Background/Purpose: Patients with RA have previously demonstrated significant differences in morning stiffness (MS), a debilitating symptom of RA, and other disease measures with delayed release (DR)-prednisone versus immediate release (IR)-prednisone in a randomized trial and an open-label switch extension study (1,2). Previous randomized trials did not allow prednisone dose to be adjusted (1). We conducted a prospective open label switch study in the US to see if the results from controlled trials could be replicated in a real world clinical setting.

Methods: Twelve sites within the US enrolled 56 moderate-severe patients with RA into a 12 week study. At baseline patients were switched from IR- to DR-prednisone while maintaining other existing background therapies. MS severity (VAS1-100) the primary outcome, MS duration (minutes), swollen joint counts (SJC), DAS28, MDHAQ, RAPID3 and patient/physician global assessment (PGA/PhGA 10 cm VAS), among others, were measured (change from baseline). The overall group, those completing 10 wks, and those with >60 minutes of MS at baseline were analyzed, specifically. T-tests and Pearson’s Correlations were used for significance and associations.

Results: 52 patients had at least one follow-up visit and were similar to patients in the previous controlled trial with regard to baseline mean age (63), DAS28CRP (5.2) but had lower baseline morning stiffness (114 minutes) and shorter duration of RA (5yrs). From a mean starting dose of 6 mg, the dose of prednisone decreased by 13% after switch to DR-prednisone in those treated ≥10 wks while demonstrating significant reductions in SJC, DAS28CRP, PhGA, RAPID3 and MDHAQ pain (all p ≤ 0.04). Patients on treatment for ≥10 wks and who had baseline >60 min of MS produced similar results in SJC/PhGA as well as reductions in duration and severity of MS (both p<0.03, Figure 1). In the later analysis, MS severity (-20%) and duration (-34%) improvements were moderately correlated with each other (R²=0.43) and no other correlations were demonstrated.

Conclusion: Patients switched to DR-prednisone from IR-prednisone in this practice based study maintained or improved their outcomes across a variety of domains and the results were comparable to previous controlled trials in which patients completed at least 10 wks of therapy. Further, there was a reduction in total prednisone dose over the treatment period comparable to the 18% found in a previous analysis (3).  References:  (1)        Buttgereit, et al. Lancet 2008; 371: 205. (2)        Buttgereit, et al. Ann Rheum Dis 2010;69:1275. (3)        Cutolo, et al. Clin Exp Rheumatol 2013; 31:498.