Imlunestrant in Premenopausal ER+ HER2- Early Breast Cancer

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This phase 2 trial has two cohorts enrolling premenopausal women with ER+/HER2- early breast cancer. Cohort 1 compares imlunestrant with and without ovarian suppression against tamoxifen, with treatment up to 29 days and with tumor sample collection around treatment. Cohort 2 evaluates the ovarian effects of imlunestrant without suppression, comparing it to tamoxifen, for up to 6 weeks of treatment. The study is sponsored by Eli Lilly and involves multiple U.S. sites to evaluate biological effects and tolerability in this specific patient population.

Why it matters

Who can join: the full rules

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.

Where it's running

• USC/Norris Comprehensive Cancer Center
  Los Angeles, California, United States Recruiting
• Banner MD Anderson Cancer Center at North Colorado Medical Center
  Greeley, Colorado, United States Recruiting
• Banner MD Anderson Cancer Center at McKee Medical Center
  Loveland, Colorado, United States Recruiting
• Indiana University Melvin and Bren Simon Cancer Center
  Indianapolis, Indiana, United States Recruiting
• New York Cancer and Blood Specialists
  Shirley, New York, United States Recruiting
• Providence Portland Medical Center
  Portland, Oregon, United States Recruiting

+40 more sites. See ClinicalTrials.gov for the full list.

Study contacts

• Study coordinator: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or
• Email: LillyTrials@Lilly.com
• Phone: 1-317-615-4559

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.