Microscopic polyangiitis and non-HBV polyarteritis nodosa with poor-prognosis factors: 10-year results of the prospective CHUSPAN trial.

Objectives: To analyse the 10-year outcomes of 64 patients with non-HBV polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA) and Five-Factor Score-defined poor-prognosis factors enrolled (1994-2000) in the prospective, randomised, open-label CHUSPAN trial.
Methods: The 64 patients were randomised to receive 12 (33: 23 MPA, 10 PAN) or 6 (31: 17 MPA, 14 PAN) cyclophosphamide (CYC) pulses combined with glucocorticoids. Ten-year follow-up of these patients included times to relapse(s), failure(s) and/or deaths calculated from treatment onset. Data were censored after 120 months of follow-up.
Results: Eleven patients were lost to-follow-up (mean±SD follow-up: 61.9±35.2 months), with no between-group difference. As previously reported, baseline clinical characteristics and laboratory values were comparable for the 2 groups. After induction, 53/64 (83%) entered remission, with comparable percentages for both groups. The regimen was intensified for 11 initial non-responders: 4 achieved remission and 8 died before doing so. During extended follow-up, 26 patients experienced ≥1 relapse(s): 12 in the 12-pulse group and 14 in the 6-pulse group (p=0.47). At 10 years, overall and disease-free survival rates were 57.4% and 29.9%, with no between-group differences (p=0.185 and p=0.367, respectively). Factors associated with shorter disease-free survival were age ≥65 years and alveolar haemorrhage at diagnosis.
Conclusions: Although the 3-year CHUSPAN trial results indicated the superiority of 12 vs. 6 CYC pulses, that early advantage progressively declined and became non-significant by 10 years.