Adverse events

Participants received the combination therapy during Run-in phase starting with 20 milligrams (mg) dexamethasone as premedication followed by daratumumab 1800 mg on Day 1 Cycle 1, then cyclophosphamide 300 milligram per meter square (mg/m\^2) orally or intravenous (IV) maximum weekly dose 500 mg, followed by bortezomib 1.3 mg/m\^2 subcutaneous (SC) injection once every week and dexamethasone remaining 20 mg post daratumumab dosing for up to 1 cycle (28 Days) to assess the safety before randomizing participants in CyBorD or daratumumab plus CyBorD arms. However, participants also continued daratumumab plus CyBorD for up to 6 cycles and then daratumumab monotherapy for up to 24 months from the start of treatment. After completion of treatment phase participants entered into the post treatment observation phase and were continued with disease evaluations every 8 weeks post last dose up to disease progression (up to 6.5 years). Participants then entered into long term follow up phase and were followed up for survival every 16 weeks (up to 7.1 years).

Participants received dexamethasone (40 mg weekly dose)starting from cycle 1 day1 in every 28-day cycle followed by cyclophosphamide 300 mg/m\^2 orally or IV maximum weekly dose 500 mg and then bortezomib 1.3 mg/m\^2 SC injection once weekly up to 7.33 months. All cycles were of 28 days. After completion of treatment phase participants entered into the post treatment observation phase and were continued with disease evaluations every 8 weeks post last dose up to disease progression (up to 6.5 years). Participants then entered into long term follow up phase and were followed up for survival every 16 weeks (up to 7.1 years).

Participants received combination therapy for six cycles of 28 days each, daratumumab 1800 mg SC weekly starting from cycles 1 day 1 and cycle 2, every 2 weeks in cycles 3 through 6, dexamethasone 40 mg weekly (on days of daratumumab dosing, dexamethasone was split, 20 mg as premedication and 20 mg as post daratumumab dosing), cyclophosphamide 300 mg/m\^2 orally or IV maximum weekly dose 500 mg, bortezomib 1.3 mg/m\^2 SC injection once weekly. After 6 cycles, participants continued to receive daratumumab SC monotherapy until disease progression, start of subsequent therapy or up to 26.71 months from the first dose of study treatment. All cycles were of 28 days. After completion of treatment phase participants entered into the post treatment observation phase and were continued with disease evaluations every 8 weeks post last dose up to disease progression (up to 6.5 years). Participants then entered into long term follow up phase and were followed up for survival every 16 weeks (up to 7.1 years).