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

Status

Recruiting

Phases

Phase 1

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT07284797

Enrollment

Registered

2025-12-16

Start date

2026-02-24

Completion date

2028-10-01

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy, Idiopathic Inflammatory Myopathies, Sjögren's Disease, Systemic Sclerosis

Keywords

Myopathy, Myositis, Scleroderma, Autoimmune Diseases, IIM, SjD, SSc

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.

Detailed description

This is a Phase 1 study to determine the safety, tolerability, pharmacokinetic (PK), and pharmacodynamics (PD), and immunogenicity of XmAb657 in healthy adult participants and participants with autoimmune diseases.

Interventions

BIOLOGICALXmAb657

Biological

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 75 Years

Healthy volunteers

Yes

Inclusion criteria

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

Exclusion criteria

* 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 Note: Additional, more specific inclusion/

Design outcomes

Primary

Measure	Time frame
Percentage of participants with treatment emergent adverse events (TEAEs) and serious adverse events (SAEs)	Through Week 52

Secondary

Measure	Time frame
Serum concentration of XmAb657	Through Week 52

Countries

Australia

Contacts

CONTACT657-01 Study Information

657-aiinfo@xencor.com

STUDY_DIRECTOR657-01 Study Information

Xencor, Inc.

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 4, 2026