Arzerra (ofatumumab) is administered by an intravenous infusion. It is diluted into a sterile bag of 1000mL sodium chloride for intravenous infusion which is then hung up and the infusion administered into one of your veins via an intravenous line. How long the infusion takes depends on your stage of Chronic Lymphocytic Leukemia (CLL) and if you have had treatment before, but initially Arzerra is usually administered over about 6 hours. The time of the infusion may be shortened, depending on how well you tolerate Arzerra.