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.
3 other identifiers
interventional
141
1 country
9
Brief 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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_1
Started Dec 2025
Typical duration for phase_1
9 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
November 21, 2025
CompletedFirst Posted
Study publicly available on registry
December 2, 2025
CompletedStudy Start
First participant enrolled
December 2, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
March 1, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
March 1, 2028
May 4, 2026
April 1, 2026
2.2 years
November 21, 2025
April 28, 2026
Conditions
Outcome Measures
Primary Outcomes (1)
Number of Participants with One or More Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration
A summary of SAEs regardless of causality, will be reported in the Reported Adverse Events module
Baseline up to Week 33
Secondary Outcomes (2)
Pharmacokinetics (PK): Maximum Concentration (Cmax) of LY4213663
Baseline up to Week 33
PK: Area Under the Concentration Versus Time Curve (AUC) of LY4213663
Baseline up to Week 33
Study Arms (5)
LY4213663 (Part A)
EXPERIMENTALSingle-ascending dose (SAD) of LY4213663 administered subcutaneously (SC) and intravenously (IV) in healthy participants
Placebo (Part A)
PLACEBO COMPARATORSAD placebo administered SC and IV
LY4213663 (Part B)
EXPERIMENTALMultiple-ascending doses (MAD) of LY4213663 administered SC and IV in healthy participants
Placebo (Part B)
PLACEBO COMPARATORMAD placebo administered SC and IV
LY4213663 (Parts C and D)
EXPERIMENTALMultiple doses of LY4213663 administered SC and IV in participants with RA
Interventions
Eligibility Criteria
You may qualify if:
- 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
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (9)
Pinnacle Research Group, LLC
Anniston, Alabama, 36207, United States
Arizona Research Center
Phoenix, Arizona, 85053, United States
Clinical Research of West Florida, Inc. (Clearwater)
Clearwater, Florida, 33765, United States
GNP Research at Mark Jaffe, MD
Cooper City, Florida, 33024, United States
Fortrea Clinical Research Unit
Daytona Beach, Florida, 32117, United States
AGA Clinical Trials
Hialeah, Florida, 33012, United States
Advanced Pharma CR, LLC
Miami, Florida, 33417, United States
Floridian Clinical Research
Miami Lakes, Florida, 33016, United States
Oasis Clinical Research
Las Vegas, Nevada, 89121, United States
Related Links
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- STUDY DIRECTOR
Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 8 AM - 8 PM Eastern time (UTC/GMT - 5 hours, EST)
Eli Lilly and Company
Central Study Contacts
Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or
CONTACT
Physicians interested in becoming principal investigators please contact
CONTACT
Study Design
- Study Type
- interventional
- Phase
- phase 1
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
November 21, 2025
First Posted
December 2, 2025
Study Start
December 2, 2025
Primary Completion (Estimated)
March 1, 2028
Study Completion (Estimated)
March 1, 2028
Last Updated
May 4, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will not share