PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks

  3. Parts D, I: Number of Participants With Treatment-Emergent Adverse Events and Treatment-Emergent Serious Adverse Events (TESAEs)

    AE was any untoward medical occurrence in a participant or clinical investigation participant administered with a pharmaceutical product and which did not necessarily had a causal relationship with the treatment. SAE was any untoward medical occurrence that at any dose, resulted in death, was life-threatening, required in-patient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was a medically important event. TEAEs were AEs that developed or worsened or became serious during the treatment period.

    Time frame: From first dose of study treatment administration (Day 1) up to 30 days after the last dose of study treatment administration; approximately 232 weeks for Part D and 11 weeks for Part I

Secondary outcomes

  1. Parts A, B, C, F, H, J: Number of Participants With Treatment-Emergent Adverse Events and Treatment-Emergent Serious Adverse Events

    AE was any untoward medical occurrence in a participant or clinical investigation participant administered with a pharmaceutical product and which did not necessarily had a causal relationship with the treatment. SAE was any untoward medical occurrence that at any dose, resulted in death, was life-threatening, required in-patient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was a medically important event. TEAEs were AEs that developed or worsened or became serious during the treatment period.

    Time frame: From first dose of study treatment administration (Day 1) up to 30 days after the last dose of study treatment administration; approximately 94, 282, 144, 96, 59, 130 weeks for Parts A, B, C, F, H, J respectively

  2. Parts A, B, C, D, F, H, I, J: Objective Response Rate as Determined by Investigators/Local Radiologists

    ORR was determined by dividing the number of participants who achieved confirmed CR or PR by the number of participants from the analysis population. ORR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively

  3. Parts A, B, C, D, F, H, I, J: Clinical Benefit Rate (CBR) as Determined by Investigators/Local Radiologists

    CBR was determined by dividing the number of participants who achieved confirmed CR, PR as best overall response (BOR) or stable disease (SD) for ≥24 weeks by the number of participants from the analysis population. CBR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest sum diameters while on study.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively

  4. Part B: Clinical Benefit Rate as Determined by Independent Central Review

    CBR was determined by dividing the number of participants who achieved confirmed CR, PR as BOR or SD for ≥24 weeks by the number of participants from the analysis population. CBR was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks

  5. Parts A, B, C, D, F, H, I, J: Duration of Response (DOR) as Determined by Investigators/Local Radiologists

    DOR was defined as the time interval from the date of the first occurrence of confirmed CR or PR to the date of the first documentation of disease progression or death due to disease progression, whichever occurred first. DOR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study, an absolute increase of at least 5 mm in the sum. Appearance of 1 or more new lesions was also considered progression.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively

  6. Part B: Duration of Response as Determined by Independent Central Review

    DOR was defined as the time interval from the date of the first occurrence of confirmed CR or PR to the date of the first documentation of disease progression or death due to disease progression, whichever occurred first. DOR was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study, an absolute increase of at least 5 mm in the sum. Appearance of 1 or more new lesions was also considered progression.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks

  7. Parts A, B, C, D, F, H, I, J: Progression-Free Survival (PFS) as Determined by Investigators/Local Radiologists

    PFS was defined as time from the date of the first treatment intake to the date of the first documentation of objective PD according to RECIST v1.1, clinical PD or death due to any cause, whichever occurred first. PFS was assessed by investigators/local radiologists. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study, an absolute increase of at least 5 mm in the sum. Appearance of 1 or more new lesions was also considered progression.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively

  8. Parts A, B, C, D: Objective Response Rate as Determined by Investigators/Local Radiologists According to Estrogen Receptor 1 (ESR1) Mutation at Baseline

    ORR was determined by dividing the number of participants who achieved confirmed CR or PR by the number of participants from the analysis population. ORR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. The ESR1 gene mutation status (mutated or wild-type) was analyzed by multiplex droplet digital polymerase chain reaction (ddPCR) after extraction of plasma circulating deoxyribonucleic acid (DNA). The baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

    Time frame: From Baseline (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228 weeks for Parts A, B, C, D respectively

  9. Part B: Objective Response Rate as Determined by Independent Central Review According to Estrogen Receptor 1 Mutation at Baseline

    ORR was determined by dividing the number of participants who achieved confirmed CR or PR by the number of participants from the analysis population. ORR was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. The ESR1 gene mutation status (mutated or wild-type) was analyzed by multiplex ddPCR after extraction of plasma circulating DNA. The baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

    Time frame: Baseline (Day 1) up to maximum exposure of study treatment; approximately 278 weeks

  10. Parts A, B, C, D: Clinical Benefit Rate as Determined by Investigators/Local Radiologists According to Estrogen Receptor 1 Mutation at Baseline

    CBR was determined by dividing the number of participants who achieved confirmed CR, PR as BOR or SD for ≥24 weeks by the number of participants from analysis population. CBR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. The ESR1 gene mutation status (mutated or wild-type) was analyzed by multiplex ddPCR after extraction of plasma circulating DNA. Baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

    Time frame: From Baseline (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228 weeks for Parts A, B, C, D respectively

  11. Parts B, D, I: Time to First Confirmed Response as Determined by Investigators/Local Radiologists

    The time to first confirmed response was defined as the time interval from the date of first administration of the study treatment to the date of the first occurrence of confirmed CR or PR. The time to first confirmed response was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively

  12. Part B: Time to First Confirmed Response as Determined by Independent Central Review

    The time to first confirmed response was defined as the time interval from the date of first administration of the study treatment to the date of the first occurrence of confirmed CR or PR. The time to first confirmed response was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

    Time frame: From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks

  13. Part A: Number of Participants With 18F-Fluorestradiol Positron Emission Tomography Percentage Reduction

    Inhibition of estrogen receptor (ER) occupancy investigation using 18F-FES-PET imaging was a limited invasive procedure that allowed assessment of ER presence by assessing the binding of radiolabeled estradiol, the ligand of ER (signal extinction). Number of participants with percentage reduction (≥90%, ≥70%, ≥50% and ≥30%) in 18F-FES-PET signal are reported. The baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

    Time frame: Baseline (within 3 days or more prior to Day 1) and between Day 11 and Day 15 of Cycle 1 (cycle duration=28 days)

  14. Parts A, B, C, D, H, I, J: Time Interval Between Administration and the Sampling Preceding the First Concentration Above the Lower Limit of Quantification (LLOQ) (Tlag) of Amcenestrant After a Single Oral Administration

    Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. LLOQ value for amcenestrant was 5 nanograms per milliliter (ng/mL).

    Time frame: Cycle 1 Day 1 (cycle duration=28 days)

  15. Parts A, B, C, D, H, I, J: Time to Reach Maximum Plasma Concentration (Tmax) of Amcenestrant After a Single Oral Administration

    Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

    Time frame: Cycle 1 Day 1 (cycle duration=28 days)

  16. Parts A, B, C, D, H, I, J: Maximum Plasma Concentration (Cmax) of Amcenestrant After a Single Oral Administration

    Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

    Time frame: Cycle 1 Day 1 (cycle duration=28 days)

  17. Parts A, B, C, D, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval (AUC0-tau) of Amcenestrant After a Single Oral Administration

    Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis. tau=12 h for Part A BID dosing and 24 h for other parts.

    Time frame: Cycle 1 Day 1 (cycle duration=28 days)

  18. Parts A, B, C, D, F, H, I, J: Time to Reach Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations

    Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

    Time frame: Parts A, B, F, H, I, J: Cycle 1 Day 22; Parts C and D: Cycle 1 Day 21 (cycle duration=28 days)

  19. Parts A, B, C, D, F, H, I, J: Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations

    Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

    Time frame: Parts A, B, F, H, I, J: Cycle 1 Day 22; Parts C and D: Cycle 1 Day 21 (cycle duration=28 days)

  20. Parts A, B, C, D, F, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval of Amcenestrant After Repeated Oral Administrations

    Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis. tau=12 h for Part A BID dosing and 24 h for other parts.

    Time frame: Parts A, B, F, H, I, J: Cycle 1 Day 22; Parts C and D: Cycle 1 Day 21 (cycle duration=28 days)

  21. Parts A, B, C, D, F, H, I, J: Plasma Concentration Observed Before Treatment Administration (Ctrough) of Amcenestrant

    Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations.

    Time frame: Cycle 1: Pre-dose (0 hour) on Day 8 (Parts A, B, C, D), Day 15 (Parts B, C, D), Day 21 (Parts C and D) and Day 22 (Parts A, B, F, H, I, J) (cycle duration=28 days)

  22. Part B: Cumulated Amount of Amcenestrant Excreted in Urine From Time 0 to 24 Hours (Ae0-24)

    Urine samples were collected at the specified timepoints for the measurement of amcenestrant amount excreted in urine.

    Time frame: Day 22 of Cycle 1 (cycle duration=28 days)

  23. Part A (QD Regimen): Geometric Mean Ratio of Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours (AUC0-24) of Amcenestrant

    The food effect was assessed by comparing the geometric means of AUC0-24 between Cycle 1 Day 1 (fasted condition) and Cycle 1 Day 3 (fed condition) in Part A.

    Time frame: Days 1 and 3 of Cycle 1 (cycle duration=28 days)

  24. Part A (QD Regimen): Geometric Mean Ratio of Maximum Plasma Concentration of Amcenestrant

    The food effect was assessed by comparing the geometric means of Cmax between Cycle 1 Day 1 (fasted condition) and Cycle 1 Day 3 (fed condition) in Part A.

    Time frame: Days 1 and 3 of Cycle 1 (cycle duration=28 days)

  25. Parts C and D: Time to Reach Maximum Plasma Concentration of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 21) of palbociclib in combination with amcenestrant for the measurement of palbociclib concentrations. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 21 of Cycle 1 (cycle duration=28 days)

  26. Parts C and D: Maximum Plasma Concentration of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 21) of palbociclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 21 of Cycle 1 (cycle duration=28 days)

  27. Parts C and D: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 21) of palbociclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 21 of Cycle 1 (cycle duration=28 days)

  28. Part F: Time to Reach Maximum Plasma Concentration of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant

    Blood samples were collected after 3-day repeated oral administrations of alpelisib as monotherapy (Day 3) and after 22-day repeated oral administrations of alpelisib in combination with repeated doses of amcenestrant (Day 22). PK parameters were determined by non-compartmental analysis.

    Time frame: Days 3 and 22 of Cycle 1 (cycle duration=28 days)

  29. Part F: Maximum Plasma Concentration of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant

    Blood samples were collected after 3-day repeated oral administrations of alpelisib as monotherapy (Day 3) and after 22-day repeated oral administrations of alpelisib in combination with repeated doses of amcenestrant (Day 22). PK parameters were determined by non-compartmental analysis.

    Time frame: Days 3 and 22 of Cycle 1 (cycle duration=28 days)

  30. Part F: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant

    Blood samples were collected after 3-day repeated oral administrations of alpelisib as monotherapy (Day 3) and after 22-day repeated oral administrations of alpelisib in combination with repeated doses of amcenestrant (Day 22). PK parameters were determined by non-compartmental analysis.

    Time frame: Days 3 and 22 of Cycle 1 (cycle duration=28 days)

  31. Parts H and I: Time to Reach Maximum Plasma Concentration of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of everolimus in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 22 of Cycle 1 (cycle duration=28 days)

  32. Parts H and I: Maximum Plasma Concentration of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of everolimus in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 22 of Cycle 1 (cycle duration=28 days)

  33. Parts H and I: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of everolimus in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 22 of Cycle 1 (cycle duration=28 days)

  34. Part J: Time to Reach Maximum Plasma Concentration of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of abemaciclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 22 of Cycle 1 (cycle duration=28 days)

  35. Part J: Maximum Plasma Concentration of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of abemaciclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 22 of Cycle 1 (cycle duration=28 days)

  36. Part J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 12 Hours of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

    Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of abemaciclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

    Time frame: Days 1 and 22 of Cycle 1 (cycle duration=28 days)

  37. Parts A, B, J: Post/Pre--Treatment Ratio of 4 Beta (β)-Hydroxycholesterol

    Ratios of 4β-hydroxycholesterol concentrations were calculated from plasma samples collected before and after amcenestrant administration.

    Time frame: Pre-treatment on Day 1 of Cycle 1; post-treatment on Day 22 of Cycle 1, Day 1 and Day 28 (only for Part J) of Cycle 2 (cycle duration=28 days)

06

Results

Posted Nov 24, 2025
Limitations and caveats
Sponsor decision to prematurely stop the study, it was not linked to any safety concern.

Participant flow

This study was conducted at 25 sites in 10 countries between 20-Sep-2017 and 08-Nov-2024. A total of 136 participants were enrolled in the study. Sponsor decided to prematurely stop the study, it was not linked to any safety concern.

Participant flow — Overall Study
MilestonePart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Started334336499630833132
Completed0000000000000000
Not completed334336499630833132
Withdrew: Adverse event0000011104110000
Withdrew: Progressive disease334335458518723112
Withdrew: Withdrawal by subject0000000002000000
Withdrew: Other0000003016000020

Outcome measures

PrimaryParts A, C, F, H, J: Number of Participants With Study Treatment-Related Dose-Limiting Toxicities (DLTs)

DLTs: any treatment-emergent adverse event(TEAE) related to study treatment per National Cancer Institute Common Terminology Criteria for AE scale version (v) 4.03:Grade(G)≥3 nonhematological toxicity except:G3 nausea/vomiting resolved to G≤1 in 48 hours(h),G3 diarrhea with therapy and lasting\<48h,G3 hyperglycemia resolved to G≤1 in 48h(Part H);G≥3 hematological toxicity except:G3 anemia,G4 neutropenia\<7days(d),G3 neutropenia without fever/infection,G3 thrombocytopenia without bleeding;elevated total serum bilirubin(BL)\>2xupper limit of normal(except Part F),Part F:G3 hyperglycemia not resolved to G≤2 in 7d after antidiabetic treatment,G2 hyperglycemia not resolved to G≤1 in 21d,G2 alanine aminotransferase(ALT) increase in conjunction with total blood BL G≥2 without liver metastases,G≥3 ALT/aspartate aminotransferase increase for\>4d,G3 rash/maculopapular rash not resolved to G≤1 in 7d;treatment related toxicity causing≥7d omission in Cycle 1 or \>2 weeks delay in Cycle 2 in Part C.

Time frame:
Cycle 1 Day 1 to Cycle 1 Day 28 (cycle duration=28 days)
Reported as:
Count of participants · Participants
Parts A, C, F, H, J: Number of Participants With Study Treatment-Related Dose-Limiting Toxicities (DLTs)
ParticipantsPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, C, F, H, J: Number of Participants With Study Treatment-Related Dose-Limiting Toxicities (DLTs)0000000000000
PrimaryPart B: Objective Response Rate (ORR) as Determined by Independent Central Review (ICR)

ORR was determined by dividing the number of participants who achieved confirmed complete response (CR) or partial response (PR) by the number of participants from the analysis population. ORR was assessed by ICR according to response evaluation criteria in solid tumors (RECIST) v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 millimeters (mm). PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks
Reported as:
Number · percentage of participants
Part B: Objective Response Rate (ORR) as Determined by Independent Central Review (ICR)
percentage of participantsPart B: Amcenestrant 400 mg
Part B: Objective Response Rate (ORR) as Determined by Independent Central Review (ICR)10.9 (4.4 to 21.5)
PrimaryParts D, I: Number of Participants With Treatment-Emergent Adverse Events and Treatment-Emergent Serious Adverse Events (TESAEs)

AE was any untoward medical occurrence in a participant or clinical investigation participant administered with a pharmaceutical product and which did not necessarily had a causal relationship with the treatment. SAE was any untoward medical occurrence that at any dose, resulted in death, was life-threatening, required in-patient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was a medically important event. TEAEs were AEs that developed or worsened or became serious during the treatment period.

Time frame:
From first dose of study treatment administration (Day 1) up to 30 days after the last dose of study treatment administration; approximately 232 weeks for Part D and 11 weeks for Part I
Reported as:
Count of participants · Participants
Parts D, I: Number of Participants With Treatment-Emergent Adverse Events and Treatment-Emergent Serious Adverse Events (TESAEs)
ParticipantsPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart I: Amcenestrant 200 mg + Everolimus 10 mg
TEAEs301
TESAEs81
SecondaryParts A, B, C, F, H, J: Number of Participants With Treatment-Emergent Adverse Events and Treatment-Emergent Serious Adverse Events

AE was any untoward medical occurrence in a participant or clinical investigation participant administered with a pharmaceutical product and which did not necessarily had a causal relationship with the treatment. SAE was any untoward medical occurrence that at any dose, resulted in death, was life-threatening, required in-patient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was a medically important event. TEAEs were AEs that developed or worsened or became serious during the treatment period.

Time frame:
From first dose of study treatment administration (Day 1) up to 30 days after the last dose of study treatment administration; approximately 94, 282, 144, 96, 59, 130 weeks for Parts A, B, C, F, H, J respectively
Reported as:
Count of participants · Participants
Parts A, B, C, F, H, J: Number of Participants With Treatment-Emergent Adverse Events and Treatment-Emergent Serious Adverse Events
ParticipantsPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
TEAEs334336499683332
TESAEs011013152161001
SecondaryParts A, B, C, D, F, H, I, J: Objective Response Rate as Determined by Investigators/Local Radiologists

ORR was determined by dividing the number of participants who achieved confirmed CR or PR by the number of participants from the analysis population. ORR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively
Reported as:
Number · percentage of participants
Parts A, B, C, D, F, H, I, J: Objective Response Rate as Determined by Investigators/Local Radiologists
percentage of participantsPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Objective Response Rate as Determined by Investigators/Local Radiologists0 (NA to NA)33.3 (1.7 to 86.5)0 (NA to NA)0 (NA to NA)0 (NA to NA)0 (NA to NA)8.7 (3.0 to 18.8)22.2 (4.1 to 55.0)0 (0.0 to 39.3)34.5 (20.0 to 51.4)0 (NA to NA)0 (NA to NA)0 (NA to NA)0 (NA to NA)0 (NA to NA)50 (NA to NA)
SecondaryParts A, B, C, D, F, H, I, J: Clinical Benefit Rate (CBR) as Determined by Investigators/Local Radiologists

CBR was determined by dividing the number of participants who achieved confirmed CR, PR as best overall response (BOR) or stable disease (SD) for ≥24 weeks by the number of participants from the analysis population. CBR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest sum diameters while on study.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively
Reported as:
Number · percentage of participants
Parts A, B, C, D, F, H, I, J: Clinical Benefit Rate (CBR) as Determined by Investigators/Local Radiologists
percentage of participantsPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Clinical Benefit Rate (CBR) as Determined by Investigators/Local Radiologists0 (NA to NA)66.7 (13.5 to 98.3)75.0 (24.9 to 98.7)66.7 (13.5 to 98.3)33.3 (1.7 to 86.5)25.0 (1.3 to 75.1)26.1 (15.8 to 38.8)44.4 (16.9 to 74.9)50.0 (15.3 to 84.7)75.9 (59.4 to 88.1)14.3 (NA to NA)50 (NA to NA)33.3 (NA to NA)0 (NA to NA)66.7 (NA to NA)50 (NA to NA)
SecondaryPart B: Clinical Benefit Rate as Determined by Independent Central Review

CBR was determined by dividing the number of participants who achieved confirmed CR, PR as BOR or SD for ≥24 weeks by the number of participants from the analysis population. CBR was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks
Reported as:
Number · percentage of participants
Part B: Clinical Benefit Rate as Determined by Independent Central Review
percentage of participantsPart B: Amcenestrant 400 mg
Part B: Clinical Benefit Rate as Determined by Independent Central Review28.3 (17.6 to 41.1)
SecondaryParts A, B, C, D, F, H, I, J: Duration of Response (DOR) as Determined by Investigators/Local Radiologists

DOR was defined as the time interval from the date of the first occurrence of confirmed CR or PR to the date of the first documentation of disease progression or death due to disease progression, whichever occurred first. DOR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study, an absolute increase of at least 5 mm in the sum. Appearance of 1 or more new lesions was also considered progression.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively
Reported as:
Median · weeks
Parts A, B, C, D, F, H, I, J: Duration of Response (DOR) as Determined by Investigators/Local Radiologists
weeksPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Duration of Response (DOR) as Determined by Investigators/Local Radiologists—23.9 (NA to NA)————NA (32.14 to NA)32.2 (24.14 to NA)—52.4 (16.00 to NA)—————11.43 (NA to NA)
SecondaryPart B: Duration of Response as Determined by Independent Central Review

DOR was defined as the time interval from the date of the first occurrence of confirmed CR or PR to the date of the first documentation of disease progression or death due to disease progression, whichever occurred first. DOR was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study, an absolute increase of at least 5 mm in the sum. Appearance of 1 or more new lesions was also considered progression.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks
Reported as:
Median · weeks
Part B: Duration of Response as Determined by Independent Central Review
weeksPart B: Amcenestrant 400 mg
Part B: Duration of Response as Determined by Independent Central ReviewNA (18.71 to NA)
SecondaryParts A, B, C, D, F, H, I, J: Progression-Free Survival (PFS) as Determined by Investigators/Local Radiologists

PFS was defined as time from the date of the first treatment intake to the date of the first documentation of objective PD according to RECIST v1.1, clinical PD or death due to any cause, whichever occurred first. PFS was assessed by investigators/local radiologists. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study, an absolute increase of at least 5 mm in the sum. Appearance of 1 or more new lesions was also considered progression.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively
Reported as:
Median · weeks
Parts A, B, C, D, F, H, I, J: Progression-Free Survival (PFS) as Determined by Investigators/Local Radiologists
weeksPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Progression-Free Survival (PFS) as Determined by Investigators/Local Radiologists7.3 (6.29 to 15.29)31.3 (5.29 to 41.71)31.3 (6.14 to 31.57)32.3 (8.43 to 90.57)7.9 (7.57 to 39.00)7.7 (7.14 to 32.00)8.3 (7.86 to 23.14)44.3 (7.43 to 80.43)60.0 (7.43 to NA)79.7 (40.00 to NA)NA (NA to NA)NA (NA to NA)NA (NA to NA)NA (NA to NA)NA (NA to NA)NA (NA to NA)
SecondaryParts A, B, C, D: Objective Response Rate as Determined by Investigators/Local Radiologists According to Estrogen Receptor 1 (ESR1) Mutation at Baseline

ORR was determined by dividing the number of participants who achieved confirmed CR or PR by the number of participants from the analysis population. ORR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. The ESR1 gene mutation status (mutated or wild-type) was analyzed by multiplex droplet digital polymerase chain reaction (ddPCR) after extraction of plasma circulating deoxyribonucleic acid (DNA). The baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

Time frame:
From Baseline (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228 weeks for Parts A, B, C, D respectively
Reported as:
Number · percentage of participants
Parts A, B, C, D: Objective Response Rate as Determined by Investigators/Local Radiologists According to Estrogen Receptor 1 (ESR1) Mutation at Baseline
percentage of participantsPart A and B: Amcenestrant (Dose >20 mg)Parts C and D: Amcenestrant 200 mg + Palbociclib 125 mg
Wild-Type13.3 (4.7 to 28.0)33.3 (18.6 to 50.9)
Mutated3.6 (0.2 to 15.9)27.3 (7.9 to 56.4)
Unknown0 (NA to NA)—
SecondaryPart B: Objective Response Rate as Determined by Independent Central Review According to Estrogen Receptor 1 Mutation at Baseline

ORR was determined by dividing the number of participants who achieved confirmed CR or PR by the number of participants from the analysis population. ORR was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. The ESR1 gene mutation status (mutated or wild-type) was analyzed by multiplex ddPCR after extraction of plasma circulating DNA. The baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

Time frame:
Baseline (Day 1) up to maximum exposure of study treatment; approximately 278 weeks
Reported as:
Number · percentage of participants
Part B: Objective Response Rate as Determined by Independent Central Review According to Estrogen Receptor 1 Mutation at Baseline
percentage of participantsPart B: Amcenestrant 400 mg
Wild-Type15.4 (5.4 to 31.8)
Mutated5.3 (0.3 to 22.6)
Unknown0 (NA to NA)
SecondaryParts A, B, C, D: Clinical Benefit Rate as Determined by Investigators/Local Radiologists According to Estrogen Receptor 1 Mutation at Baseline

CBR was determined by dividing the number of participants who achieved confirmed CR, PR as BOR or SD for ≥24 weeks by the number of participants from analysis population. CBR was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. The ESR1 gene mutation status (mutated or wild-type) was analyzed by multiplex ddPCR after extraction of plasma circulating DNA. Baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

Time frame:
From Baseline (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228 weeks for Parts A, B, C, D respectively
Reported as:
Number · percentage of participants
Parts A, B, C, D: Clinical Benefit Rate as Determined by Investigators/Local Radiologists According to Estrogen Receptor 1 Mutation at Baseline
percentage of participantsPart A and B: Amcenestrant (Dose >20 mg)Parts C and D: Amcenestrant 200 mg + Palbociclib 125 mg
Wild-Type36.7 (22.1 to 53.3)70.4 (52.9 to 84.3)
Mutated32.1 (17.9 to 49.4)63.6 (35.0 to 86.5)
Unknown0 (NA to NA)—
SecondaryParts B, D, I: Time to First Confirmed Response as Determined by Investigators/Local Radiologists

The time to first confirmed response was defined as the time interval from the date of first administration of the study treatment to the date of the first occurrence of confirmed CR or PR. The time to first confirmed response was assessed by investigators/local radiologists according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 90, 278, 140, 228, 92, 55, 7, 126 weeks for Parts A, B, C, D, F, H, I, J respectively
Reported as:
Median · weeks
Parts B, D, I: Time to First Confirmed Response as Determined by Investigators/Local Radiologists
weeksPart B: Amcenestrant 400 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart I: Amcenestrant 200 mg + Everolimus 10 mg
Parts B, D, I: Time to First Confirmed Response as Determined by Investigators/Local Radiologists8.1 (8 to 40)16.2 (8 to 32)—
SecondaryPart B: Time to First Confirmed Response as Determined by Independent Central Review

The time to first confirmed response was defined as the time interval from the date of first administration of the study treatment to the date of the first occurrence of confirmed CR or PR. The time to first confirmed response was assessed by ICR according to RECIST v1.1. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had a reduction in short axis to \<10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.

Time frame:
From first dose of study treatment administration (Day 1) up to maximum exposure of study treatment; approximately 278 weeks
Reported as:
Median · weeks
Part B: Time to First Confirmed Response as Determined by Independent Central Review
weeksPart B: Amcenestrant 400 mg
Part B: Time to First Confirmed Response as Determined by Independent Central Review31.1 (23 to 68)
SecondaryPart A: Number of Participants With 18F-Fluorestradiol Positron Emission Tomography Percentage Reduction

Inhibition of estrogen receptor (ER) occupancy investigation using 18F-FES-PET imaging was a limited invasive procedure that allowed assessment of ER presence by assessing the binding of radiolabeled estradiol, the ligand of ER (signal extinction). Number of participants with percentage reduction (≥90%, ≥70%, ≥50% and ≥30%) in 18F-FES-PET signal are reported. The baseline value was defined as the last value or measurement taken up to the date and time of the first dose of study treatment irrespective of the treatment.

Time frame:
Baseline (within 3 days or more prior to Day 1) and between Day 11 and Day 15 of Cycle 1 (cycle duration=28 days)
Reported as:
Count of participants · Participants
Part A: Number of Participants With 18F-Fluorestradiol Positron Emission Tomography Percentage Reduction
ParticipantsPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BID
≥90% Reduction032232
≥70% Reduction133332
≥50% Reduction134332
≥30% Reduction134333
SecondaryParts A, B, C, D, H, I, J: Time Interval Between Administration and the Sampling Preceding the First Concentration Above the Lower Limit of Quantification (LLOQ) (Tlag) of Amcenestrant After a Single Oral Administration

Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. LLOQ value for amcenestrant was 5 nanograms per milliliter (ng/mL).

Time frame:
Cycle 1 Day 1 (cycle duration=28 days)
Reported as:
Median · hour
Parts A, B, C, D, H, I, J: Time Interval Between Administration and the Sampling Preceding the First Concentration Above the Lower Limit of Quantification (LLOQ) (Tlag) of Amcenestrant After a Single Oral Administration
hourPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, H, I, J: Time Interval Between Administration and the Sampling Preceding the First Concentration Above the Lower Limit of Quantification (LLOQ) (Tlag) of Amcenestrant After a Single Oral Administration0.00 (0.00 to 0.50)0.00 (0.00 to 1.58)0.00 (0.00 to 0.50)0.00 (0.00 to 0.00)0.00 (0.00 to 0.00)0.00 (0.00 to 0.00)0.00 (0.00 to 1.02)0.00 (0.00 to 1.00)0.00 (0.00 to 1.00)0.470 (0.00 to 1.08)0.00 (0.00 to 0.980)0.00 (0.00 to 0.980)0.00 (0.00 to 0.00)0.00 (0.00 to 0.00)0.00 (0.00 to 0.00)
SecondaryParts A, B, C, D, H, I, J: Time to Reach Maximum Plasma Concentration (Tmax) of Amcenestrant After a Single Oral Administration

Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

Time frame:
Cycle 1 Day 1 (cycle duration=28 days)
Reported as:
Median · hour
Parts A, B, C, D, H, I, J: Time to Reach Maximum Plasma Concentration (Tmax) of Amcenestrant After a Single Oral Administration
hourPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, H, I, J: Time to Reach Maximum Plasma Concentration (Tmax) of Amcenestrant After a Single Oral Administration1.52 (1.50 to 2.00)3.00 (3.00 to 24.77)2.98 (1.98 to 4.02)3.00 (1.50 to 3.83)3.03 (2.02 to 4.00)2.98 (2.00 to 5.95)3.98 (1.97 to 9.98)5.82 (2.00 to 9.12)4.97 (1.00 to 6.13)3.03 (2.00 to 23.90)4.02 (3.00 to 4.05)3.98 (2.00 to 7.92)4.00 (4.00 to 4.00)3.88 (3.00 to 4.00)3.50 (3.00 to 4.00)
SecondaryParts A, B, C, D, H, I, J: Maximum Plasma Concentration (Cmax) of Amcenestrant After a Single Oral Administration

Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

Time frame:
Cycle 1 Day 1 (cycle duration=28 days)
Reported as:
Mean · ng/mL
Parts A, B, C, D, H, I, J: Maximum Plasma Concentration (Cmax) of Amcenestrant After a Single Oral Administration
ng/mLPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, H, I, J: Maximum Plasma Concentration (Cmax) of Amcenestrant After a Single Oral Administration187 ± 46.71310 ± 13801650 ± 13404740 ± 29207010 ± 41804620 ± 27406020 ± 28102270 ± 11305470 ± 12802500 ± 11101700 ± 3551940 ± 6642330 ± NA4500 ± 28605360 ± 750
SecondaryParts A, B, C, D, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval (AUC0-tau) of Amcenestrant After a Single Oral Administration

Blood samples were collected at the specified timepoint for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis. tau=12 h for Part A BID dosing and 24 h for other parts.

Time frame:
Cycle 1 Day 1 (cycle duration=28 days)
Reported as:
Mean · ng*h/mL
Parts A, B, C, D, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval (AUC0-tau) of Amcenestrant After a Single Oral Administration
ng*h/mLPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval (AUC0-tau) of Amcenestrant After a Single Oral Administration1040 ± 5609140 ± 873013600 ± 1380040400 ± 1750061100 ± 3630028200 ± 1690050900 ± 2600021300 ± 591046400 ± 440021400 ± 1000014100 ± 319020900 ± 433017900 ± NA36500 ± 2510038000 ± 13800
SecondaryParts A, B, C, D, F, H, I, J: Time to Reach Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations

Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

Time frame:
Parts A, B, F, H, I, J: Cycle 1 Day 22; Parts C and D: Cycle 1 Day 21 (cycle duration=28 days)
Reported as:
Median · hour
Parts A, B, C, D, F, H, I, J: Time to Reach Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations
hourPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Time to Reach Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations2.17 (2.00 to 4.02)2.97 (2.93 to 3.00)2.07 (2.00 to 3.03)2.95 (2.02 to 3.78)3.00 (3.00 to 4.00)2.98 (2.00 to 3.00)3.00 (1.02 to 6.00)4.88 (1.37 to 8.17)4.00 (1.83 to 10.00)4.00 (1.75 to 6.00)3.22 (1.97 to 3.98)2.47 (2.03 to 4.03)4.17 (3.95 to 5.92)4.07 (4.07 to 4.07)2.67 (2.05 to 3.00)3.33 (3.33 to 3.33)
SecondaryParts A, B, C, D, F, H, I, J: Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations

Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis.

Time frame:
Parts A, B, F, H, I, J: Cycle 1 Day 22; Parts C and D: Cycle 1 Day 21 (cycle duration=28 days)
Reported as:
Mean · ng/mL
Parts A, B, C, D, F, H, I, J: Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations
ng/mLPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Maximum Plasma Concentration of Amcenestrant After Repeated Oral Administrations218 ± 95.32390 ± 12002150 ± 8734020 ± 24605570 ± 9625200 ± 2964380 ± 12302060 ± 8314350 ± 31902120 ± 6914230 ± 12503300 ± 13902760 ± 411848 ± NA3350 ± 12303820 ± NA
SecondaryParts A, B, C, D, F, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval of Amcenestrant After Repeated Oral Administrations

Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations. PK parameters were determined by non-compartmental analysis. tau=12 h for Part A BID dosing and 24 h for other parts.

Time frame:
Parts A, B, F, H, I, J: Cycle 1 Day 22; Parts C and D: Cycle 1 Day 21 (cycle duration=28 days)
Reported as:
Mean · ng*h/mL
Parts A, B, C, D, F, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval of Amcenestrant After Repeated Oral Administrations
ng*h/mLPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Parts A, B, C, D, F, H, I, J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to Dosing Interval of Amcenestrant After Repeated Oral Administrations1630 ± 112015900 ± 735013900 ± 438036800 ± 2350042700 ± 1120036500 ± 768043200 ± 1620020600 ± 752033100 ± 1140017600 ± 754030600 ± 1190028300 ± 2110025000 ± 71808270 ± NA26600 ± 1290030300 ± NA
SecondaryParts A, B, C, D, F, H, I, J: Plasma Concentration Observed Before Treatment Administration (Ctrough) of Amcenestrant

Blood samples were collected at the specified timepoints for the measurement of amcenestrant concentrations.

Time frame:
Cycle 1: Pre-dose (0 hour) on Day 8 (Parts A, B, C, D), Day 15 (Parts B, C, D), Day 21 (Parts C and D) and Day 22 (Parts A, B, F, H, I, J) (cycle duration=28 days)
Reported as:
Mean · ng/mL
Parts A, B, C, D, F, H, I, J: Plasma Concentration Observed Before Treatment Administration (Ctrough) of Amcenestrant
ng/mLPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Cycle 1 Day 80 ± NA91.4 ± NA159 ± 35.8871 ± NA302 ± NA2220 ± 1100665 ± 581348 ± 180389 ± 234303 ± 294——————
Cycle 1 Day 15——————553 ± 605328 ± 168243 ± 151226 ± 198——————
Cycle 1 Day 21———————359 ± 132297 ± 144223 ± 187——————
Cycle 1 Day 226.80 ± 9.6275.1 ± NA76.1 ± 56.0388 ± 327348 ± 1971510 ± 1030598 ± 460———410 ± 449326 ± 216346 ± 128114 ± NA214 ± 138229 ± NA
SecondaryPart B: Cumulated Amount of Amcenestrant Excreted in Urine From Time 0 to 24 Hours (Ae0-24)

Urine samples were collected at the specified timepoints for the measurement of amcenestrant amount excreted in urine.

Time frame:
Day 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng
Part B: Cumulated Amount of Amcenestrant Excreted in Urine From Time 0 to 24 Hours (Ae0-24)
ngPart B: Amcenestrant 400 mg
Part B: Cumulated Amount of Amcenestrant Excreted in Urine From Time 0 to 24 Hours (Ae0-24)30800 ± 36100
SecondaryPart A (QD Regimen): Geometric Mean Ratio of Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours (AUC0-24) of Amcenestrant

The food effect was assessed by comparing the geometric means of AUC0-24 between Cycle 1 Day 1 (fasted condition) and Cycle 1 Day 3 (fed condition) in Part A.

Time frame:
Days 1 and 3 of Cycle 1 (cycle duration=28 days)
Reported as:
Number · ratio
Part A (QD Regimen): Geometric Mean Ratio of Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours (AUC0-24) of Amcenestrant
ratioPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mg
Part A (QD Regimen): Geometric Mean Ratio of Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours (AUC0-24) of Amcenestrant1.05 (0.60 to 1.83)0.69 (0.31 to 1.50)1.77 (1.20 to 2.62)1.12 (0.51 to 2.45)1.38 (0.88 to 2.17)
SecondaryPart A (QD Regimen): Geometric Mean Ratio of Maximum Plasma Concentration of Amcenestrant

The food effect was assessed by comparing the geometric means of Cmax between Cycle 1 Day 1 (fasted condition) and Cycle 1 Day 3 (fed condition) in Part A.

Time frame:
Days 1 and 3 of Cycle 1 (cycle duration=28 days)
Reported as:
Number · ratio
Part A (QD Regimen): Geometric Mean Ratio of Maximum Plasma Concentration of Amcenestrant
ratioPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mg
Part A (QD Regimen): Geometric Mean Ratio of Maximum Plasma Concentration of Amcenestrant0.80 (0.41 to 1.58)0.41 (0.16 to 1.07)1.67 (1.04 to 2.69)1.38 (0.53 to 3.59)1.43 (0.83 to 2.48)
SecondaryParts C and D: Time to Reach Maximum Plasma Concentration of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 21) of palbociclib in combination with amcenestrant for the measurement of palbociclib concentrations. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 21 of Cycle 1 (cycle duration=28 days)
Reported as:
Median · hour
Parts C and D: Time to Reach Maximum Plasma Concentration of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
hourPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mg
Cycle 1 Day 15.70 (3.00 to 10.00)3.99 (2.02 to 7.98)6.00 (2.07 to 24.00)
Cycle 1 Day 214.10 (1.93 to 9.97)6.00 (3.02 to 8.08)4.75 (3.00 to 9.58)
SecondaryParts C and D: Maximum Plasma Concentration of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 21) of palbociclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 21 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng/mL
Parts C and D: Maximum Plasma Concentration of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
ng/mLPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mg
Cycle 1 Day 170.4 ± 26.164.7 ± 28.462.3 ± 17.5
Cycle 1 Day 2198.1 ± 37.659.4 ± 28.196.3 ± 34.9
SecondaryParts C and D: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 21) of palbociclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 21 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng*h/mL
Parts C and D: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Palbociclib After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
ng*h/mLPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mg
Cycle 1 Day 11040 ± 257889 ± 376949 ± 265
Cycle 1 Day 211660 ± 751823 ± 2661570 ± 523
SecondaryPart F: Time to Reach Maximum Plasma Concentration of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant

Blood samples were collected after 3-day repeated oral administrations of alpelisib as monotherapy (Day 3) and after 22-day repeated oral administrations of alpelisib in combination with repeated doses of amcenestrant (Day 22). PK parameters were determined by non-compartmental analysis.

Time frame:
Days 3 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Median · hour
Part F: Time to Reach Maximum Plasma Concentration of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant
hourPart F: Amcenestrant 200 mg + Alpelisib 300 mg
Cycle 1 Day 33.02 (1.02 to 9.00)
Cycle 1 Day 221.69 (1.25 to 2.12)
SecondaryPart F: Maximum Plasma Concentration of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant

Blood samples were collected after 3-day repeated oral administrations of alpelisib as monotherapy (Day 3) and after 22-day repeated oral administrations of alpelisib in combination with repeated doses of amcenestrant (Day 22). PK parameters were determined by non-compartmental analysis.

Time frame:
Days 3 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng/mL
Part F: Maximum Plasma Concentration of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant
ng/mLPart F: Amcenestrant 200 mg + Alpelisib 300 mg
Cycle 1 Day 32430 ± 631
Cycle 1 Day 223480 ± 516
SecondaryPart F: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant

Blood samples were collected after 3-day repeated oral administrations of alpelisib as monotherapy (Day 3) and after 22-day repeated oral administrations of alpelisib in combination with repeated doses of amcenestrant (Day 22). PK parameters were determined by non-compartmental analysis.

Time frame:
Days 3 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng*h/mL
Part F: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Alpelisib After Repeated Oral Administrations Alone or in Combination With Amcenestrant
ng*h/mLPart F: Amcenestrant 200 mg + Alpelisib 300 mg
Cycle 1 Day 328700 ± 7890
Cycle 1 Day 2227300 ± 6910
SecondaryParts H and I: Time to Reach Maximum Plasma Concentration of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of everolimus in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Median · hour
Parts H and I: Time to Reach Maximum Plasma Concentration of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
hourPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mg
Cycle 1 Day 11.02 (1.00 to 3.00)2.00 (0.98 to 3.02)1.00 (1.00 to 1.00)
Cycle 1 Day 221.00 (0.97 to 1.47)2.08 (0.98 to 3.03)1.10 (1.10 to 1.10)
SecondaryParts H and I: Maximum Plasma Concentration of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of everolimus in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng/mL
Parts H and I: Maximum Plasma Concentration of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
ng/mLPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mg
Cycle 1 Day 138.7 ± 21.964.8 ± 3.5443.5 ± NA
Cycle 1 Day 2224.4 ± 6.3237.6 ± 15.546.7 ± NA
SecondaryParts H and I: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of everolimus in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng*h/mL
Parts H and I: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 24 Hours of Everolimus After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
ng*h/mLPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mg
Cycle 1 Day 1210 ± 117381 ± 159246 ± NA
Cycle 1 Day 22144 ± 35.0319 ± 156295 ± NA
SecondaryPart J: Time to Reach Maximum Plasma Concentration of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of abemaciclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Median · hour
Part J: Time to Reach Maximum Plasma Concentration of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
hourPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Abemaciclib: Cycle 1 Day 15.75 (3.00 to 9.00)6.00 (4.00 to 8.00)
Abemaciclib: Cycle 1 Day 223.00 (2.67 to 4.03)8.00 (8.00 to 8.00)
M2: Cycle 1 Day 13.88 (3.00 to 4.00)6.50 (4.00 to 9.00)
M2: Cycle 1 Day 222.67 (1.03 to 3.00)4.00 (4.00 to 4.00)
M18: Cycle 1 Day 14.00 (3.88 to 8.00)8.00 (8.00 to 8.00)
M18: Cycle 1 Day 222.67 (1.97 to 4.00)4.00 (4.00 to 4.00)
M20: Cycle 1 Day 18.07 (3.00 to 9.00)8.50 (8.00 to 9.00)
M20: Cycle 1 Day 221.03 (0.00 to 4.67)8.67 (8.67 to 8.67)
SecondaryPart J: Maximum Plasma Concentration of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of abemaciclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng/mL
Part J: Maximum Plasma Concentration of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
ng/mLPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Abemaciclib: Cycle 1 Day 191.6 ± 58.4152 ± 44.5
Abemaciclib: Cycle 1 Day 22109 ± 45.687.8 ± NA
M2: Cycle 1 Day 117.8 ± 3.4655.3 ± 22.0
M2: Cycle 1 Day 2269.1 ± 20.5106 ± NA
M18: Cycle 1 Day 16.37 ± 0.51422.0 ± 4.24
M18: Cycle 1 Day 2235.1 ± 17.289.5 ± NA
M20: Cycle 1 Day 131.2 ± 2.8465.5 ± 8.13
M20: Cycle 1 Day 22100 ± 17.3153 ± NA
SecondaryPart J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 12 Hours of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant

Blood samples were collected after single dose (Day 1) and repeated oral administrations (Day 22) of abemaciclib in combination with amcenestrant. PK parameters were determined by non-compartmental analysis.

Time frame:
Days 1 and 22 of Cycle 1 (cycle duration=28 days)
Reported as:
Mean · ng*h/mL
Part J: Area Under the Plasma Concentration Versus Time Curve From Time Zero to 12 Hours of Abemaciclib and Its Metabolites M2, M18 and M20 After First Dose and Repeated Oral Administrations in Combination With Amcenestrant
ng*h/mLPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Abemaciclib: Cycle 1 Day 1994 ± 7001330 ± 478
Abemaciclib: Cycle 1 Day 221050 ± 532—
M2: Cycle 1 Day 1160 ± 45.0554 ± NA
M2: Cycle 1 Day 22610 ± 1701130 ± NA
M18: Cycle 1 Day 147.6 ± 0.468218 ± NA
M18: Cycle 1 Day 22314 ± 141926 ± NA
M20: Cycle 1 Day 1295 ± 9.12—
M20: Cycle 1 Day 22997 ± 219—
SecondaryParts A, B, J: Post/Pre--Treatment Ratio of 4 Beta (β)-Hydroxycholesterol

Ratios of 4β-hydroxycholesterol concentrations were calculated from plasma samples collected before and after amcenestrant administration.

Time frame:
Pre-treatment on Day 1 of Cycle 1; post-treatment on Day 22 of Cycle 1, Day 1 and Day 28 (only for Part J) of Cycle 2 (cycle duration=28 days)
Reported as:
Mean · ratio
Parts A, B, J: Post/Pre--Treatment Ratio of 4 Beta (β)-Hydroxycholesterol
ratioPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Cycle 1 Day 22/Cycle 1 Day 10.817 ± 0.1681.18 ± 0.2941.29 ± 0.2631.61 ± 0.3362.24 ± 1.292.17 ± 0.3771.68 ± 0.577——
Cycle 2 Day 1/Cycle 1 Day 11.09 ± 0.3041.13 ± 0.4321.39 ± 0.2071.83 ± 0.5692.40 ± 0.5592.99 ± 1.581.89 ± 0.627——

Adverse events

Collected over Adverse events were collected from first dose of study treatment administration (Day 1) up to 30 days after the last dose of study treatment administration; approximately 94, 282, 144, 232, 96, 59, 11, 130 weeks for Parts A, B, C, D, F, H, I, J respectively. All-cause mortality (deaths) were collected from first dose of study treatment administration (Day 1) to the end of follow-up for death for each participant; up to approximately 372 weeks. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Part A: Amcenestrant 20 mg1/3 (33.3%)0/3 (0%)3/3 (100%)
Part A: Amcenestrant 150 mg1/3 (33.3%)1/3 (33.3%)3/3 (100%)
Part A: Amcenestrant 200 mg0/4 (0%)1/4 (25%)4/4 (100%)
Part A: Amcenestrant 400 mg0/3 (0%)0/3 (0%)3/3 (100%)
Part A: Amcenestrant 600 mg1/3 (33.3%)1/3 (33.3%)3/3 (100%)
Part A: Amcenestrant 300 mg BID0/6 (0%)3/6 (50%)6/6 (100%)
Part B: Amcenestrant 400 mg4/49 (8.2%)15/49 (30.6%)49/49 (100%)
Part C: Amcenestrant 200 mg + Palbociclib 125 mg1/9 (11.1%)2/9 (22.2%)9/9 (100%)
Part C: Amcenestrant 400 mg + Palbociclib 125 mg0/6 (0%)1/6 (16.7%)6/6 (100%)
Part D: Amcenestrant 200 mg + Palbociclib 125 mg0/30 (0%)8/30 (26.7%)29/30 (96.7%)
Part F: Amcenestrant 200 mg + Alpelisib 300 mg2/8 (25%)6/8 (75%)8/8 (100%)
Part H: Amcenestrant 200 mg + Everolimus 5 mg0/3 (0%)1/3 (33.3%)3/3 (100%)
Part H: Amcenestrant 200 mg + Everolimus 10 mg0/3 (0%)0/3 (0%)3/3 (100%)
Part I: Amcenestrant 200 mg + Everolimus 10 mg0/1 (0%)1/1 (100%)1/1 (100%)
Part J: Amcenestrant 200 mg + Abemaciclib 100 mg BID0/3 (0%)0/3 (0%)3/3 (100%)
Part J: Amcenestrant 200 mg + Abemaciclib 150 mg BID0/2 (0%)1/2 (50%)2/2 (100%)
Most frequent serious events
Showing 10 of 48
Most frequent serious events
EventPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
SepsisInfections and infestations0/30/30/40/30/30/60/490/90/60/300/80/30/31/10/30/2
ConstipationGastrointestinal disorders0/30/30/40/30/30/60/490/90/60/300/80/30/30/10/31/2
PneumothoraxRespiratory, thoracic and mediastinal disorders0/30/30/40/30/31/60/490/90/60/300/81/30/30/10/30/2
Back PainMusculoskeletal and connective tissue disorders0/31/30/40/30/30/60/490/90/61/300/80/30/30/10/30/2
Disease ProgressionGeneral disorders0/31/30/40/30/30/61/490/90/60/300/80/30/30/10/30/2
FatigueGeneral disorders0/30/30/40/31/30/60/490/90/60/300/80/30/30/10/30/2
DyspnoeaRespiratory, thoracic and mediastinal disorders0/30/31/40/30/30/62/490/90/60/301/80/30/30/10/30/2
HypophosphataemiaMetabolism and nutrition disorders0/30/30/40/30/31/60/490/90/60/300/80/30/30/10/30/2
Superior Vena Cava SyndromeVascular disorders0/30/30/40/30/31/60/490/90/60/300/80/30/30/10/30/2
Pulmonary EmbolismRespiratory, thoracic and mediastinal disorders0/30/30/40/30/31/62/490/90/60/300/80/30/30/10/30/2
Most frequent other events
Showing 10 of 196
Most frequent other events
EventPart A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BID
Decreased AppetiteMetabolism and nutrition disorders0/31/30/42/33/31/67/490/92/61/303/82/30/30/10/30/2
DiarrhoeaGastrointestinal disorders0/31/32/43/30/33/68/491/93/68/306/81/32/31/12/31/2
Dry SkinSkin and subcutaneous tissue disorders0/31/30/40/31/30/63/492/90/66/301/80/32/31/11/30/2
RashSkin and subcutaneous tissue disorders0/30/31/40/31/32/61/490/90/66/302/80/31/31/10/30/2
ArthralgiaMusculoskeletal and connective tissue disorders0/31/31/41/31/31/610/492/92/68/301/81/33/30/11/30/2
FatigueGeneral disorders1/30/31/40/31/31/612/492/91/612/302/82/32/31/12/30/2
Weight DecreasedInvestigations0/30/30/40/30/30/62/490/90/61/300/81/30/31/10/30/2
Urinary Tract InfectionInfections and infestations0/31/30/41/32/30/65/491/91/65/301/80/30/30/10/31/2
HeadacheNervous system disorders0/30/30/40/31/31/63/491/90/66/301/80/32/30/12/30/2
Hot FlushVascular disorders0/32/31/42/31/30/67/493/90/61/300/81/31/30/10/30/2

Baseline characteristics

The safety population included all registered participants exposed to the study treatment, regardless of the amount of treatment administered.

Age, Customized
Age, Customized(Participants)Part A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BIDTotal
From 18 - 64 years13313529621942212083
From 65 - 84 years2012001734941101247
85 years and over00000130020000006
Sex: Female, Male
Sex: Female, Male(Participants)Part A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BIDTotal
Female334336499630833132136
Male00000000000000000
Race/Ethnicity, Customized
Race/Ethnicity, Customized(Participants)Part A: Amcenestrant 20 mgPart A: Amcenestrant 150 mgPart A: Amcenestrant 200 mgPart A: Amcenestrant 400 mgPart A: Amcenestrant 600 mgPart A: Amcenestrant 300 mg BIDPart B: Amcenestrant 400 mgPart C: Amcenestrant 200 mg + Palbociclib 125 mgPart C: Amcenestrant 400 mg + Palbociclib 125 mgPart D: Amcenestrant 200 mg + Palbociclib 125 mgPart F: Amcenestrant 200 mg + Alpelisib 300 mgPart H: Amcenestrant 200 mg + Everolimus 5 mgPart H: Amcenestrant 200 mg + Everolimus 10 mgPart I: Amcenestrant 200 mg + Everolimus 10 mgPart J: Amcenestrant 200 mg + Abemaciclib 100 mg BIDPart J: Amcenestrant 200 mg + Abemaciclib 150 mg BIDTotal
White13132335442960302298
Black or African American00000101010000003
Asian00000010000000001
Not reported2020121332023011032
Unknown00100001000000002
07

Study locations

25 sites
  • University of Colorado - Anschutz Medical Campus- Site Number : 8400005
    Aurora, Colorado 80045, United States
  • Massachusetts General Hospital- Site Number : 8400002
    Boston, Massachusetts 02114, United States
  • Memorial Sloan Kettering Cancer Center - New York - York Avenue- Site Number : 8400003
    New York, New York 10065, United States
  • Fred Hutchinson Cancer Center- Site Number : 8400001
    Seattle, Washington 98109, United States
  • Investigational Site Number : 0560001
    Leuven, 3000, Belgium
  • Investigational Site Number : 1240004
    Edmonton, Alberta T6G 1Z2, Canada
  • Investigational Site Number : 1240003
    Vancouver, British Columbia V5Z 1L3, Canada
  • Investigational Site Number : 1240002
    Toronto, Ontario M4N 3M5, Canada
  • Investigational Site Number : 2030002
    Brno, 656 53, Czechia
  • Investigational Site Number : 2030001
    Prague, 128 08, Czechia
  • Investigational Site Number : 2030003
    Prague, 140 59, Czechia
  • Investigational Site Number : 2500002
    Bordeaux, 33076, France
  • Investigational Site Number : 2500005
    Lille, 59000, France
  • Investigational Site Number : 2500003
    Lyon, 69373, France
  • Investigational Site Number : 2500001
    Saint-Herblain, 44805, France
  • Investigational Site Number : 2500004
    Villejuif, 94805, France
  • Investigational Site Number : 3800003
    Milan, Milano 20141, Italy
  • Investigational Site Number : 6160004
    Gdynia, Pomeranian Voivodeship 81-519, Poland
  • Investigational Site Number : 6200001
    Lisbon, 1649-035, Portugal
  • Investigational Site Number : 6200002
    Lisbon, 1998-018, Portugal
  • Investigational Site Number : 7240007
    Madrid, 28034, Spain
  • Investigational Site Number : 7240001
    Madrid, 28041, Spain
  • Investigational Site Number : 7240002
    Madrid, 28050, Spain
  • Investigational Site Number : 8260002
    Cardiff, Cardiff [Caerdydd Gb-crd] CF14 2TL, United Kingdom
  • Investigational Site Number : 8260003
    Oxford, Oxfordshire OX3 7LE, United Kingdom
08

References and documents

Publications

  • Bardia A, Chandarlapaty S, Linden HM, Ulaner GA, Gosselin A, Cartot-Cotton S, Cohen P, Doroumian S, Paux G, Celanovic M, Pelekanou V, Ming JE, Ternes N, Bouaboula M, Lee JS, Bauchet AL, Campone M. AMEERA-1 phase 1/2 study of amcenestrant, SAR439859, in postmenopausal women with ER-positive/HER2-negative advanced breast cancer. Nat Commun. 2022 Jul 15;13(1):4116. doi: 10.1038/s41467-022-31668-8. PubMed 35840573 ↗

Study documents

  • Study protocol · Dec 8, 2021
  • Statistical analysis plan · Jul 27, 2021

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Yes — Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

09

Registry details

Key details

Study ID
NCT03284957
Lead sponsor
Sanofi
Responsible party
Sponsor
First posted
Sep 15, 2017
Start date
Sep 20, 2017
Primary completion
Nov 8, 2024
Completion
Nov 8, 2024
Results posted
Nov 24, 2025
Last update
Nov 24, 2025

Study contacts

Clinical Sciences & Operations
study director · Sanofi

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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