Compounds of Formula I:and pharmaceutically acceptable salts thereof, wherein ring A, ring B, W, m, D, R2, R2a, R3, R3a, and Z are as defined herein, are inhibitors of Trk kinases and are useful in the treatment of pain, cancer, inflammation, neurodegenerative diseases and certain infectious diseases.一種通式I所示的化合物及其醫藥上可接受的鹽,其中環A, 環B, W, m, D, R2, R2a, R3, R3a和Z如本文所定義,其為Trk激酶的抑制劑,並且可以用於治療疼痛、癌症、炎症、神經退化性疾病和某些傳染病。