A Genome-Wide Association Study in Psoriasis Patients Reveals Variants Associated with Response to Treatment with Interleukin-17A Pathway Inhibitors.

BACKGROUND/

OBJECTIVES

Psoriasis is currently treated with biologics targeting the IL-17A signaling, which plays a major role in immune response and keratinocyte hyperproliferation. These include inhibitors of IL-17A and/or its heterodimer with IL-17F (Secukinumab, Ixekinumab and Bimekizumab) and the receptor IL17-RA (Brodalumab). Although these drugs are safe and highly effective, there is significant variability in response among patients. This can be partly attributed to the patients' genetic background, thus pointing to the need to identify pharmacogenetic markers for treatment response.

METHODS

The study involved 88 Greek patients who were treated with inhibitors of the IL-17A signaling for at least 6 months. Patients were classified as responders and non-responders according to the change in Psoriasis Area Severity Index. A total of 730,000 variants were genotyped and analyzed for association with the 3-month and 6-month responses to treatment.

RESULTS

The analysis identified 21 variants which were associated with the response, showing statistical significance after Bonferroni correction. These include variants located in protein coding genes (TP63, NRG1, SCN8A, TAF9, TMEM9, SMIM36, SYT14, BPIFC, SEZ6L2, PCARE), as well as intergenic and long non-coding RNA intronic variants. The functional significance of the variants was assessed using in silico analysis and for several variants, a link with immune processes was proposed. Notably, rs11649499 status, which was associated with complete clinical remission at 3 months, may influence key lipid mediators involved in psoriasis.

CONCLUSIONS

This GWAS identified novel variants that could be utilized upon validation in larger populations as predictive markers regarding patient response to drugs targeting the IL-17A pathway.