Association of gender and systemic therapy treatment outcomes in psoriasis: a two-country, multi-centre, prospective, non-interventional registry study.

BACKGROUND Psoriasis is a stigmatizing disease that often affects female patients more negatively than male patients. Very little systematic data on the treatment responses related to gender exists. OBJECTIVES This two-country, multi-centre, prospective, non-interventional registry study aimed to evaluate potential gender differences with respect to systemic anti-psoriatic treatment. METHODS Data of patients with moderate to severe psoriasis participating in the German (PsoBest) or Swiss (SDNTT) psoriasis registry were analysed. Treatment response was defined as reaching PASI75 or PASI ≤ 3 at months 3, 6 and 12 of treatment and was supplemented by patient reported outcomes, i.e. DLQI ≤ 1 and Delta DLQI ≥ 4. RESULTS 5,346 patients registered between 2007 and 2016 were included in the analyses (4,896 from PsoBest and 450 from SDNTT). The majority of patients received a non-biologic treatment: 67.3 % of male and 69.8 % of female patients. Overall, women showed slightly higher PASI response rates after 3, 6 and 12 months, respectively 54.8 vs. 47.2 %, p ≤ 0.001, 70.8 vs. 63.8 %, p ≤ 0.001, 72.3 vs. 66.1%, p ≤ 0.004. In line with this, we found significantly higher proportions of female patients achieving a DLQI reduction ≥ 4: 61.4 vs 54.8 % at month 3 (p ≤ 0.001), 69.6 vs. 62.4 % at month 6 (p ≤ 0.001) and 70.7 vs. 64.4 % at months 12 (p ≤ 0.002), respectively. Females on biologics showed a significantly superior treatment response in the PASI ≤ 3 at 3 (57.8 vs 48.5%) p ≤ 0.004 and 6 months (69.2 vs 60.9%) p ≤ 0.018. The non-biologics group had a significant better treatment response (PASI response, PASI 75 and PASI ≤ 3) in females over the whole treatment year. Differences found in single treatments only occurred at individual points in time and did not show a uniform trend or can be regarded as methodological artefacts. CONCLUSION Our data provide evidence that women experience better treatment outcome as measured by PASI to systemic anti-psoriatic therapy than men. Several factors may contribute to this observation, including adherence to treatment, weight, or different lifestyle behavior.