Denosumab is not associated with risk of malignancy: systematic review and meta-analysis of randomized controlled trials

The immunomodulatory effects of denosumab have raised concerns for risk of malignancy. This meta-analysis of 25 randomized controlled trials (21,523 patients) shows similar risk of malignancy between denosumab (60 mg every 6 months, up to 48 months) and any comparator. Post-marketing surveillance may detect rare or late-occurring drug effects. Possible increased risk of malignancy in patients treated with denosumab has been concerned due to inhibition of the immune modulator receptor activator of nuclear factor kappa-Beta ligand (RANKL). We aimed to assess the risk of malignancy associated with denosumab treatment. PubMed and Cochrane Central Register of Controlled Trials were searched up to May 27, 2019 to include all randomized controlled trials of denosumab (60 mg every 6 months) versus any comparator. Trials using higher drug doses for prevention of skeletal-related events were excluded. Data were independently extracted by two reviewers and analyzed using a fixed-effect model to pool risk ratios (RRs) with 95% confidence intervals (CI). Twenty-five trials (21,523 patients) were included. The risk of malignancy was similar between denosumab and other comparators (absolute risk difference 0%, RR 1.08 [95% CI, 0.93-1.24], I-2 = 0%). Sensitivity analysis based on adequate allocation concealment showed similar results. The risk of malignancy did not differ between groups in any of the subgroup analyses, including stratification by race, individual comparators, indications for treatment, and longer drug exposure (>= 24 months, 9 studies). The risk ratio of malignancy-related death was similar between groups. Early concerns about a potential increased risk of malignancy resulting from an immunomodulatory effect of denosumab are not supported by evidence from this meta-analysis of 25 RCTs with drug exposure of up to 48 months. Since RCTs with longer observation for safety outcomes are not expected, post-marketing surveillance will be the main means for detection of rare or late-occurring events.