Some clinical factors affecting quality of the response to ustekinumab for psoriasis.

Ustekinumab has demonstrated efficacy for psoriasis. However, it is known that approximately 30% of patients have shown insufficient response. The aim of the current study is to clarify the specific clinical factors that could be associated with response to ustekinumab treatment. We reviewed the medical records of all patients who were treated with ustekinumab. The Psoriasis Area and Severity Index (PASI) score was calculated, and the efficacy was evaluated at week 0 and week 16. The relationship between clinical efficacy and the patients' background was investigated. The patients, who showed a <74% reduction in the PASI score, were classified as insufficient-responders. A total of 74 patients (average 60.3 years old, male to female ratio 54:20) were examined retrospectively. Eighteen patients were identified as insufficient-responders. Each of the factors, body weight (BW) over 80 kg, body mass index (BMI) over 25, or smoking habit over 20 cigarettes/day showed a higher proportion of insufficient-responders compared with responders, although the difference was not statistically significant. Patients with previous exposure to biologics showed a significantly lower response to the treatment. Furthermore, a statistical difference was identified between patients with none of these factors and patients with some of these factors. Our data suggest that some factors, such as high BW, high BMI, a smoking habit over 20 cigarettes/day, or exposure previous treatment with biologics are likely to affect the quality of the response to ustekinumab. Therefore, these factors need to be taken into account when ustekinumab is administrated.