Tofacitinib: A Review in Psoriatic Arthritis

Tofacitinib (Xeljanz((R))) is the first Janus kinase (JAK) inhibitor approved at a dosage of 5mg twice daily (BID) in the EU and the USA for the treatment of active psoriatic arthritis (PsA), where it is indicated in combination with methotrexate for patients who have had an inadequate response or who have been intolerant to a prior therapy with a disease-modifying antirheumatic drug (DMARD). Two well-designed phaseIII trials (OPAL Broaden and OPAL Beyond) in patients with PsA with or without prior tumour necrosis factor inhibitor (TNFi) therapy showed that tofacitinib 5mg BID (co-administered with methotrexate or another approved conventional synthetic DMARD) significantly improved the key clinical signs/symptoms and disability associated with PsA after 3months of treatment, while also improving skin psoriasis, enthesitis, dactylitis, physical function and fatigue. According to interim data, the improvements in clinical signs/symptoms were maintained for up to 30months in the ongoing long-term extension study OPAL Balance, with minimal radiographic progression seen after 12months' therapy in the OPAL Broaden study. Tofacitinib 5mg BID had an acceptable tolerability profile, with low incidences of serious infections, malignancies, cardiovascular events and gastrointestinal perforations over 36months. Changes in laboratory parameters generally remained stable over 36months of treatment. Although further studies are required to more definitively establish its efficacy and safety, currently available evidence indicates that tofacitinib expands the treatment options available for the treatment of PsA in patients who have had an inadequate response or who have been intolerant to a prior DMARD therapy.