EP2855461A1 - CRYSTALLINE FORM A OF 1,5-DIMETHYL-6-THIOXO-3-(2,2,7-TRIFLUORO-3-OXO-4-(PROP-2-YNYL)-3,4-DIHYDRO-2H-BENZO[B][1,4]OXAZIN-6-YL)-1,3,5-TRIAZINANE-2,4-DIONE