Treatment of relapsed/refractory multiple myeloma in the bortezomib and lenalidomide era: a systematic review and network meta-analysis

Multiple myeloma (MM) is an incurable disease, and patients usually receive multiple lines of therapy. Due to the abundance of novel treatments for MM, we conducted a network meta-analysis to identify combinations that could fare better than others in relapsed/refractory MM, in the setting of novel drugs. We searched PubMed and Cochrane databases for phase III trials in previously treated MM that had lenalidomide or bortezomib in the control arm. The primary endpoint was progression-free survival (PFS), extracted as hazard-ratio. We used the P score to rank treatments. Thirteen studies were included. All but two studies compared one novel agent against two, with or without dexamethasone. Based on the P score, daratumumab and pegylated liposomal doxorubicin had a higher probability of achieving better PFS, followed by isatuximab, carfilzomib, pomalidomide, and panobinostat. Although most overall survival data were not mature enough, the addition of a second or third novel agent to either immunomodulatory (IMID) or proteasome inhibitor (PI) backbone seemed to improve survival (HR = 0.84, 95CI 0.77-0.92). Severe adverse events were more frequent with isatuximab, panobinostat, and pomalidomide. In summary, in the absence of trials directly comparing two novel agents-based therapies, we provide a tool that indirectly compares these newer therapies and that can help physicians to prioritize some regimens over others.