A series of quinoline derivatives, substituted by an optionally substituted bicyclic heteroaryl moiety consisting of two fused six-membered aromatic rings attached via an alkylene chain optionally linked to a heteroatom, being selective inhibitors of PI3 kinase enzymes, are accordingly of benefit in medicine, for example in the treatment of inflammatory, autoimmune, cardiovascular, neurodegenerative, metabolic, oncological, nociceptive or ophthalmic conditions.