The present invention relates to pharmaceutical compositions suitable for oral administration, and more particularly to pharmaceutical compositions, including pharmaceutical tablet compositions, containing N-(2-{2-dimethylaminoethyl-methyl-amino}-4-methoxy-5-{[4-(1-methylindol-3-yl)pyrimidin-2-yl]amino}phenyl)prop-2-enamide (“AZD9291”) or a pharmaceutically acceptable salt thereof, wherein such compositions comprise a certain amount of microcrystalline cellulose and at least one other pharmaceutical diluent.
