The present invention relates to novel crystalline forms of compound (I), (3-Amino-oxetan-3-ylmethyl)-[2-(5,5-dioxo-5,6,7,9-tetrahydro-5lambda*6*-thia-8-aza-benzocyclohepten-8-yl)-6-methyl-quinazolin-4-yl]-amine and pharmaceutical compositions comprising the crystalline forms thereof disclosed herein, which may be used for the treatment or prophylaxis of a viral disease in a patient relating to respiratory syncytial virus (RSV) infection or a disease caused by RSV infection.本發明係關於化合物(I)(3-胺基-環氧丙-3-基甲基)-[2-(5,5-二氧-5,6,7,9-四氫-5λ*6*-硫-8-氮雜-苯并環庚烯-8-基)-6-甲基-喹唑啉-4-基]-胺之新穎晶形，及包含本文揭示之其晶形的醫藥組合物，其可用於治療或預防患者之與呼吸道融合病毒(RSV)感染或由RSV感染引發之疾病有關的病毒性疾病。
