[Head-to-head studies on psoriasis and psoriatic arthritis]

Given the ever-increasing number of approved therapies for the treatment of psoriasis (PsO) and psoriatic arthritis (PsA), head-to-head (H2H) comparative studies are essential. These are aimed primarily at a comparative analysis of treatment effectiveness. In both PsO and PsA, biological disease-modifying antirheumatic drugs (bDMARD) have been shown to be superior to conventional therapies in H2H studies. In PsO interleukin 17 (IL-17) and IL-23 inhibitors proved superiority compared to tumor necrosis factor (TNF) inhibitors (etanercept and adalimumab) in several studies. Ustekinumab was more effective than etanercept, but less effective than IL-17 and IL-23 inhibitors. Only a few H2H studies have been published on the treatment of PsA. In the Spirit H2H study ixekizumab was superior to adalimumab using a combined endpoint of arthritis and psoriasis response (ACR-50 and PASI-100). When looking at arthritic symptoms only (ACR-20), secukinumab was not significantly superior to adalimumab in the EXCEED study but was superior in terms of the effect on skin involvement (PASI90). Other H2H studies focused on the treatment of enthesitis (ECLIPSA study), the efficacy of Janus kinase (JAK) inhibition (SELECT-PSA-1) or the additional administration of methotrexate to bDMARD treatment (MUST study). The H2H data have been incorporated into the treatment guidelines and have led to IL-17 and IL-23 inhibition being preferred over TNF inhibition in cases of relevant skin involvement in PsA.