Rituximab, a chimaeric anti-CD20 monoclonal antibody, in the treatment of hairy cell leukaemia.

The introduction of first alpha-interferon and later the purine analogues has revolutionized the treatment of hairy cell leukaemia (HCL). However, there are still some patients that initially or eventually fail to respond and, thus, there is a need for alternative treatment modalities. We have treated 11 HCL patients (eight relapsing and three newly diagnosed) with a chimaeric monoclonal antibody, rituximab, in a dose of 375 mg/m2 once a week for 4 weeks. The response rate was seven out of eleven (64%) with six complete remissions and one partial remission, all which have lasted between 0 and 34 months (median 14 months). Rituximab appears promising in the treatment of HCL and warrants further studies.