The primary objective will be to compare the antitumour efficacy of Lanreotide Autogel/Depot 120 mg (LAN) plus Best Supportive Care (BSC) every 28 days versus placebo plus BSC, in terms of progression free survival (PFS), measured by central review using Response Evaluation Criteria in Solid Tumours (RECIST) v1.1 criteria, every 12 weeks, in subjects with unresectable and/or metastatic well differentiated, typical or atypical lung neuroendocrine tumours