Squaric acid Derivatives of formula (1) are described:
wherein
R1 is an integrin binding group;
R2 is a hydrogen atom or a C1-6alkyl group;
L1 is a covalent bond or a linker atom or group;
n is zero or the integer 1;
Alk1 is an optionally substituted aliphatic chain;
R3 is a hydrogen atom or an optionally substituted heteroaliphatic, cycloaliphatic, heterocycloaliphatic, polycycloaliphatic, polyheterocycloaliphatic, aromatic or heteroaromatic group: and the salts, solvates, hydrates and N-oxides thereof.
The compounds are able to inhibit the binding of integrins to their ligands and are of use in the prophylaxis and treatment of immune of inflammatory disorders, or disorders involving the inappropriate growth or migration of cells.