Patient Acceptable Symptom State (PASS) in European patients with moderate-severe plaque psoriasis OBJECTIVES: To determine a Patient Acceptable Symptom State (PASS) for European patients with moderate-severe plaque psoriasis, and to compare Psoriasis Activity and Severity Index (PASI) improvement for patients attaining this state to the current clinical trial benchmark of 75% PASI improvement from baseline. METHODS: Patients with Psoriasis Area and Severity Index (PASI) > 10 were randomized 1:1 to Enbrel 25 mg BIW or Enbrel 50 mg BIW for twelve weeks as the first stage of a 54-week trial.  PASI scores can range from 0 to 72, with higher scores indicating more severe disease and scores > 10 indicating moderate-severe disease. Patients on the higher dose were temporarily removed from treatment if their Physician Global Assessment score determined their skin disease had become mild, almost clear or clear.  PASI was assessed at baseline and at week 12.  Patients completed a satisfaction questionnaire at week 12.  Patients reporting that they were ‘very satisfied’ or ‘satisfied’ were counted as satisfied; all others – including those who reported that they were ‘somewhat satisfied’ – were counted as not satisfied.  The PASS method for determining a symptom state that patients find acceptable was developed for osteoarthritis by Turbach, Ravaud, Baron, et al. (Annals of the Rheumatic Diseases, 2005) among other authors and other diseases.  Following the Turbach et al method, a cumulative percentage of satisfied patients as well as a cumulative percentage of patients who were not satisfied was plotted vs. week-12 PASI.  The week-12 PASI score with the greatest separation between the two cumulative curves was judged to be an acceptable state.  The PASI improvement from baseline for patients with week-12 PASI scores closest to this state were obtained and a mean PASI improvement for them was calculated.  Patients were pooled across treatment arms for these analyses. RESULTS: Baseline mean PASI was 22.32 for the 711 patients.  At week 12, mean PASI was 8.70, representing a 61% PASI improvement from baseline.  PASS was determined to be a week-12 PASI of 6.9, with 66.2% of satisfied patients having a week-12 PASI below (better than) 6.9 compared to 25.6% of not-satisfied patients.  A sensitivity analysis counting only ‘very satisfied’ patients as satisfied also determined PASS at week 12 to be a PASI of 6.9. A week-12 PASI interval of 6.6 to 7.2 and centered on 6.9 included 32 patients, for whom the mean PASI improvement from baseline was 62.5% with a 95% confidence interval of 58.2% to 66.9%.  This percent improvement is less than the 75% PASI improvement from baseline threshold commonly used as a primary endpoint in clinical trials.  CONCLUSIONS:  These 711 moderate-severe psoriasis patients had a Patient Acceptable Symptom State (PASS) worse than the 75% PASI improvement commonly used as a primary endpoint in clinical trials.  Further research is needed on ways to explicitly incorporate patient preference in estimates of clinical response.