The present invention relates to a compound of formula (I), or a pharmaceutically acceptable salt or hydrate thereof, wherein: the group X—Y is —NHSO2— or —SO2NH—; Z is a monocyclic aryl or heteroaryl group, each of which is optionally substituted by one or more substituents selected from alkyl, cycloalkyl, halo, alkoxy, CN, haloalkyl and OH; R1 is H or alkyl; R2 is selected from COOH and a tetrazolyl group; R3 is selected from H, C land alkyl; R4 is selected from H and halo; R5 is selected from H, alkyl, haloalkyl, SO2-alkyl, Cl, alkoxy, OH, CN, hydroxyalkyl, alkylthio, heteroaryl, cycloalkyl, heterocycloalkyl and haloalkoxy; R6 is H; R7 is selected from H, CN, haloalkyl, halo, SO2-alkyl, SO2NR12R13, heteroaryl, CONR10R11 and alkyl, wherein said heteroaryl group is optionally substituted by one or more substituents selected from alkyl, halo, alkoxy, CN, haloalkyl and OH; R8 is selected from H, alkyl, haloalkyl and halo; and R9 is H, alkyl or halo; R10 and R11 are each independently H or alkyl; and R12 and R13 are each independently H or alkyl. Further aspects of the invention relate to such compounds for use in the field of immuno-oncology and related applications. Another aspect of the invention relates to compounds of formulae (1a) and (1b).