F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. have discovered new heteroarylphenyl ether derivatives acting as cyclin-dependent kinase CDK8/cyclin C inhibitors. As such, they are reported to be useful for the treatment of graft-vs.-host disease, transplant rejection, multiple sclerosis, rheumatoid arthritis, atopic dermatitis, psoriasis, amyotrophic lateral sclerosis and stroke, among others.