Clinical trial · Interventional
A Study of Imlunestrant (LY3484356) in Premenopausal Women With Estrogen Receptor-Positive (ER+) Human Epidermal Growth Factor Receptor 2 Negative (HER2-) Early Breast Cancer
preEMBER: A Phase 2, Open-label Study Evaluating Imlunestrant in Premenopausal Women With Estrogen Receptor-Positive, HER2-Negative Breast Cancer
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 26, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260926-000001
Summary
Brief summary (as posted)
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.
Conditions
Conditions (1)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Breast Neoplasms | Breast Neoplasm | ONTOLOGY_EXACT | 0.98 |
Interventions
Interventions (3)
| Intervention | Type | Mapped drug | Match |
|---|---|---|---|
| Goserelin | Drug | Goserelin | ALIAS |
| Imlunestrant | Drug | Imlunestrant | ALIAS |
| Tamoxifen 20 mg | Drug | Tamoxifen | ALIAS |
Design
Arms and outcomes
Arms (5)
- type
- EXPERIMENTAL
- label
- Cohort 1 Arm A
- description
- Imlunestrant will be given orally
- interventionNames
- Drug: Imlunestrant
- type
- EXPERIMENTAL
- label
- Cohort 1 Arm B - Imlunestrant + Goserelin
- description
- Imlunestrant will be given orally and goserelin will be given subcutaneously (SC)
- interventionNames
- Drug: Imlunestrant
- Drug: Goserelin
- type
- ACTIVE_COMPARATOR
- label
- Cohort 1 Arm C - Tamoxifen
- description
- Tamoxifen will be given orally
Eligibility
Eligibility (as posted)
- Sex
- Female
- Minimum age
- 18 Years
Show eligibility criteria text
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 ovarian ablation. * Have a serious medical condition * Had major surgery within 28 days prior to randomization. * Have a history of other cancer (except non melanoma skin cancer, Stage I uterine cancer, or carcinoma in situ of the cervix or other in situ cancer), unless in complete remission with no therapy for a minimum of 1 year. * Plan to receive concurrent neoadjuvant therapy with any other non-protocol anticancer therapy. * Have had any prior therapy for an invasive or non-invasive breast cancer. * Have had prior radiotherapy to the ipsilateral chest wall for any malignancy. * Have received prior anti-estrogen therapy, including for osteoporosis or prevention of breast cancer. * Have had prior treatment with any Gonadotropin-releasing hormone (GnRH) agonist within 12 months prior to randomization. * Receiving current exogenous reproductive hormone therapy Cohort 2: * Have ovarian cyst(s) greater than (\>) 1 centimeter (cm) at screening. * Have metastatic occult primary, or inflammatory breast cancer. * Have had prior bilateral oophorectomy or ovarian ablation. * Have a serious medical condition * Had major surgery within 28 days prior to randomization. * Have a history of other cancer (except non melanoma skin cancer or carcinoma in situ of the cervix or other in situ cancer), unless in complete remission with no therapy for a minimum of 1 year. * Completed or discontinued prior adjuvant ET \>6 months prior to screening. * Have received prior therapy with any selective estrogen receptor degrader (SERD). * Receiving current exogenous reproductive hormone therapy.
References
Publications (0)
Data not yet available