A Phase 3b, Multicenter, Open-label, Daratumumab Long-term Extension Study

Inclusion Criteria: * Participants must be actively receiving daratumumab (either as monotherapy or in combination with other study treatment) in certain Janssen research and development (R\&D) studies or receiving other study treatment in a Janssen R\&D daratumumab study for participants with multiple myeloma or smoldering multiple myeloma which has reached clinical cutoff for final analysis continue to benefit from study treatment, not have experienced disease progression or unmanageable toxicity while receiving daratumumab, not have met the withdrawal criteria set forth in the parent study, and have had the last dose of study treatment within the previous 3 months * Investigator's assessment that the benefit of continued study treatment will outweigh the risks * A female participant of childbearing potential must have a negative pregnancy test at screening and must agree to further serum or urine pregnancy tests during the study * A male participant must agree not to donate sperm for the purpose of reproduction during the study and for a minimum of 3 months after receiving the last dose of study treatment * Must sign an informed consent form (ICF; or their legally acceptable representative must sign) indicating that the participant understands the purpose of, and procedures required for, the study and is willing to participate in the study * Willing and able to adhere to the lifestyle restrictions specified in this protocol Exclusion Criteria: * Has taken any disallowed therapies or treatment for the disease under study between the completion of the parent study and the planned first dose of study treatment * Any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant (for example, compromise the well-being) or that could prevent, limit, or confound the protocol-specified assessments * Known allergies, hypersensitivity, or intolerance to study treatments or their excipients (refer to the daratumumab investigator brochure (IB) and local country prescribing information for dexamethasone, carfilzomib, pomalidomide, and lenalidomide) * Vaccinated with an investigational vaccine (except for Coronavirus disease \[COVID-19\])or live attenuated or replicating viral vector vaccines within 4 weeks prior to enrollment