Outcomes of bendamustine- or cyclophosphamide-based first-line chemotherapy in older patients with indolent B-cell lymphoma.

ABSTRACT

Clinical trials comparing bendamustine/rituximab (BR) with cyclophosphamide-based regimens (RCHOP/RCVP) have pooled various histologies of indolent B-cell lymphomas. We examined real-life outcomes of older patients with follicular (FL), mantle cell (MCL), or marginal zone/lymphoplasmacytic lymphoma (MZL/LPL), treated with these first-line regimens. We identified Medicare beneficiaries with FL, MCL, or MZL/LPL, who received either first-line BR or RCHOP/RCVP in 2009-2016, and matched groups using a propensity score. Outcomes of claims-based event-free survival (EFS), overall survival (OS), toxicity, secondary cancers, and costs were compared in the aggregate cohort (N = 2736), and in separately matched histology-specific subcohorts. In the aggregate cohort, EFS was better with BR than with RCHOP/RCVP (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.70-0.87). Acute toxicity was lower with BR, including rates of hospitalizations (33% vs 45%), infections (21% vs 30%), cardiovascular events, and transfusions, yet OS did not differ (HR, 1.03; 95% CI, 0.91-1.17) and Medicare spending was higher. There was no difference in the cumulative incidence of secondary cancers (subhazard ratio, 1.11; 95% CI, 0.83-1.48). The EFS advantage of BR was pronounced in MCL (N = 690; HR, 0.64; 95% CI, 0.54-0.76), but less so in FL (N = 1330; HR, 0.83; 95% CI, 0.69-0.98) and absent in MZL/LPL (N = 574; HR, 0.92; 95% CI, 0.73-1.17). Despite improved EFS and lower toxicity, the shift from RCHOP/RCVP to BR in clinical practice did not improve OS for older patients with indolent B-cell lymphomas. Frequent infections and hospitalizations underscore the need for safer treatment approaches in this population. Secondary cancers do not appear to be increased after BR compared with RCHOP/RCVP.