EXPERT ANALYSIS FROM WCD 2015

VANCOUVER (FRONTLINE MEDICAL NEWS)Evidence-based therapy for nail psoriasis is in a sorry state because of a lack of consensus on a reliable nail psoriasis scoring system for use in clinical trials, according to a coauthor of the Cochrane systematic review of interventions for nail psoriasis.

“The last 12 randomized clinical trials used 21 ways of scoring the results of treatment, so comparing the studies means comparing apples to oranges. Which is the most effective treatment? What should we advise our patients? We don’t know. Comparison is impossible,” Dr. Marcel C. Pasch said at the World Congress of Dermatology.

The Cochrane report ( Cochrane Database Syst Rev. 2013 Jan 31;1:CD007633 ) deemed the evidence for topical therapies as “inconclusive and weak,” even though topicals are the treatment mainstay for this localized expression of psoriasis. Indeed, Dr. Pasch and his coauthors found that no topical therapy has been shown effective in improving nail psoriasis. The Cochrane group concluded that just five therapies rise to the standard of being evidence based in terms of efficacy: the tumor necrosis factor (TNF) inhibitors infliximab (Remicade) and golimumab (Simponi), superficial radiation therapy, Grenz rays, and electron beam therapy. All five are strikingly impractical for use in clinical practice.

“The findings are quite disappointing because nobody sends a patient with psoriasis to the radiotherapist, and while giving an anti-TNF biologic only for the nails will be effective, at least in my country it won’t be reimbursed,” wrote Dr. Pasch, a dermatologist at Radboud University Nijmegen (the Netherlands) Medical Centre.

The presence and severity of nail psoriasis is unrelated to the severity of cutaneous psoriasis. Moreover, nail psoriasis without cutaneous involvement occurs in 5%-10% of psoriasis patients.

Since publication of the Cochrane systematic review, 12 new randomized controlled trials of treatments for nail psoriasis have appeared. Six focused on biologics: the anti-TNF agents certolizumab (Cimzia), etanercept (Enbrel), and adalimumab (Humira); the anti–interleukin-12/23 agent ustekinumab (Stelara); and the interleukin-17A inhibitor secukiumab (Cosentyx). Dr. Pasch said in his opinion all five biologics were supported by convincing studies and now can be added to the short list of evidence-based nail psoriasis therapies.

Of the six recent studies of topical therapies, two provided persuasive evidence of efficacy, in his view: tacrolimus ointment and indigo naturalis extract in oil (Lindioil), a variant of a traditional Chinese medicine therapy, which at this time isn’t commercially available.

In contrast, studies of clobetasol nail lacquer, pulsed dye laser therapy, a nail lacquer based upon chitin from crab shells, and a study of calcitriol ointment versus betamethasone dipropionate ointment failed to be convincing either because of methodologic problems or lack of efficacy, he continued.

These 12 recent randomized clinical trials utilized 21 different nail psoriasis scoring systems.

“Which scoring system is best? The answer is, we don’t know,” Dr. Pasch said.

He and his coinvestigators compared eight different scoring systems in a prospective study and concluded that the Nijmegen–Nail Psoriasis Activity Index Tool (N-NAIL), which Dr. Pasch helped develop, best reflected the clinical severity of nail psoriasis ( J Am Acad Dermatol. 2014 Jun;70[6]:1061-6 ).

However, he added that at present there is no validated scoring system for nail psoriasis. And creation of a single validated scoring system that researchers can agree on as the standard is a prerequisite for making major advances in the treatment of nail psoriasis, in Dr. Pasch’s view.

He is so convinced of this that he has created an organization whose goal is to achieve consensus on one reliable, validated nail psoriasis scoring system for use in clinical trials. At the World Congress of Dermatology, he invited stakeholders – including academic and community dermatologists, patient organizations, and the pharmaceutical industry – to join ( www.nailinitiative.org ).

Session chair Dr. Peter van de Kerkhof, chairman of dermatology at Radboud University, said he sees the NAPSI (Nail Psoriasis Severity Index) being used in lots of clinical trials in psoriasis. What’s wrong with building a consensus around NAPSI? he asked.

“The problem is not the NAPSI score,” Dr. Pasch replied. “The problem is that in each trial a modified NAPSI score is used, but they are all modified in different ways. We have the single-hand NAPSI, the eight-finger NAPSI, the 10-finger NAPSI, the target NAPSI. The NAPSI doesn’t exist anymore.”

He reported receiving research grants from Pfizer and Janssen-Cilag.

bjancin@frontlinemedcom.com

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