NICE has published guidance (TA 180) recommending ustekinumab as a treatment option for adults with plaque psoriasis when the following criteria are met:

• The disease is severe, as defined by a total Psoriasis Area Severity Index (PASI) score of 10 or more and a Dermatology Life Quality Index (DLQI) score of more than 10.

• The psoriasis has not responded to standard systemic therapies, including ciclosporin, methotrexate and PUVA, or the person is intolerant of or has a contraindication to these treatments.

• The manufacturer provides the 90 mg dose (two 45 mg vials) for people who weigh more than 100 kg at the same total cost as for a single 45 mg vial.

Ustekinumab treatment should be stopped in people whose psoriasis has not responded adequately by 16 weeks after starting treatment. An adequate response is defined as either:

• A 75% reduction in the PASI score (PASI 75) from when treatment started or
• A 50% reduction in the PASI score (PASI 50) and a 5-point reduction in the DLQI score from when treatment started.

When using the DLQI, healthcare professionals should take into account any physical, sensory or learning disabilities, or communication difficulties that could affect the responses to the DLQI and make any adjustments they consider appropriate.

The cost of ustekinumab in the first year is £10,735, with an annual cost thereafter of £9335 (assuming an average of 4.3 injections per year). Costs may vary in different settings because of negotiated procurement discounts.