Retrospective Survey of Re-treatment With Bortezomib

This is an international, multicenter, non-interventional, retrospective study to evaluate the efficacy and safety of bortezomib in 100 adult patients diagnosed with multiple myeloma (MM) who responded to bortezomib as first-line treatment, experienced partial response or better, presented with relapsed disease, and were re-treated (second-line) with bortezomib (for at least 3 cycles) after a treatment-free interruption of at least 6 months. As this is a non-interventional study, no changes to the current treatment that the patient receives will be required, and no additional treatment will be provided by the company. The decision of the patients to take part in this study will not have any impact on the care they receive. All the appropriate treatment-related decisions will have been made by the treating physician(s), and only data available from clinical practice will be collected. Retrospective data will be collected at a single time point for each patient (the data collection visit). Each investigator should collect data from patients fulfilling all inclusion and exclusion criteria. After receiving the signed informed consent form (ICF) from the patient (if required by local regulations), the investigator will start documenting the retrospective data for each patient using electronic data capture (eDC). After confirmation of the patient's eligibility, the patient's last visit, patient characteristics, predefined risk factors (if available), MM-related data, and first- and second-line bortezomib-related data will be documented in the Case Report Form (CRF). The patient's status after re-treatment with bortezomib, medical resource utilization data, as well as (serious) adverse drug reactions (\[S\]ADRs) will be collected. No blood, urine, or other biological samples will be taken, and no additional investigations will be performed. the current therapy of the patient will be maintained with no changes