Last week the FDA announced approval for obinutuzumab (Gazyva) in combination with chlorambucil for the treatment of patients with previously untreated CLL. Obinutuzumab is the first designated “Breakthrough Therapy” to be granted FDA approval, receiving a priority review through its demonstration of “significant improvement” in safety or effectiveness over available therapies.
Obinutuzumab is a 3rd generation type II anti-CD20 antibody. Acting as an immunomodulator, obinutuzumab selectively binds to the extracellular domain of the human CD20 antigen on malignant human B cells.
This “significant improvement” was demonstrated in a phase III study. Patients treated with a combination of obinutuzumab and chlorambucil experienced significant improvement in progression free survival, increasing to an average of 23 months, compared to 11 months for chlorambucil therapy.