A carboxylic acid compound represented by the following formula or a pharmacologically acceptable salt thereof for use in the treatment or prophylaxis of a disease involving or caused by autotaxin: wherein, R 1 is wherein X 1a is -C(R 1a) 2 - wherein plural symbols R 1a are the same or different and each is a hydrogen atom, a halogen atom, C 1 -C 2 perfluoroalkyl, C 1 -C 2 perfluoroalkoxy or Ci-Ce alkyl, or plural symbols R 1a are bonded to form 1,1-C 3 -C 6 cycloalkylene or -NR 1b - wherein R 1b is a hydrogen atom or C 1 -C 2 perfluoroalkyl, X 1b and X 1c are the same or different and each is -O- or -CH 2 - provided X 1b and X 1c are not simultaneously -O-, R 1c is a hydrogen atom, a halogen atom, C 1 -C 2 perfluoroalkyl, C 1 -C 2 perfluoroalkoxy, Ci-Ce alkyl or C 1 -C 2 perfluoroalkylthio, R 1d is a hydrogen atom, a halogen atom or Ci-Ce alkyl, and R 1e is a hydrogen atom, C 1 -C 2 perfluoroalkyl or C 1 -C 2 perfluoroalkoxy, X is -N= or -CH=, ring A is or wherein X 2a is -N= or -CR 2a = wherein R 2a is a hydrogen atom, a halogen atom, Ci-Ce alkyl or Ci-Ce alkoxy, R 2b is a hydrogen atom, a halogen atom, Ci-Ce alkyl or Ci-Ce alkoxy, R 2c is a hydrogen atom or Ci-Ce alkyl, X 2b is -O-, -NR 2d - wherein R 2d is a hydrogen atom or C 1 -C 2 perfluoroalkyl or - CHR 2e - wherein R 2e is a hydrogen atom or Ci-Ce alkyl, X 2c is -(CH 2) n' - wherein n' is 0 or 1 or -O-, L is -(CHR 3a) n - wherein n is 0, 1, 2 or 3, plural symbols R 3a are the same or different and each is a hydrogen atom or a C 1 -C 6 alkyl, -(CH 2) m -O-(CH 2) m' -wherein m and m' are the same or different and each is 0, 1 or 2, C 2 -C 3 alkenylene, wherein R 3b and R 3c are the same or different and each is a hydrogen atom or C 1 -C 6 alkyl, R 3d is a hydrogen atom, Ci-Ce alkoxy, Ci-Ce alkyl or C 1 -C 2 perfluoroalkyl, R 3e is a hydrogen atom, C 1 -C 6 alkoxy, Ci-Ce alkyl or C 1 -C 2 perfluoroalkyl. wherein, R 1 is wherein X 1a is -C(R 1a) 2 - wherein plural symbols R 1a are the same or different and each is a hydrogen atom, a halogen atom, C 1 -C 2 perfluoroalkyl, C 1 -C 2 perfluoroalkoxy or Ci-Ce alkyl, or plural symbols R 1a are bonded to form 1,1-C 3 -C 6 cycloalkylene or -NR 1b - wherein R 1b is a hydrogen atom or C 1 -C 2 perfluoroalkyl, X 1b and X 1c are the same or different and each is -O- or -CH 2 - provided X 1b and X 1c are not simultaneously -O-, R 1c is a hydrogen atom, a halogen atom, C 1 -C 2 perfluoroalkyl, C 1 -C 2 perfluoroalkoxy, Ci-Ce alkyl or C 1 -C 2 perfluoroalkylthio, R 1d is a hydrogen atom, a halogen atom or Ci-Ce alkyl, and R 1e is a hydrogen atom, C 1 -C 2 perfluoroalkyl or C 1 -C 2 perfluoroalkoxy, X is -N= or -CH=, ring A is or wherein X 2a is -N= or -CR 2a = wherein R 2a is a hydrogen atom, a halogen atom, Ci-Ce alkyl or Ci-Ce alkoxy, R 2b is a hydrogen atom, a halogen atom, Ci-Ce alkyl or Ci-Ce alkoxy, R 2c is a hydrogen atom or Ci-Ce alkyl, X 2b is -O-, -NR 2d - wherein R 2d is a hydrogen atom or C 1 -C 2 perfluoroalkyl or - CHR 2e - wherein R 2e is a hydrogen atom or Ci-Ce alkyl, X 2c is -(CH 2) n' - wherein n' is 0 or 1 or -O-, L is -(CHR 3a) n - wherein n is 0, 1, 2 or 3, plural symbols R 3a are the same or different and each is a hydrogen atom or a C 1 -C 6 alkyl, -(CH 2) m -O-(CH 2) m' -wherein m and m' are the same or different and each is 0, 1 or 2, C 2 -C 3 alkenylene, wherein R 3b and R 3c are the same or different and each is a hydrogen atom or C 1 -C 6 alkyl, R 3d is a hydrogen atom, Ci-Ce alkoxy, Ci-Ce alkyl or C 1 -C 2 perfluoroalkyl, R 3e is a hydrogen atom, C 1 -C 6 alkoxy, Ci-Ce alkyl or C 1 -C 2 perfluoroalkyl.