The invention relates pyridine amide derivative of Formula (I) or a pharmaceutically acceptable salt thereof, wherein R1 and R2 are indipendently hydrogen, linear o branched (C1-C3)alkyl or joined together they form a cyclopropyl ring； R is independently selected from the group consisting of halogens and trifluoromethyl and p is 1, 2 or 3； A is C or N； E is a group of formula (B) or (C), wherein B is C(O)OH, C(O)O(C1-C3)alkyl, and C is selected from the group consisting of m is 1, 2 or 3, n is 0 or 1, W is -O-, -O(C1-C3 alkyl)-； -(C1-C3 alkyl)O-； -C(O)-； -C(=N-O(C1-C3 alkyl))-； -NH- or -NH(C1-C3alkyl)-； Ar is phenyl, optionally substituted with one or more substituents selected from the group consisting of halogen, trifluoromethyl, trifluoromethoxy, methyl, -NH(C1-C3alkyl)-； -N(C1-C3alkyl)(C1-C3alkyl)-, a from 5 to 7 membered heterocyclic ring containing one nitrogen atom which is convalently bonded to Ar and optionally containing one or two heteroatoms selected from N, O and S； and a 5- or 6-membered heteroaromatic ring containing 1 to 3 heteroatoms selected from S, O e N, such heteroaromatic ring being substituted with one or two substituents selected from the group consisting of (C1-C3)alkyl, (C3-C5)cycloalkyloxy, (C1-C3)alkylcarbonyl. The compounds of the invention could be used for manufacturing a medicament for the treatment of pathologies which require the use of an antagonist of the EP4 receptor, such as the treatment of acute and chronic pain, inflammatory pain, osteoarthritis, inflammation-associated disorder as arthritis, rheumatoid artrhritis, cancer, endometriosis and migraine.本發明係關於式(I)吡啶醯胺衍生物或其醫藥上可接受鹽，其中R1以及R2係獨立為氫、直鏈或分支(C1-C3)烷基或一起連接而形成環丙基環；R係獨立選自由鹵素與三氟甲基組成之群且p係1、2或3；A係C或N；E係式(B)或(C)之基團，其中B係C(O)OH、C(O)O(C1-C3)烷基，以及C係選自由以下組成之群：m係1、2或3，n係0或1，W係-O-、-O(C1-C3烷基)-；-(C1-C3烷基)O-；-C(O)-；-C(=N-O(C1-C3烷基))-；-NH-或-NH(C1-C3烷基)-；Ar係苯基、視需要經1或多個選自由鹵素、三氟甲基、三氟甲氧基、甲基、-NH(C1-C3烷基)-所組成之群之取代基所取代；-N(C1-C3烷基)(C1-C3烷基)-、從5至7員雜環，其包含一個共鍵價鍵結至Ar的氮原子且需要包含1或2個選自N、O以及S的
