hello. just seen this. My husband has WM since 2012 and had 6 rounds of Rutiximab etc when gave him a good remission but last year he relapsed and was put on Ibrutinib. Everyone is different of course but I have to say he had very few problems (one day of diarrhoea, a couple of weeks with little sleep because all of a sudden soo much energy) then it settled down. He went back to work and has been stable with an IgM of less than 1 for nearly a year
So don’t be too worried. As I say everyone is different but hopefully this helps a little bit to calm your nerves. Your consultant will see you through. good luck.