Clinical Trial Finder

Inclusion Criteria:

• - Cohort A: Received a minimum of 1 to a maximum of 3 prior lines of therapy including a proteasome inhibitor (PI) and immunomodulatory therapy (IMiD), and lenalidomide refractory per International Myeloma Working Group (IMWG) guidelines.

• - Cohort B: Received one line of prior therapy including a PI and an IMiD, and disease progression per IMWG criteria less than or equal to (<=) 12 months after treatment with autologous stem cell transplantation (ASCT) or <=12 months from the start of anti-myeloma therapy for participants who have not had an ASCT.

• - Cohort C: Previously treated with a PI, an IMiD, an anti-CD38 monoclonal antibody and B-cell maturation antigen (BCMA)-directed therapy.

• - Cohort D: Newly diagnosed multiple myeloma per IMWG with a history of 4 to 8 total cycles of initial therapy, including induction, high-dose therapy, and ASCT with or without consolidation.

• - Cohort E: Have newly diagnosed multiple myeloma without prior therapy (one cycle of prior therapy before enrollment is acceptable) and classified as high risk defined as either: 1) International Staging System (ISS) stage III criteria, Beta 2 microglobulin greater than or equal to (>=) 5.5 milligram per liter (mg/L) (via local or central laboratory assessment) or 2) high risk cytogenetic features del(17/17p), t (14;16), t(14;20), 1q amplification (at least 4 total copies) in at least 20 percent (%) of the total plasma cell population.

• - Cohort F: - Participant must have a documented efficacy response of very good partial response (VGPR) or better, without progressive disease prior to enrollment, as assessed per IMWG 2016 criteria.

• - Received initial therapy as specified below.

The dose/schedule of cycles administered will be as per standard of care. It is acceptable for up to 1 cycle of the protocol-specified regimens to be missing one of the listed agents (example, held due to toxicity). Acceptable combinations include: At least 5 to 8 cycles of initial therapy with daratumumab, bortezomib, lenalidomide and dexamethasone (D-VRd). The dose/schedule of cycles administered will be as per standard of care or; at least 4 to 8 cycles of initial therapy with daratumumab, lenalidomide and dexamethasone (D-Rd) or; at least 4 to 8 cycles of initial therapy with a carfilzomib-based triplet or quadruplet regimen.

• - Cohorts A, B, C, E: - Serum monoclonal paraprotein (M-protein) level greater than or equal to (>=) 1.0 gram per deciliter (g/dL) or urine M-protein level >=200 milligram (mg)/24 hours.

• - Light chain multiple myeloma in whom only measurable disease is by serum free light chain (FLC) levels in the serum: Serum immunoglobulin FLC >=10 mg/dL and abnormal serum immunoglobulin kappa lambda FLC ratio.

• - Cohort A: For participants with neither serum nor urine measurable disease, baseline positron emission tomography/ computed tomography (PET/CT) or whole -body magnetic resonance imaging (MRI) may be used to satisfy the measurable disease criteria.

A minimum of one lesion with a bi-dimensional measurement of at least 1 centimeter (cm)*1 cm is required.

• - Cohorts B, C: For participants with neither serum nor urine measurable disease, baseline positron emission tomography/ computed tomography (PET/CT) or whole body magnetic resonance imaging (MRI) may be used to satisfy the measurable disease criteria.

• - Cohorts A, B, C, D, E, F: Eastern Cooperative Oncology Group (ECOG) performance status grade of 0 or 1.

Exclusion Criteria:

• - Cohorts A, B, D, F: Any therapy that is targeted to BCMA.

• - Cohorts A, B, C, D, F: Prior treatment with chimeric antigen receptor T (CAR-T) therapy directed at any target.

• - Cohorts A, B, C, D, F: - Ongoing toxicity from previous anticancer therapy must resolve to baseline levels or to Grade 1 or less except for alopecia or peripheral neuropathy.

• - Received a cumulative dose of corticosteroids equivalent to >=70 mg of prednisone within the 7 days (Cohort A, B, C, F) or 14 days (Cohort D) prior to apheresis.

• - Serious underlying medical condition, such as (a) evidence of active viral or bacterial infection requiring systemic antimicrobial therapy, or uncontrolled systemic fungal infection; (b) active autoimmune disease or a history of autoimmune disease within 3 years; (c) overt clinical evidence of dementia or altered mental status; (d) any history of Parkinson's disease or other neurodegenerative disorder.

- Cohorts A, B, C, D, E, F: Known active, or prior history of central nervous system (CNS) involvement or exhibits clinical signs of meningeal involvement of multiple myeloma

Multiple myeloma is characterized by the production of monoclonal immunoglobulin (Ig) proteins or protein fragments (M proteins) that have lost their function. The main aim of the study is to determine the safety and efficacy of JNJ-68284528 in various clinical settings. JNJ-68284528 is an autologous chimeric antigen receptor T-cell (CAR-T) therapy that targets B-cell maturation antigen (BCMA). The study comprises of a Screening Phase (less than or equal to [<=] 28 days prior to apheresis) followed by Apheresis (will occur upon enrollment); a Treatment Phase including a conditioning regimen followed by infusion of JNJ-68284528 and post-infusion assessments from Day 1 to Day 100 (participants who receive an infusion of JNJ-68284528 should continue all subsequent assessments); and a Post-treatment Phase (Day 101 and up to the end of each study cohort). Safety evaluations will include a review of adverse events, laboratory test results, vital sign measurements, physical examination findings (including neurologic examination), assessment of cardiac function, immune effector cell-associated encephalopathy (ICE) score, handwriting assessment, and assessment of Eastern Cooperative Oncology Group (ECOG) performance status grade. Efficacy evaluations will include measurements of tumor burden/residual disease, myeloma proteins, bone marrow examinations, skeletal surveys, extramedullary plasmacytomas, and serum calcium corrected for albumin. For certain participants (those without measurable disease in serum or urine) efficacy will be assessed via imaging: positron emission tomography/ computed tomography (PET/CT) or whole body magnetic resonance imaging (MRI). The overall duration of the study is up to 2.5 years.

Arms

Experimental: JNJ-68284528

Single group assignment-After lymphodepletion, JNJ-68284528 will be administered as single infusion to participants in cohort A (Progressive disease after 1-3 prior lines of therapy), cohort B (Early relapse after front-line), cohort C (Relapsed/refractory multiple myeloma after PI, IMiD, anti-CD38, and anti- BCMA therapy), cohort D (Less than CR after ASCT front-line therapy; some participants will be administered JNJ-68284528 followed by lenalidomide), cohort F (Newly diagnosed multiple myeloma [NDMM] with standard risk [international staging system {ISS} Stage I and II] and after initiation of therapy). Participants in cohort E (NDMM, transplant not planned, high risk disease) will first be administered with quadruplet induction regimen of daratumumab, bortezomib, lenalidomide and dexamethasone (D-VRd), followed by lymphodepletion and JNJ-68284528, followed by consolidation regimen of lenalidomide.

Interventions

Drug: - JNJ-68284528

Participants in cohort A,B,C, D, E and F will receive JNJ-68284528 intravenously.

Drug: - Lenalidomide

Some participants in cohort D and all participants in cohort E will also receive lenalidomide capsules orally.

Drug: - Daratumumab

Participants in cohort E will also receive daratumumab subcutaneous (SC) injection.

Drug: - Bortezomib

Participants in cohort E will also receive bortezomib subcutaneously.

Drug: - Dexamethasone

Participants in cohort E will also receive dexamethasone orally or intravenously.