The present disclosure relates to a pharmaceutical composition for combination therapy for preventing or treating cancer, which contains a first pharmaceutical ingredient containing a drug conjugate wherein an anticancer agent is bound at one end of an amphiphilic peptide represented by SEQ ID NO 1 and a poloxamer; and a second pharmaceutical ingredient containing an anti-PD-L1 antibody; as active ingredients. The pharmaceutical composition significantly inhibits cancer growth in in-vivo experiments and exhibits an effect of significantly enhancing immunotherapeutic effect by activating immune cells in cancerous tissues.
In particular, the pharmaceutical composition for combination therapy according to the present disclosure has superior tumor accumulation efficiency and selectivity as compared to existing anticancer agents, and is very stable with little toxicity to normal tissues other than cancerous tissues.