Study of IgPro20 to Prevent Infection in People With Multiple Myeloma and Hypogammaglobulinemia

Inclusion Criteria:

• Diagnosis of RRMM receiving a commercially available bispecific antibody

• Received at least 1 but no more than 4 cycles of BsAb

• Received 2 or more lines of therapy for MM IgG ≤ 4 g/L excluding paraprotein. ForIgG Kappa MM, hypogammaglobulinemia will be determined by subtracting the M spikefrom IgG

• Males or females greater than or equal to 18 years old at the time of consent

• ECOG ≤ 3

• Life expectancy > 12 months

Exclusion Criteria:

• HSCT within 3 months before enrollment

• Planned CAR-T therapy in the next 6 months

• >1 major (deep-seated) infection within the preceding 3 months

• HIV infection, Active HCV, or Active HBV infection

• Pregnancy

• Neutrophils < 500 x 10^9 per mL, Platelets < 30 x 10^9 per mL

• History of cancer other than MM in the last 3 years requiring active chemotherapy orradiation

• Known reaction/allergy to IgG products

• Intracranial hemorrhage or embolic CVA in the last 6 months

• Hyperproteinemia

• Protein-losing enteropathy

• Creatinine Cl <30 ml/min

• Documented progression on BsAb

• Known history of Hyperprolinemia

• On current or previous IVIG (in the last 3 months)