This study is researching an experimental drug called linvoseltamab (also called "study drug") compared to another drug called daratumumab, in participants with Smoldering Multiple Myeloma (SMM), who are at a High Risk (HR) of developing active multiple myeloma.

The aim of this study is to find out whether linvoseltamab is better than daratumumab in delaying the development of MM.

The study is looking at several other research questions, including:

• What side effects may happen from taking the study drug
• How much study drug is in the blood at different times
• Whether the body makes antibodies against the study drug (which could make the drug less effective or could lead to side effects)

Key Inclusion Criteria:

1. Eastern Cooperative Oncology Group performance status score ≤1
2. SMM diagnosis per IMWG criteria as defined in the protocol
3. Meets HR-SMM criteria by 1 of the risk models as defined in the protocol

Key Exclusion Criteria:

1. Evidence of myeloma-defining events attributable to the underlying plasma cell dyscrasia, as defined in the protocol
2. Diagnosis of systemic light chain amyloidosis, Waldenström macroglobulinemia (lymphoplasmacytic lymphoma), plasma cell leukemia, or soft tissue plasmacytoma
3. History of neurodegenerative condition, progressive multifocal leukoencephalopathy, or Central Nervous System (CNS) movement disorder
4. History of a seizure within the 12 months of randomization
5. Prior exposure to any approved or investigational treatments directed against a clonal plasma cell disorder (including but not limited to conventional chemotherapies, radiotherapy, immunomodulatory drugs, proteasome inhibitors, anti-CD38 antibodies). Ongoing treatment with other monoclonal antibodies (eg, infliximab, rituximab) or other treatments likely to interfere with study procedures or results, as described in the protocol.

NOTE: Other protocol defined inclusion/exclusion criteria apply

All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.

When Regeneron has:

• received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development
• made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry)
• the legal authority to share the data, and
• ensured the ability to protect participant privacy

Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf