Study Evaluating the Efficacy and Tolerance of a Zanubrutinib and BGB-11417 Combination in Patients Previously Treated for Waldenström Macroglobulinemia

This is a French multicenter open label non-randomized Phase II trial evaluating the efficacy and tolerance of a combination of oral zanubrutinib and BGB-11417 in subjects aged 18 years and older with previously treated Waldenström macroglobulinemia (WM) who require therapy according to the consensus panel criteria from the Second International Workshop on Waldenström's macroglobulinemia. population : Patients with previously treated Waldenstrom macroglobulinemia The investigational medicinal products (IMP) are Zanubrutinib (BGB- 3111) and BGB-11417.Treatment will be administered for a total of twenty 28 day cycles: * Cycle 1 with zanubrutinib only * Cycle 2 with zanubrutinib plus BGB-11417 ramp-up * cycle 2, day 1 : 10mg * cycle 2, day 2 : 20 mg * cycle 2, day 3 : 40mg * cycle 2, day 4-7 : 80md daily * cycle 2, day 8 and beyond : 160 mg daily * Cycles 3-20 with zanubrutinib plus BGB-11417 full dose