598078 Disclosed is the use of Macitentan (also known as [N-[5-(4-bromophenyl)-6-(2-(5-bromopyrimidin-2-yloxy)ethoxy)-pyrimidin-4-yl]-Npropylaminosulfonamide] in the manufacture of a medicament for the prevention or treatment of brain metastases, wherein the medicament is adapted for administration in combination with a cytotoxic chemotherapy agent selected from paclitaxel, temozolomide and a mixture of paclitaxel and temozolomide, with radiotherapy or with both radiotherapy and a cytotoxic chemotherapy agent selected from paclitaxel, temozolomide and a mixture of paclitaxel and temozolomide. Paclitaxel is also known as (2?,4?,5?,7?,10?,13?)-4,10-bis(acetyloxy)-13-{ [(2R,3S)-3-(benzoylamino)-2-hydroxy-3-phenylpropanoyl]oxy} -1,7-dihydroxy-9-oxo-5,20-epoxytax-11-en-2-yl benzoate. Temozolomide is also known as 4-methyl-5-oxo-2,3,4,6,8-pentazabicyclo[4.3.0]nona-2,7,9-triene-9-carboxamide.