A Study to Evaluate the Long-term Safety, Tolerability and Efficacy of Bimekizumab in Patients With Chronic Plaque Psoriasis

Treatment-emergent Adverse Events (TEAEs) were defined as those events which started on or after the date of first dose of PS0011 investigational medicinal product (IMP), or events in which severity worsened on or after the date of first dose of PS0011 study medication. The exposure adjusted incidence rate (EAIR) is defined as the number of subjects (n) with a specific AE adjusted for the exposure and was scaled to 100 subject-years: where the numerator is the total number of subjects experiencing the AE and the denominator is the total time at risk scaled to 100 subject-years; that is, the total summation of individual subject-years at risk up to the first occurrence of the AE for subjects with that AE, and the total subject-years at risk for those subjects not experiencing that AE, divided by 100.

The PASI90 response assessments are based on at least 90% improvement in the PASI score from Baseline. It averages the redness, thickness, and scaliness of the psoriatic lesions (on a 0-4 scale) and weights the resulting score by the area of skin involved. Body divided into 4 areas: head, arms, trunk to groin, and legs to top of buttocks. Assignment of an average score for the redness, thickness, and scaling for each of the 4 body areas with a score of 0 (clear) to 4 (very marked). The PASI score ranges from 0 to 72 with a higher score indicating increased disease severity. PASI90 response is defined to be equal to 1 if the percentage improvement from Baseline in the PASI scores is 90% or greater and 0 if the percentage improvement from Baseline is less than 90%. This Outcome Measure presents results relative to PS0010 Baseline starting at PS0011 Baseline by PS0010 Week 12 response status.

The Investigator's Global Assessment (IGA) measures the overall severity following a 5-point scale (0-4), where scale 0= clear, no signs of psoriasis; presence of post-inflammatory hyperpigmentation, scale 1= almost clear, no thickening; normal to pink coloration; no to minimal focal scaling, scale 2= mild thickening, pink to light red coloration and predominately fine scaling, 3= moderate, clearly distinguishable to moderate thickening; dull to bright red, clearly distinguishable to moderate thickening; moderate scaling and 4= severe thickening with hard edges; bright to deep dark red coloration; severe/coarse scaling covering almost all or all lesions. IGA response is defined as clear (0) or almost clear (1) with at least a two category improvement from Baseline. This Outcome Measure presents results relative to PS0010 Baseline starting at PS0011 Baseline by PS0010 Week 12 response status.