Efficacy and Safety of the Thrombopoietin Receptor Agonist Romiplostim in Patients Aged ≥ 65 Years with Immune Thrombocytopenia

Thrombopoietin receptor agonists increase platelet counts and reduce bleeding risk in patients with immune thrombocytopenia (ITP). Studies have reported that these agents may represent a risk factor for thromboembolic events, especially in the elderly, who are at increased risk for such complications relative to younger patients. In this retrospective analysis, efficacy and safety data for romiplostim in patients with ITP aged ≥65 years versus those aged <65 years are described. Data from 3 studies (N = 159; 24.5% ≥ 65 years of age) were analyzed for efficacy. Data from 13 studies (N = 1037; 28.4% ≥ 65 years of age) were analyzed for adverse events (AEs). Relative risk (RR) ratios with 95% CIs were calculated for duration-adjusted incidences of AEs for romiplostim versus placebo/standard of care (SOC) in patients ≥ 65 and <65 years. Slightly higher platelet response rates were seen among romiplostim-treated patients ≥ 65 versus <65 years. In the safety analyses, 65 (6.3%) received placebo/SOC, 69 (6.7%) received placebo/SOC and then romiplostim, and 903 (87.1%) received romiplostim only. Duration-adjusted AE rates were similar for romiplostim versus placebo/SOC in older and younger patients. The risks for grade ≥ 3 bleeding (RR 1.92; 95% CI, 0.47-7.95) and thromboembolic events (RR 3.85; 95% CI, 0.53-27.96) were numerically but not significantly higher for romiplostim versus placebo/SOC in patients ≥ 65 years. Romiplostim is effective and, with the exception of nonsignificant trends showing increased risks of grade ≥ 3 bleeding and thromboembolic events (a trend observed in other studies), generally well tolerated in older patients with ITP.