Real-world Safety and Efficacy of Bendamustine Plus Rituximab for Indolent NHL or MCL

Bendamustine plus rituximab is feasible for patients with non-Hodgkin lymphoma (NHL) or mantle cell lymphoma (MCL) in the real-world setting, demonstrating similar efficacy and safety to that seen in clinical trials, according to a study presented at the virtual 2021 ASCO Annual Meeting.

The BRIGHT and STIL trials led to bendamustine plus rituximab becoming the preferred first line therapy for patients with previously untreated indolent NHL and MCL, however, there is very little real-world data available on the efficacy and safety of this combination.

Rouslan Kotchetkov, MD, PhD, Simcoe Muskoka Regional Cancer Program, Barrie, ON, Canada, and colleagues conducted a retrospective review of patients with indolent NHL and MCL who received more than one cycle of bendamustine plus rituximab, in order to evaluate its efficacy and safety in a real-world setting.

Of the 201 patients who received therapy with standard doses of bendamustine plus rituximab in the Simcoe Muskoka Regional Cancer Program between June 2013 and January 2021, 56% were males and 44% were females, with a median age of 72 years upon bendamustine plus rituximab initiation.

The most common forms of indolent NHL were follicular lymphoma (FL, 50.3%), marginal zone lymphoma (19.4%), and lymphoplasmacytic lymphoma (14.5%), with stage 3 and 4 diseases present in 19.9% and 68.6% of patients, respectively, and extranodal disease found in 35.8%. 

The proportion of patients with high-risk disease in the FL group, Lymphplasmacytic lymphoma group, and MCL group were 48.5%, 86.6%, and 80.5%, respectively.

Overall, 23.4% of patients had a history of secondary malignancy and 11.4% had ECOG 3. Bulky symptomatic lymphadenopathy (69.1%), cytopenia (36.8%), and constitutional symptoms (36.8%) were the most common indications for bendamustine plus rituximab initiation.

The median number of bendamustine plus rituximab cycles adminstered was 6, and the median dose of bendamustine was 90 mg/m2. Overall, 66.7% of patients received full doses of treatment and 33.3% had a dose reductions, with a mean dose of 78.3 mg/m2. There were no delays in the 6 cycle treatments in 50.8% of patients. For those who did experience treatment delays, the mean delay time was 1.8 weeks.

Overall response was 94.5%, with 77.6% complete and 16.9% partial remission. The median duration of follow-up was 35 months (range 4-91). At the end of follow-up, event free survival (EFS) was 77.1% and overall survival (OS) was 79.6%. In total, 6% of patients relapsed, 8% developed secondary hematological malignancies, and 16.9% required support with G-CSF. 

Common adverse events from rituximab-associated infusions included skin rash, thrombophlebitis, and infection. Overall, 80.6% of patients proceeded to rituximab maintenance.

“B+R [bendamustine plus rituximab] chemoimmunotherapy is feasible to administer in non-clinical trial setting” concluded Dr Kotchetkov, adding, “Despite more dose reduction as compared to STIL trial, B+R retained its efficacy with comparable EFS and OS.”—Marta Rybczynski