The present invention describes combination treatments comprising a PD-1 axis binding antagonist and a MEK inhibitor, and methods of use thereof, which include enhancing tumor immunogenicity for enhanced immunogenicity, eg, treatment of cancer. It includes a method of treating a condition where it is desirable to increase. [Selection] Figure 1本発明は、PD-1軸結合アンタゴニスト及びMEK阻害剤を含む併用処置、ならびにその使用方法について記載し、本方法には、免疫原性の増強、例えば癌の処置のために腫瘍免疫原性を増加させることなどが望ましい場合の状態を処置する方法を含む。【選択図】図1