New combo therapy aims to tame rare blood vessel disease

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * male or female patients * aged over 18 years * new diagnosis of microscopic polyangiitis, polyarteritis nodosa or eosinophilic granulomatosis with polyangiitis (Churg Strauss syndrome), satisfying ACR 1990 and/or Chapel Hill Nomenclature criteria (positive biopsy is not mandatory providing those criteria are fulfilled) * with no factor of poor prognosis according to the French five factors score (FFS=0) * at diagnosis or within the first 21 days following initiation of corticosteroids * signed information and consent form * patients covered by Health Insurance * having had a baseline physical examination Exclusion Criteria: * patients with microscopic polyangiitis, polyarteritis nodosa or eosinophilic granulomatosis with polyangiitis (Churg Strauss syndrome) with one or more factor(s) of poor prognosis according to the French five factors score (FFS ≥ 1) * patients with polyarteritis nodosa with ANCA, not satisfying the criteria for microscopic polyangiitis * patients with clinically overt alveolar hemorrhage or respiratory distress syndrome * patient treated with corticosteroids for more than 15 days or already receiving another immunosuppressant * relapsing vasculitis * other vasculitis, especially secondary vasculitides * vasculitis secondary or associated with a viral infection, such as hepatitis B or C virus, or HIV * malignancy * pregnancy and breast feeding,women of child-bearing age not willing or with contra-indication to receive contraception * contra-indication to any of the study agents * need to continue allopurinol for those patients taking allopurinol * consent deny or inability to receive information and give consent * participation in another concomitant therapeutic trial * no affiliation to any of the general French health care system