sCR rate is defined as the percentage of participants who achieve a sCR according to IMWG response criteria.

MRD negative rate is defined as the percentage of participants with negative MRD status according to IMWG response criteria.

CBR is defined as the percentage of participants with clinical benefit. CBR=ORR (sCR + CR + VGPR + PR) + minimal response (MR).

DOR is defined as time from the date of initial documentation of a response (PR or better) to the date of first documented evidence of progressive disease as defined in the IMWG criteria.

TTR is defined as the time between the date of Day 1 of Cycle 1 and the first clinical response evaluation that the participant has met all criteria for PR or better response.

Time to best response is defined as the time between the date of Day 1 of Cycle 1 and best objective response.

TTNT is defined as the time from diagnosis to the start of the next-line treatment.

PFS is defined as the time from the date of Day 1 of Cycle 1 to the date of first documented disease progression (as defined in the IMWG response criteria) or death due to any cause, whichever occurs first.

PFS2 is defined as the time from the date of Day 1 of Cycle 1 to progression on the next line of subsequent antimyeloma therapy or death, whichever occurs first.

OS is the duration from the date of Day 1 of Cycle 1 to the date of the participant's death or study completion, whichever occurs first.

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 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).

EORTC QLQ-IL39 (four single items from the EORTC QLQMY20) will be performed to assess emotional health status (feel restless or agitated, thinking about your illness, worried about dying, worried about health in the future) on scale of 1 (not at all) to 4 (very much).

An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study.

Severity of AEs has 5 grades based on CTCAE criteria: Grade 1: Mild; Grade 2: Moderate; Grade 3: Severe; Grade 4: Life-threatening consequences; Grade 5: Death related to adverse event.

PRO-CTCAE consist of 1-8 questions of common AEs 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. The following items were selected for inclusion for patients with multiple myeloma: nausea, vomiting, diarrhea, shortness of breath, rash, dizziness, headache, taste changes, and fatigue/tiredness/lack of energy.

The Epstein Taste Survey consists of 17 items from the full 71 item PRO instrument, specific to taste changes. Developed for use in patients with head and neck cancer.

Overall Response Rate is defined as the percentage of participants who achieve a partial response (PR) or better response according to the International Myeloma Working Group (IMWG) response criteria, as assessed by Response Review Committee (RRC). Overall response for subsequent therapies, including BCMA-targeted therapies after treatment with talquetamab will be reported.