Elacestrant versus Standard Endocrine Therapy in Women and Men with Node-positive, Estrogen Receptor-positive, HER2-negative, Early Breast Cancer with High Risk of Recurrence - A Global, Multicenter, Randomized, Open-label Phase 3 Study (ELEGANT)

Overview

Sponsor-declared trial summary

Key facts

Sponsor

Stemline Therapeutics Inc.

Participant type

Patients

Age range

18-64 years, 65+ years

Gender

Male and Female

Therapeutic area

Diseases [C] - Neoplasms [C04]

Trial duration

24 Mar 2025 → ongoing

Decision date (initial)

2025-03-17

Transition trial

No

Low-intervention

No

Rare-disease indication

No

Vulnerable population

Yes

Funding sources

Stemline Therapeutics, Inc.

External identifiers

EU CT number

2024-515445-42-00

ClinicalTrials.gov

NCT06492616

Trial design

CTIS Part I — objectives, methods, condition coding

Main objective

Scope: Therapy, Safety, Efficacy, Pharmacokinetic

Evaluate the efficacy of elacestrant relative to standard endocrine therapy in terms of Invasive breast cancer-free survival (IBCFS) in participants with node-positive, estrogen receptor-positive, HER2-negative early breast cancer with high risk of recurrence.

Secondary objectives 6

1. Evaluate the efficacy of elacestrant relative to standard of care (SoC) in terms of distant relapse-free survival (DRFS).
2. Evaluate the efficacy of elacestrant relative to SoC in terms of overall survival (OS).
3. Evaluate the efficacy of elacestrant relative to SoC in terms of invasive disease-free survival (IDFS).
4. Characterize the safety of elacestrant in the trial patient population.
5. Evaluate the effect of elacestrant relative to SoC on patient-reported outcomes (PROs).
6. Characterize elacestrant steady-state pharmacokinetics (PK) and exposure-response relationships (efficacy and safety) in a subset of participants enrolled in the elacestrant arm at United States (US) clinical sites.

Conditions and MedDRA coding

Node-positive, Estrogen Receptor-positive, HER2-negative, Early Breast Cancer with High Risk of Recurrence

Regulatory references

Scientific advice from competent authorities

Food And Drug Administration

Plan to share IPD

No

IPD plan description

N/A

Eligibility criteria

Principal inclusion / exclusion criteria as submitted by sponsor

Inclusion criteria 2

1. 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.
2. Participants who have received at least 24 months but not more than 60 months of endocrine therapy (AIs or tamoxifen) with or without a CDK4/6i and with or without an LHRH agonist. Participants who received prior CDK4/6i or a poly ADP-ribose polymerase (PARP) inhibitor must have already completed or discontinued these treatments.

Exclusion criteria 3

1. Participants with inflammatory breast cancer.
2. History of any prior (ipsilateral and/or contralateral) invasive breast cancer.
3. Participants who had more than 6-month continuous interruption of prior SoC adjuvant endocrine therapy or who discontinued adjuvant endocrine therapy more than 6 months prior to randomization.

Endpoints

Primary and secondary outcome measures (English text)

Primary endpoints 1

1. IBCFS: the time from date of randomization to the date of first occurrence of: • ipsilateral invasive breast tumor recurrence, • local/regional invasive breast cancer recurrence, • distant recurrence, • contralateral invasive breast cancer, or • death attributable to any cause.

Secondary endpoints 9

1. DRFS: the time from randomization to distant recurrence or death from any cause, whichever occurred first.
2. OS: the time from randomization to death from any cause.
3. IDFS: the time from randomization to the first occurrence of local or regional recurrence, contralateral recurrence, second primary non-breast invasive cancer, distant recurrence, or death attributable to any cause.
4. Adverse events (AEs), treatment emergent adverse events (TEAEs) and serious adverse events (SAEs) as well as changes in clinical laboratory values and vital sign measurements.
5. Change from baseline in the global health status quality of life scale score at 6 and 12 months and annually thereafter, as assessed by the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30).
6. Change from baseline in the physical functioning sub-scale score at 6 and 12 months and annually thereafter, as assessed by EORTC QLQ-C30.
7. Change from baseline in the breast cancer Endocrine Therapy Symptoms sub-scale score at 6 and 12 months and annually thereafter, as assessed by the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Breast Cancer module (EORTC QLQ-BR42).
8. Change from baseline in side effects/tolerability at 6 and 12 months and annually thereafter, as assessed by the Question 168 of the European Organization for the Research and Treatment of Cancer Question Library (EORTC Q168).
9. Elacestrant PK parameters, exposure-response analyses between elacestrant PK and efficacy/safety endpoints.

Investigational products

Investigational medicinal products (IMPs), comparators, placebo, auxiliary

Test 2

Comparator 4

Sponsors and contacts

Sponsor organisations, regulatory contacts, third parties

Stemline Therapeutics Inc.

Sponsor organisation

Stemline Therapeutics Inc.

Address

750 Lexington Avenue

City

New York

Postcode

10022-1200

Country

United States

Scientific contact point

Organisation

Stemline Therapeutics Inc.

Contact name

Clinical Development and Clinical Operations

Public contact point

Organisation

Stemline Therapeutics Inc.

Contact name

Clinical Development and Clinical Operations

Third parties 7

Locations

15 EU/EEA countries · 207 investigational sites

By country

Investigational sites

Country notifications

Trial-start, recruitment-start, end and early-termination notifications submitted per Member State

Results and documents

Annex IV summary of results, Annex V layperson summary, and all documents registered in CTIS for this trial

Documents 235 files

Public protocol annexes, IB summaries, regulatory submissions and post-authorisation documents registered in CTIS.

Application history

17 submissions — initial application plus substantial / non-substantial modifications