Benefit of rituximab maintenance after first-line bendamustine-rituximab in mantle cell lymphoma.

• DOI: 10.1200/jco.2024.42.16_suppl.7006
• Publication Date: 2024-06-28T20:19:52Z
• Authors: Yucai Wang; Melissa C. Larson; Anita Kumar; Brian T Hill; David Alan Bond; Brad S. Kahl; Alexey Valeryevic...; Reid Merryman; Natalie Sophia Gr...; Aung M. Tun; Sabarish Ram Ayya...; Georgios Pongas; Craig Anthony Por...; Javier Munoz; Patrick Michael R...; Muhamad Alhaj Mou...; Priyanka Avinash ...; Irl Brian Greenwell; Jonathon Brett Cohen; Peter Martin
• Keywords: Bendamustine; Progression-free survival

7006 Background: Rituximab maintenance (RM) after first-line (1L) bendamustine and rituximab (BR) in MCL did not improve progression-free survival the MAINTAIN trial (Rummel et al, ASCO 2016) but was associated with improved outcomes a North American observational study (Martin JCO 2023). We sought to examine potential benefit of RM BR using large cohort from 26 US academic centers. Methods: Patients who received 1L (without stem cell transplant) outside clinical trials were included. At landmark 3 months end BR, patients achieved complete response (CR) or partial (PR) had no evidence progressive disease (PD) second-line (2L) therapy deemed eligible for RM. Event-free (EFS) defined as time progression, relapse, retreatment, death. EFS2 retreatment following 2L considered line either endpoint. OS Survival analysis done Kaplan-Meier methods Cox regression models adjusting sex simplified MIPI. Results: Among 796 2007-2020, 693 CR PR. 3-month post-BR landmark, 613 PD, among whom 318 (52%) 295 not. The group younger (median age 70 vs 72, p = 0.010) more predominantly male (78% 69%, 0.047). There statistical difference stage, MIPI, histology (blastoid pleomorphic classic), Ki-67, TP53 alteration, complex karyotype, year start, best between two groups. median follow-up 61.3 (95% CI 62.6-70.4). number doses 10 (IQR 5-12). EFS 47.1 29.7 months, adjusted HR 0.59, 95% 0.48-0.73), 89.1 48.3 0.63, 0.50-0.81), 136.1 74.3 0.57, 0.44-0.75) (all values < 0.001). In (n=527), 271 (51%) RM, 11 6-12) doses. this subgroup, 60.6 31.5 0.56, 0.44-0.71), 0.62, 0.48-0.81), 75.6 0.44-0.79) Analysis PR limited by sample size (n=86, 47 RM). numeric differences (20.8 11.5, log-rank 0.370), (48.9 30.3, 0.210) (87.3 46.9, 0.067) statistically significant. Conclusions: multicenter study, OS, supporting its use routine practice newly diagnosed MCL.