Prospective, multicentre, post-authorisation observational study. Study population: Patients with relapsed multiple myeloma and with CrCl <50 mL/min/1.73 m2, for whom the investigator decides to start a new line of anti-myeloma treatment as per normal clinical practice. The decision to prescribe treatment will be clearly disassociated from the decision to include the patient in the study.~300 patients are expected to be recruited (225 for Group 1 and 75 for Group 2) from 40 sites (approximately 7-8 patients for each site). Patients will be included consecutively in the study.~The inclusion will be stratified to ensure the presence of all stages of renal impairment (RI) in two groups:~Documentation of 300 patients is planned (a maximum of 225 in group 1 and a minimum of 75 in group 2) at 40 sites (approximately 7-8 patients per each site). The patients will be included in the study in a consecutive manner.~In order to ensure the correct stratification of the sample group a real time central registry will be kept for the patients included in each group. Once the required number of patients for one of the groups is completed, inclusion in that group will be closed at all sites, keeping inclusion for other groups open, and so on until the entire sample size is complete.~Primary objective: To assess the response of renal function in clinical practice to anti-multiple myeloma therapy in patients with relapsed MM and creatinine clearance <50 mL/min/1.73 m2 (CrCl <50 mL/min/1.73m2).~The prospective follow-up period will cover two phases:~Treatment phase: covers the entire time the patient is receiving the first anti-myeloma treatment for relapse* for which he/she is included in this study.~Follow-up phase: A 36-month extension period after the end of the first anti-myeloma treatment for relapse for which he/she was included in the study.~Any change in therapeutic regimens, for example, discontinuation or addition of a drug (except for changes in dose for some of the initial drugs) will mark the end of the treatment phase and the passing of the patient to the follow-up phase. In case of temporary interruptions in treatment under 30 days (or of any duration if the reason for interruption is toxicity) the patient will continue in the treatment phase, provided that the initial treatment regimen for the relapse it resumed.~Secondary objectives:~To describe the clinical and demographic characteristics of patients with relapsed multiple myeloma and CrCl <50 mL/min/1.73 m2.~To assess the response rate of renal function in clinical practice to anti-multiple myeloma therapy in patients with relapsed multiple myeloma and CrCl <50 mL/min/1.73 m2.~To assess the response of renal function based on the therapeutic regimens administered.~To explore the concordance of the kidney function response and that of the myeloma in the clinical practice to the anti-myeloma treatment between consecutive relapses in the same patient.~To assess time-dependent response parameters.~To analyse the safety of treatments administered in clinical practice.~To describe the use of resources associated with anti-myeloma therapy in clinical practice that can be measured financially, and to explore the possible differences between the various therapeutic regimens administered.
A prospective, multicentre, post-authorisation observational study. The objective of this study is assess the response of renal function in clinical practice to anti-multiple myeloma therapy in patients with relapsed MM and CrCl <50 mL/min/1.73 m2.