Background: Ustekinumab is a fully human monoclonal antibody approved for the treatment of chronic moderate-to-severe plaque psoriasis in adults. However, factors including efficacy, tolerability, ease of use, and cost burden may affect ustekinumab utilization. Noncompliance may, in turn, affect treatment response. Objective: To evaluate ustekinumab utilization in the real-world setting in Asia-Pacific countries. Methods: In this phase 4 observational study conducted in Indonesia, Malaysia, Singapore, Korea, and Taiwan, adults with plaque psoriasis receiving ustekinumab were followed for up to 52 weeks. Study endpoints were the proportion of all patients using ustekinumab according to label-recommended intervals and the proportion of Korean patients who achieved a psoriasis area severity index 75 response at week 16. Safety was assessed by monitoring adverse events. Results: Overall, 169 patients received ustekinumab (Korea, n=102; other countries, n=67). Just over half (56.2%) of patients used ustekinumab with the label-recommended interval from baseline to week 40; the proportion was higher in Korea (73.5%) than in other countries (29.9%), probably because ustekinumab was provided without charge for Korean patients up to week 40. Noncompliance increased after week 40 in Korea and from week 28 in other Asia-Pacific countries, with cost cited as the most common reason. At week 16, 56.9% of Korean patients achieved a Psoriasis Area Severity Index 75 response. Safety results were in line with those seen in previous studies. Conclusion: More than half of all patients in Asia-Pacific countries used ustekinumab as per the label-recommended dose interval, but reimbursement variations between countries may have confounded overall results.
- Plaque psoriasis