Introduction:
Despite significant recent advances in the treatment of chronic lymphocytic leukaemia (CLL), most cases of the disease are still incurable. Treatment with monoclonal antibodies, such as ofatumumab, is one of the new therapeutic options.

Objective:
Retrospective analysis of the efficacy of ofatumumab in patients with chronic lymphocytic leukaemia (CLL) treated in the Haematooncology and Bone Marrow Transplantation Department of the Medical University of Lublin, Poland, during 2011–2013.

Material and Methods:
The analysis included 5 patients (3 women and 2 men), aged 47–65, with Rai stage II-IV CLL, after a few lines of treatment. Three patients received ofatumumab in monotherapy and 2 patients received ofatumumab in combination with cyclophosphamide (50 mg/day) and dexamethasone (40 mg/day). All patients included in the study were diagnosed with an active form of leukaemia with symptoms such as lymphocytosis or massive lymphadenopathy.

Results:
All patients responded to the treatment. Within the first 8 weeks of the treatment, levels of white blood cells returned to normal in patients with baseline lymphocytosis (3 patients). An increase in platelet levels was reported in 3 patients. Haemoglobin levels were higher or comparable to the baseline values in all studied patients after the completion of immunotherapy. In the patient with massive lymphadenopathy and hepato- and splenomegaly, the size of the lymph nodes, spleen and liver decreased and neutrophil levels increased. Time of progression was 5–12 months, and in one patient partial remission has been maintained. The treatment was well-tolerated in most cases. Asymptomatic neutropenia and an infection with Candida glabrata were observed.

Conclusions:
Ofatumumab may be a new and safe therapeutic option for patients with CLL after a few lines of treatment.