Patent ID: 7732403

Claim:
A method of reducing the symptoms, severity or both of a T-cell mediated disease comprising administering to an animal in need thereof an effective amount of a diketopiperazine having the following formula: wherein: R 1 and R 2 , which may be the same or different, each is: (a) a side chain of an amino acid, wherein the amino acid is glycine, alanine, valine, norvaline, α-aminoisobutyric acid, 2,4-diaminobutyric acid, 2,3-diaminobutyric acid, leucine, isoleucine, norleucine, seine, homoserine, threonine, lysine, hydroxylysine, arginine, homoarginine, citrulline, p-aminophenylalanine, tyrosine, thyroxine or ornithine; or (b) a derivative of a side chain of an amino acid, wherein the amino acid is one of those recited in (a), and the derivatized side chain has: (i) an —NH 2 group replaced by an —NHR 3 or —N(R 3 ) 2 group, wherein each R 3 may independently be a substituted or unsubstituted alkyl, cycloalkyl, heterocycloalkyl, aryl, alkylaryl, arylalkyl or heteroaryl; (ii) an —OH group replaced by an —O—PO 3 H 2 or —OR 3 group, wherein each R 3 may independently be a substituted or unsubstituted alkyl, cycloalkyl, heterocycloalkyl, aryl, alkylaryl, arylalkyl or heteroaryl; (iii) a —CH 2 — group replaced by a —CH(NH 2 )— or a —CH(OH)— group; (iv) a —CH 3 group replaced by a —CH 2 —NH 2 or a —CH 2 —OH group; and/or (v) an H which is attached to a carbon atom replaced by a halogen; or a physiologically-acceptable salt thereof.