Inhibition of Co-Stimulation in Rheumatoid Arthritis

Study Overview
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Brief Summary
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The purpose of this study is to use abatacept as a clinical molecular probe to evaluate the effects of inhibiting costimulation on immune responses in patients with rheumatoid arthritis (RA).

Detailed Description
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Rheumatoid arthritis (RA) is a chronic inflammatory immune mediated arthritis which leads to pain, swelling and destruction of joints. RA affects more than 500,000 subjects in the United Kingdom (UK) and incurs significant health and economic cost. Most patients require potent immune suppressing drugs such as methotrexate, which help reduce pain and stiffness, and protect the joints against damage. However, many patients do not respond or are unable to tolerate methotrexate. In these patients, biologic drugs such as abatacept are used to try to control the arthritis. Abatacept is designed to target and inhibit a specific molecule involved in costimulation of the inflammatory signal that is thought to be important in RA. While abatacept has been shown to be effective in trials and clinical practice, the exact mechanism of action of abatacept in RA has not been fully elucidated. Understanding these actions is likely to inform both the use of abatacept in RA and lead to increased understanding of inflammation in humans with implications for further therapies. This six month prospective open label study, therefore, aims to investigate the effects of inhibiting costimulation on a variety of important inflammatory cell types and processes in humans with RA. 25 participants with RA who have bad prognostic genetic markers (Anti-citrullinated protein antibodies (ACPA) and human leukocyte antigen (HLADR4) and who were scheduled to receive subcutaneous abatacept as part of their standard clinical treatment will be recruited. Consenting participants will followed for a total of 24 weeks during which time they will have additional venous blood and urine samples taken to investigate the effects of abatacept on their immune cells and system. The primary endpoint of the study is the characterisation of the immune response following costimulatory modulation in RA patients at 12 weeks. Secondary endpoints include change in immunological response and its association with clinical outcome measures up to 24 weeks.

Official Title
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Inhibition of Co-Stimulation in Rheumatoid Arthritis

Conditions
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Arthritis, Rheumatoid

Intervention / Treatment
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* Drug: Abatacept


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: RA as defined by the 2010 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria Eligible for abatacept therapy according to local/national guidelines Active RA defined by DAS28 score required by local guidelines for eligibility for abatacept Have previously failed (efficacy or tolerance) at least one disease-modifying antirheumatic drug (DMARD) Have no contraindications to treatment with abatacept Be able to tolerate methotrexate at dose of 10-25mg/week, either orally or subcutaneously Anti-cyclic citrullinated peptide (CCP) positive Human leukocyte antigen D related (HLA-DR) B1*0401 or 0404) positive Able and willing to give written informed consent and comply with the requirements of the study protocol Exclusion Criteria: History of or current autoimmune rheumatic disease other than RA Concomitant use of any biologic agent, including tumor necrosis factor (TNF) inhibitors Previous abatacept treatment Patients requiring >10mg prednisolone daily or intramuscular (IM) corticosteroids Active infection Known HIV or hepatitis B/C infection Latent tuberculosis (TB) infection Malignancy (other than non-melanoma skin cell cancers) within 5 years Women who are pregnant, women of childbearing potential who are unwilling to use appropriate contraception or breast-feeding Inability to give informed consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Abatacept<br>Abatacept 125mg administered via subcutaneous injection once a week for 24 weeks | Drug: Abatacept<br>* Abatacept 125mg/ml<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immunological response | Change in T cell immune response to citrullinated peptides following costimulatory modulation | Baseline and 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Immunological response | Change in immunological response from baseline, as measured by transcriptional profile of relevant cell subset | Baseline, 4, 12 and 24 weeks | 
| Clinical response American College of Rheumatology (ACR) 20 | Change in ACR 20 from baseline | Baseline and 24 weeks | 
| Clinical response Disease Activity Score (DAS)28 | Change in DAS 28 from baseline | Baseline and 24 weeks | 
| T cell profile | Change in T cell subpopulation profile from baseline | Baseline, 12 and 24 weeks | 
| T cell response | Antigen-specific T cell response to tetanus | 24 weeks | 
| DC (CD11c+) phenotype | Dendritic cell (DC) (CD11c+) phenotype as measured by major histocompatibility complex (MHC) II expression | 24 weeks | 
| Biomarkers | Preliminary identification of biomarkers of response using urinary metabol/proteomic analysis | 24 weeks |