The purposes of the protocol amendment are: • To re-define processes related to SAEs management and evaluation of MRD (Minimal Residual Disease), as a result of the delegation of these activities to Nerviano Medical Sciences S.r.l. (NMS). • To remove the list of clinical centers participating in the trial reported in the original protocol since it became out of date; the updated list of participating investigators and relevant clinical centers will be provided as a separate document. • To add the signature of principal investigator and the signature of the relevant investigator by clinical site. • To modify exclusion criterion n. 14, from ‘Creatinine Clearance < 70 mL/min’ into ‘Creatinine Clearance < 60 mL/min’; this better represents the normal condition of renal efficiency in elderly patients. • To add the ofatumumab pharmacokinetic assessment among the secondary study objectives/endpoints, as well as overall survival (OS) and time-to-progression (TTP) for consistency purpose.

The purpose of the present protocol amendment is: • To modify Ofatumumab Pharmacokinetic Profile Assessment. In order to improve patient compliance and optimize study organization, from April 2013 the number of blood samples collected for pharmacokinetic assessment has been reduced (21 samples required, instead of 33 at all) and timepoints scheduled only during patient’s cycles monitoring visit.