Compounds of formula (I):
wherein:
when X is NR
5
, Y is absent or is CH
2
;
when X is CH
2
, Y is absent, CH
2
, NR
6
, O, S, S(O) or S(O)
2
;
Z is a 5- or 6-membered heterocyclyl ring;
compositions comprising them, processes for preparing them and their use in medical therapy (for example modulating CCR5 receptor activity in a warm blooded animal).