The goal of this clinical trial is to evaluate whether iopofosine I 131 is more effective than the combination Rituximab-Cyclophosphamide-Dexamethasone (R-CD). The main question the study aims to answer is:
• Does iopofosine I 131 work better than R-CD when looking at the length of time during and after the treatment that a patient lives with WM but it does not get worse.
Participants will:
* Be randomly assigned to received either iopofosine I 131 or R-CD. * If assigned to iopofosine I 131, have it administered via infusion 2 times each cycle for a total of 2 cycles (each cycle is about 3 months long). * If assigned to R-CD, it will be administered for up to six cycles, and each cycle is 3-weeks long * Visit the clinic once every 3 weeks for checkups and testing. * Report any side effects or new medications.
Histologically and serologically confirmed diagnosis of WM.
Received at least one prior therapy for WM.
Received treatment with a BTKi (including covalent BTKi or non-covalent BTKi).
Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2.
Anti CD-20 MoAb < 6 months prior to study drug administration.
Any conventional cytotoxic chemotherapy ≤ four weeks prior to study drug administration.
Non-anti CD20 MoAb therapy for the treatment of WM ≤ three months prior to study drug administration. i. The only exception to this is for those patients who have documented evidence of progression while receiving non-anti CD20 MoAb therapy.
BTKi therapy ≤ 48 hours prior to study drug administration.