A Study of Imlunestrant (LY3484356) in Healthy Women

The Effect of Repeat Dosing of Imlunestrant on CYP3A Activity in Healthy Women of Non-childbearing Potential

The main purpose of this study is to evaluate the effect of imlunestrant (LY3484356) when administered orally on the levels of midazolam in the blood stream in healthy women of non-childbearing potential. The study will also evaluate the safety and tolerability of imlunestrant in healthy women of non-childbearing potential. This study will last up to approximately 6 weeks for each participant including the screening period.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Drug: Midazolam; Drug: Imlunestrant

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Florida
    • Daytona Beach, Florida, United States, 32117
      • LabCorp CRU, Inc.
  • Texas
    • Dallas, Texas, United States, 75247
      • LabCorp CRU, Inc.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Women not of childbearing potential
• Participants who are overtly healthy as determined by medical assessment
• Participants with body mass index (BMI) of 18.0 and 35.0 kilograms per meter squared (kg/m²), inclusive

Exclusion Criteria:

• Have known allergies to imlunestrant, related compounds or any components of the formulation or midazolam
• Significant history or clinical manifestation of any metabolic, allergic, dermatological, hepatic, renal, hematological, pulmonary, cardiovascular, gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder
• Use or intend to use medications that are substrate drugs of P-glycoprotein

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Midazolam + Imlunestrant; Participants received 400 milligram (mg) Imlunestrant (2 × 200 mg) tablets administered once daily (QD) orally for 7 days on Days 3 to 9 and a single dose of 0.5 mg midazolam solution orally on Day 1 and Day 9 as per below dosing sequence: Day 1: 0.5 mg midazolam alone Days 3 to 8: 400 mg imlunestrant QD alone Day 9: 0.5 mg midazolam + 400 mg imlunestrant There was a washout period of 8 days between doses of midazolam.

Drug: Midazolam; Administered orally.; Drug: Imlunestrant; Administered orally.; Other Names: LY3484356

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pharmacokinetics (PK): Area Under the Concentration Versus Time Curve From Zero to Infinity (AUC[0-∞]) of Midazolam	PK: AUC[0-∞] of Midazolam	Day 1: Predose, 0.25hours (h), 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h and 24h postdose; Day 9: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h, 24, 36, 48h postdose
PK: Maximum Observed Concentration (Cmax) of Midazolam	PK: Cmax of Midazolam	Day 1: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h and 24h postdose; Day 9: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h, 24, 36, 48h postdose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PK: AUC[0-∞] of 1'-Hydroxymidazolam	PK: AUC[0-∞] of 1'-hydroxymidazolam	Day 1: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h and 24h postdose; Day 9: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h, 24, 36, 48h postdose
PK: Cmax of 1'-Hydroxymidazolam	PK: Cmax of 1'-hydroxymidazolam	Day 1: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h and 24h postdose; Day 9: Predose, 0.25h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h, 24, 36, 48h postdose
PK: Area Under the Concentration Versus Time Curve From Zero to 24 Hours at Steady State (AUC[0-24], ss) of Imlunestrant When Dosed in the Presence of Midazolam	PK: AUC[0-24], ss of Imlunestrant	Day 9: Predose, 0.25 h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h and 24h postdose
PK: Maximum Observed Concentration at Steady State (Cmax, ss) of Imlunestrant When Dosed in the Presence of Midazolam	PK: Cmax, ss of Imlunestrant when dosed in the presence of Midazolam is evaluated.	Day 9: Predose, 0.25 h, 0.5h, 1h, 2h, 3h, 4h, 6h, 8h, 12h and 24h postdose

Collaborators and Investigators

• Sponsor: Eli Lilly and Company
• Investigators: Study Director: 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 record dates

Study Major Dates

• Study Start (Actual): September 12, 2022
• Primary Completion (Actual): November 30, 2022
• Study Completion (Actual): November 30, 2022

Study Registration Dates

• First Submitted: August 19, 2022
• First Submitted That Met QC Criteria: August 19, 2022
• First Posted (Actual): August 22, 2022

Study Record Updates

• Last Update Posted (Actual): November 12, 2025
• Last Update Submitted That Met QC Criteria: October 22, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Benzazepines; Benzodiazepines; Midazolam; Imlunestrant
• Other Study ID Numbers: 18416; J2J-MC-JZLK (Other Identifier: Eli Lilly and Company)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No