What is the recommended maintenance therapy regimen for ANCA disease using Rituxan (rituximab)?

Rituximab Maintenance Therapy for ANCA-Associated Vasculitis

Rituximab is the preferred maintenance therapy for ANCA-associated vasculitis, administered as 500 mg intravenous infusions every 6 months for 18 months to 4 years based on relapse risk factors. 1

Recommended Maintenance Regimen

Dosing Schedule

• After cyclophosphamide induction:

  • 500 mg IV rituximab every 6 months 1
  • Begin maintenance within 4 weeks of achieving disease control 2

• After rituximab induction:

  • 500 mg IV rituximab every 6 months 1, 2
  • Begin maintenance within 24 weeks after last induction dose, but no sooner than 16 weeks 2

Duration of Therapy

• Standard duration: 18 months to 4 years 1
• Extended duration considerations:
  • Longer maintenance (up to 4 years) for high-risk patients 1
  • Extending beyond 18 months has been shown to reduce relapse rates compared to placebo 1

Patient Risk Stratification for Maintenance Duration

High-Risk Patients (Consider Longer Duration)

• PR3-ANCA positive serology 1
• History of relapsing disease 1
• Persistent ANCA positivity after induction 1
• Cardiovascular or lung involvement 1

Lower-Risk Patients (Consider Shorter Duration)

• MPO-ANCA positive patients with no extrarenal manifestations 1
• Patients on dialysis with MPO-ANCA and no extrarenal symptoms 1

Evidence Supporting Rituximab Maintenance

Rituximab maintenance therapy is superior to azathioprine for preventing relapses in ANCA vasculitis:

• The MAINRITSAN trial demonstrated significantly fewer major relapses in the rituximab group (3 relapses) compared to the azathioprine group (17 relapses) at 28 months 1
• Renal relapses occurred in 0/3 patients in the rituximab group versus 8/17 in the azathioprine group 1
• Health-related quality of life improvements were significantly better in the rituximab group 1

Monitoring During Maintenance Therapy

• Regular clinical assessment with validated scoring system (e.g., BVAS)
• Inflammatory markers and kidney function tests 1
• Regular ANCA serologies, especially if considering discontinuation 1
• Monitor serum immunoglobulins every 6 months 1
• Consider PJP prophylaxis during rituximab therapy 1

Special Considerations

Potential Adverse Effects

• Long-term rituximab use may lead to secondary immunodeficiency 1
• Infection risk is comparable to other maintenance therapies 1
• Lower malignancy risk compared to cyclophosphamide-based regimens 3

Alternative Maintenance Options

If rituximab is unavailable or contraindicated:

• Azathioprine (2 mg/kg/day) with low-dose glucocorticoids 1
• Mycophenolate mofetil for patients intolerant to azathioprine 1
• Methotrexate for patients with GFR >60 ml/min per 1.73 m² 1

Pitfalls and Caveats

1. Do not discontinue maintenance therapy prematurely in high-risk patients (PR3-ANCA positive, history of relapse) as this significantly increases relapse risk 1

2. Do not use methotrexate in patients with GFR <60 ml/min per 1.73 m² 1

3. Avoid underestimating infection risk - while rituximab has favorable safety profile, vigilant monitoring for infections remains essential 1

4. Do not overlook the need for maintenance even in patients on dialysis if they have extrarenal manifestations of vasculitis 1

5. Consider cost implications - while rituximab is more expensive than alternatives, preventing relapses reduces hospitalization costs and need for repeated induction therapy 1