Retrospective analysis of WM patient outcomes receiving combination therapy and rituximab maintenance

A research paper was published on 28 December 2017 in the British Journal of Haematology presenting study results of combined therapy and rituximab maintenance in patients with Waldenström macroglobulinemia (WM) by Jorge Castillo, Dana-Farber Cancer Institute, Massachusetts, and colleagues.

One hundred and eighty-two WM patients receiving specified primary therapy combinations were included in this retrospective study from a database between January 2005 and December 2016. Patients received primary therapy with either bendamustine and rituximab (Benda-R, n = 57), bortezomib-dexamethasone-rituximab (BDR, n = 87) or cyclophosphamide-dexamethasone-rituximab (CDR, n = 38). After primary therapy, 116 patients (64%) received maintenance rituximab.

Key Findings

• Progression-free survival (PFS) results:
  • Median overall = 5.8 years (95% CI, 4.9–6.8 years)
  • Benda-R median = 5.5 years (95% CI, 4.9–not reached (NR))
  • BDR median = 5.8 years (95% CI, 4.4–7.4 years)
  • CDR median = 4.9 years (95% CI, 2.8–7.0 years)
  • Median PFS for patients who received R-maintenance and who did not = 6.8 years (95% CI, 5.9–NR) vs 8 years (95% CI, 2.1–4.1 years), respectively
• Overall survival (OS) results:
  • Median overall follow-up time = 3.5 years (95% CI, 3–4 years)
  • Estimated overall 5- and 10-year OS = 92% (95% CI, 84–96%) and 79% (95% CI, 61–89%), respectively
  • Median overall OS = NR
  • Benda-R estimated 5-year = 95% (95% CI, 81–99%)
  • BDR estimated 5-year = 96% (95% CI, 85–99%)
  • CDR estimated 5-year = 81% (95% CI, 60–92%)

The authors found from their results and exploratory analyses that Benda-R and BDR produced higher response rates and longer PFS than CDR. Additionally, they noted that OS appeared longer in patients treated with BDR compared with CDR. Superior OS and PFS was found in patients receiving rituximab maintenance.

The authors concluded that from their study, they found Benda-R and BDR a viable primary therapy option for WM patients due to faster and better duration of response. They also recommended that since the primary therapy options explored in the study were not curative, “treatment of patients with WM has to be personalized,” and taking into account, “the patient’s disease presentation, the efficacy and toxicity of the regimen to be used and the patient’s preferences and goals of care.”