A specific crystalline mesylate salt form of (3S)-Tetrahydrofuran-3-yl (4S)-4-isopropyl-1,4,6,7-tetrahydro-5H-imidazo[4,5-c]pyridine-5-carboxylate, and the use of the same in medicine. (Formula (I))L'invention concerne une forme saline de mésylate cristallin spécifique d(3S)-tétrahydrofuran-3-yl (4S)-4-isopropyl-1,4,6,7-tétrahydro-5H-imidazo[4,5-c]pyridine-5-carboxylate, et l'utilisation de celle-ci en médecine. (Formule (I))