Inclusion Criteria:  Male or female patients over the age of 18 years Patients beginning carfilzomib treatment in the framework of expanded access or compassionate use in France (KRd or Kd regimen) Patients who received carfilzomib in first or second MM relapse Patients receiving at least one complete course of carfilzomib  Exclusion Criteria:  Patients already included in an interventional research protocol using carfilzomib at the time of treatment initiation Patients refusing to allow the computerization of their data Patients for whom hospital medical records are not accessible