Psoriasis – briakinumab
Systemic treatments for psoriasis like methotrexate and cyclosporin work in some cases, but side-effects are a problem, and efficacy is rarely particularly high
Psoriasis is an autoimmune disease that is difficult to treat. While topical treatments can make some improvements, their effectiveness is limited by adherence and side-effects. Systemic treatments like methotrexate and cyclosporin work in some cases, but again side-effects are a problem, and efficacy is rarely particularly high.
More recently, tumour necrosis factor inhibitors such as etanercept have been introduced, which work better, and there is also a humanised mouse-derived antibody against the p40 subunit of interleukins 12 and 23, ustekinumab, which is effective in some cases. However, some patients do not respond, and in others the drugs lose their efficacy over time.
Briakinumab is another biologic medicine that is being developed as a potential treatment for psoriasis.1 It is a fully human anti-IL12 and IL23 antibody, first created by Cambridge Antibody Technology and now being developed by Abbott, and binds to the shared p40 subunit of these two interleukins.
A Phase II trial was carried out in 180 patients with psoriasis, who were given the drug in subcutaneous doses of 200mg at week 0, 100 or 200mg every other week for 12 weeks, 200mg every week for four or 12 weeks, or placebo.2 The primary outcome was a 75% reduction the Psoriasis Area and Severity Index response. The PASI 75 response was over 90% in those given all the longer-term dosing schedules, 63% for the single 200mg dose group, and 3% for placebo.
A Phase III study compared the effectiveness of briakinumab and etanercept with placebo in patients with moderate to severe chronic plaque psoriasis.3 In the 12 week trial, 347 patients were given 200mg briakinumab at weeks 0 and 4 and then 100mg at week 8, or 50mg etanercept twice a week at weeks 0-11, or placebo. In the briakinumab group, 71% of patients achieved a Physician’s Global Assessment of 0/1 at week 12, compared with 40% of the etanercept group and 3% of those given placebo. In the second assessment, PASI 75 response at week 12, 82% of the briakinumab group achieved the response, 56% of the etanercept group and 7% of those on placebo. Serious adverse event rates were very low.
references
1. A.B. Kimball et al. Arch. Dermatol. 2008, 144, 200
2. A.B. Kimball et al. J. Am. Acad. Dermatol. 2010, 64, 263
3. A.B. Gottleib et al. Br. J. Dermatol. 2011, epub ahead of print, doi:10.111/j.1365-2133.2011.10418.x
