Bortezomib, Rituximab and Dexamethasone Regimen (BDR) in Waldenström Macroglobulinaemia: A Retrospective Real-World Analysis.

INTRODUCTION

We retrospectively analysed bortezomib-dexamethasone-rituximab (BDR) combination in patients with Waldenström macroglobulinaemia (WM) in a real world setting.

METHODS

A total of 87 patients were included: 49 patients (56%) were treated in frontline, 22 (25%) in second line and 16 (19%) in third or further line settings. A log-rank test was used to compare overall and event-free survival (OS and EFS) whereas a Gray's test was performed to compare cumulative incidence of deaths and relapse (CID and CIR) according to the IPSS-WM groups, MYD88/CXCR4 mutational status and line of therapy.

RESULTS

The overall response rate was 88% with five patients (6%) achieving complete response, 20 (24%) very good partial response, 38 (45%) partial response and 11 (13%) minor response. The median time to achieve the best overall response was 9 months and the median EFS was 33 months for whole cohort. Patients treated in third line or further relapse settings had significantly lower median EFS compared to those treated in second- or first-line setting (13 vs. 36 vs. 47 months, respectively, = 0.01) and a higher 7-year CID (50% vs. 13% vs. 12% respectively, = 0.02). Among patients for whom mutational status was available, MYD88 mutation or double mutation MYD88/CXCR4 did not influence OS or EFS. Severe peripheral neurotoxicity affected 7% of patients and 52 (62%) patients relapsed or died as result of WM whereas 21 patients (24%) died of unrelated causes.

CONCLUSION

BDR represents an interesting chemo-free, fixed duration regimen for patients in first or second line, regardless of mutational status.

TRIAL REGISTRATION

The authors have confirmed clinical trial registration is not needed for this submission.