https://www.has-sante.fr/jcms/p_3478087/fr/opdivo-yervoy-ipilimumab/nivolumab-cancer-de-l-oesophage 2023 France evaluation of the transparency committee Nivolumab esophageal neoplasms Ipilimumab yervoy esophagospasm cancer of esophagus Childhood Esophageal Carcinoma neoplasm, malignant Opdivo