Treatment-related serious adverse events and fatal adverse events with regorafenib in cancer patients: a meta-analysis of phase 3 randomized controlled trials

Regorafenib (Stivarga) is an oral small-molecule multikinase inhibitor commonly used against a variety of cancers. We performed a meta-analysis of all phase 3 randomized controlled trials (RCTs) of regorafenib to quantify the increased risk of SAEs and FAEs. We carried out a systematic search of electronic databases for studies published from inception to February 2017 without any restrictions. Eligibility criteria included phase 3 RCTs of tumors comparing regorafenib, alone or in combination with non-targeted chemotherapy (regorafenib arm) versus placebo or non-targeted chemotherapy (control arm). Data on SAEs and FAEs were extracted from each study and pooled to determine the overall incidence, relative risks (RRs) and 95% confidence intervals (CIs). A total of four phase 3 RCTs involving 1736 cancer patients met the eligibility criteria and were included. The overall incidence of SAEs and FAEs with regorafenib were 0.23 (95%CI, 0.05–0.40) and 0.02 (95%CI, 0.01–0.03), respectively. Compared with control, the summary RR of developing a regorafenib-related SAE was 1.60 (95%CI, 0.95–2.68, P=0.07), the summary RR of developing a regorafenib-related FAE was 1.71 (95%CI, 0.69–4.24, P=0.25). No evidence was found for the association between regorafenib and higher risk of SAEs and FAEs. This association varied significantly with cancer types (P=0.02) for SAEs but no evidence of heterogeneity was found for FAEs. This meta-analysis demonstrates no evidence for the association between regorafenib and higher risk of SAEs and FAEs. This analysis will be important when considering the trade-off of regorafenib treatment during clinical decision-making.