Nivolumab [Opdivo]
DrugNivolumab (OPDIVO®) is a marketed pharmaceuticals material authorized in the European Union. This study uses an off-label route of administration of nivolumab. Subjects with leptomeningeal disease in solid tumours with an approved indication for intravenous treatment with the PD1 antibody will receive an intrathecal application of nivolumab. A total of six i.th. applications will be performed every 14 days. The intrathecal administration will be performed via an Ommaya reservoir or another intraventricular catheter.