Combined pharmaceutical formulation comprising gemcitabine-containing liposome composition and immune checkpoint inhibitor

An object of the present invention is to provide a combined pharmaceutical formulation obtained by combining a liposome composition and an immune checkpoint inhibitor, in which gemcitabine is encapsulated in a dissolved state in liposomes in the liposome composition. According to the present invention, there is provided a pharmaceutical formulation including (A) a liposome composition in combination with (B) an immune checkpoint inhibitor, in which the liposome composition includes liposomes each having an inner water phase, and an aqueous solution constituting an outer water phase and having the liposomes dispersed therein, gemcitabine is encapsulated in a dissolved state in the liposomes, and the liposome composition and the immune checkpoint inhibitor are administered simultaneously or sequentially.