Compounds

A prodrug of a compound of formula (I):

• or a pharmaceutically acceptable salt or solvate thereof, wherein:
• Q is selected from O or S;
• R1 is a 5- or 6-membered heteroaryl group, wherein the 5- or 6-membered ring structure consists of one or more carbon atoms, and one or more nitrogen and/or oxygen atoms, wherein the 5- or 6-membered heteroaryl group of R1 is substituted with a monovalent cycloalkyl, cycloalkenyl or heterocyclic group, wherein a ring atom of the monovalent cycloalkyl, cycloalkenyl or heterocyclic group is directly attached to a ring atom of the 5- or 6-membered heteroaryl group of R1, wherein the monovalent cycloalkyl, cycloalkenyl or heterocyclic group may optionally be substituted, and wherein the 5- or 6-membered heteroaryl group of R1 may optionally be further substituted;
• R2 is a cyclic group substituted at the α and α′ positions, wherein R2 may optionally be further substituted;
• R3 is hydrogen, halogen, —OH, —NH2, —CN, —R5, —OR5, —NHR5 or —N(R5)2;
• R4 is 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 cyclic group, wherein the cyclic group may optionally be substituted;
• and
• R5 is independently an optionally substituted C1-C4 alkyl group.