To assess the efficacy of systemic corticosteroids (CS) alone as first-line treatment in patients with Churg-Strauss syndrome (CSS) without poor-prognosis factors, as defined by the Five-Factors Score (FFS), and to compare the efficacy and safety of oral azathioprine (AZA) versus intravenous pulse cyclophosphamide (CYC) as adjuvant immunosuppressive therapy for treatment failure or relapse.
This multicenter, prospective, randomized, open-label therapeutic trial included 72 patients with newly diagnosed CSS (FFS of 0) treated with CS alone. At treatment failure or relapse, patients were randomized to receive 6 months of oral AZA or 6 pulses of CYC. Analyses were performed according to an intent-to-treat strategy.
The mean ± SD followup was 56.2 ± 31.7 months. Among the 72 patients studied, 93% achieved remission with CS therapy alone, and 35% relapsed, mainly during the first year of treatment. Among the 19 patients randomized to additional immunosuppression because of treatment failure or relapse, 5 of 10 receiving AZA and 7 of 9 receiving pulse CYC achieved remission, but the difference was not statistically significant. Survival rates in all patients at 1 and 5 years were 100% and 97%, respectively. At the end of followup, 79% of the patients whose disease was in remission required low-dose CS therapy, mainly to control respiratory disease. CS-related adverse events were observed in 31% of the 72 patients.
In CSS patients with an FFS of 0, survival was excellent, confirming the predictive value of the FFS in this disease. First-line therapy with CS achieved remission in most patients, but relapses were common, and one-third of them required additional immunosuppressive therapy. AZA or pulse CYC was fairly effective in treating CS-resistant disease or major relapses. Over the long term, most patients continued to take oral CS, which might explain the high rate of CS-related adverse events.