The present invention provides a pharmaceutical composition comprising as an active ingredient at least one polypeptide of the following (a) ~ a (d): A polypeptide comprising the amino acid sequence of 1,: (a) SEQ ID NO: Plural amino acids are deleted, inserted, a polypeptide that has a platelet adhesion inhibitory activity and platelet aggregation inhibitory activity and / or comprises an amino acid sequence that has been added or substituted or 1 in the amino acid sequence (b) as described above in (a), A polypeptide comprising the amino acid sequence of 3,: (c) SEQ ID NO: Plural amino acids are deleted, inserted, the polypeptide having a platelet adhesion inhibitory activity and platelet aggregation inhibitory activity and / or comprises an amino acid sequence are substituted or added, or 1 amino acid sequence in (d) above (c).本発明は、以下の(a)~(d)の少なくとも1種のポリペプチドを有効成分として含有する医薬組成物を提供する:(a) 配列番号:1のアミノ酸配列を含むポリペプチド、(b) 上記(a)のアミノ酸配列において1若しくは複数個のアミノ酸が欠失、挿入、置換または付加されたアミノ酸配列を含み且つ血小板凝集阻害作用及び/又は血小板接着阻害作用を有するポリペプチド、(c) 配列番号:3のアミノ酸配列を含むポリペプチド、(d) 上記(c)のアミノ酸配列において1若しくは複数個のアミノ酸が欠失、挿入、置換または付加されたアミノ酸配列を含み且つ血小板凝集阻害作用及び/又は血小板接着阻害作用を有するポリペプチド。
