Tofacitinib is intended to be used as second line therapy for the treatment of chronic moderate-to-severe plaque psoriasis. If licensed, it will provide an additional oral treatment option for this patient group. Tofacitinib is a novel janus kinase (JAK) inhibitor that inhibits JAK1, 2 and 3 in vitro, with functional specificity for JAK1 and 3. Inhibition of JAK1 and 3 blocks signalling of several cytokines which are required for lymphocyte activation, proliferation, and function, and therefore may result in modulation of the immune response. Tofacitinib does not currently have Marketing Authorisation in the EU for any indication.
An estimated 900,000 people have psoriasis in England, with around 90% of these being plaque psoriasis. Approximately 20% have moderate-to-severe disease. Plaque psoriasis is characterised by well-delineated red scaly plaques on the skin that vary in extent from a few patches to generalised involvement. The plaques are often painful and severely itchy, with flare-ups triggered by factors such as stress, anxiety, hormonal changes, or certain infections or medications. Due to the visible nature of psoriasis, those affected may experience profound function, psychological, and social morbidity, and as a result may suffer unemployment, social isolation, and depression.
Topical treatments are offered as first line therapy, followed by phototherapy and/or systemic therapies as second line treatment, and biological therapies as third line regimes. Tofacitinib is currently in a number of phase III clinical trials comparing its effect on psoriasis severity against treatment with placebo, and etanercept.
Secukinumab as a subcutaneous injection is in clinical development for the treatment of enthesitis related arthritis (ERA) and juvenile psoriatic arthritis (JPsA). These conditions belong to a group of arthritis conditions of unknown cause known as juvenile idiopathic arthritis which affect children. JPsA patients have arthritis and psoriasis, an inflammatory skin disease and ERA patients have arthritis and enthesitis, inflammation of the ligaments and tendons. These conditions are the result of the immune system mistakenly attacking the body’s own cells at the joints and the skin or tendons, causing swelling, pain and reduced mobility.