Induced resistance to ofatumumab-mediated cell clearance mechanisms, including complement-dependent cytotoxicity, in chronic lymphocytic leukemia.

ABSTRACT: Ofatumumab (OFA), a human CD20-targeting mAb, kills B lymphocytes using the innate immune system including complement-dependent cytotoxicity (CDC). The efficacy of OFA in patients with chronic lymphocytic leukemia (CLL) is limited by drug resistance, which is not well characterized. To better understand mechanisms of resistance, we prospectively studied CLL cells isolated from blood samples collected before and after in vivo exposure to the initial dose of OFA therapy in 25 patients undergoing their first treatment for progressive CLL. As previously reported, OFA therapy rapidly decreased the absolute lymphocyte count, CD20 expression by CLL cells, and serum complement levels. We now show that after administration of the first dose of OFA, there was a modest rebound in the absolute lymphoc

SUBMITTER: Baig NA 

PROVIDER: S-EPMC4391060 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature