Clinical value of minor responses after 4 doses of rituximab in Waldenström macroglobulinaemia: a follow-up of the Eastern Cooperative Oncology Group E3A98 trial

Abstract

Waldenström macroglobulinaemia is a low-grade, lymphoplasmacytic lymphoma that is responsive to rituximab. We report the role of a minor response in predicting overall outcomes. We extended follow-up of a previously described cohort (n = 69) treated with 4 weekly doses of rituximab and observed durable responses (median time to progression, 30 months; 5-year survival rate, 66%). Patients achieving a minor response [25-50% immunoglobulin M (IgM) reduction] appeared to do as well as those achieving an objective response (>50% IgM reduction), which suggests that more aggressive or intensive therapy for minor responders is not required. Future studies of Waldenström macroglobulinaemia should report minor responses because they are associated with clinically meaningful benefits. This trial was registered at http://www.clinicaltrials.gov as #NCT00005609.

Conflict of interest statement

Authorship and conflicts of interest

All authors participated in study design. H.U. collected data. All authors participated in data analysis and interpretation. M.A.G. drafted the manuscript.

No authors have any potential conflicts of interest or competing financial interests to disclose.

Figures

Fig 1

Overall survival of all patients, stratified by degree of response. Survival was calculated (landmark analysis) starting 4 months after trial enrolment.

Fig 2

Progression-free survival of all patients, stratified by degree of response. Survival was calculated (landmark analysis) starting 4 months after trial enrolment.