Background: It is well known that psoriasis significantly impacts patients' quality of life (QoL). With the introduction of improved treatment modalities with biologic agents, more patients with moderate to severe psoriasis are able to achieve better results as measured by the Psoriasis Area and Severity Index (PASI). PASI 75 indicates a 75% or greater reduction in PASI scores from baseline and is indicative of excellent disease improvement. With newer biologic agents such as secukinumab, ixekizumab and brodalumab, patients are now capable of achieving PASI 90, introducing additional clinical decisions for physicians when considering treatment options. However, little is known regarding how the difference between achieving PASI-75 versus PASI-90 impacts patients' QoL.
Objectives: The purpose of this study was to compare how achieving PASI 75 versus PASI 90 impacts QoL for patients with moderate to severe plaque psoriasis by using validated psychometric instruments that have been widely used in both dermatologic and non-dermatologic settings.
Methods: Two separate open-label clinical trials were conducted to specifically assess QoL in patients with moderate to severe psoriasis on adalimumab or ustekinumab over 24 weeks. In addition to clinical assessments of psoriasis, patients completed two surveys: The Psychological General Well-Being (PGWB) Index and the Dermatology Life Quality Index (DLQI). Changes in total PGWB score and DLQI score at weeks 12 and 24 compared to baseline were compared between groups achieving PASI 75 and PASI 90.
Results: There was no statistically significant difference in PGWB scores between patients achieving PASI 75 and patients achieving PASI 90 in the adalimumab treatment group (week 12 p = .21, but there was at week 24 p = .05). There was a statistically significant difference in DLQI between the patients achieving PASI 75 and the patients achieving PASI 90 in the adalimumab treatment group at week 24 (p = .01), but not week 12 (p = .11). There was no statistically significant difference in PGWB scores between patients achieving PASI 75 and patients achieving PASI 90 in the ustekinumab treatment group (week 12 p = .11, week 24 p = .35). There was no statistically significant difference in DLQI between the patients achieving PASI 75 and the patients achieving PASI 90 in the ustekinumab treatment group at week 24 (week 12 p = .49, week 24 p = .11).
Conclusions: There has been tremendous attention surrounding newer biologic agents that can achieve PASI 90 and even PASI 100. Although the results are impressive with regard to physical improvement of psoriasis, there may not be a clinically significant difference in QoL when comparing patients who achieve PASI-75 versus PASI 90.
Keywords: PASI; Quality of life; adalimumab; psoriasis; ustekinumab.