Role of HLA- C*06 in clinical response to ustekinumab: evidence from real-life in a large cohort of European patients.

Little is known about role of HLA-C*06 related to response to psoriasis treatments. OBJECTIVES: This study that involved four European centres aims to confirm the role of HLA-C*06 in a new large cohort of patients, as a pharmacogenetic marker of response to ustekinumab. METHODS: In this retrospective multicenter study we reviewed data of 255 psoriasis patients genotyped for HLA-C*06, which have started ustekinumab treatment between January 2014 and March 2015. The severity of psoriasis and response to treatment were evaluated using the PASI score at baseline and then at follow up visits on weeks 4, 12, 28, 40 and 52. The primary endpoint was the proportion of patients achieving at least 50% reduction in the PASI score (PASI 50) at week 4. A 75% reduction in the PASI score (PASI 75) and a 90% reduction in the PASI score (PASI 90) after 12 weeks were our secondary endpoints. RESULTS: PASI 50 at week 4, was seen in 71.7% and 35.2% of HLA-C*06 (C*06POS) and HLA-C*06-negative (C*06NEG) patients, respectively. At week 12, 84.1% of C*06POS patients reached PASI 75, while 40.5% of C*06NEG patients reached PASI 75. After 52 weeks, 85.7% of C*06POS patients reached PASI 75, while 58.8% of C*06NEG patients reached PASI 75. CONCLUSIONS: In this paper we reported a new data of a large cohort of European patients, treated with ustekinumab in daily clinical practice. Our new results confirmed the role HLA-C*06 as a potential predictor of response to ustekinumab. This article is protected by copyright. All rights reserved.