The investigational interleukin-17 inhibitor brodalumab was safe and effective in a small phase III Japanese study of adults with two rare and severe types of psoriasis, generalized pustular psoriasis (GPP) and psoriatic erythroderma (PsE). The results were published in the British Journal of Dermatology.

The 52-week open label study evaluated the safety and efficacy of brodalumab in 30 Japanese adults (mean age 48 years) with GPP (12 patients) and PsE (18 patients). Brodalumab, a human monoclonal antibody against human IL-17RA that blocks the biologic activities of IL-17, was administered by subcutaneous injection. Efficacy was assessed via Clinical Global Impression of Improvement (CGI) scores, the primary endpoint ( Br J Dermatol. 2016 April 23. doi: 10.1111/bjd.14702 ).

A high proportion of patients with either disease achieved “improved” or “remission” CGI scores at weeks 2, 12, and 52, reported Dr. Kenshi Yamasaki, of the department of dermatology at Tohoku University, Miyagi, Japan, and his associates

At week 52, almost 92% of those with GPP and 100% of those with PsE had achieved “improved” or “remission” scores. The most common adverse event was nasopharyngitis, which occurred in one-third of patients. Infection-related adverse events were grade 1 or 2, no adverse events were fatal, and none of the five serious adverse events noted were considered to be attributable to treatment, they added. Although anti-brodalumab neutralizing antibodies were not detected, one patient tested positive for anti-brodalumab binding antibodies.

Noting that treatment with brodalumab has been associated with significant improvements in patients with plaque psoriasis and psoriatic arthritis in phase II and III studies, “results from this study confirm that brodalumab can improve patient symptoms not long after treatment is initiated,” in patients with GPP and PsE, the authors concluded. While acknowledging the study limitations, including the open label design and a small sample size, they added, “IL-17RA blocking will be a promising therapeutic target in patients with GPP and PsE.”

The safety profile and low expression of anti-brodalumab antibodies indicated that brodalumab was suitable for long-term use, they said.

The study was funded by Kyowa Hakko Kirin. All authors disclosed ties to pharmaceutical companies, including the funding source; one author is an employee of the company.