NCT07258849

A Study of LY4213663 in Healthy Participants and Participants With Rheumatoid Arthritis

A Phase 1, Multicenter, Randomized, Placebo-Controlled, Investigator- and Participant-Blinded, Single- and Multiple-Ascending Dose Study to Evaluate Safety, Tolerability, and Pharmacokinetics of LY4213663 in Healthy Participants, and Two Open-Label, Multiple-Dose Evaluations of LY4213663 in Patients With Rheumatoid Arthritis.

• Status: Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 134 (estimated)
• Sponsor: Eli Lilly and Company · Industry
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

The purpose of this study is to evaluate how well LY4213663 is tolerated and what side effects may occur in healthy participants and participants with rheumatoid arthritis (RA). The study drug will be administered either subcutaneously (SC) (under the skin) or intravenously (IV) (into a vein in the arm). Blood tests will be performed to investigate how the body processes the study drug and how the study drug affects the body. The study will last approximately 33 weeks excluding screening.

Conditions

• Healthy
• Rheumatoid Arthritis (RA)

Interventions

Type	Name	Description
DRUG	LY4213663	Administered SC
DRUG	LY4213663	Administered IV
DRUG	Placebo	Administered SC
DRUG	Placebo	Administered IV

Timeline

• Start date: 2025-12-02
• Primary completion: 2028-03-01
• Completion: 2028-03-01
• First posted: 2025-12-02
• Last updated: 2026-04-17

Locations

9 sites across 1 country: United States

Regulatory

• FDA-regulated drug study