The purpose of this clinical trial it to test the safety and tolerability of the study drugs mosunetuzumab in combination with pirtobrutinib in patients with relapsed or refractory Waldenstrom's Macroglobulinemia.
Subjects aged ≥ 18 years with documented diagnosis of WM with the definition of measurable disease
Subjects who are able to comply with the study protocol.
Subjects with relapsed or refractory WM who have received at least one prior line of therapy.
Must have received prior treatment with covalent BTK inhibitor or have declined such treatment.
History of transformation of indolent disease to DLBCL
Active or history of CNS lymphoma or leptomeningeal infiltration
Prior treatment with a non-covalent BTK inhibitor
Prior treatment with CD20-directed bispecific antibody therapy