The invention relates to a combination of CXCR4 antagonist 6-{4-[1 -(Propan-2-yl)piperidin-4-yl]-1,4-diazepan-1-yl}-N-(pyridin-4-yl)pyridine-2-carboxamide and an immune checkpoint inhibitor, and the use of the same in the treatment of tumours and/or cancers.