Study of Iopofosine I-131 (CLR 131) in Select B-Cell Malignancies (CLOVER-1) With Expansion in Waldenstrom

\[CLOVER-1\] Inclusion Criteria: All Patients * Histologically or cytologically confirmed MM; Patients with primary or secondary CNSL may be enrolled. * ECOG performance status of 0 to 2 * 18 years of age or older * Life expectancy of at least 6 months * Platelets ≥ 75,000/µL (if full-dose anticoagulation therapy is used, platelets ≥ 100,000/µL are required) * WBC count ≥ 3000/µL * Absolute neutrophil count ≥ 1500/µL * Hemoglobin ≥ 9 g/dL (last transfusion, if any, must be at least 1 week prior to study registration, and no transfusions are allowed between registration and dosing) * Estimated glomerular filtration rate ≥ 30 mL/min/1.73 m2 * Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) ≤ 2.5 × upper limit of normal (ULN) * Bilirubin \< 1.5 × ULN * International normalized ratio (INR) \< 2.5 * If patient is on full-dose anticoagulation therapy, the anticoagulation therapy must be reversible and reversal of the anticoagulation therapy must not be life-threatening, as judged by the Investigator * Patients who have undergone stem cell transplant must be at least 100 days from transplant Patients with Multiple Myeloma * At least 5 prior regimens, which must include at least 1 approved proteasome inhibitor (bortezomib, carfilzomib, or ixazomib), at least 1 approved immunomodulatory agent (thalidomide, lenalidomide, or pomalidomide), and at least 1 approved monoclonal antibody (e.g., daratumumab or elotuzumab) with or without maintenance therapy, unless pati…