Adverse events

Induction and Consolidation Phase (12-week induction phase followed by autologous stem cell mobilization, high-dose chemotherapy \[HDT\] and autologous stem cell transplantation \[ASCT\]; 6-week consolidation phase)- participants received lenalidomide 25 milligrams (mg) orally on Days 1 to 14 of Cycles 1 through 6), bortezomib 1.3 mg per meter square (mg/m\^2) subcutaneously (SC) on Days 1, 4, 8, and 11 and dexamethasone 40 mg orally weekly (20 mg on Days 1, 2, 8, 9, 15 and 16); Maintenance phase (up to 104 week \[until disease progression/up to maximum of 2 years\])- participants received lenalidomide 10 mg orally on Days 1 to 21 throughout each 28-day cycle on Cycles 7 through 9 during maintenance treatment. Beginning at Cycle 10, lenalidomide dose was increased to 15 mg, unless there was tolerability concern. After 2 years of maintenance therapy, participants could continue to lenalidomide monotherapy per standard of care. Long-term follow-up phase- all participants were followed for at least 1 year after last dose of study drug and to continue until death, withdrawal of consent or end of study.

Induction and Consolidation Phase (12 week induction phase followed by autologous stem cell mobilization, HDT and ASCT; a 6-week consolidation phase)-participants received RVd with daratumumab 16 milligrams per kilogram (mg/kg) intravenously (IV) weekly on Days 1, 8, and 15 of Cycles 1 to 4 during induction treatment and every 3 weeks on Day 1 of Cycles 5 and 6 during consolidation treatment; Maintenance phase (up to 104-week \[until disease progression/up to maximum of 2 years\])- participants received daratumumab 16 mg/kg every 4 weeks/8 weeks plus lenalidomide 10 mg orally on Days 1 to 21 throughout each 28-day cycle on Cycles 7 through 9 during maintenance treatment. Beginning at Cycle 10, the lenalidomide dose was increased to 15 mg, unless there was a tolerability concern. After 2 years of maintenance therapy, participants could continue to lenalidomide monotherapy per standard of care. Long-term follow-up phase- all participants were followed for at least 1 year after last dose of study drug and to continue until death, withdrawal of consent or end of study. Per protocol amendment 4, to provide flexibility and prioritize safety during the global coronavirus-19 (COVID-19) pandemic, participants were given the option to switch from daratumumab IV to daratumumab SC at the discretion of the investigator.

Induction and Consolidation Phase (12 week induction phase followed by autologous stem cell mobilization, HDT and ASCT; a 6-week consolidation phase)-participants received RVd with daratumumab 16 mg/kg IV weekly on Days 1, 8, and 15 of Cycles 1 to 4 during induction treatment and every 3 weeks on Day 1 of Cycles 5 and 6 during consolidation treatment; Maintenance phase (up to 104-week \[until disease progression/up to maximum of 2 years\])- participants received daratumumab 16 mg/kg every 4 weeks/8 weeks plus lenalidomide 10 mg orally on Days 1 to 21 throughout each 28-day cycle on Cycles 7 through 9 during maintenance treatment. Beginning at Cycle 10, the lenalidomide dose was increased to 15 mg, unless there was a tolerability concern. After 2 years of maintenance therapy, participants could continue to lenalidomide monotherapy per standard of care. Long-term follow-up phase- all participants were followed for at least 1 year after last dose of study drug and to continue until death, withdrawal of consent or end of study.