Activity and safety of avelumab in high-grade neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas progressive after chemotherapy (AveNEC trial)
Abstract. Background: Neuroendocrine neoplasias grade 3 (NEN G3) are rare tumors with poor prognosis and no established second-line therapy. The role of immune checkpoint blockade in these aggressive tumors remains unclear. Methods: The phase II AVENEC study evaluated the effect of avelumab (AVE, 10 mg/kg IV Q2W) in 60 patients with well-differentiated high-grade neuroendocrine tumors (NET G3, N=22) or poorly differentiated neuroendocrine carcinomas (NEC, N=38) progressing after ≥ one prior chemotherapy (excluding Merkel cell and small-cell lung cancer). Results: The best overall response according to iRECIST was partial response (PR) in 3 (5%) and stable disease (SD) in 9 (15%) patients, with a disease control rate at 16 weeks of 15% (3 PR, 6 SD), and a median duration of response of 4.3 months. Six patients (10%) achieved SD or PR for > 6 months and two for > one year. Response rates were similar regardless of differentiation, Ki67 expression, or primary localization. The median prog
