Data on sustained remission of granulomatosis with polyangiitis (GPA) after discontinuation of therapy (referred to as GPA with sustained remission off-therapy [SROT]) are scarce. In the present study, SROT among GPA patients from the French Vasculitis Study Group Registry was evaluated to identify factors associated with its occurrence and durability.
For inclusion of patients in the study, the diagnosis of GPA had to meet the GPA classification criteria defined by the American College of Rheumatology and/or the revised Chapel Hill Consensus Conference nomenclature for vasculitis. SROT was defined as achievement of remission (a Birmingham Vasculitis Activity Score of 0) that was sustained for ≥6 consecutive months after having discontinued glucocorticoid (GC) and immunosuppressant treatments. The characteristics of the patients at baseline and treatments received were compared at 3, 5, and 10 years postdiagnosis according to whether or not SROT had been reached and maintained.
Among 795 patients with GPA, 92 GPA patients with SROT at 3 years postdiagnosis were compared to 342 control subjects who had experienced disease relapse and/or were still receiving GCs or immunosuppressants. No baseline differences were found, but patients with SROT at 3 years postdiagnosis had more frequently received intravenous cyclophosphamide as induction therapy compared to control subjects (P = 0.01), with a higher median number of infusions (P = 0.05). At 5 years postdiagnosis, no baseline differences were observed between groups, but patients with SROT at 5 years postdiagnosis had received more cyclophosphamide infusions compared to control subjects (P = 0.03). More patients with SROT had received rituximab as maintenance therapy than control subjects at 3 years and 5 years postdiagnosis (P = 0.09 and P < 0.001, respectively). Of the 74 patients enrolled in the GPA Registry with 10-year follow-up data after having received conventional maintenance therapy, 15 (20%) had reached SROT at 3 years, and 5 (7%) maintained SROT at 10 years postdiagnosis.
After conventional therapies, 7% of GPA patients had reached SROT at 10 years postdiagnosis. No baseline vasculitis characteristics distinguished patients who achieved/maintained SROT from those who experienced disease relapse and/or those who continued to receive GCs or immunosuppressant therapy, but patients with SROT had received more intensive induction therapy and rituximab as maintenance therapy more frequently.