A Study of LY3484356 in Women With Breast Cancer Before Having Surgery

NCT04647487 | Completed Phase 1 Results FDA Drug

• 3 other identifiers: 17575J2J-MC-JZLB2020-002810-42
• Study Type: interventional
• Target: 87
• Locations: 6 countries
• Sites: 19

Brief Summary

The purpose for this study is to see if the study drug, LY3484356, is safe and to determine what effects it has on breast cancer in participants with Estrogen Receptor Positive (ER+), HER2 Negative (HER2-) early stage (stage I-III) breast cancer, when given prior to surgery. Participation in this study could last up to 2.5 months.

Conditions

Breast Cancer

Keywords

SERD

Outcome Measures

Primary Outcomes (1)

• Percent Change From Baseline in Estrogen Receptor (ER) Expression

  Tumor tissue collected by biopsy is used to determine ER expression. ER expression is measured by immunohistochemistry (IHC) and quantified by H-score. The H-score was calculated as the sum of multiplying the tumor cell ER staining intensity level 0 to 3 (0=none, 1=low, 2=moderate, 3=high) by the percentage (0 to 100) of cells at each intensity. Total ER H-score ranged from 0 to 300, where a higher score indicated stronger ER expression. Percent change in ER expression was defined as 100\*(ER expression on-treatment - ER expression pre-treatment)/(ER expression pre-treatment). Geometric mean percent change and 90 percent (%) confidence interval for percent change were obtained from a t-test of the log ratio i.e. log(ER expression on-treatment/ER expression pre-treatment).

  Baseline, Day 15

Secondary Outcomes (3)

• Percent Change From Baseline in Ki-67

  Baseline, Day 15

• Percent Change From Baseline in Progesterone Receptor (PR) Expression

  Baseline, Day 15

• Pharmacokinetics (PK): Plasma Concentration of LY3484356

  Day 1: 3.5 hours (h) postdose; Day 8: Predose; Day 8: 3.5 h postdose

Study Arms (3)

200 milligrams (mg) LY3484356

EXPERIMENTAL

Participants received 200 mg LY3484356 administered orally once daily for 15 days

Drug: LY3484356

400 mg LY3484356

EXPERIMENTAL

Participants received 400 mg LY3484356 administered orally once daily for 15 days

Drug: LY3484356

800 mg LY3484356

EXPERIMENTAL

Participants received 800 mg LY3484356 administered orally once daily for 15 days

Drug: LY3484356

Interventions

LY3484356 DRUG

Administered orally.

Also known as: Imlunestrant

200 milligrams (mg) LY3484356; 400 mg LY3484356; 800 mg LY3484356

Eligibility Criteria

• Age: 18 Years+
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Have histologically confirmed invasive ER+, HER2- breast carcinoma
• Be willing and able to provide pre- and on-treatment tumor samples
• Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group scale
• Have adequate organ function
• Be able to swallow capsules
• Be a postmenopausal woman

You may not qualify if:

• Have bilateral invasive breast cancer
• Have metastatic breast cancer
• Plan to receive concurrent neoadjuvant therapy with any other non-protocol anti-cancer therapy
• Have had prior therapy (of any kind) for an invasive or non-invasive breast cancer
• Have had prior radiotherapy to the ipsilateral chest wall for any malignancy
• Have had prior anti-estrogen therapy with raloxifene, tamoxifen, aromatase inhibitor, or other selective estrogen receptor modulator (SERM), either for osteoporosis or prevention of breast cancer
• Have had prior hormone-replacement therapy within 4 weeks of the start of study treatment
• Have had major surgery within 28 days prior to randomization to allow for post-operative healing of the surgical wound and site(s)
• Have certain infections such as hepatitis or tuberculosis or HIV that are not well controlled
• Have another serious medical condition
• Have a history of any other cancer (except nonmelanoma skin cancer or carcinoma in-situ of the cervix), unless in complete remission with no therapy for a minimum of 3 years

Sponsors & Collaborators

• Eli Lilly and Company: lead

Study Sites (19)

Winship Cancer Center Emory University

Atlanta, Georgia, 30322, United States

Location

Northwestern Memorial Hosptial

Chicago, Illinois, 60611, United States

Location

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

Location

Washington University School of Medicine

St Louis, Missouri, 63110, United States

Location

Sarah Cannon Research Institute SCRI

Nashville, Tennessee, 37203, United States

Location

Baylor College of Medicine

Houston, Texas, 77030, United States

Location

University of Texas MD Anderson Cancer Center

Houston, Texas, 77030, United States

Location

University of Vermont Medical Center

Burlington, Vermont, 05401, United States

Location

Institut Jules Bordet

Brussel - Capital, 1070, Belgium

Location

Universitaire Ziekenhuizen Leuven - Campus Gasthuisberg

Leuven, 3000, Belgium

Location

Hôpital René Huguenin

Saint-Cloud, Hauts-de-Seine, 92210, France

Location

Universitätsklinikum Erlangen

Erlangen, Bavaria, 91054, Germany

Location

Helios Kliniken Schwerin

Schwerin, Mecklenburg-Vorpommern, 19049, Germany

Location

Klinikum der Universitaet Muenchen

München, 80336, Germany

Location

Hospital Clinic I Provincial

Barcelona, 08036, Spain

Location

Hospital General Universitario Gregorio Marañon

Madrid, 28007, Spain

Location

Hospital Madrid Norte Sanchinarro

Madrid, 28050, Spain

Location

The Royal Cornwall Hospital

Truro, Cornwall, TR1 3LJ, United Kingdom

Location

Barts Cancer Institute

London, London City, EC1A 7BE, United Kingdom

Location

Related Links

• A Study of LY3484356 in Women With Breast Cancer Before Having Surgery (EMBER-2)

MeSH Terms

Conditions

Breast Neoplasms

Interventions

Imlunestrant

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Results Point of Contact

• Title: Chief Medical Officer
• Organization: Eli Lilly and Company

ClinicalTrials.gov@lilly.com

800-545-5979

Study Officials

• Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST)

  Eli Lilly and Company

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: GT60
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 30, 2020
• First Posted: December 1, 2020
• Study Start: April 21, 2021
• Primary Completion: November 11, 2022
• Study Completion: November 11, 2022
• Last Updated: November 12, 2025
• Results First Posted: November 12, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

GB (2); US (8); BE (2); ES (3); FR (1); DE (3)