| abstract |
The invention relates to tricyclic heterocyclic derivatives, or pharmaceutically-acceptable salts or in vivo hydrolysable esters thereof, which possess anti-cancer activity. The invention also relates to processes for the manufacture of said tricyclic heterocyclic derivatives, to novel pharmaceutical compositions containing them and to the use of said tricyclic heterocyclic derivatives in the manufacture of a medicament for the production of an anti-cancer effect. n The invention provides an optionally substituted tricyclic heterocyclic derivative of the formula In n wherein A together with the adjacent vinylene group of the 4-oxo-1,4-dihydropyrid-1-yl ring completes a benzene or pyridine ring; n R¹ and R², which may be the same or different, each is (1-4C)alkyl or (1-4C)alkoxy; n and R³ is hydrogen, (1-4C)alkyl or (1-4C)alkoxy; n or a pharmaceutically-acceptable salt or in vivo hydrolysable ester thereof. |