Adult Still’s Disease is labeled as a rare disease as the prevalence of the disease is low – in some reports it is as low as 0.16 per 100,000 population. Adult Still’s disease constitutes Adult onset Still’s disease and “carry-over” systemic juvenile idiopathic arthritis (sJIA) which essentially is the same spectrum of disease. It is characterized by fevers, arthritis and a typical rash.
There are many differential diagnosis for the clinical presentations for Still’s and delays in the diagnosis. By the time patients present to rheumatologists, often with flares and complications, they can be exposed to a lot of steroids. Given the low prevalence of Still’s disease, it is difficult to have large scale patient data to study medication patterns, especially that of steroids.
A Japanese large scale claims data study presented at ACR22 (abstract#0826) was able to collect 5-year data to study the treatment patterns in Still’s. In May 2019, intravenous tocilizumab was approved in Japan for Still’s disease.
The study was designed to see patterns of steroid exposure before and after the approval of this intravenous IL-6 receptor inhibitor (data from 2017 to 2021). Data from 193 patients who took IV tocilizumab were compared to 4800 patients who didn’t. 85% of the cohort received oral steroids at the start of their treatment, which seems consistent with the current practices in most places. The primary end point of the study was <5 mg oral steroids on a daily basis at year 1. Patients who were on IV tocilizumab had a clear trend of decreasing steroid usage initially only 24% of patients were <5mg steroids, but after a year it was up to 66%.
This well-designed population based study clearly demonstrates the steroid sparing effect of biologics in Still’s disease. Given the adverse effects associated with steroid use, it is important to consider the risks of steroids themselves when treating patients with still’s disease and consider steroid sparing options.