PROBLEM TO BE SOLVED: To provide a combination therapy for treating cancer, particularly for treating a cancer showing a positive reaction of ALK, PD-L1, or both ALK and PD-L1. A medicament comprising an antagonist of programmed death 1 protein (PD-1) for use in combination with an anaplastic lymphoma kinase (ALK) inhibitor for treating cancer in humans, said PD-1 The antagonist is an anti-PD-1 monoclonal antibody comprising a heavy chain and a light chain, wherein the heavy chain and the light chain each comprise a specific amino acid sequence, and further the ALK inhibitor is crizotinib or a pharmaceutically acceptable form thereof. The above medicament, which is an acceptable salt. [Selection diagram] None【課題】癌の処置のための、特にALK、PD-L1、又はALK及びPD-L1の双方の陽性反応を示す癌を処置するための併用療法の提供。【解決手段】ヒトにおいて癌を処置するための、未分化リンパ腫キナーゼ(ALK)阻害剤との併用のためのプログラム死1タンパク質(PD-1)のアンタゴニストを含む医薬であって、該PD-1アンタゴニストは、重鎖および軽鎖を含む抗PD-1モノクローナル抗体であり、該重鎖および該軽鎖はそれぞれ、特定のアミノ酸配列を含み、さらに、該ALK阻害剤は、クリゾチニブ又はその医薬的に許容可能な塩である、前記医薬。【選択図】なし