Key study variables:~Demographic data, ISS, R-ISS, cytogenetic abnormalities on FISH and G-banding, previous treatment regimens, response to previous treatment regimens, existence of extramedullary plasmacytoma, MM-related symptoms, whether or not M protein has increased twice or more in 2-3 months at the time of KRd commencement, response to KRd therapy, duration of KRd treatment, adverse events during KRd therapy, disease progression and progression date, survival, and censored date or day of death
Research question: Is KRd therapy effective and safe in the real-world Asian patients?~Primay objective: To evaluate the effectiveness of KRd in RRMM patients~Secondary objectives:~To evaluate the effectiveness of investigational treatment strategy by~PFS difference according to the high-risk disease subgroups and previous treatment~OS~Overall response rate and clinical benefit rate~Duration of response To evaluate the safety and tolerability of KRd in RRMM patients