Inclusion Criteria for newly diagnosed multiple myeloma (NDMM) and relapsed or refractory multiple myeloma (R/R MM):

• Have documented initial diagnosis of multiple myeloma according to IMWG diagnostic criteria
• Meet treatment regimen-specific requirements as follows: Treatment regimen A (JNJ-79635322+daratumumab):Treatment regimens A1 and A3: Have been treated with 1 to 3 prior lines of therapy, including a proteasome inhibitor (PI) and an inhibitor, immunomodulatory drug (IMiD) therapy for the treatment of multiple myeloma (MM); Treatment regimens A2 and A4: Newly diagnosed MM naïve to multiple myeloma (or other related plasma cell neoplasm)-directed treatments; Treatment regimen B (JNJ-79635322+pomalidomide): Have received greater than or equal to (>=) 1 prior line of therapy, including a PI and lenalidomide, and are lenalidomide refractory OR >=2 prior lines of therapy, including a PI and lenalidomide; Treatment Regimens C, D, and E: Newly diagnosed MM naïve to multiple myeloma (or other related plasma cell neoplasm)-directed treatments
• Have a weight >=40 kilograms
• Must have an Eastern Cooperative Oncology Group status of 0 or 2
• Have measurable disease at screening as defined by at least 1 of the following: a) Serum monoclonal protein (M-protein) level >= 0.5 gram per deciliter (g/dL); or b) Urine M-protein level >=200 milligram (mg)/24 hours; or c) Light chain multiple myeloma: Serum immunoglobulin (Ig) free light chain (FLC) >= 10 mg/dL and abnormal serum Ig kappa lambda FLC ratio. d) For participants without measurable disease in the serum, urine, or involved FLC: presence of 1 or more focus of extramedullary disease which meets the following criteria: extramedullary plasmacytoma not contiguous with a bone lesion, at least 1 lesion >=2 centimeter (cm) (at its greatest dimension) diameter on whole body positron emission tomography-computed tomography (or whole-body magnetic resonance imaging approved by sponsor), and not previously radiated

Inclusion criteria for newly diagnosed amyloid light chain (ND AL) Amyloidosis

• Have a histopathological diagnosis of amyloidosis
• Have an ECOG performance status of 0 to 1

Inclusion criteria for High-risk smoldering multiple myeloma (SMM)

• Have a diagnosis of SMM (per IMWG criteria) for less than or equal to (<=) 5 years with measurable disease at the time of enrollment as defined in the protocol
• Have an ECOG performance status of 0 to 1

Exclusion Criteria for NDMM and R/R MM:

• Prior antitumor therapy as follows, in the specified time frame prior to the first dose of study treatment: a) Targeted therapy, epigenetic therapy, monoclonal antibody (mAb) treatment, or treatment with an investigational drug or an invasive investigational medical device within 21 days or 5 half-lives, whichever is less. b) Gene-modified adoptive cell therapy (example, chimeric antigen receptor [CAR] modified T cells, natural killer cells) within 90 days. c) Prior anti-CD38 directed therapy within 90 days (for treatment regimens A, C, D and E only; within 21 days for treatment regimen B). d) Conventional chemotherapy within 21 days. e) PI therapy within 14 days. f) Immunomodulatory agent therapy within 7 days. g) Radiotherapy within 14 days
• Stem cell transplantation: a) Allogeneic stem cell transplant within 6 months before the first dose of study treatment. b) Received an autologous stem cell transplant <=12 weeks before the first dose of study treatment
• Nonhematologic toxicity from prior anticancer therapy that has not resolved to baseline level or to grade <=1 (except alopecia, tissue post-RT fibrosis [any grade] or peripheral neuropathy grade <=3)
• Prior treatment with CD3-redirecting therapy

Exclusion Criteria for ND AL Amyloidosis

• Previous or current diagnosis of symptomatic multiple myeloma, including the presence of lytic bone disease, plasmacytomas, >=60 percent (%) plasma cells in the bone marrow, or hypercalcemia
• Macroglossia that impairs swallowing difficulty
• Prior therapy for AL amyloidosis or multiple myeloma

Exclusion Criteria for High-risk SMM

• Multiple myeloma, requiring treatment
• Primary systemic AL (immunoglobulin light chain) amyloidosis

Exclusion criteria for all participants:

• Any serious underlying medical conditions, such as: Evidence of active viral, bacterial, or systemic fungal infection requiring ongoing antiviral, antibacterial, or antifungal treatment; active autoimmune disease requiring systemic immunosuppressive therapy within 6 months before start of study treatment; cardiovascular dysfunction; pulmonary compromise requiring supplemental oxygen use to maintain adequate oxygenation; human immunodeficiency (HIV) infection; active hepatitis B or C infection; stroke or seizure within 6 months prior to first dose of study treatment
• Known or suspected chronic obstructive pulmonary disease (COPD) with a forced expiratory volume in 1 second (FEV1) less than (<) 50 percent (%)