The present invention relates to phenylsulfonylureas and phenylsulfonylthioureas, wherein the phenyl ring is substituted either (i) at the ortho-position with a halo group, or (ii) at the meta- and para-positions, and wherein the group attached to the terminal nitrogen atom of the urea group is a 6-membered cyclic group substituted across the 2,3-positions with a fused ring and further substituted at the 4-position. The present invention further relates to salts, solvates and prodrugs of such compounds, to pharmaceutical compositions comprising such compounds, and to the use of such compounds in the treatment and prevention of medical disorders and diseases, most especially by NLRP3 inhibition.