A Study of Elacestrant Versus Standard Endocrine Therapy in Women and Men With ER+,HER2-, Early Breast Cancer With High Risk of Recurrence (ELEGANT)

Stemline Therapeutics

Status and phase: Enrolling; Phase 3

Conditions: Breast Cancer

Treatments: Drug: Elacestrant; Drug: Tamoxifen; Drug: Exemestane; Drug: Letrozole; Drug: Anastrozole

Study type: Interventional

Funder types: Industry

Identifiers

NCT06492616

2024-515445-42-00 (EU Trial (CTIS) Number)

STML-ELA-0422

Details and patient eligibility

About

The primary goal of this study is to evaluate the effectiveness of elacestrant versus standard endocrine therapy in participants with node-positive, Estrogen Receptor-positive (ER+), Human Epidermal Growth Factor-2 negative (HER2-) early breast cancer with high risk of recurrence.

Enrollment: 4,220 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria:

• Histopathologically or cytologically confirmed ER-positive (≥ 10% by immunohistochemistry [IHC]), HER2-negative [IHC = 0 or 1, or (IHC = 2 and in situ hybridization [ISH]-negative)] on tumor biopsy or final surgical pathology specimen early stage resected invasive breast cancer without evidence of recurrence or distant metastases, per local laboratory, according to the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines
• Participants considered at high risk of recurrence at initial staging
• Participants who have received at least 24 months but not more than 60 months of endocrine therapy (AIs or tamoxifen) with or without a CDK 4 and CKD 6 inhibitor (CDK4/6i)
• Participants who received prior CDK4/6i or a poly adenosine diphosphate-ribose polymerase (PARP) inhibitor must have already completed or discontinued these treatments.

Key Exclusion Criteria:

• Participants with inflammatory breast cancer
• History of any prior (ipsilateral and/or contralateral) invasive breast cancer
• Participant with history of malignancy within 3 years of the date of randomization, except for adequately treated basal or squamous cell skin cancer, superficial bladder cancer or carcinoma in situ of the cervix
• Participants who have had more than a 6-month continuous interruption of prior SoC adjuvant endocrine therapy or who discontinued adjuvant endocrine therapy more than 6 months prior to randomization

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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4,220 participants in 2 patient groups

Elacestrant

Experimental group

Description:

Participants will receive 345 milligrams (mg) elacestrant once daily (QD) for 5 years

Treatment:

Drug: Elacestrant

Standard of Care (SoC) Endocrine Therapy

Experimental group

Description:

Participants will receive the SoC endocrine therapy that was used prior to randomization: * AI (anastrozole 1 mg QD, letrozole 2.5 mg QD, or exemestane 25 mg QD); or * Tamoxifen 20 mg QD

Treatment:

Drug: Anastrozole

Drug: Letrozole

Drug: Exemestane

Drug: Tamoxifen