Nivolumab plus ipilimumab versus nivolumab in advanced neuroendocrine carcinoma phase II trial

PURPOSE: There is no standard second-line therapy for gastroenteropancreatic (GEP) and lung large-cell neuroendocrine carcinoma (NEC) after the failure of platinum-based chemotherapy. This study aimed to investigate the efficacy of nivolumab ± ipilimumab. METHODS: The GCO-001-NIPINEC (ClinicalTrials.gov identifier: NCT03591731) trial was a noncomparative, open-label, phase II trial. The main inclusion criteria were age ≥18 years, performance status (PS) ≤2, advanced large- and small-cell GEP-NEC and large-cell lung NEC, and second- or third-line treatment for NECs refractory to platinum-based chemotherapy. Patients were randomly assigned (1:1) and stratified by age and PS to receive nivolumab (3 mg/kg/once every 2 weeks) ± ipilimumab (1 mg/kg/once every 6 weeks) for 2 years or until progression or unacceptable toxicity. The primary end point was objective response rate (ORR) at 8 weeks, assessed by investigators. RESULTS: A total of 185 patients (91 in the nivolumab arm and 94 in the nivolumab-ipilimumab arm) were enrolled between December 2018 and March 2021; 169 were analyzed (median age of 64.5 years, 71% male, 91% PS 0-1). The main primary tumor locations were lungs (50%), colorectal (15%), gastroesophageal (14%), and pancreatic (13%) regions. The ORR at 8 weeks was 7.2% (95% CI, 2.7 to 15.1]) in the nivolumab arm and 14.0% (95% CI, 7.4 to 23.1) in the nivolumab-ipilimumab arm. The best ORR was 9.6% and 20.9%, respectively, whereas the median progression-free and overall survival were approximately 2 months and 6 months in both arms. One treatment-related death occurred, in the nivolumab arm. The grade 3-4 adverse events (≥5%) were asthenia (13%), gamma-glutamyl transferase increase (10%), alkaline phosphatase increase (9%), dyspnea (7%), and anemia (6%) in the nivolumab-ipilimumab arm. CONCLUSION: Nivolumab-ipilimumab could be a second-/third-line treatment option for patients with NECs. However, given the limited magnitude of benefit, studies are warranted to evaluate its use earlier and/or associated with chemotherapy.