Pomalidomide will be administered orally.

Dexamethasone will be administered orally or intravenously.

Bortezomib will be administered SC injection.

Teclistamab will be administered SC injection.

CR or better is defined as participants who achieve a CR or better response per IMWG criteria.

MRD-negativity is defined as participants who achieve MRD negativity at a threshold of 10^-5 at any timepoint after the date of randomization and before disease progression or start of subsequent antimyeloma 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.

OS is measured from the date of randomization to the date of the participant's death.

TTNT is defined as the interval time from randomization to the start of subsequent antimyeloma treatment.

Duration of response will be calculated among responders (with a PR or better response) from the date of initial documentation of a 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.

Number of participants with AEs by Severity will be reported.

Serum samples will be analyzed to determine concentrations of teclistamab using a validated, specific, and sensitive method.

Number of participants with ADAs to teclistamab and daratumumab will be reported.

Time to worsening is measured as the interval from the date of randomization to the start date of meaningful change.

The EORTC-QLQ-C30 Version 3 includes 30 items in 5 functional scales (physical, role, emotional, cognitive, and social), 1 global health status scale, 3 symptom scales (pain, fatigue, and nausea/vomiting), and 6 single symptom items (dyspnea, insomnia, appetite loss, constipation, diarrhea, and financial difficulties). The responses are reported using a verbal and numeric rating scales. The item and scale scores are transformed to a 0 to 100 scale. A high scale score represents a higher response level. Thus, a high score for a functional scale represents a high/healthy level of functioning and a high score for the global health status represents high HRQoL, but a high score for a symptom scale/item represents a high level of symptomatology/problems.

The MySIm-Q is a disease-specific PRO assessment 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.

The PROMIS-SD is used to assess self-reported perceptions of sleep quality, sleep depth and restoration associated with sleep. The 8-item short form will be used in this study, in which responses are scored 1 to 5 for each item. Higher overall score indicates more sleep disturbance.

The National Cancer Institute's (NCI's) PRO-CTCAE is an item library of common adverse events experienced by people with cancer that are appropriate for self-reporting of treatment tolerability. Each symptom selected for inclusion can be rated by up to 3 attributes characterizing the presence/frequency, severity, and/or interference of the AEs. It ranges from 0 to 4 with higher scores indicating higher frequency or greater severity/impact.

The EQ-5D-5L is a generic measure of health status. The EQ-5D-5L is a 5-item questionnaire that assesses 5 domains including mobility, self-care, usual activities, pain/discomfort, and anxiety/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 PGIS contains 2 questions on how the participant would currently rate severity of symptoms and impacts with a 7-day recall period. The response options are presented as a 5-point verbal rating scale from 1="none" to 5="very severe."

PFS in participants with high-risk molecular features will be reported.

Depth of response in participants in high-risk molecular features will be reported.