OBJECTIVES : The physician-reported PASI assessment is commonly used in clinical trials. However, patients with 100% improvement in PASI response still report symptoms and experience the impact of disease.

METHODS : By following PRO development guidance from the FDA, the Psoriasis Symptoms and Signs Diary (PSSD) was developed based on patient interviews (N=20), literature review, input from dermatologists. Reliability and validity were tested in an observational study (N=106) and response criteria were developed from an open-label Phase III study (N=866). The PSSD was implemented in the VOYAGE-1 and 2 studies, which compared outcomes for guselkumab vs adalimumab treatment in patients with moderate-severe psoriasis.

RESULTS : The PSSD instrument includes 5 items for symptoms (itch, pain, stinging, burning, and skin tightness) and 6 items for signs (skin dryness, cracking, scaling, shedding or flaking, redness and bleeding) using a 0-10 numerical rating scale with a recall period of the past 24 hours or past 7 days. Summary symptom and sign scores were derived using a scale of 0-100. Test-retest reliability ranged from 0.82-0.95 and validity was demonstrated by significant correlations with PASI (r=0.52-0.63), IGA (r=0.56-0.66) and DLQI (r=0.74-0.76) responses. In VOYAGE-1, greater proportions of patients in the guselkumab group achieved clinically meaningful improvements (≥40 points reduction) in the symptoms (79.9% vs. 63.8%) and signs (78.7% vs. 65.2%) scores, or achieved symptom-free (36.3% vs. 21.6%) or sign-free (29.4%, 14.56) scores of 0 at Weeks 24 than in the adalimumab group (all p<0.01). Improvements in the PSSD were sustained through Week 48. Similar results were obtained from the VOYAGE-2 study through Week 28. Further analysis showed that achievement of PSSD symptom-free or sign-free responses was more stringent than PASI 100 response and were more relevant to patients achieving a normalized health related quality of life.

CONCLUSIONS : The PSSD is a reliable and valid PRO instrument for assessing psoriasis-associated symptoms and signs.