Age does not influence efficacy of ramucirumab in advanced gastric cancer: Subgroup analyses of REGARD and RAINBOW

Background and Aim: REGARD and RAINBOW were global, phase 3, randomized, double-blind trials of second-line ramucirumab for metastatic gastric or gastroesophageal junction adenocarcinoma. Exploratory subgroup analyses were described to assess the efficacy and safety of ramucirumab in REGARD and RAINBOW in young (≤ 45 and < 65 years) and elderly (≥ 65, ≥ 70, and ≥ 75 years) patients. Methods: Patients were randomized 2:1 to receive ramucirumab plus best supportive care or placebo plus best supportive care (REGARD) or 1:1 to ramucirumab plus paclitaxel or placebo plus paclitaxel (RAINBOW). Subpopulation Treatment Effect Pattern Plots assessed efficacy and adverse events by age groups for ramucirumab versus placebo. Results: The hazard ratios (HRs) for overall survival favored treatment with ramucirumab: REGARD ≤ 45 years (HR: 0.59, 95% confidence interval: 0.27–1.26), < 65 years (0.80, 0.59–1.10), ≥ 65 years (0.72, 0.48–1.08), ≥ 70 years (0.73, 0.44–1.23), and ≥ 75 years (0.59, 0.25–1.37); and RAINBOW ≤ 45 years (0.56, 0.33–0.93), < 65 years (0.78, 0.63–0.97), ≥ 65 years (0.88, 0.66–1.18), and ≥ 70 years (0.88, 0.60–1.28). The exception was elderly patients aged ≥ 75 years in RAINBOW (0.97, 0.47–2.01); however, patient numbers were low in this subgroup (n = 36). Similar findings were observed for progression-free survival, for which HRs numerically favored ramucirumab-treated patients. Adverse events (including grade ≥ 3) were not associated with age. Conclusions: In comparison with placebo, ramucirumab conferred improvements in efficacy across age groups with a tolerable safety profile. Despite some limitations, these exploratory analyses support the use of ramucirumab in advanced gastric cancer, irrespective of age.