Chlorambucil plus ofatumumab is an important treatment option for treatment-naive patients with chronic lymphocytic leukemia (CLL) who cannot tolerate more intensive therapy because they are elderly or have comorbidities, a new study published online early in the journal The Lancet has shown.

Chlorambucil is the standard of care in many countries for the treatment of patients with CLL who cannot tolerate fludarabine-based chemoimmunotherapies.

Therefore, researchers sought to investigate whether the addition of ofatumumab to chlorambucil could be more effective than chlorambucil alone, while also being tolerable.

Continue Reading

Researchers enrolled 447 patients and randomly assigned them 1:1 to receive oral chlorambucil 10mg/m2 on days 1-7 with or without intravenous ofatumumab 300mg on day 1 and 1000mg on day 8 of cycle 1, then 1000mg on day 1 of subsequent cycles, for three to 12 28-day cycles.

RELATED: Good Prognosis in Chronic Leukemia Progression After Stem Cell Transplant

Results showed that median progression-free survival was 22.4 months (95% CI: 19.0-25.2) in the chlorambucil plus ofatumumab group versus 13.1 months (95% CI: 10.6-13.8) in the chlorambucil only group (HR = 0.57; 95% CI: 0.45-0.72; P < 0.0001).

In regard to safety, grade 3-5 adverse events were more common in the combination group. Grade 3 or higher neutropenia occurred in 26% of the combination group compared with 14% of the chlorambucil alone group. Grade 3 or greater infusion-related adverse events occurred in 10% of patients who received ofatumumab.


  1. Hillmen P, Robak T, Janssens A, et al. Chlorambucil plus ofatumumab versus chlorambucil alone in previously untreated patients with chronic lymphocytic leukemia (COMPLEMENT 1): a randomised, multicentre, open-label phase 3 trial. Lancet. 2015. [Epub ahead of print]. doi: 10.1016/S0140-6736(15)60027-7.