Etanercept and infliximab for the treatment of psoriatic arthritis: a systematic review

OBJECTIVE:

The aim of this review was to evaluate the clinical effectiveness, safety, tolerability and costeffectiveness of etanercept and infliximab for the treatment of active and progressive psoriatic arthritis (PsA) in patients who have inadequate response to standard treatment, including diseasemodifying antirheumatic drug (DMARD) therapy.

BACKGROUND:

PsA is defined as an inflammatory arthropathy associated with psoriasis, which is usually negative for rheumatoid factor (RF) [an antibody produced by plasma cells and found in around 70% of cases of rheumatoid arthritis (RA)]. It is a hyperproliferative and inflammatory arthritis that is distinct from RA and closely associated with psoriasis. Overall, because PsA involves both skin and joints, it can result in significant quality of life impairment, joint deformity and psychosocial disability. Owing to the lack of a precise definition and diagnostic marker for psoriatic arthritis, it is difficult to gauge its prevalence. The UK adjusted prevalence of PsA in the primary care setting has been estimated to be 0.3%. In the UK both etanercept (Enbrel®) and infliximab (Remicade®) are recently licensed drugs for the treatment of adults with active and progressive PsA in patients who have responded inadequately to DMARDs. Both etanercept and infliximab are new biological agents, which target pathological T cell activity (anti-tumour necrosis factors drugs). Other therapies available for the treatment of psoriatic arthritis are DMARDs such as sulfasalazine, methotrexate and ciclosporin, all of which have limitations to their use owing to limited efficacy or serious long-term adverse effects. There is also a new DMARD, leflunomide, which is the only drug other than etanercept and infliximab licensed for the treatment of psoriatic arthritis.