Risankizumab as an effective therapeutic option in severe psoriasis unsuccessfully treated with therapies involving anti- TNF-α and anti-IL-17

Introduction
Lack or loss of efficacy of biologic treatment in patients with severe plaque psoriasis is more and more often observed in clinical practice. A new group of drugs, which antagonize the p19 subunit of interleukin 23, is an interesting therapeutic option in this group of patients.

Objective
To show difficulties in choosing an effective biologic treatment in a patient with severe plaque psoriasis.

Case report
A 36-year-old man with severe psoriasis had been administered adalimumab and infliximab; however, in both cases loss of treatment efficacy was observed. Then, ixekizumab was administered to the patient. During a 16-week therapy, further exacerbation of psoriasis was observed – at the moment when the drug was discontinued PASI equalled 51, and BSA – 89%. The patient was started on risankizumab, and a complete remission of psoriasis was achieved in subsequent weeks of the treatment.

Conclusions
The case is being presented due to difficulties in choosing the right treatment, extreme exacerbation of psoriatic lesions, and a rarely observed complete inefficacy of anti-IL-17A biologic drug. Risankizumab proved to be an effective drug when other biologic drugs turned out to be ineffective.