Background Biological agents targeting interleukin such as ustekinumab and secukinumab are strategies employed in psoriasis treatment. Ustekinumab requires double doses in patients over 100 kg, which implies an increase in costs due to the absence of a 90 mg injectable solution in our national market. Secukinumab, recently approved for psoriasis, does not require dose modification based on weight.

Purpose To describe the experience and assess the clinical response and economic impact of switching from ustekinumab to secukinumab in moderate–severe plaque psoriasis patients weighing more than 100 kg in the maintenance phase with optimal (Psoriasis Area and Severity Index (PASI) <5) or suboptimal (PASI 5–10) response.

Material and methods This was a retrospective observational study of psoriasis patients previously treated with ustekinumab double dose, from March to October 2016. Variables were: sex, age, weight, diagnosis, previous therapy with ustekinumab 90 mg quarterly and PASI. Patients with PASI 5–10 during maintenance received secukinumab 300 mg with reduced induction (weeks 1, 3) instead of normal induction (weeks 1, 2, 3, 4), followed by monthly administration; and patients with PASI <5 had no induction (monthly). Clinical response was assessed as no change in PASI in patients with optimal response or improvement in those with suboptimal response. Economic impact was measured comparing the patient year cost of ustekinumab double dose versus secukinumab to calculate the patient year savings.

Results 6 patients, 83.3% men, mean age 55 years (49–67), were evaluated. 3 patients had suboptimal response with ustekinumab (mean PASI 6.8); they received secukinumab with reduced induction and 2 achieved improvement in PASI and the third has not yet been evaluated. 3 patients had optimal response with ustekinumab (mean PASI 3.1); they received secukinumab without induction, achieving improvement in PASI. Switching from ustekinumab double dose to secukinumab with reduced induction involved an economic patient year saving of €8971.68 (34%) compared with ustekinumab maintenance; while switching to secukinumab without induction gave a patient year saving of €10 218.66 (39%).

Conclusion Optimisation of anti-interleukin biological agents is a strategy to manage psoriasis patients over 100 kg based on clinical activity criteria and costs in our settings. Our experience using alternative dosing of secukinumab induction depending on PASI revealed a decrease in costs, providing direct savings for the hospital while maintaining treatment efficacy.

No conflict of interest