Ramucirumab for the treatment of metastatic gastric or gastroesophageal junction adenocarcinoma following disease progression on first-line platinum- or fluoropyrimidine-containing combination therapy in Japanese patients: a phase 2, open-label study

Background Ramucirumab, a monoclonal antibody vascular endothelial growth factor receptor-2 antagonist, given as monotherapy improved survival in a global phase 3 study (REGARD) of patients with gastric cancer. However, REGARD did not include Japanese patients. This study evaluated the efficacy and safety of ramucirumab monotherapy in Japanese patients with advanced gastric cancer. Methods This multicenter, open-label, nonrandomized phase 2 study (Clinicaltrials.gov: NCT01983878) was performed at 16 Japanese sites. Patients with advanced gastric or gastroesophageal junction cancer after disease progression following first-line chemotherapy received intravenous ramucirumab 8 mg/kg every 2 weeks. Primary efficacy outcome: 12-week progression-free survival rate (PFS). Results Thirty-six patients were enrolled. The 12-week PFS rate was 23.8% [90% confidence interval (CI) 12.4-37.2); the primary outcome was not met as the lower limit of the CI was outside the threshold of 16%. Median PFS was 6.6 weeks (90% CI 6.1-7.1). No patients achieved an objective response, and 11 (31%) patients achieved disease control. Median overall survival was 8.6 months (90% CI 5.7-10.7). The most frequent treatment-emergent adverse events (TEAEs) were diarrhea (9/36; 25%) and decreased appetite (8/36; 22%). Three patients reported Grade >= 3 ileus; all other Grade >= 3 TEAEs were reported by <= 2 patients. The most frequent adverse events of special interest (AESIs) were hypertension (10/36; 28%), bleeding/hemorrhage (7/36; 19%), and proteinuria (7/36; 19%). All Grade >= 3 AESIs were reported by <= 2 patients. Conclusions These findings suggest that ramucirumab monotherapy has clinical activity and a manageable safety profile in Japanese patients with gastric cancer after disease progression following first-line chemotherapy.