Refers to a form of Crystalline bisulfate Salt of (S) - 1 - (4-chloro phenyl) - 7 - isopropoxi - 6 - methoxy - 3 - (4 - (methyl - [4 - (4 - methyl - 3 - oxo piperazin-1-yl) - trans - cyclohexyl methyl] amino} - phenyl) - 1,4 - dihydro - 2H - isoquinolin - 3-one whose pattern of x-ray Powder diffraction using cu Ka Radiation Presents The Peaks and 18.8, 21.3 22.7 expressed in Angle 2 Theta, with an error of + \/ - 0.2\ufffd.It also relates to a Pharmaceutical composition. The Crystalline form is useful in the treatment of diseases associated with the p53 \/ MDM2 Interaction such as Sarcoma, osteosarcoma, melanoma, LeukemiaSE REFIERE A UNA FORMA CRISTALINA DE LA SAL DE BISULFATO DE LA (S)-1-(4-CLORO-FENIL)-7-ISOPROPOXI-6-METOXI-2-(4-{METIL-[4-(4-METIL-3-OXO-PIPERAZIN-1-IL)-TRANS-CICLOHEXIL-METIL]-AMINO}-FENIL)-1,4-DIHIDRO-2H-ISOQUINOLIN-3-ONA CUYO PATRON DE DIFRACCION EN POLVO DE RAYOS X UTILIZANDO RADIACION DE Cu Ka PRESENTA LOS PICOS 18.8, 21.3 Y 22.7 EXPRESADOS EN ANGULO 2-THETA Y CON UN ERROR DE +/- 0.2�. TAMBIEN SE REFIERE A UNA COMPOSICION FARMACEUTICA. DICHA FORMA CRISTALINA ES UTIL EN EL TRATAMIENTO DE ENFERMEDADES ASOCIADAS CON LA INTERACCION DE MDM2/p53 TALES COMO SARCOMA, OSTEOSARCOMA, MELANOMA, LEUCEMIA