Use of a CXCR4 antagonistic peptide and an immune-check point regulator in the treatment of cancer is provided. Accordingly there is provided a method of treating cancer in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a peptide having an amino acid sequence as set forth in SEQ ID NO: 1 or an analog or derivative thereof; and a therapeutically effective amount of a PD1 antagonist, a PDL-1 antagonist, a CTLA-4 antagonist, a LAG-3 antagonist, a TIM-3 antagonist, a KIR antagonist, an IDO antagonist, an OX40 agonist, a CD137 agonist, a CD27 agonist, a CD40 agonist, a GITR agonist, a CD28 agonist or an ICOS agonist, thereby treating the cancer in the subject. Also provided are pharmaceutical compositions and articles of manufacture.