A poly(arylene ether) composition includes a hydrogenated block copolymer of an alkenyl aromatic compound and a conjugated diene, a flame retardant, and a poly(arylene ether)-polysiloxane block copolymer reaction product that itself includes a poly(arylene ether)-polysiloxane block copolymer. The composition is useful for forming extruded articles, including insulation for wire and cable. The poly(arylene ether)-polysiloxane block copolymer contributes improved flame retardancy and, in many cases, improved physical properties to the composition.