A Proof-of-Concept Study to Learn Whether Linvoseltamab Can Eliminate Abnormal Plasma Cells That May Lead to Multiple Myeloma in Adult Patients With High-Risk Monoclonal Gammopathy of Undetermined Significance or Non-High-Risk Smoldering Multiple Myeloma

Key Inclusion Criteria:

1. HR-MGUS or NHR-SMM as defined in the protocol
2. Eastern Cooperative Oncology Group (ECOG) performance status ≤1
3. Adequate hematologic and hepatic function, as described in the protocol
4. Estimated glomerular filtration rate (GFR) ≥30 mL/min/1.73 m\^2 by the Modification of Diet in Renal Disease (MDRD) equation

Key Exclusion Criteria:

1. High-risk SMM, as defined in the protocol
2. Evidence of any of myeloma-defining events, as described in the protocol
3. Diagnosis of systemic light-chain amyloidosis, Waldenström macroglobulinemia (lymphoplasmacytic lymphoma), solitary plasmacytoma, or symptomatic MM
4. Clinically significant cardiac or vascular disease within 3 months of study enrollment, as described in the protocol
5. Any infection requiring hospitalization or treatment with intravenous (IV) anti-infectives within 28 days of the first dose of linvoseltamab
6. Uncontrolled Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), or Hepatitis C Virus (HCV) infection; or other uncontrolled infection or unexplained signs of infection, as described in the protocol

NOTE: Other protocol defined inclusion/exclusion criteria apply