PASI 100 response rates in moderate to severe psoriasis: a systematic literature review and analysis of clinical practice guidelines

Background Response to treatments in psoriasis can be assessed using the PASI response 50, 75, 90 or 100. Achieving a PASI 100 response would mean a complete resolution of the patient's basal lesions. Therefore, PASI 100 score has been increasingly used in the context of research, but its role in daily practice is currently controversial. Objective (1) To analyze PASI 100 response rates to pharmacological treatments; (2) To examine clinical practice guidelines (CPGs) recommendations/comments on PASI 100. Methods We conducted a systematic literature review (SLR). Selection criteria concerned patients with psoriasis, reporting PASI 100. Results Overall, 65 studies were included. Patients on methotrexate achieved at 16 weeks a PASI 100 of 7.3%. For TNF inhibitors rates were: 3.7-11.1% at 12 weeks, 13.7-20% at 16 weeks, 10.7-24% at 24 weeks and 21.8-34.8% at 1 year. IL-17 inhibitors achieved 23.3-44% at 12 weeks, 44.3-57.2% at 16 weeks, 39.7-67.5% at 24 weeks and 41.4-67.5% at 1 year. And the reported by IL-12/23 inhibitors were 12%/23.8% at 12 weeks, 32.7%/50% at 16 weeks, 44% at 24 weeks and 41.8%/56.3% at 1 year. PASI 100 response is scarcely commented in the CPGs. Conclusions PASI 100 response rate is an endpoint fundamentally restricted to research.