Janus Kinase Inhibitor Use Among People With Inflammatory Disease in Australia

AIM: To describe Australian trends in JAKi uptake, where there are no restrictions on the sequence of their use in clinical practice. METHODS: We included all people aged 18 years and over initiating a JAKi between 1 October 2015 and 31 August 2022. We used national dispensing claims data for a random 10% sample of Australians to: describe the number of people initiating JAKi per quarter; the characteristics of new JAKi users including demographics, use of other medicines to manage cardiovascular comorbid disease; and use of prior targeted therapy (biologics or small molecule inhibitors). We used Kaplan-Meier analysis to estimate the proportion of initiators who were persistent on their initial JAKi to 365 days. RESULTS: We identified 2904 people initiating JAKi treatment between 1 October 2015 and 31 August 2022; new use increased consistently during the study period. 45% of initiators had not been dispensed a prior subsidised targeted therapy in 365 days prior to JAKi initiation; 72% of new users were female and 62% were aged 55 years or older. Almost half of people initiating JAKi had at least one marker of higher cardiovascular risk, with 30% dispensed medicines to treat or prevent cardiovascular disease in the year prior to initiation; and 34% being aged 65 years or older. 60% of people persisted on their initial JAKi therapy to 365 days. Of those who stopped, 51% switched to a biologic and 15% switched to a different JAKi. CONCLUSION: In a setting where JAKi are permitted to be used in any line of therapy, 45% of new users of JAKi were naïve to targeted therapy and half had at least one marker of cardiovascular risk. Continued monitoring is required to understand the risk profile of JAKi, particularly in those with high baseline cardiovascular disease risk.