Ofatumumab Can Induce Remission in Refractory Burkitt's Lymphoma – A Case Report

Burkitt's lymphoma (BL) is a rare condition accounting between 1– 5% of Non Hodgkin's lymphomas. Standard treatment consists of intensive chemotherapy with fractionated alkylating agents and cell cycle phase specific agents that cross the blood brain barrier. Patients who achieve only partial response after front-line treatment or in first relapse can be treated with autologous stem cell transplantation (SCT) or in rare cases with allogeneic SCT. Rituximab added to various chemotherapy regimens can improve the results. Ofatumumab is a new anti-CD20 monoclonal antibody active in refractory or high risk patients with chronic lymphocytic leukemia (CLL). We present a patient with refractory BL after standard chemo/immunotherapy and autologous SCT who achieved remission after ofatumumab treatment.

A 31-year old male patient was diagnosed with Burkitt's lymphoma (stage IIIb) in April 2011. He was put on BMF protocol but progressed after two cycles. Rituximab was added in therapy. After two additional cycles there was no response to treatment. A salvage protocol DA-R-EPOCH was employed and after four cycles patient went into partial remission. Stem cell mobilization was performed with rituximab/cyclophosphamide/filgrastim and plerixafor because of poor initial mobilization result. In September 2011 patient received autologous SCT after BEAM conditioning. Six weeks after the procedure assessment of disease showed presence of 0.14 % BL cells on bone marrow flow cytometry and residual disease in abdomen on PET-CT. The patient started with ofatumumab according to protocol used in CLL and began with local radiotherapy. After seven weeks on ofatumumab bone marrow showed no residual BL on flow cytometry. Due to high risk disease and poor graft function after autologous SCT we decided for additional allogeneic SCT which was performed in January 2012 after myeloablative conditioning with cyclophosphamide and total body irradiation. The donor was a 9/10 HLA match. Post transplant period was complicated with cytomegalovirus reactivation and side effects of cyclosporine. On day +66 the patient presented with Pneumocystis carinii pneumonia that required ventilation support. Bone marrow examination in April 2012 showed no residual BL. After short improvement the patient's condition was complicated with secondary pneumonia, acute respiratory distress syndrome and septic shock. The patient expired on day +94 after allogeneic SCT.

Ofatumumab induced remission in a patient with refractory BL after two chemotherapy regimens, rituximab and autologous SCT. The patient went into remission after eleven weeks on ofatumumab CLL protocol and was able to proceed to allogeneic SCT. He remained in remission three months post SCT. The cause of patient's death was infection. Studies would be required to address ofatumumab's role in refractory BL.

Off Label Use: Ofatumumab is registered for treatment of CLL.