A Study Comparing JNJ-79635322 and an Anti-B-cell Maturation Antigen (BCMA)xCD3 Bispecific Antibody in Participants With Relapsed or Refractory Multiple Myeloma

Overall response is defined as having achieved partial response (PR) or better, according to the international myeloma working group (IMWG) response criteria, as assessed any time after first administration of study treatment, but prior to progression of disease (PD) or subsequent antimyeloma therapy.

PFS is defined as the duration from the date of randomization to either progressive disease (PD) or death, whichever comes first. Disease progression will be determined according to the IMWG response criteria.

VGPR or better is defined as achieving VGPR, complete response (CR), or stringent complete response (sCR) in accordance with the IMWG criteria during or after the study treatment but prior to subsequent antimyeloma therapy.

CR or better is defined as achieving CR or sCR in accordance with the IMWG criteria during or after the study treatment but prior to subsequent antimyeloma therapy.

DoR is defined as the time interval between the date of initial documentation of a response (partial response [PR] or better) to the date of first documented evidence of progressive disease according to the IMWG response criteria or death due to any cause, whichever occurs first.

MRD-negative CR is defined as the participants who achieve MRD-negative status, as determined by next-generation flow cytometry (NGF), at any time point after the date of randomization and prior to PD or subsequent antimyeloma therapy. Additionally, participants must achieve CR or better, according to IMWG response criteria at any time from the date of randomization and within 3 months after achieving MRD negative status, prior to PD or subsequent antimyeloma therapy.

MRD-negative CR at 12 months is defined as the participants who achieve MRD-negative status at the analysis time window of 12 months (+/-3 months) from the date of randomization, as determined by NGF prior to PD or subsequent anti-myeloma therapy. Additionally, participants must also achieve CR or better, according to IMWG criteria at any time from the date of randomization up to and including 12 months (+/-3 months), prior to PD or subsequent antimyeloma therapy.

Sustained MRD-negative CR is defined as participants who achieve MRD-negative CR status, as determined by NGF, for at least 12 months without any examination showing MRD-positive status and prior to PD or subsequent anti-myeloma therapy.

PFS2 is defined as the time interval between the date of randomization and date of event, which is defined as progressive disease as assessed by investigator on the first subsequent line of antimyeloma therapy, or death from any cause, whichever occurs first. Those who are alive and for whom a second disease progression has not been observed are censored at the last date of follow-up.

OS is defined as the time from the date of randomization to the date of the participant's death due to any cause.

Time to subsequent anti-myeloma therapy is defined as the time from randomization to the start of subsequent antimyeloma treatment. Death due to progressive disease without the start of any subsequent antimyeloma therapy will be considered as an event.

An AE is any untoward medical occurrence in a clinical study participant administered a pharmaceutical (investigational or non investigational) product. An AE does not necessarily have a causal relationship with the treatment. Any new or worsening AE occurring at or after the initial administration of study treatment through the day of last dose plus 30 days or prior to the start of subsequent anticancer therapy, whichever is earlier, or any follow-up AE with onset date and time beyond 30 days after the last dose of study treatment but prior to the start of subsequent therapy or any AE that is considered treatment-related regardless of the start date of the event is considered to be treatment-emergent. TEAEs will be graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) Version 6.0. Severity scale ranges from Grade 1= mild, Grade 2= moderate, Grade 3= severe, Grade 4= life-threatening, to Grade 5= death related to adverse event.

Number of participants with abnormalities in clinical laboratories results (serum chemistry and hematology) will be reported.

Change from baseline in symptoms, functioning, and health-related quality of life (HRQoL) as assessed by multiple myeloma symptom and impact questionnaire (MySIm-Q) score will be reported. The MySIm-Q is a disease-specific patient-reported outcome (PRO) assessment with established content validity for participants with relapsed or refractory multiple myeloma (RRMM) and newly diagnosed MM.

Change from baseline in symptoms, functioning, and HRQoL as assessed by european organization for research and treatment of cancer quality of life questionnaire core 30 (EORTC-QLQ-C30) score will be reported.

The EQ-5D-5L is a generic measure of health status that contains 5-item questionnaire that assesses 5 domains (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) plus a visual analog scale rating "health today" with anchors ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). The scores for the 5 dimensions are used to compute a single utility score, ranging from zero (0.0) to 1 (1.0), representing the general health status of the individual.

Time to worsening in symptoms, functioning, and HRQoL as assessed by MySIm-Q score will be reported. The MySIm-Q is a disease-specific PRO assessment with established content validity for participants with RRMM and newly diagnosed MM.

Time to worsening in symptoms, functioning, and HRQoL as assessed by EORTC-QLQ-C30 score will be reported.

The EQ-5D-5L is a generic measure of health status that contains 5-item questionnaire that assesses 5 domains (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) plus a visual analog scale rating "health today" with anchors ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). The scores for the 5 dimensions are used to compute a single utility score, ranging from zero (0.0) to 1 (1.0), representing the general health status of the individual.

The MySIm-Q is a disease-specific PRO assessment with established content validity for participants with RRMM and newly diagnosed MM. It is included to be complementary to the EORTC-QLQ-C30. It includes 17 items resulting in a symptom subscale and an impact subscale. The recall period is the "past 7 days" and responses are reported on a 5-point verbal rating scale.

Percentage of participants with meaningful improvement in symptoms, functioning, and HRQoL as assessed by EORTC-QLQ-C30 score will be reported.

The EQ-5D-5L is a generic measure of health status that contains 5-item questionnaire that assesses 5 domains (mobility, self-care, usual activities, pain or discomfort, and anxiety or depression) plus a visual analog scale rating "health today" with anchors ranging from 0 (worst imaginable health state) to 100 (best imaginable health state). The scores for the 5 dimensions are used to compute a single utility score, ranging from zero (0.0) to 1 (1.0), representing the general health status of the individual.

Percentage of participants with side effects burden on the EORTC IL46 will be reported. The EORTC IL46 measures the global impression of burden due to treatment-related symptoms.

Serum concentrations of JNJ-79635322 will be reported.

Serum samples will be analyzed for the detection of ADA to JNJ-79635322 using a validated assay method.

Number of participants who are ADA-positive will be assessed for the presence of NAbs.