A quinazoline derivative of the Formula (I): wherein the substituents are as defined in the text for use in the production of an anti proliferative effect which effect is produced alone or in part by inhibiting erbB2 receptor tyrosine kinase in a warm-blooded animal such as man.
A quinazoline derivative of the Formula (I): wherein the substituents are as defined in the text for use in the production of an anti proliferative effect which effect is produced alone or in part by inhibiting erbB2 receptor tyrosine kinase in a warm-blooded animal such as man.