A step towards personalized care for psoriasis

Psoriasis is a chronic inflammatory skin disease which can lead to a significant burden on quality of life. There is no cure yet, but the availability of biologics therapies targeting selective key immune pathways has radically transformed treatment.
This thesis concerns the evaluation of benefits and harms of systemic combination therapy (Part I), examination of biomarkers for treatment with ustekinumab (Part II), and assessment of efficacy and safety of nail psoriasis interventions with a first step towards the development of a core outcome set (Part III).
Part I demonstrated that combination of systemic agents is prescribed regularly among patients with moderate to severe psoriasis. The type of combinations used differs geographically. A specific and promising combination, adalimumab with methotrexate, was investigated with RCT design.
Part II showed a correlation between anti-ustekinumab antibodies and treatment response. Measurement of antibodies against ustekinumab may therefore be considered if treatment response is unsatisfactory. Correlations between ustekinumab trough concentrations or HLA-Cw6 as a pharmacogenetic and treatment response were not detected. Future research on pharmacogenetic markers and immune profiling is desired to optimize personalized care for psoriasis patients.
Data presented in Part III illustrate that there are wide variations in outcome measurements used in RCTs on nail psoriasis, which limits possibility to perform a meta-analysis. As the number of RCTs performed in this field had increased significantly over the last few years witch mainly adds on to evidence for biologic therapies, harmonization of outcomes is urgently needed to reduce waste in research.