Ofatumumab Shows Promise As Alternative Agent for Relapsed/Refractory B-Cell Lymphoma

A study released in the July 25 issue of Blood suggests the new drug ofatumumab may be a promising alternative to rituximab in combination therapy for B-cell lymphoma patients for whom first line therapies fail. Researchers, including SAB members Myron Czuczman, MD of Roswell Park Cancer Institute, Izidore Lossos, MD of the University of Miami Sylvester Comprehensive Cancer Center, and Craig Moskowitz, MD of Memorial Sloan-Kettering, treated patients with relapsed or refractory (unresponsive to treatment) diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and transformed follicular lymphoma (tFL) who had already been previously treated with a rituximab combination therapy. Like rituximab, ofatumumab is a monoclonal antibody against the CD20 protein commonly found in B-cell lymphomas.

Patients in the study received ofatumumab in combination with standard chemoimmunotherapy regimens ICE (ifosfamide, carboplatin, and etoposide) or DHAP (dexamethasone, cytarabine, and cisplatin). Of the 61 patients in the study, 61 percent had at least a partial response to treatment, with a complete response rate of 37 percent. Additionally, the number of patients who had to discontinue or delay treatment due to toxic side effects was not significantly higher than in patients treated with rituximab. As most of the patients were not only relapsed/refractory, but had tumors with additional poor prognosis markers, the strong response rate was an encouraging sign for the effectiveness of ofatumumab as an alternative for patients who fail first line therapies.

The study was the first reported to evaluate a 2nd-generation anti-CD20 and chemotherapy combined to treat relapsed or refractory NHL. Dr. Czuczman, who was second author on the study, said "This study and others evaluating novel anti-CD20 monoclonal antibodies in combination with chemotherapy will give us a better perspective on their optimal therapeutic use in the near future."

Researchers are continuing to evaluate ofatumumab in an ongoing, international randomized trial in which patients receive either ofatumumab or rituximab in combination with DHAP.

The full text of the study may be accessed online through Blood.

September 2013