An observational study of outcomes after initial infused therapy in Medicare patients diagnosed with chronic lymphocytic leukemia.

The study goal was to characterize older chronic lymphocytic leukemia (CLL) patients and to evaluate outcomes in those patients who initiated infused therapy. Patients 66 years of age and older in the Surveillance, Epidemiology, and End Results (SEER) program with a CLL diagnosis were matched to their Medicare Part A and Part B claims for long-term follow-up. Treatment patterns, survival after initiation of infused therapy, and both hematologic and hospitalization outcomes were assessed. There were 6433 CLL patients identified, and 2040 received infused therapy. Treated patients were categorized as receiving rituximab monotherapy (16%), rituximab plus chemotherapy (14%), and chemotherapy alone (70%) based on the initial 60 days after infusion. Rituximab plus chemotherapy compared with chemotherapy alone was associated with a 25% lower risk of overall mortality (95% confidence interval, 9%-38%). Restricting to patients age 70 years and older did not change the risk reduction for rituximab plus chemotherapy. Hematologic interventions were more common with rituximab plus chemotherapy compared with chemotherapy alone, but there was no difference in all-cause hospitalizations. These analyses, based on observational data, suggest that the benefits of initial therapy with rituximab in a heterogeneous group of older CLL patients are comparable with those demonstrated in younger patients.