Rituximab Efficacy in MAINRITSAN Long-Term Studies Save

The original randomized controlled, prospective MAINRITSAN study of 115 patients (87 with granulomatosis with polyangiitis, 23 with microscopic polyangiitis, and 5 with renal-limited ANCA-associated vasculitis [AAV]) demonstrated superiority of rituximab (RTX) over azathioprine (AZA) for maintenance of remission at 22 months in ANCA-associated vasculitis patients after CYC remission induction.

The long-term efficacy and safety of the MAINRITSAN  and MAINRITSAN2 study showed the 84-month remission rate to be higher with an 18-month fixed RTX regimen compared with AZA and 18-month tailored RTX.

The current study compared remission rates in systemic ANCA-associated Vasculitis (AAV) who achieve remission after cyclophosphamide induction and went on to receive:

• 18-month fixed-schedule RTX versus AZA (MAINRITSAN)
• 18-month fixed-schedule RTX versus 18-month tailored-RTX (MAINRITSAN2);
• and extended therapy to 36 months with four additional RTX infusions after MAINRITSAN2 versus placebo (MAINRITSAN3).

Patients were then followed through month. The primary endpoint was relapse-free survival at month 84. 

From a total of  277 AAV patients, prevention of major relapses at month 84 was best with the 18-month fixed-schedule RTX  (superior to AZA) (HR 0.38, 95% CI 0.20 to 0.71). The

Maintenance of remission is higher in AAV patients who were treated with an 18-month fixed RTX regimen (compared with AZA or 18-month tailored RTX).