The Development of a Patient-Reported Outcome Measure for Assessment of Genital Psoriasis Symptoms: The Genital Psoriasis Symptoms Scale (GPSS)

Abstract

IntroductionPatient-reported outcome measures (PROs) specific for genital psoriasis (GenPs) have not been described.MethodsIn this cross-sectional, qualitative study in patients with moderate-to-severe GenPs, we sought to develop a PRO useful for GenPs symptom assessment. A literature review was performed to identify relevant psoriasis or GenPs symptoms and existing PROs that may be useful in the evaluation of symptom severity in GenPs patients. The literature review findings were discussed with clinicians, and then patients with GenPs.ResultsRelevant psoriasis or GenPs symptoms from the literature review included itch, pain, scaling, redness/erythema, and stinging/burning. The validity of these symptoms for GenPs and potentially relevant PROs was corroborated by clinical experts. After gap analysis, a draft symptom scale consisting of Numeric Rating Scale (NRS) items was constructed. We then conducted interviews with GenPs patients (n = 20) to support content validity and use of the draft symptom NRS items in routine practice and in clinical trials. Participants identified and confirmed relevant symptoms and evaluated the utility of the draft PRO. A new PRO was developed: the Genital Psoriasis Symptoms Scale (GPSS). Cognitive debriefing and cultural adaptation/translation interviews with a second group of patients confirmed cultural appropriateness of the GPSS.ConclusionThe GPSS may be useful for assessing symptoms before, during, and after treatment in routine clinical practice and in clinical trials involving patients with GenPs.FundingEli Lilly & Company.Plain Language SummaryPlain language summary available for this article.Electronic supplementary materialThe online version of this article (10.1007/s13555-017-0213-2) contains supplementary material, which is available to authorized users.

Ixekizumab Improved Patient-Reported Genital Psoriasis Symptoms and Impact of Symptoms on Sexual Activity vs Placebo in a Randomized, Double-Blind Study

“…14 The validated (based on data from IXORA-Q) Genital Psoriasis Symptoms Scale (GPSS) uses an NRS (range, 0e10; 0 ¼ no symptom, 10 ¼ worst imaginable) for 8 common symptoms of GenPs (itch, pain, discomfort, stinging, burning, redness, scaling, and cracking) and also includes a total score (range 0e80). 15 In accordance with published Food and Drug Administration (FDA) guidance, a clinically meaningful improvement in GPSS itch NRS was derived by anchoring the change of itch score on the clinician assessment sPGA-G; a 3-point improvement from baseline was thereby defined as clinically meaningful, and was assessed at week 12 as a prespecified major secondary end point of IXORA-Q. 13,16 In addition, we completed a sensitivity analysis to evaluate response for genital itch (GPSS itch) 4 point improvement from baseline, as a 4-point improvement has historically been accepted by regulatory agencies such as the FDA.…”

The impact of genital psoriasis on quality of life: a systematic review

“…However, outcome measure scales are currently being developed to allow for better characterization of the quality of life impact that genital psoriasis has on patients’ lives 37,38. These instruments may allow researchers and clinicians to better understand how different treatments impact quality of life in patients in clinical trials, an area where high-quality evidence is currently lacking 39.…”

Efficacy and safety of ixekizumab in a randomized, double-blinded, placebo-controlled phase IIIb study of patients with moderate-to-severe genital psoriasis

“…The primary end point was to determine whether ixekizumab was superior to placebo at week 12 as determined by the percentage of patients achieving 0 or 1 (clear or minimal) on the sPGA‐G . The major secondary end points were to determine whether ixekizumab was superior to placebo at week 12 as determined by the percentage of patients achieving 0 or 1 (clear or minimal) on the overall sPGA, a clinically meaningful (≥ 3‐point) improvement from baseline for patients with ≥ 3 at baseline on the GenPs itch numerical rating scale (NRS), and a GenPs Sexual Frequency Questionnaire (GenPs‐SFQ) item 2 score of 0 or 1 for patients with a score ≥ 2 at baseline. Additional secondary end points included mean change from baseline in the modified GenPs Area and Severity Index (mGPASI) and in the Dermatology Life Quality Index (DLQI) at week 12.…”