Arthritis Prevention In the Pre-clinical Phase of Rheumatoid Arthritis with Abatacept

INTERVENTION: Participants will be randomised into one of two arms: 1. Abatacept 2. Matching placebo Participants will receive weekly injections of 125 mg/ml of abatacept or placebo, starting from baseline (week 0) for a period of 52 weeks. They will be trained to self‐administer the study drug subcutaneously using the single‐dose prefilled syringe according to local practices for the administration of biological therapy as part of standard care. They will be followed up for an additional period of 52 weeks. Participants will be seen at 3 monthly intervals throughout the duration of the study. CONDITION: Topic: Musculoskeletal disorders; Subtopic: Musculoskeletal (all Subtopics); Disease: Musculoskeletal ; Musculoskeletal Diseases PRIMARY OUTCOME: Time to development of clinical synovitis or RA SECONDARY OUTCOME: The development of RA according to the ACR/EULAR 2010 criteria INCLUSION CRITERIA: 1. Male or female subjects, aged 18 years or over 2. Arthralgia, defined as non‐traumatic joint pain localised to synovial joints including, but not necessarily confined to, hands, wrists or feet, and in the opinion of the supervising rheumatologist considered to be inflammatory in nature 3. Positive for serum rheumatoid factor (RF) and antibodies to citrullinated protein antigens (ACPA) as defined by local clinical laboratory testing. Subjects who are RF negative, but who carry high levels of serum ACPA (defined as being = 3 x upper limit of normal [ULN] for the assay) may be included 4. Able and willing to give written informed consent and comply with the requirements of the study protocol