Rituximab
Anti-CD20 monoclonal antibody
- Response rate
- ~25-40% (monotherapy); higher in combinations
- Onset
- Months
- Route
- IV 375mg/m2 weekly x4 or extended schedule
- Line
- 1st
- IgM effect
- Moderate reduction (caution: IgM flare in 40-50%)
Evidence summary
Foundation of most WM combination regimens. Targets CD20+ lymphoplasmacytic cells. Important caveat: can cause transient IgM flare (increase) in 40-50% of patients in first weeks, potentially worsening hyperviscosity. Should be avoided as initial therapy in patients with high IgM or hyperviscosity symptoms.