What is the best dosage regimen for patients who at first don't respond completely to ixekizumab?

Ixekizumab (Taltz®) is a modern injectable treatment (“biologic”) for patients with moderate to severe psoriasis. It works by counteracting the effect of interleukin 17A (IL‐17A), a powerful stimulator of the psoriasis process. It was licensed for use in the USA and Europe in 2016. The licensed (labelled) dosage regimen is 160mg (week 0), 80mg (weeks 2,4,6,8,10,12), then 80mg every 4 weeks. This international study was funded by Ely Lilly + Co., the manufacturers of ixekizumab (Taltz®). The authors have indirectly compared results from four clinical trials (IXORA‐P, UNCOVER‐1, UNCOVER‐2, UNCOVER‐3). It is already established that if patients’ skin is either clear, or nearly clear after the first 12 weeks of standard dosing, reducing the frequency of injections from every 2 to every 4 weeks is not associated with an appreciable loss of control of psoriasis. The aim here was to establish whether there was evidence for a different dosage regimen after the first 12 weeks for patients whose skin was neither clear, nor nearly clear of psoriasis at that point. They found that among patients who did not have clear or almost clear skin at week 12, nearly 30% more patients who were treated continuously with ixekizumab every 2 weeks (IXORA‐P) had clear or almost clear skin at week 52 when compared indirectly with those who were treated using the licensed (labelled) psoriasis 4‐weekly dosing in integrated UNCOVER studies. In addition, they found that the more frequent 2‐weekly dosing from week 12 to 52 was not associated with an increase in adverse events (e.g. unwanted side effects). Linked Article:   Papp et al. Br J Dermatol 2020; 183 :52–59.