Rituximab, an anti-CD20 monoclonal antibody, is licensed for previously treated and previously untreated patients suffering from chronic lymphocytic leukaemia in Europe. Of note, the chemotherapy regimen rituximab should be combined with is not further defined in Europe, whereas rituximab is licensed only in combination with FC in the US.
The benefit of adding rituximab to a chemotherapy regimen consisting of fludarabine + cyclophosphamide (FC) was assessed in two phase III trials, both showing improvements in progression-free survival and tumour response for patients treated with rituximab in comparison to patients treated with chemotherapy only. Based on these trials, rituximab + FC has increasingly become standard therapy for younger and fitter patients in the first-line setting. For previously treated patients, it remains unclear if patients will benefit when retreated with this combination therapy.