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

Lilly

Status and phase: Enrolling; Phase 1

Conditions: Healthy; Rheumatoid Arthritis (RA)

Treatments: Drug: LY4213663; Drug: Placebo

Study type: Interventional

Funder types: Industry

Identifiers

NCT07258849

2025-523980-39-00 (EU Trial (CTIS) Number)

J6T-MC-KYAA (Other Identifier)

27749

Details and patient eligibility

About

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.

Enrollment: 134 estimated patients

Sex: All

Ages: 18 to 75 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Have a body mass index (BMI) of 18.0 to 32.0 kilogram per square meter (kg/m²), inclusive

Part C and D Only:

• Have a body weight at least 50 kilograms and BMI within the range 18.0 to 40.0 kg/m² (inclusive) at screening
• Have a diagnosis of adult-onset RA for at least 3 months prior to screening

Exclusion criteria

Healthy Participants for SAD Part A and MAD Part B Only:

• Have a history or presence of cardiovascular, respiratory, hepatic, ophthalmological, renal, gastrointestinal, endocrine, hematological, neurological, or psychiatric disorders capable of significantly altering the absorption, metabolism, or elimination of drugs

Participants with RA for Parts C and D Only:

• Have Class 4 RA according to American College of Rheumatology (ACR) revised criteria
• Have a 12-lead electrocardiogram (ECG) abnormality at screening
• Have a current or recent acute active infection

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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134 participants in 5 patient groups, including a placebo group

LY4213663 (Part A)

Experimental group

Description:

Single-ascending dose (SAD) of LY4213663 administered subcutaneously (SC) and intravenously (IV) in healthy participants

Treatment:

Drug: LY4213663

Drug: LY4213663

Placebo (Part A)

Placebo Comparator group

Description:

SAD placebo administered SC and IV

Treatment:

Drug: Placebo

Drug: Placebo

LY4213663 (Part B)

Experimental group

Description:

Multiple-ascending doses (MAD) of LY4213663 administered SC and IV in healthy participants

Treatment:

Drug: LY4213663

Drug: LY4213663

Placebo (Part B)

Placebo Comparator group

Description:

MAD placebo administered SC and IV

Treatment:

Drug: Placebo

Drug: Placebo

LY4213663 (Parts C and D)

Experimental group

Description:

Multiple doses of LY4213663 administered SC and IV in participants with RA

Treatment:

Drug: LY4213663

Drug: LY4213663