Footnotes

• Contributors JMV, NCN, SD, MPL, WLvdP, MJK, STP and MCM initiated and designed the study. JMV, NCN, SD, WK, MMR, JC, RG and MCM performed the research. JMV, NCN, STP and MCM performed data analysis. JMV, NCN, SD, MJK, STP and MCM wrote the paper. All authors reviewed the manuscript and approved the final version.

• Funding This research was supported by grants from Fonds Stimulans and the International Waldenstrom Macroglobulinaemia Foundation (IWMF).

• Competing interests MJK has consulted for or received compensation for presentations from Gilead, Celgene, Novartis, Roche, Millennium/Takeda, Kite Pharma and BMS, and has received research support from Celgene, Roche, Millennium and Sanofi. SD has received honoraria from Janssen. MPL has received honoraria from CSL Behring Grifols, UCB Pharma, Baxter and LfB. MCM has consulted for Jansen Cilag, Takeda, Amgen, BMS. The other authors had no disclosures to report.

• Ethics approval UMCU and Leeds East Research Ethics Committees.

• Provenance and peer review Not commissioned; externally peer reviewed.