A Study of JNJ-87562761 in Participants With Relapsed or Refractory Multiple Myeloma

Inclusion Criteria: * Relapsed, refractory multiple myeloma with measurable disease defined as: (a) Serum monoclonal paraprotein (M-protein) level greater than (\>)0.5 grams per deciliter (g/dL); or (b) Urine M-protein level \>200 milligrams per 24 hours (mg/24 hours); or (c) Light chain multiple myeloma: serum immunoglobulin free light chain (FLC) \>10 milligrams per deciliter (mg/dL) and abnormal serum immunoglobulin kappa-lambda FLC ratio * Must have had prior therapy including a proteasome inhibitor, immunomodulatory agent and anti-CD38 therapy * Have an eastern cooperative oncology group (ECOG) performance status of 0 to 1 * Have an estimated glomerular filtration rate (eGFR), of \> 30 millilitres (mL)/min/1.73 meter square (m\^2) computed per 2021 chronic kidney disease epidemiology collaboration (CKD-EPI) creatinine equation * While on study treatment and for 6 months after the last dose of study treatment, a participant must: (a) Not breastfeed or be pregnant; (b) Not donate gametes (that is, eggs or sperm) or freeze for future use for the purposes of assisted reproduction; (c) Wear an external condom Exclusion Criteria: * Active plasma cell leukemia, Waldenström's macroglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes), or immunoglobulin light chain amyloidosis * Prior allogeneic transplant within 6 months before the start of study treatment administration or autologous transplant within 12 weeks before the sta…