A Study to Learn About a Medicine Called PF-08154225 in Participants With Autoimmune Diseases

NCT07782450 | Not Yet Recruiting Phase 1 DMC

• 1 other identifier: C6441001
• Study Type: interventional
• Target: 54
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this study is to learn about the safety and effects of the study medication called PF-08154225 for the potential treatment of autoimmune diseases. An autoimmune disease is a condition that makes a person's immune system attack its healthy cells by mistake. This study is particularly looking at autoimmune diseases called as Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA), Idiopathic Inflammatory Myositis (IIM) or Systemic Sclerosis (SSc). This study is divided into 3 parts: Part 1a, Part 1b and Part 2. Parts 1a and 1b are seeking participants with Systemic Lupus Erythematosus (SLE) or Rheumatoid Arthritis and Part 2 with also Idiopathic Inflammatory Myositis (IIM) or Systemic Sclerosis (SSc). Participants can take part only in one part of the study. All participants in this study will receive PF-08154225 at the study clinic. In Part 1a participants will receive single administration of PF-08154225 after which they will be observed at the study clinic during regular visits through week 16 or longer. In Part 1b the participants will receive multiple administration of PF-08154225 after which they will be monitored in similar a manner as in Part 1a through week 24 or longer. In Part 2 participants will receive multiple administrations of PF-08154225. After the last injection they will be monitored for safety through week 52 or longer.

Conditions

Systemic Lupus Erythematosus; Rheumatoid Arthritis; Idiopathic Inflammatory Myositis; Systemic Sclerosis

Outcome Measures

Primary Outcomes (3)

• Incidence and severity of Treatment Emergent Adverse Event (AE) including protocol specified adverse event of special interest(AESI)

  An AE is defined as any untoward medical event that occurs after a participant receives the investigational drug, which may be manifested as symptoms, signs, diseases, or laboratory abnormalities, but may not necessarily have a causal relationship with the investigational drug.

  From first dose through End of Study (up to Week 16 in Part 1a, Week 24 in Part 1b and Week 52 in Part2)

• Dose Limiting Toxicity (DLT)

  During the DLT observation period (up to 22 days after the last dose)

• Frequencies of abnormal safety laboratory tests, vital signs, ECGs.

  From first dose of study intervention through End of Study (up to Week 16 in Part 1a, Week 24 in Part 1b and Week 52 in Part 2)

Secondary Outcomes (22)

• Maximum Observed Serum Concentration (Cmax) of PF-08154225

  From first dose through the last pharmacokinetic assessment (up to Week 16 in Part 1a and up to Week 24 in Part 1b)

• Time to Maximum Observed Serum Concentration (Tmax) of PF-08154225

  From first dose through the last pharmacokinetic assessment (up to Week 16 in Part 1a and up to Week 24 in Part 1b)

• Area Under the Serum Concentration-Time Curve (AUC) of PF-08154225

  From first dose through the last pharmacokinetic assessment (up to Week 16 in Part 1a and up to Week 24 in Part 1b)

• Circulating B-Cell Counts

  From first dose of study intervention through End of Study (Week 16 for Part 1a, week 24 for Part 1b and Week 52 for Part 2 or longer if extension of the follow up was needed

• Participants With Anti-Drug Antibodies (ADAs) Against PF-08154225

  From first dose of study intervention through End of Study (Week 16 for Part 1a, Week 24 for Part 1b and Week 52 for Part2

Study Arms (1)

several cohorts with the target doses

EXPERIMENTAL

Single and multiple dose cohorts. Part 1: Participants will receive different target doses of PF-08154225 in a single and multiple dose escalation stage to evaluate their safety, tolerability, Pharmacokinetic (PK), Pharmacodynamic (PD). Part 2: Participants will receive different doses of PF-08154225 in an open label single arm setting to evaluate their safety, tolerability, PK, PD and preliminary efficacy.

Drug: PF-08154225

Interventions

PF-08154225 DRUG

immune-modulating agent

several cohorts with the target doses

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• At age between 18 and 70 years at Screening.
• Confirmed diagnosis of RA according to the 2010 American College of Rheumatology (ACR)/ European Alliance of Associations for Rheumatology (EULAR) criteria at Screening, with symptom at least 6 months prior to Screening
• Clinical diagnosis of SLE according to the 1997 ACR Criteria for the Classification of SLE Or confirmed diagnosis of SLE according to the Systemic Lupus International Collaborating Clinics (SLICC) Classification Criteria at Screening, with symptom at least 6 months prior to Screening.
• Clinical diagnosis of 1 of the 3 IIM subtypes based on phenotype, and/or prior muscle biopsy, and positive myositis-specific autoantibody (MSA) / myositis-associated antibody (MMA)
• Classification of SSc according to the 2013 ACR/EULAR criteria at Screening

You may not qualify if:

• Any medical or psychiatric condition, including active suicidal ideation or any laboratory abnormality, that increases study risk or makes the participant unsuitable.
• Active central nervous system (CNS) co-morbidity
• Any complications of disease under study that in the judgement of the investigator may be life or organ threatening or require prohibited medication
• Known history of a primary immunodeficiency, splenectomy, or any underlying condition that predisposes the participant to infection
• Active or recent clinically significant infections
• Chronic or active Hepatitis B and C
• Past or current therapies with T-cell engager (TCEs), bone marrow cell transplant, stem cell transplant, chimeric antigen receptor T-cell (CAR-T) cell therapy.
• For SLE, no catastrophic or severe antiphospholipid syndrome (APS), severe unstable neuropsychiatric SLE.
• Felty's syndrome, juvenile arthritis or idiopathic arthritis before age of 16
• SSc renal crisis within 6 months prior to screening, UIP pattern if entering on interstitial lung disease interstitial lung disease (ILD) criteria

Sponsors & Collaborators

• Syneos: collaborator
• Pfizer: lead

Related Links

• To obtain contact information for a study center near you, click here.

MeSH Terms

Conditions

Lupus Erythematosus, Systemic; Arthritis, Rheumatoid; Myositis; Scleroderma, Systemic

Condition Hierarchy (Ancestors)

Connective Tissue Diseases; Skin and Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Muscular Diseases; Neuromuscular Diseases; Nervous System Diseases; Skin Diseases

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Central Study Contacts

Pfizer CT.gov Call Center

CONTACT

1-800-718-1021; ClinicalTrials.gov_Inquiries@pfizer.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: open label, single arm, sequential dose escalation cohorts

Study Record Dates

• First Submitted: August 11, 2026
• First Posted: August 24, 2026
• Study Start (Estimated): September 10, 2026
• Primary Completion (Estimated): February 22, 2031
• Study Completion (Estimated): February 22, 2031
• Last Updated: August 28, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share