Maintenance therapy for 2 years with rituximab prolonged progression-free survival (PFS) among elderly patients with previously untreated chronic lymphocytic leukemia (CLL), a study published in the Lancet Haematology has shown.

Although fludarabine, cyclophosphamide, plus rituximab (FCR) is the current standard of therapy for fit patients with CLL, elderly patients require dose reductions and commonly experience poorer outcomes and relapse.

For this open-label, phase 3 study, investigators assessed the effect of 2-year rituximab maintenance therapy among elderly patients with CLL who achieved a complete response to abbreviated FCR induction therapy. Four-hundred nine patients were randomly assigned 1:1 to receive rituximab 500 mg/m2 every 8 weeks for 2 years or to be in the observation arm; eligible patients needed to have recovered from FCR toxicity and were willing to participate in the study.

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After a median follow-up of 47.7 months, the median PFS in the rituximab arm was 59.3 months (95% CI, 49.6 – not estimable) compared with 49.0 months (95% CI, 39.9-60.5) in the observation arm (hazard ratio [HR], 0.55; 95% CI, 0.40-0.75; P =.0002).

Neutropenia and grade 3 to 4 infections were the most frequently observed adverse events (AEs) among patients receiving rituximab maintenance; the most common grade 3 to 4 adverse event was lower respiratory tract infection. Incidence of secondary malignancies were similar in both study arms, and 11% and 8% of patients in the rituximab arm compared with the observation arm, respectively, died due to associated adverse events.

The authors of the study note that while rituximab maintenance therapy prolonged PFS, there is an increased incidence of adverse events among this population and note that “the ability to live without relapse and second-line therapy must be balanced against the adverse events associated with rituximab maintenance.” They concluded saying that “maintenance with rituximab […] could be a valuable treatment in elderly patients with chronic lymphocytic leukemia.” 

Reference

Dartigeas C, Van Den Neste E, Leger J, et al. Rituximab maintenance versus observation following abbreviated induction with chemoimmunotherapy in elderly patients with previously untreated chronic lymphocytic leukaemia (CLL2007SA): an open-label, randomised phase 3 study [published online December 20, 2017]. Lancet Haematol. doi: 10.1016/S2352-3026(17)30235-1