Efficacy and safety of obinutuzumab-chlorambucil combination in the frontline treatment of elderly patients with chronic lymphocytic leukemia and comorbidities : real‑life data from Polish Adult Leukemia Group (PALG) analysis

Fludarabine- or bendamustine‑based upfront immunochemotherapy is the current standard of care in fit patients with chronic lymphocytic leukemia (CLL). These regimens are poorly tolerated by patients with comorbidities, for whom the obinutuzumab-chlorambucil combination became the recommended first‑line treatment. We aimed to analyze real‑life experience with the obinutuzumab-chlorambucil combination as the frontline treatment in elderly and unfit patients. The retrospective analysis included 86 elderly patients (median age, 74 years) with CLL and a significant burden of comorbidities, treated with obinutuzumab-chlorambucil as the frontline regimen. All patients had a Cumulative Illness Rating Scale score greater than 6 and/or creatinine clearance of 30 to 69 ml/min. Overall response rate at 2 months after treatment completion was 95.3%, with complete remission (CR) rate of 43% and partial remission (PR) rate of 52.3%. Stable disease rate was 4.7%. Progressive disease was not observed after treatment completion. The median progression‑free survival (PFS) was not reached after a median follow‑up of 18 months; estimated PFS at 30 months was 62%. We observed 6 relapses (7%), 3 (3.5%) in patients obtaining CR, and 3 (3.5%) in those with PR after immunochemotherapy. The most frequent adverse events were neutropenia and infusion‑related reactions (IRRs). Grade-3 neutropenia occurred in 11.6% of patients, and grade-3 IRRs, in 2.3%. There were no adverse events of grade 4 or 5. Our data confirm that the obinutuzumab-chlorambucil combination is an effective and well‑tolerated regimen in untreated CLL patients with comorbidities.