A Study of Imlunestrant (LY3484356) in Premenopausal Women With Estrogen Receptor-Positive (ER+) … (NCT07287098) | Clinical Trial Compass
RecruitingPhase 2
A Study of Imlunestrant (LY3484356) in Premenopausal Women With Estrogen Receptor-Positive (ER+) Human Epidermal Growth Factor Receptor 2 Negative (HER2-) Early Breast Cancer
United States, Belgium, France600 participantsStarted 2026-05-13
Plain-language summary
This study will include two groups of patients: Cohort 1 and Cohort 2.
Cohort 1: will help researchers learn how a medicine called imlunestrant (LY3484356) affects a specific type of breast cancer. Some patients will take both imlunestrant and another treatment to suppress their ovarian function. Some will take it without ovarian suppression. Researchers will compare the effects in breast cancer cells to those of another medicine called tamoxifen. All patients in this group will be premenopausal women who have a type of early breast cancer called estrogen receptor-positive, HER2-negative. The treatment in this group will last for up to 29 days.
Cohort 2: will help researchers understand how imlunestrant affects the ovaries when it is taken without ovarian suppression. Researchers will compare the effects to those of another medicine called tamoxifen. This group will also include premenopausal women with the same type of breast cancer. The treatment in this group will last for up to 6 months.
Who can participate
Age range
18 Years
Sex
FEMALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
Cohort 1:
* Have histologically confirmed Stage I to III Estrogen Receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) invasive breast carcinoma with Ki-67 at least 10%
* Be willing and able to provide pre- and on-treatment tumor samples.
* Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
* Be able to swallow capsules or tablets.
* Be premenopausal women.
* If of childbearing potential must use 1 highly effective method of non-hormonal contraception while receiving study treatment and for the duration specified in protocol.
* Have adequate organ function.
Cohort 2:
* Have a diagnosis of ER+, HER2- early-stage, resected, invasive breast cancer without evidence of distant metastasis
* Have undergone definitive loco-regional therapy.
* Have received at least 4.5 years of any adjuvant endocrine therapy (ET), or at least 2 years of adjuvant ET with no additional ovarian suppression planned.
* Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
* Be able to swallow capsules or tablets.
* Be premenopausal women
* If of childbearing potential must use 1 highly effective method of non-hormonal contraception while receiving study treatment and for the duration specified in protocol.
* Have adequate organ function.
Exclusion Criteria:
Cohort 1:
* Have bilateral invasive metastatic, occult primary, or inflammatory breast cancer.
* Have had prior bilateral oophorectomy or ov…
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1This trial is specifically for premenopausal women with ER-positive, HER2-negative early breast cancer — based on my diagnosis and menopausal status, is this the kind of trial that would even make sense to consider for my situation?
2The trial is measuring changes in Ki-67, which is a marker of how fast cancer cells are growing — can you explain what that means for me and how tracking it in a Phase 2 study like this differs from having solid proof that the drug improves long-term outcomes?
3One of the things this trial is specifically monitoring is the rate of symptomatic ovarian cysts — how common is that side effect with this type of drug, and what would it mean for my health or fertility if that happened to me?
4Since this trial is listed as not yet recruiting, how would we even know when it opens, and is there a standard treatment I should be starting now rather than waiting to see if I might be eligible?
5Imlunestrant is being studied as a newer type of estrogen receptor-targeting drug — how does it compare to the hormone therapies that are already available for early-stage ER-positive breast cancer, and why might a doctor consider one over the other for someone in my situation?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Change from Baseline in Antigen Kiel (Ki-67) Expression
Timeframe: Baseline, Day 29
2
Rate of Symptomatic Ovarian Cysts
Timeframe: Up to Day 180
Trial details
NCT IDNCT07287098
SponsorEli Lilly and Company
Sponsor typeINDUSTRY
Study typeINTERVENTIONAL
Primary completion2029-01
Contact for this trial
Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or