PROBLEM TO BE SOLVED: To provide anti-canine PD-I antibodies that have a high binding affinity to canine PD-1, as well as have the ability to block the binding of canine PD-1 to canine PD-L1.SOLUTION: The present invention discloses antibodies to canine PD-1 that have specific sequences and a high binding affinity for canine PD-1. The invention also discloses the use of the antibodies of the present invention in the treatment of cancer in dogs.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2020,JPO&INPIT【課題】イヌPD-1に高い結合親和性を有し、ならびにイヌPD-1のイヌPD-L1への結合をブロックする能力を備える抗イヌPD-1抗体を提供する。【解決手段】特定の配列を有し、およびイヌPD-1に高い結合親和性を有する、イヌPD-1に対する抗体を開示する。本発明はまた、イヌの癌の処置における本発明の抗体の使用も開示する。【選択図】図2