Obinutuzumab (GA101) plus chlorambucil (Clb) or rituximab (R) plus Clb versus Clb alone in patients with chronic lymphocytic leukemia (CLL) and preexisting medical conditions (comorbidities): Final stage 1 results of the CLL11 (BO21004) phase III trial

7004 Background: Chemoimmunotherapy (CIT) is standard of care in young and physically fit patients (pts) with CLL. Development of CIT for older and less fit CLL pts is ongoing, but data from phase III trials are sparse. CLL11 is the largest trial to evaluate three treatments in previously untreated CLL pts with comorbidities: Clb alone, GA101 + Clb (GClb), R + Clb (RClb). The final analysis of CLL11 stage 1 efficacy and safety results is presented here. Methods: Treatment-naïve CLL pts with a Cumulative Illness Rating Scale (CIRS) total score >6 and/or an estimated creatinine clearance (CrCl) 2 iv d1 cycle 1, 500 mg/m2 d1 cycles 2-6). Primary endpoint was investigator-assessed progression-free survival (PFS). Results: Median age, CIRS score, and CrCl at baseline were 73 years, 8, and 61.1 mL/min for stage 1a (Clb vs GClb, 356 pts) and 73 years, 8, and 62.1 mL/min for stage 1b (Clb vs RClb, 351 pts, triggered by a different event rate). Key efficacy and safety results are shown in the Table.Grade 3-4 infusion-related reactions with GClb occurred at first infusion only. Management required splitting the first dose over 2 days. Conclusions: CIT with GClb or RClb significantly prolongs PFS vs Clb alone. The results demonstrate that GClb and RClb are very active in CLL and superior treament options in this population. GClb vs RClb will be compared in stage 2 analysis with more follow-up available. Clinical trial information: NCT01010061. [Table: see text]