Doubling rituximab in high-risk patients with aggressive B-cell lymphoma -results of the DENSE-R-MegaCHOEP trial.

To further improve outcome in young high-risk patients with diffuse large B-cell lymphoma (DLBCL) the number of rituximab (R) infusions was doubled in combination with standard CHOEP (cyclophosphamide, doxorubicin, etoposide, vincristine, prednisone) chemotherapy. Seventy-seven patients (aged 18-60 years) with an age-adjusted International Prognostic Index of 2-3 received 12 × R (375 mg/m2 ) on days 0, 1, 4, 8, 15, 22, 29, 43, 57, 71, 85 and 99 together with eight cycles of CHOEP-14. Results were retrospectively compared to those of patients receiving 6 × R and 8 × CHOEP-14 in the standard arm of the randomized R-MegaCHOEP trial. Two-year overall survival (OS) was 82% [95% confidence interval (CI) 73%-92%]; 2-year event-free (EFS) and progression-free survival (PFS) was 69% (95% CI 59-80%) and 76% (95% CI 66%--6%), respectively. Comparing 12 to six doses of R revealed no differences (univariate/multivariate) in EFS (at 2 years: 69% vs. 71%), PFS (76% vs. 75%) and OS (82% vs. 85%), with P = 0·766, P = 0·871 and P = 0·843, respectively. Doubling the number of R infusions concomitant to CHOEP did not improve treatment outcomes. Nonetheless, OS and PFS of young high-risk patients who received only six infusions of R combined with CHOEP remain excellent and were confirmed in an independent cohort of patients.