The present invention provides novel 3,4-disubstituted-1H-pyrrolo[2,3-b]pyridine derivatives and 4,5-disubstituted-7H-pyrrolo[2,3-c]pyridazine derivatives of Formula I, and the pharmaceutically acceptable salts thereof wherein R1, R2, R3, R4 and X are as defined in the specification. The invention is also directed to pharmaceutical compositions comprising the compounds of formula I and to use of the compounds in the treatment of diseases associated with LRRK2, such as neurodegenerative diseases including Parkinson's disease or Alzheimer's disease, cancer, Crohn's disease or leprosy.