Systematic literature review of non-topical treatments for early, untreated (systemic therapy naïve) psoriatic disease: a GRAPPA initiative

Background Psoriatic disease (PsD) is a complex systemic disorder with cutaneous and musculoskeletal manifestations. Current evidence on pharmacological interventions, effective across the spectrum of clinical manifestations of early, systemic treatment-naïve PsD, is limited. This review aims to appraise such evidence. Methods This systematic review examined seven patient–intervention–comparator–outcome research questions to address the efficacy of the interventions on the following: across the spectrum of clinical manifestations PsD activity; peripheral arthritis; dactylitis; spondylitis; enthesitis; skin; and nails. Early PsD was defined as a disease duration of ≤2 years, except for studies investigating outcomes restricted to the skin. Eligible references were clinical trials or well-designed prospective studies/series reporting on adult humans, untreated, with cutaneous and/or musculoskeletal features of PsD. Results Nine references (out of 160 319, publication range 1946–2019) fulfilled the eligibility criteria. No study adopted comprehensive (that is, simultaneous assessment of different PsD manifestations) composite indices as primary outcome measures. Individual studies reported that apremilast and biologics successfully improved outcomes (disease activity index for PsA, minimal disease activity, PsA DAS, psoriasis area and severity index, PsA response criteria) when efficacy analyses were restricted to single manifestations of untreated PsD. Only qualitative synthesis of evidence was possible, owing to the following factors: data heterogeneity (disease classification criteria, outcome measures); unavailable data subsets (focused on early, untreated PsD) at the single study level; and insufficient data on the exposure of participants to previous treatment. Conclusion Effective interventions, albeit limited in scope, were found for early, treatment-naïve PsD. No study provided evidence about the management of co-occurring cutaneous and musculoskeletal manifestations in early, treatment-naïve PsD. This review highlights an unmet need in research on early PsD.