Questions remain for wonder drug that clears psoriasis in eight out of 10 patients

A new drug called ixekizumab clears psoriasis in 80 per cent of patients, according to three clinical trials led by Northwestern Medicine, a hospital and research centre in Chicago.

Psoriasis is an inflammatory disease that causes irritation and red skin. It is associated with an increased risk of depression, heart disease and diabetes. It affects about three per cent of the population.

During the clinical trials, 3,736 adult patients with psoriasis covering 10 per cent or more of the body were randomly assigned to receive injections of ixekizumab or a placebo for a period of more than a year.

By the 12th week, between 76.4 and 81.8 per cent of patients were ‘clear’ of the condition, compared to 3.2 per cent of patients on the placebo. These include patients who were cured and those who were deemed to have an ‘extremely high response rate’ to the drug.

Dr Kenneth Gordon, the lead author of the study, which has been published in the New England Journal of Medicine, said: ‘This group of studies not only shows very high and consistent levels of safety and efficacy, but also that the great majority of the responses persist at least 60 weeks.

‘Based on these findings, we expect that 80 per cent of patients will have an extremely high response rate to ixekizumab, and about 40 per cent will be completely cleared of psoriasis.

‘Ten years ago, we thought complete clearance of this disease was impossible. It wasn’t something we would even try to do. Now with this drug, we’re obtaining response levels higher than ever seen before.’

Instant analysis
These reports do, in fact, relate to the results of phase III trials of an immunosuppressive drug. The methodology, reported in the Lancet, seems scientifically robust, although one possible confounding factor is the fact that using aggregated data from 100 study sites in 21 countries could potentially lead to variability in the subjective interpretation of responses to treatment.

The acceptability to patients of regular injections, and the potential cost of this to the NHS, may affect any decision by NICE (the National Institute for Health and Care Excellence) to approve this drug for use in Britain.

Of paramount importance are the possible safety implications of long-term injected immunosuppressive therapy. The published data seem only to have evaluated this to one year. It remains to be seen how many patients with moderate psoriasis would be willing to undergo such immunosuppressive therapy, whose noted adverse effects include neutropenia (low white blood cell count), yeast infection and inflammatory bowel disease.

That the author of the paper is a paid consultant for the pharmaceutical company funding the research is noteworthy and it would be reassuring to first monitor the long-term safety effects of this therapy before declaring it safe for long-term use.
JCH
Research score: 3/5