A series of substituted fused tricyclic imidazole derivatives, in particular dihydro-1H-pyrano[4′,3′:4,5]imidazo[1,2-a]pyridine, 1,2,3,4-tetrahydroimidazo[1,2-a:5,4-c′]dipyridine, dihydro-1H-pyrano[3′,4′:4,5]imidazo[1,2-a]pyridine and tetrahydro-6H-cyclohepta[4,5]imidazo[1,2-a]pyridine, and analogs thereof, being potent modulators of human TNFα activity, are accordingly of benefit in the treatment and/or prevention of various human ailments, including autoimmune and inflammatory disorders; neurological and neurodegenerative disorders; pain and nociceptive disorders; cardiovascular disorders; metabolic disorders; ocular disorders; and oncological disorders.