Only one week after approving a new drug for kidney cancer, the Food and Drug Administration approved another new cancer drug--Arzerra (ofatumumab) for patients with chronic lymphocytic leukemia.The approval was based on a study in which about half of patients whose cancers didn't respond to other therapies responded to Arzerra. Similar to Rituxan (rituximab), Arzerra is a monoclonal antibody that targets the CD20 receptor on cancer cells. (Read more about Rituxan in "Trying Something New" from the Spring 2009 issue.)Because Arzerra was approved under the FDA's accelerated approval process, which allows early approval of treatments that meet an unmet need for a specific disease, research is still ongoing to look at how well the agent delays progression of the cancer.The FDA said the most serious side effects of Arzerra are increased risk of infections, including a brain infection called progressive multifocal leukoencephalopathy that is generally fatal. The agency said patients who are at high risk for hepatitis B should be screened before taking Arzerra. Common side effects include a decrease in blood counts, pneumonia, fever, and fatigue, among others.For more, visit CURE's leukemia page.