Treatment Escalation of JIA in Local Setting: Timing, Role of Disease Activity Index

Introduction The paradigm of managing JIA has been changing. There is ongoing discussion whether using bDMARDs early in the treatment course is superior to sequential use after cDMARDs1. On the other hand, with a treat to target approach, it is shown both approaches achieve comparable outcome2. We aim to investigate the real life experience of a single-centre JIA cohort regarding treatment escalation, including the timing and the role of disease activity index. Method A chart review on all the JIA attending the Paediatric Rheumatology Clinic at the Prince of Wales Hospital between JUL 2023 to AUG 2024 was performed. SJIA was excluded as it follows different treatment algorithm. Outcome of interests are time to cDMARDs or bDMARDs from first clinic visit, time to escalation to cDMARDs and bDMARDs, disease activity indexes (cJADAS, BASDAI and BASFI for ERA) at the time of treatment escalation. Results are presented in descriptive analysis. Result Total 17 cases with 30 treatment escalation events were recorded. The median age at last FU was 15 years old (IQR 9.5-18.5), with a median duration of FU of 51 months (IQR 25-79.5). For the whole group the median time from first clinic visit to cDMARDs was 1 month (IQR 0-26), to bDMARDs was 12 months (IQR 5-33). 3 cases required further switch. The median time to 1st treatment escalation was 1 month (IQR 0-26). The median time between 1st and 2nd treatment escalation was 4.5 months (IQR 3-17). These usually involved change from cDMARDs to bDMARDs. cJADAS scores were recorded at the time of switch in 23 events. The median score at each treatment escalation was 14 (IQR 8.9-18). It signified high or moderate disease activity in oligoarticular or polyarticular course JIA, respectively. For the eight ERA, the median time to first cDMARDs was 6 months (IQR 0-28). It was 17 months (IQR 3-29) to next treatment, mostly bDMARDs. Regarding disease activity index at the time of switch, the median cJADAS of 13 events was 11.2 (IQR 6.5-14), ie moderate disease activity, while the median BASDAI of 14 events was 2.55 (IQR2.07-4.4), ie not active disease. Conclusion Overall the timing of cDMARDs use, treatment switch and performance of cJADAS were inline with other centres. In this small cohort BASDAI is not optimal in terms of indicating treatment switch in ERA. 1 Kimura Y et al. Arthritis Rheumatol. 2021 Oct;73(10):1898-1909. 2 Hissink Muller P et a1. Ann. Rheum. Dis. 2019;78:51–59