A Real-World Study of Elacestrant in Patients With HR+/HER2- Advanced Breast Cancer and ESR1 Mutations

Recruiting

• Conditions: Breast Cancer Metastatic; HR+/HER2- Advanced Breast Cancer; ESR1 Gene Mutation; Elacestrant

• Registration Number: NCT07076680
• Lead Sponsor: SciClone Pharmaceuticals

Brief Summary

The goal of this observational study is to learn about the safety and effectiveness of elacestrant in people with advanced breast cancer that is hormone receptor-positive (HR+), HER2-negative (HER2-), and has a mutation in the ESR1 gene.

The main questions it aims to answer are:

How safe is elacestrant when used in real-world clinical settings?

How well does elacestrant work in controlling disease in people with ESR1 mutations?

Participants will:

Already be prescribed elacestrant by their doctor as part of regular treatment

Allow researchers to collect medical data during routine care

Be followed for signs of treatment effectiveness and any medical problems that happen while taking the drug

This study will help researchers better understand how elacestrant is used and how well it works in real-life healthcare settings in China.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-06
• Study First Submitted: 2025-06-17
• Study First Submitted QC: 2025-07-21
• Last Update Submitted: 2025-07-21
• Study First Posted: 2025-07-22
• Last Update Posted: 2025-07-22
• Study Start: 2025-08-01
• Primary Completion: 2027-02-01
• Study Completion: 2027-07-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 100

Inclusion Criteria

• 1. must have a histologically or cytologically confirmed diagnosis of breast cancer and evidence of locally advanced or metastatic disease that is not amenable to surgical resection.

  2. Women or men ≥ 18 years of age. 3. must be confirmed as HR+ and HER2- by local laboratory tests. Confirmation of this status can be done by a first visit tissue sample or a post-treatment sample (recent biopsy sample preferred if available).

  3. Testing to confirm ESR1 mutation positivity should be performed on tumor DNA taken from tissue samples or circulating tumor DNA (ctDNA) obtained from plasma samples using a well-validated assay. Accept the results of the central laboratory or local laboratory tests, and in the event of inconsistency between the two test results, the investigator determines whether enrollment is possible.

  4. previous treatment with at least one endocrine therapy, either as monotherapy or in combination with another drug, at an advanced stage.

  5. have a life expectancy greater than 3 months and normal organ function (as assessed by the investigator).

Exclusion Criteria

• 1. Pregnant or lactating females. 2. Known difficulty tolerating oral medications, or the presence of conditions that would interfere with the absorption of oral medications or allergies to medications and their excipients.

3. Other conditions that the investigator considers inappropriate for enrollment.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Incidence of Adverse Events (AEs)	From first dose of elacestrant until 30 days after last dose or end of follow-up (approximately 6 to 12 months)	The number and percentage of participants who experience any adverse event (AE) during elacestrant treatment, regardless of severity or causality. Events will be coded using standard terminology (e.g., MedDRA).

Secondary Outcome Measures

Name	Time	Method
Incidence of Serious Adverse Events (SAEs)	From first dose of elacestrant until 30 days after last dose or end of follow-up	The number and percentage of participants who experience any serious adverse event (SAE), defined per ICH-GCP and local regulatory standards.
Rate of Dose Modifications Due to Adverse Events	From Day 1 (first dose) through the end of elacestrant treatment (up to 24 months)	The number and percentage of participants who require dose reductions or interruptions of elacestrant due to treatment-related adverse events.
Rate of Discontinuation Due to Adverse Events	From Day 1 (first dose) through the end of elacestrant treatment (up to 24 months)	The number and percentage of participants who permanently stop taking elacestrant due to treatment-related adverse events.
Progression-Free Survival (PFS)	From first dose of elacestrant to documented progression or death (up to 60 months)	Time from the start of elacestrant treatment to disease progression (as assessed by the treating physician based on imaging or clinical judgment) or death from any cause.
Overall Survival (OS)	From first dose of elacestrant to death or last follow-up (up to 60 months)	Time from the start of elacestrant treatment to death from any cause. Participants who are alive at the time of analysis will be censored at the date of last contact.
Treatment Adherence Rate	From Day 1 (first dose) through the end of elacestrant treatment (approximately 6 to 12 months)	The percentage of participants who complete elacestrant treatment as prescribed without missed doses, early discontinuation, or unplanned interruption.
Investigator-Assessed Objective Response Rate (INV-ORR)	From Day 1 (first dose) through the end of elacestrant treatment (up to 12 months)	The proportion of participants who achieve a complete response (CR) or partial response (PR) during elacestrant treatment, as assessed by the investigator based on RECIST 1.1.
Investigator-Assessed Duration of Response (INV-DoR)	From first response to disease progression or death (up to 36 months)	The time from first documented CR or PR to disease progression or death, whichever occurs first, based on investigator assessment per RECIST 1.1.
Investigator-Assessed Clinical Benefit Rate at Week 24 (INV-CBR)	At 24 weeks after treatment initiation	The proportion of participants with CR, PR, or stable disease lasting at least 24 weeks, as assessed by investigators using RECIST 1.1.
Time to Treatment Discontinuation (TTD)	From treatment start to last dose (up to 36 months)	The time from the first dose of elacestrant to the date of last dose, regardless of reason for discontinuation, based on prescription and visit records.
Time to Next Treatment (TTNT)	From treatment start to first dose of next systemic therapy (up to 60 months)	The time from the start of elacestrant treatment to the initiation of the next line of anti-cancer therapy, based on clinical records.

Trial Locations

Locations (1)

Sun Yat-sen Memorial Hospital, Sun Yat-sen University; 🇨🇳 Guangzhou, China