Rituximab

  • Monoclonal antibody against CD20 found on mature B cells and induce apoptosis 
  • Chimeric (mouse 25% 2 variable regions; human 75% 2 IgG1 heavy chains and 2 light chain kappa) 
  • Half-life: 21 days

  • FDA: chronic lymphocytic leukemia, non-Hodgkin lymphoma and rheumatoid arthritis, granulomatosis with polyangiitis, microscopic polyangiitis, pemphigus vulgaris
  • Off label: cutaneous B cell lymphomas, immunobullous disorders, GVHD, lupus erythematosus, dermatomyositis, cryoglobulinemic vasculitis and other type of vasculitis

  • Subcutaneous
  • Lymphoma Dosing
    • 375 mg/m2 weekly for 3-4 weeks 
  • Rheumatoid-Arthritis Dosing
    • 1gm at day 0 and 14, then every 4-6 months as directed by anti-desmoglein 
  • FDA approved dosing 
    • 1g at days 0 and 14 days then 500 mg at 12 months then 500 mg every 6 months PRN
    • If relapse, then 1gm + corticosteroids

  • Hypersensitivity to murine protein
  • Hypotension, bronchospasm and angioedema
  • Cardiac arrhythmia
  • Hepatitis B
  • Active infection
  • High tumor burden

  • Pregnancy Category C

  • Infusion reaction most common (can lead to death; death-related infusion reactions occur in the first 24 hours)
  • Arrhythmia with infusion
  • AKI because of tumor lysis (in patients with lymphoma)
  • Progressive multifocal leukoencephalopathy
  • Reactivation of Hepatitis B
  • SJS/TEN
  • Infection
  • Bowel perforation
  • Late onset neutropenia (weeks to months) – self limited
  • Risk of malignancy

Baseline

  • CBC, complete metabolic panel, Hepatitis B/C, HIV, PPD or QuantiFERON TB, ECG, pregnancy test, CD 19/20 levels

Follow up

  • CBC every 2 weeks while still taking infusion then every 1-3 months
  • Anti DsG III every 4-6 months 
  • CD19/20 every 4-6 months 

  • Should be on OCP durin, and 1 years after ritux
  • Doesn’t deplete plasma cells or stem cells
  • Combination with cisplatin increases risk of nephrotoxicity
  • Antibodies higher in patient with systemic lupus erythematosus: unknown if decreases efficacy
  • Biosimilar:
    • Rituximab-abbs
  • New anti-CD 20:
    • Ocrelizumab 
    • Humanized not chimeric, less infusion reactions