2 The technology
2.1 Ustekinumab (Stelara, Janssen) is a monoclonal antibody that acts as a cytokine inhibitor by targeting interleukin‑12 (IL‑12) and interleukin‑23 (IL‑23). It is administered by subcutaneous injection. Ustekinumab has a marketing authorisation in the UK for use alone or in combination with methotrexate 'for the treatment of active psoriatic arthritis in adult patients when the response to previous non‑biological disease‑modifying antirheumatic drug (DMARD) therapy has been inadequate'.
2.2 The summary of product characteristics lists the following common adverse reactions for ustekinumab: dental and upper respiratory tract infections, nasopharyngitis, dizziness, headache, oropharyngeal pain, diarrhoea, nausea, pruritus, back pain, myalgia, arthralgia, fatigue, injection‑site erythema and injection‑site pain. For full details of adverse reactions and contraindications, see the summary of product characteristics.
2.3 The list price for ustekinumab is £2147 per 45‑mg vial (excluding VAT; British national formulary online [accessed February 2015]). The recommended dose of ustekinumab is an initial dose of 45 mg, followed by a dose 4 weeks later and further doses every 12 weeks thereafter. A dose of 90 mg may be used in people with a body weight over 100 kg. The summary of product characteristics notes that consideration should be given to stopping treatment in people whose psoriatic arthritis has shown no response after up to 28 weeks of treatment. The average annual acquisition cost for ustekinumab 45 mg is £10,735 in the first year and £9304 per year thereafter. The company has agreed a patient access scheme with the Department of Health, in which the company provides the 90‑mg dose (2 vials) at the same cost as the 45‑mg dose (1 vial), for people who weigh more than 100 kg and need the higher dose. The Department of Health considered that this patient access scheme does not constitute an excessive administrative burden on the NHS. The patient access scheme was withdrawn in January 2017 because the company now provides a 90‑mg vial at the same cost as the 45‑mg vial.