the present invention provides novel imidazoquinoline and imidazonaphthyridine derivatives of formula , and the pharmaceutically acceptable salts thereof wherein r 1 , r 1a , r 1b , r 2 , r 4 , r 5 , r 6 , x and z are as defined in the specification . the invention is also directed to pharmaceutical compositions comprising the compounds of formula and to use of the compounds in the treatment of diseases associated with lrrk2 , such as neurodegenerative diseases including parkinson &# 39 ; s disease or alzheimer &# 39 ; s disease , cancer , crohn &# 39 ; s disease or leprosy .