Multicentre, prospective, observational, open-label, single arm, post-marketing study intended to record Lenalidomide/Dexamethasone treatment data from patients with relapsed/refractory Multiple Myeloma (rrMM) treated under the settings defined by the standard clinical practice and approved Summary of Product Characteristics (SmPC).

This study aims to assess the real-life safety of Lenalidomide/Dexamethasone (Len/Dex) in patients with (Relapsed or Refractory Multiple Myeloma (rrMM), by evaluation of adverse events of special interest (infections, gastrointestinal events, thrombocytopenia, neutropenia, febrile neutropenia, and thromboembolism). In addition, due to the scarce information regarding the impact of frailty in Len/Dex treatment in rrMM, this study will prospectively assess Len/Dex safety and effectiveness by patient frailty groups.

The following study assessments will be performed:

• Recruitment: patients will be recruited within 15 days after the start of Len/Dex (from day 1 to day 15). In case patients are not recruited at the day of Len/Dex start (day 1), baseline information respective to this day will be collected retrospectively.

• Treatment period: during this period, the following assessments will be carried out:

  • Every 30 days (± 5 days) for adverse events, changes in concomitant medication and change in Len/Dex dose.
  • Every 90 days (± 15 days) for the remaining information to be collected in the treatment period

• Assessment at the end of Len/Dex treatment (until 5 days after end of treatment).

Follow-up assessment 90 days (± 15 days) after the end of Len/Dex treatment.

No visits were predefined for this study. Study data is planned to be collected when the patient goes to the study site for a clinical routine visit. No assessments will be imposed for the purposes of this study. If the patient goes to the clinical routine visit at a date out of the time intervals predicted above, no information will be collected. Information will be collected in the context of routine clinical practice.

The patient will be followed until the end of Len/Dex treatment, death or discontinuation for any reason for a maximum period of 36 months, Patients within treatment after this maximum period will stop being followed in the study.

Inclusion Criteria:

1. Patients aged 18 years or higher.
2. Patients who have voluntarily given written informed consent to participate in the study and have their data retrieved for the purposes of the study
3. Patients diagnosed with 1st or 2nd relapsed or refractory multiple myeloma and indicated for 2nd or 3rd line Len/Dex treatment, according with the SmPC (patients who have received at least one prior therapy) -

Exclusion Criteria:

1. Pregnant or lactating patients

2. Female patients of childbearing potential unable or unwilling to use effective contraceptive methods, as stated in the summary of product characteristics:

   • Implant.
   • Levonorgestrel-releasing intrauterine system.
   • Medroxyprogesterone acetate depot.
   • Tubal sterilisation.
   • Sexual intercourse with a vasectomised male partner only; vasectomy must be confirmed by two negative semen analyses.

   Ovulation inhibitory progesterone-only pills (i.e. desogestrel).

   - Male patients unable to follow or comply with the required contraceptive measures stated in the SmPC (use of condom if engaged in sexual activity with a pregnant woman or a woman of childbearing potential not using effective contraception [even if the man has had a vasectomy], during treatment and for 1 week after dose interruptions and/or cessation of treatment)

3. Hypersensitivity to the active substance or any of the excipients

4. Patients participating in a clinical trial -

Relapsed and/or Refractory multiple myeloma patient population