BACKGROUND: Multiple myeloma (MM) is a B cell malignancy, of fully differentiated plasma cells, and is the second most prevalent hematological malignancy (10%) after non-Hodgkin’s lymphoma. Despite recent advances in the treatment options for patients with MM, it remains incurable and the vast majority of patients will relapse or become refractory to treatment. To date there is little information on real world treatment outcomes for many of existing regimens. OBJECTIVES: The objective of this multi-center observational study is to assess treatment outcomes of patients with relapsed or refractory MM receiving either single or combination novel therapies in real-world clinical practice. METHODS: This is a prospective, non-interventional, cohort study that includes patients with relapsed or refractory MM who will receive treatment for MM between 2012 and 2018 in North America and Europe. In order to reflect real-world clinical practice patterns, patients currently enrolled in clinical trials are not eligible for this study. Patients will be followed for up to three years, until death, enrollment in an investigational trial, or withdrawal of consent, whichever comes first. The primary endpoints of this real world study, include disease progression/response, progression-free survival (PFS), overall survival (OS), secondary malignancy, and occurrence of adverse events. Data on patient demographics, clinical characteristics, treatment patterns, health care resources utilization, and patient-reported outcomes (e.g., EQ-5D) will also be collected by using electronic case report throughout the study.  The potential association between PFS and OS in this patient population will be also assessed. The anticipated study population across multiple geographic regions is approximately 1000 patients.  RESULTS: Findings from this prospective, non-interventional, multiregional study will contribute to the knowledge of treatment patterns for relapsed or refractory MM in real-world clinical practice.