The present invention relates to compounds of formula (I) wherein Q is selected from O or S; R1 is a saturated or unsaturated, optionally substituted hydrocarbyl group optionally including one or more heteroatoms N, O or S; R2 is a cyclic group substituted at the a and a′ positions, wherein the substituent at the α-position is a monovalent heterocyclic group or a monovalent aromatic group, wherein the heterocyclic or aromatic group may optionally be substituted, and wherein the cyclic group may optionally be further substituted; R3 and R4 are each independently hydrogen, halogen, —OH, —NH2, —CN, —R5, —OR5, —NHR5 or —N(R5)2; or R3 and R4 together with the carbon atom to which they are attached may form a 3- to 7-membered saturated or unsaturated, optionally substituted cyclic group; and R5 is independently optionally substituted C1-C4 alkyl. 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 the inhibition of NLRP3.