FDA Gives Arzerra Breakthrough Therapy Designation for CLL

Roxanne Nelson

September 19, 2013

The US Food and Drug Administration (FDA) has granted ofatumumab (Arzerra) breakthrough therapy designation for the treatment of chronic lymphocytic leukemia (CLL). The indication is for use in combination with chlorambucil for treatment-naïve patients who are not candidates for fludarabine-based therapy.

Currently, ofatumumab, which is being codeveloped by Genmab and GlaxoSmithKline, is not approved or licensed anywhere in the world other than the United States.

The breakthrough therapy designation was enacted last year as part of the 2012 FDA Safety and Innovation Act, and is the newest FDA initiative for accelerating the development and review of drugs. This designation is meant for an agent to be used alone or in combination with 1 or more other drugs to treat a serious or life-threatening disease or condition. The designation includes all the features of the fast track designation but has more intensive guidance from the FDA on the drug's clinical development program.

Ofatumumab is a cytolytic monoclonal antibody that binds specifically to the CD20 molecule expressed on the surface of normal and malignant B-lymphocytes, making them more susceptible to an attack from the immune system. The FDA initially granted accelerated approval for intravenous infusions of ofatumumab for patients with CLL that is refractory to fludarabine and alemtuzumab.

The breakthrough therapy designation was granted on the basis of results from an international, multicenter, randomized phase 3 clinical trial of more than 400 patients with previously untreated CLL.

In that study, 447 patients were randomized to receive either ofatumumab plus chlorambucil or chlorambucil alone (control group). Median progression-free survival was significantly better in the ofatumumab group than in the control group (22.4 vs 13.1 months; hazard ratio [HR], 0.57; P < .001). The study met its primary end point, and there were no unexpected safety findings.

Headline results from this trial were announced in May. Full study results have been submitted for presentation at the 2013 American Society of Hematology Annual Meeting, which will be held in December.

According to the manufacturer, ofatumumab is also being investigated for use in other oncology and autoimmune diseases, including follicular lymphoma, diffuse large B-cell lymphoma, Waldenström's macroglobulinemia, pemphigus vulgaris, and relapsing–remitting multiple sclerosis. Other conditions in which a CD20 antibody could play a role include Crohn's disease, ‎Wegener's granulomatosis, and other B-cell lymphomas, (such as mantle cell lymphoma and autoimmune disease).


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