Real-world dose adjustments of biologic treatments in psoriasis and their economic impact: a Swedish national population study

Background To date, evidence on the dose adjustments of biologics in the real-world treatment of psoriasis is limited. However, dose adjustments may have important clinical and economic implications. Aims To study the dose adjustments of individual biologics over time in real-world practice in Sweden. Methods A retrospective observational study of adults with moderate to severe psoriasis was conducted based on Swedish national registry data from 2010 to 2018. Treatment episodes were identified for individual patients from the date of drug dispensation to the end of the supply of the drug. Dosing data were expressed as the proportion of treatment episodes with accumulated syringes/vials equal to, above or below the recommended guidelines. Real-world costs were calculated and compared with costs predicted from dosing guidelines. Results The mean dose was above recommended levels for all biologics investigated. Weighted mean dose adjustments for adalimumab, etanercept, secukinumab and ustekinumab were 13%, 23%, 8% and 3%, respectively, over the entire treatment period. Higher doses translate to higher costs, including notable increases over time vs. expected costs for secukinumab. Conclusions Dose adjustments of biologics are frequent in clinical practice but differ for the various biologics. The mean observed increases in dose above guideline recommendations might indicate perceptions of suboptimal efficacy for biologics, with implications for the cost and cost-effectiveness of these treatments. Further research is warranted to understand the reasons for dose adjustments in clinical practice.