The present invention relates to derivatives of formula (I)wherein Ring A, X, Y, Z, RA, R1, R2, R3and R4are as described in the description, to their preparation, to pharmaceutically acceptable salts thereof, and to their use as pharmaceuticals, to pharmaceutical compositions containing one or more compounds of formula (I), and especially to their use as C5a receptor modulators.本發明係關於:式(I)之衍生物其中環A、X、Y、Z、RA、R1、R2、R3及R4如實施方式中所描述;其等製備;其等醫藥學上可接受之鹽及其等作為藥品之用途;含有一或多種式(I)化合物之醫藥組合物;以及尤其其等作為C5a受體調節劑之用途。