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Phase 3 Trial of Elacestrant Versus Standard of Care for the Treatment of ER+/HER2- Advanced Breast Cancer

Phase 3
Completed
Conditions
Breast Cancer
Interventions
Drug: Standard of Care
Registration Number
NCT03778931
Lead Sponsor
Stemline Therapeutics, Inc.
Brief Summary

This Phase 3 clinical study compares the efficacy and safety of elacestrant to the standard of care (SoC) options of fulvestrant or an aromatase inhibitor (AI) in women and men with breast cancer whose disease has advanced on at least one endocrine therapy including a CDK4/6 inhibitor in combination with fulvestrant or an aromatase inhibitor (AI).

Detailed Description

This is an international, multicenter, randomized, open-label, active-controlled, event-driven, Phase 3 clinical study comparing the efficacy and safety of elacestrant to the SoC options of fulvestrant or an aromatase inhibitor (AI) in postmenopausal women and in men with advanced or metastatic ER+/HER2- breast cancer, either in participants with tumors that harbor mutations in the ligand binding domain (LBD) of the estrogen receptor 1 (ESR1) gene (ESR1-mut participants) or in all participants regardless of ESR1 status (ESR1-mut and ESR1 wild type \[ESR1-wt\]) and whose disease has relapsed or progressed on at least one and no more than two prior lines of endocrine therapy (with documented progression), which must have included prior CDK4/6 inhibitor therapy in combination with fulvestrant or an aromatase inhibitor (AI) and for whom hormonal monotherapy with one of the SoC drugs (fulvestrant, anastrozole, letrozole, exemestane) is an appropriate treatment option.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
478
Inclusion Criteria
  1. Participants with proven diagnosis of adenocarcinoma of the breast with evidence of either locally advanced disease not amenable to resection or radiation therapy with curative intent or metastatic disease not amenable to curative therapy.
  2. Participants must be appropriate candidates for endocrine monotherapy
  3. Participants must have measurable disease or bone only disease with evaluable lesions
  4. Female or male participants age ≥ 18 years; female participants must be postmenopausal women, and male participants must not allow pregnancy with their sperm (abstain, do not donate sperm, et cetera).
  5. Participants must have ER+ and HER2- tumor status
  6. Participants must have previously received at least one and no more than two lines of endocrine therapy for advanced/metastatic breast cancer and meet additional previous treatment criteria.
  7. Participants must have received prior treatment with a CDK4/6 inhibitor in combination with either fulvestrant or an aromatase inhibitor (AI) for advanced/metastatic breast cancer (mBC).
  8. Participants may have received no more than one line of chemotherapy in the advanced/metastatic setting.

Critical

Exclusion Criteria
  1. Prior treatment with elacestrant or other investigational selective estrogen receptor degrader (SERD) or ER antagonist (D-0502, GDC-0810, GDC-0927, GDC-9545, G1T-48, LSZ102, AZD9496, SAR439859, ZN-c5, H3B-6545, bazedoxifene, lasofoxifene).

  2. Prior anticancer or investigational drug treatment within the following windows:

    1. Fulvestrant treatment < 42 days before first dose of study drug
    2. Any endocrine therapy < 14 days before first dose of study drug
    3. Chemotherapy < 21 days before first dose of study drug
    4. Any investigational anti-cancer drug therapy < 28 days or five half-lives (whichever is shorter) before the first dose of study drug. Enrollment of participants whose most recent therapy was an investigational agent should be discussed with the Sponsor
    5. Bisphosphonates or RANKL inhibitors initiated or dose changed < 3 months prior to first dose of study drug
  3. Presence of symptomatic visceral disease as defined in protocol.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
ElacestrantElacestrantParticipants in Arm 1 will receive elacestrant.
Standard of Care (SoC)Standard of CareParticipants in Arm 2 will receive investigator's choice of one of the standard-of-care drugs (fulvestrant, anastrozole, letrozole, or exemestane).
Primary Outcome Measures
NameTimeMethod
Progression-free Survival in ESR1-mut ParticipantsFrom Date of Randomization until Disease Progression or Death Due to Any Cause (up to 12 Months)

Progression-free survival based on blinded IRC assessment in ESR1-mut participants defined as the length of time from randomization until the date of objective disease progression per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1) as assessed by the blinded IRC or death from any cause. Progression is defined per RECIST v1.1 as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in a non-target lesion, or the appearance of new lesions.

Progression-free Survival in All ParticipantsFrom Date of Randomization until Disease Progression or Death Due to Any Cause (up to 12 Months)

Progression-free survival based on blinded imaging review committee (IRC) assessment in all (ESR1-mut and ESR1-wt) participants.

Secondary Outcome Measures
NameTimeMethod
Overall Survival in ESR1-mut ParticipantsFrom Date of Randomization until Death Due to Any Cause (Estimated up to 24 Months)

Overall survival in ESR1-mut participants, where overall survival is defined as the length of time from randomization until the date of death from any cause.

Overall Survival in All ParticipantsFrom Date of Randomization until Death Due to Any Cause (Estimated up to 24 Months)

Overall survival in all (ESR1-mut and ESR1-wt) participants.

Trial Locations

Locations (244)

The University of Arizona Cancer Center

🇺🇸

Tucson, Arizona, United States

St Bernard's Cancer Care

🇺🇸

Jonesboro, Arkansas, United States

St. Jude Heritage Healthcare

🇺🇸

Fullerton, California, United States

Adventist Health Glendale

🇺🇸

Glendale, California, United States

Moores Cancer Center at UC San Diego Health

🇺🇸

La Jolla, California, United States

Keck Hospital of USC-Norris Healthcare (HC3), Investigational Drug Service (IDS)

🇺🇸

Los Angeles, California, United States

Keck Medical Center of USC

🇺🇸

Los Angeles, California, United States

USC IDS Pharmacy

🇺🇸

Los Angeles, California, United States

UCLA Hematology/Oncology

🇺🇸

Los Angeles, California, United States

UCLA West Medical Pharmacy 159

🇺🇸

Los Angeles, California, United States

Scroll for more (234 remaining)
The University of Arizona Cancer Center
🇺🇸Tucson, Arizona, United States

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