Arzerra was given a conditional approval in the EU on April 19, 2010. The approved indication in the EU for the product is treatment of CLL in patients refractory to fludarabine and alemtuzumab. A specific obligation for this conditional approval was an agreement by GSK to conduct a post-marketing observational study in CLL patients receiving Arzerra. The data from this study is intended to enhance the evidence of the safety and efficacy of Arzerra as it is used in clinical practice, and once final data are available, together with results of a second specific obligation study, will support the transition from conditional to a full approval of Arzerra in the EU.