CHICAGO — High-dose dexamethasone pulse therapy is a good alternative to daily prednisone as first-line treatment of subacute inflammatory myopathies, Dr. Janneke van de Vlekkert reported at the annual meeting of the American Academy of Neurology.
In a prospective, multicenter, double-blind trial of 62 newly diagnosed adults with dermatomyositis or nonspecific myositis, significant difference was seen at 18 months in the composite score of six clinical outcome measures among patients receiving prednisone 70 or 90 mg/day versus those who received six cycles of oral dexamethasone 40 mg/day for 4 consecutive days at 28-day intervals.
The mean composite score was 2.8 (median 2.0) in both treatment groups, Dr. van de Vlekkert and associates reported.
No significant differences were observed among the 30 patients treated with dexamethasone and the 32 treated with prednisone for the six outcomes that comprised the composite score. These included remission (5 vs. 9 patients, respectively), remission less than 3 months (2 vs. 3 patients), no relapse (16 vs. 20 patients), Medical Research Council sum score at least 138 out of 140 (16 vs. 16 patients), visual analog scale score of 0-2 for muscle pain (18 vs. 13 patients), and no cushingoid appearance (18 vs. 13 patients).
The mean time until remission was 58 weeks in both groups, while the median time until relapse was 44 weeks in the dexamethasone group and 60 weeks in the prednisone group.
Based on these findings, the study was halted prematurely after inclusion of 62 patients instead of the planned 80 patients.
Side effects occurred in significantly fewer patients treated with dexamethasone than in patients with prednisone, including any side effect (22 vs. 29, respectively), diabetes mellitus (1 vs. 10), and mood changes (8 vs. 20), Dr. van de Vlekkert of the Academic Medical Center, Amsterdam, and associates reported.
The improved side effect profile is notable, as daily high-dose prednisone is the standard treatment of subacute inflammatory myopathies, and major drawbacks of long-term therapy with prednisone are its side effects, the investigators noted.
Dr. van de Vlekkert disclosed no conflict of interest related to the study, which was supported by the Princess Beatrix Fund, the Hague, the Netherlands.