Real-world safety and effectiveness of nivolumab in Japanese patients with unresectable advanced or recurrent gastric/gastroesophageal junction cancer that has progressed after chemotherapy: a postmarketing surveillance study

Background This postmarketing surveillance study evaluated the real-world safety and effectiveness of nivolumab as salvage (after ≥ 2 lines) therapy in Japanese patients with unresectable advanced or recurrent gastric/gastroesophageal junction (G/GEJ) cancer. Methods This multicenter, observational study was conducted at 158 centers in Japan. Patients with unresectable advanced or recurrent G/GEJ cancer were registered between Nov 1, 2017, and Oct 31, 2018, and observed for 6 months after treatment initiation with nivolumab. Correlation of background characteristics with treatment-related adverse events (TRAEs) and tumor response was explored. Results Overall, 654 patients were registered (safety analysis set, n = 650; effectiveness analysis set, n = 636; response evaluation set, n = 516). The incidences of all TRAEs and grade ≥ 3 TRAEs were 31.5 and 11.2%, respectively. TRAEs significantly correlated with the absence of peritoneal metastasis; C-reactive protein level < 1; prior G/GEJ cancer surgery; and past or concomitant pulmonary, thyroid, or renal disease (each p < 0.05). The incidence of TRAEs was significantly lower in patients with higher Glasgow prognostic scores (p < 0.05). No new safety signals were observed. Complete response, partial response, stable disease, and progressive disease were observed in 1.2, 10.1, 27.1, and 58.3% of the response evaluation set, respectively. Patients aged ≥ 65 years (13.9 vs 5.3%, p = 0.0083) and ≥ 75 years (18.8 vs 9.2%, p = 0.0036) showed a higher response rate than their younger counterparts. Conclusions The real-world safety and effectiveness of nivolumab as salvage (after ≥ 2 lines) therapy in Japanese patients with unresectable advanced or recurrent G/GEJ cancer were consistent with those observed in the phase 3 ATTRACTION-2 study.