The median age was 71 years (range: 47 to 92) with % of subjects over 65 years; % were male, and % were white; % had a Rai stage of III or IV, and % had Binet Stage C. Most subjects had adverse cytogenetic prognostic factors: % had a 17p chromosomal deletion and/or tumour protein 53 ( TP53 ) mutation, and % had unmutated genes for the immunoglobulin heavy chain variable region ( IGHV ). The median time from diagnosis of CLL to randomisation was years. Subjects had a median Cumulative Illness Rating Scale (CIRS) score of 8. The median number of prior therapies was . Nearly all (%) subjects had received prior anti-CD20 monoclonal antibodies. The primary endpoint was progression free survival (PFS). Efficacy results are summarised in Tables 3 and 4. The Kaplan-Meier curve for PFS is provided in Figure 1.