A randomised double-blind placebo controlled withdrawal clinical trial of prednisone versus placebo in patients with rheumatoid arthritis (RA), treated in usual clinical care with 1-4 mg/day prednisone, withdrawn to the same dose of 1 mg prednisone or identical placebo tablets.
All patients were from one academic setting and all trial visits were conducted in usual clinical care. Patients were taking stable doses of 1-4 mg prednisone with stable clinical status, documented quantitatively by patient questionnaire scores. The protocol included three phases: (1) equivalence: 1-4 study prednisone 1 mg tablets taken for 12 weeks to ascertain their efficacy compared with the patient's usual tablets before randomisation; (2) transfer: substitution of a 1 mg prednisone or identical placebo tablet every 4 weeks (over 0-12 weeks) to the same number as baseline prednisone; (3) comparison: observation over 24 subsequent weeks taking the same number of either placebo or prednisone tablets as at baseline. The primary outcome was withdrawal due to patient-reported lack of efficacy versus continuation in the trial for 24 weeks.
Thirty-one patients were randomised, 15 to prednisone and 16 to placebo, with three administrative discontinuations. In "intent-to-treat" analyses, 3/15 prednisone and 11/16 placebo participants withdrew (p = 0.03). Among participants eligible for the primary outcome, 3/13 prednisone and 11/15 placebo participants withdrew for lack of efficacy (p = 0.02). No meaningful adverse events were reported, as anticipated.
Efficacy of 1-4 mg prednisone was documented. Evidence of statistically significant differences with only 31 patients may suggest a robust treatment effect.