The purpose of this retrospective study is to collect information about patients who received bortezomib as their first chemotherapy and who responded well to it, but who relapsed afterwards and were treated again with bortezomib a second time after a treatment-free period of at least 6 months. During this non-interventional study (this means that no drug is being tested in this study) the safety and effectiveness (whether it works or not) of bortezomib re-treatment will be evaluated in patients with multiple myeloma. Only data already mentioned in your clinical file will be collected. About 100 adult patients will take part in the study

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

Inclusion Criteria:

• Has a current diagnosis/was diagnosed with MM or secretory MM
• Was previously treated with bortezomib-containing chemotherapy
• Responded to bortezomib as first-line treatment
• Has been re-treated with bortezomib (at least 3 cycles) due to relapse of the disease (following the first bortezomib treatment), after a treatment-free interruption of at least 6 months
• Completed bortezomib re-treatment at least 2 months ago Exclusion Criteria:
• Was a pregnant or breastfeeding woman while receiving either first-line or second-line treatment with Velcade

Has received bortezomib-containing chemotherapy for the first time following a first relapse or later

• Has participated in a clinical trial in which bortezomib was used as second-line treatment following a relapse after response to Velcade as first-line chemotherapy, and the study data are not publicly available at the time of inclusion in the current study
• Has received bortezomib as first-line therapy and was re-treated with bortezomib after first relapse in the VISTA clinical trial

Clinic; Hospital