Efficacy of bendamustine and rituximab as first salvage treatment in chronic lymphocytic leukemia and indirect comparison with ibrutinib: a GIMEMA, ERIC and UK CLL FORUM study

Abstract
We performed an observational study on the efficacy of bendamustine and rituximab as first salvage regimen in chronic lymphocytic leukemia. In an intention-to-treat analysis including 237 patients, the median progression free survival was 25 months. The presence of del(17p), unmutated IGHV and advanced stage were associated with a shorter progression free survival at multivariate analysis. The median time-to-next treatment was 31.3 months. Front-line treatment with a chemoimmunotherapy regimen was the only predictive factor for a shorter time to next treatment at multivariate analysis. The median overall survival was 74.5 months. Advanced Binet stage (i.e. III-IV or C) and resistant disease were the only parameters significantly associated with a shorter OS. Grade 3-5 infections were recorded in 6.3% of patients. A matched-adjusted indirect comparison with ibrutinib given second-line within named patient programs in the United Kingdom and in Italy was carried out with overall survival as objective endpoint. When restricting the analysis to patients with intact 17p who had received chemoimmunotherapy in first line, the overall survival did not differ between patients treated with ibrutinib (63% alive at 36 months) and patients treated with BR (74.4% alive at 36 months). BR is an efficacious first salvage regimen in chronic lymphocytic leukemia in a real-life population, including the elderly and unfit patients. BR and ibrutinib may be equally effective in terms of overall survival when used as first salvage treatment in patients without 17p deletion. ClinicalTrials.gov identifier: NCT02491398.