Impact of everolimus on Japanese patients with advanced pancreatic neuroendocrine neoplasms

Background: Although everolimus has become a key therapeutic agent in patients with advanced pancreatic neuroendocrine neoplasms (PNEN), its efficacy and safety in clinical practice remains unclear. Methods: Forty-seven patients with advanced PNEN treated with everolimus were reviewed retrospectively. To evaluate the safety of everolimus as a long-term treatment, the patients were divided into two groups according to treatment duration: group A, ≤1 year (n = 21); group B, >1 year (n = 26). Results: Among 42 patients with pancreatic neuroendocrine tumors (PNET), the median progression-free survival, overall survival, and objective response rate were 27.5 months, 60.8 months, and 19.0%, respectively. Two patients with pancreatic neuroendocrine carcinomas (PNEC) with lower Ki-67 index and well-differentiated tumors showed favorable responses. More patients in group A discontinued everolimus owing to adverse drug reactions (ADRs) than in group B. The median relative dose intensity was significantly lower in group B than group A (P = 0.045), whereas the drug interruption rate was significantly higher in group B than group A (P < 0.001). Conclusions: Everolimus showed significant clinical benefit in Japanese patients with advanced PNEN. Prevention of severe ADRs by appropriate dose reduction and interruption is necessary for a long-term continuation of everolimus.