A Phase 1 Open-label Study to Evaluate Safety in Healthy Participants and Participants With Autoimmune Diseases
A Phase 1, First-in-Human, Open-Label, Dose-Escalation Study to Evaluate the Safety and Tolerability, Pharmacokinetics, and Pharmacodynamics of XmAb657 in Healthy Participants and in Participants With Autoimmune Diseases
1 other identifier
interventional
60
1 country
1
Brief Summary
The purpose of this study is to determine the safety and tolerability of XmAb657 in healthy participants and participants with autoimmune diseases. Participants will be given XmAb657 subcutaneously (SC) by injection under the skin.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_1 healthy
Started Feb 2026
Longer than P75 for phase_1 healthy
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
December 3, 2025
CompletedFirst Posted
Study publicly available on registry
December 16, 2025
CompletedStudy Start
First participant enrolled
February 24, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
October 1, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
October 1, 2028
May 22, 2026
May 1, 2026
2.6 years
December 3, 2025
May 20, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Percentage of participants with treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)
Through Week 52
Secondary Outcomes (1)
Serum concentration of XmAb657
Through Week 52
Study Arms (1)
Dose Escalation
EXPERIMENTALXmAb657 administered SC
Interventions
Eligibility Criteria
You may qualify if:
- Healthy participants - Adult participants in good health
- Idiopathic inflammatory myopathy (IIM) participants - Adult participants that meet the 2017 European Alliance of Association Rheumatology (EULAR)/American College of Rheumatology (ACR) Classification Criterion for IIM
- Systemic sclerosis (SSc) participants - Adult participants that meet the 2013 ACR/EULAR Classification Criteria for SSc
- Sjogren's Disease participants that meet the 2016 ACR/EULAR Classification Criteria for Primary Sjogren's Syndrome
- All participants - Use of highly effective methods of contraception
You may not qualify if:
- Major surgery within 12 weeks prior to dosing or planned within the study
- Recurrent infections or active clinically significant infection
- Active or untreated latent tuberculosis
- Cancer or history of cancer or lymphoproliferative disease within the previous 5 years
- Uncontrolled cardiovascular, pulmonary, renal, hepatic, endocrine, or gastrointestinal disease
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Xencor, Inc.lead
Study Sites (1)
Xencor Investigative Site
Melbourne, Australia
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- STUDY DIRECTOR
Mark Osterman, MD, MSCE
Xencor, Inc.
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 1
- Allocation
- NA
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
December 3, 2025
First Posted
December 16, 2025
Study Start
February 24, 2026
Primary Completion (Estimated)
October 1, 2028
Study Completion (Estimated)
October 1, 2028
Last Updated
May 22, 2026
Record last verified: 2026-05