Effectiveness and safety of interleukin 6 receptor inhibitors versus conventional immunomodulatory therapy in...

To compare the effectiveness and safety of interleukin 6 receptor inhibitors (IL-6Ris) and conventional synthetic immunomodulators (csIM) in patients with polymyalgia rheumatica (PMR) who received glucocorticoids (GC) and initiated a new therapy for PMR.

We evaluated the effectiveness and safety of IL-6Ris in a retrospective comparative cohort created from the US Medicare fee-for-service medical and part D prescription claims data. Patients with PMR, on GC, without prior IL-6Ri exposure and initiating IL-6Ri/csIM therapy were identified. These patients were categorised into csIM-naïve and csIM-experienced cohorts and matched using direct methods and propensity score methods. Primary endpoints were time-to-GC discontinuation and time-to-minimal GC use (≤2 mg/day or stop GC) through year 1. Incidence rates (IRs) for adverse events of special interest were reported for IL-6Ri and csIM initiators through year 2.

We included 415 matched treatment pairs (187/228, csIM-naïve/csIM-experienced). IL-6Ri initiators were more likely to discontinue GC (adjusted HR (aHR) 1.28, 95% CI 1.02 to 1.60; p=0.031) or achieve minimal GC use (aHR 1.28, 95% CI 1.03 to 1.58; p=0.025) by year 1 versus csIM initiators. At year 1, IR (95% CI)/100 patient-years for primary hospitalised infections was higher for IL-6Ri initiators versus csIM initiators (12.2 (95% CI 8.9 to 16.3) vs 5.7 (95% CI 3.6 to 8.6)); however, it was similar for year 2 (5.8 (95% CI 3.3 to 9.6) vs 6.4 (95% CI 3.8 to 10.1)). For other events of interest, the IRs were low and comparable in both groups.

IL-6Ri therapy was more effective as a steroid-sparing agent than csIM for PMR with no new safety findings.