Acknowledgements
This work was supported by the Grupo Español de Tumores Neuroendocrinos y Endocrinos (GETNE). AstraZeneca provided durvalumab and tremelimumab and awarded a grant to GETNE to pay the costs of the study. The funder did not have a role in designing or conducting the study. The authors thank all patients and families, investigators and study staff involved in the DUNE trial; the MFAR Clinical Research team for regulatory, monitoring, and quality assurance activities; Pau Doñate PhD for manuscript and language editing; and Jordi Curto M.Sc. and Arturo Alvarez PhD for statistical support.