Reporting of adverse events of treatment interventions in multiple myeloma: an overview of systematic reviews.

The present study is an overview of systematic reviews focusing on adverse events of antimyeloma treatments. It provides a systematic description of adverse events as they are reported in the systematic reviews as well as a critical appraisal of included reviews. We conducted a comprehensive literature search in the most widely used electronic databases looking for systematic reviews that had an adverse event of an antimyeloma treatment intervention as primary outcome. Two independent reviewers conducted selection of included studies and data extraction on predesigned online forms and assessed study quality using AMSTAR 2. Overall corrected covered area (CCA) was calculated to examine the overlap of primary studies across systematic reviews. After screening eligible studies, 23 systematic reviews were included in this overview. Seven reviews with overall CCA of 14.7% examined cardiovascular adverse events of different drugs, including immunomodulatory drugs and proteasome inhibitors (mainly carfilzomib). Nine focused on infections, presenting with overall CCA of 5.8%, each one focused on a different drug or drug class. Three studied thromboembolism in patients treated either with lenalidomide, any immunomodulatory drug, or with daratumumab and had an overall CCA equal to 1.5%. Four more reviews focused on bortezomib-associated neurotoxicity, carfilzomib-associated renal toxicity, or second primary malignancies as an adverse event of lenalidomide or anti-CD38 monoclonal antibody treatment. The quality of included studies as judged by AMSTAR 2 was mostly critically low. Absence of a priori registered protocol and formal assessment of risk of bias of included primary studies were the most common shortcomings. Reporting of antimyeloma drug-associated toxicity is supported by multiple systematic reviews; nevertheless, methodological quality of existing reviews is mostly low.