The present invention provides a compound of formula I;or a pharmaceutically acceptable salt thereof, wherein R1, R2, R3, R4, R6, A1, A2, X1, s and m are defined herein. The invention also relates to a method for manufacturing the compounds of the invention, and its therapeutic uses. The present invention further provides a combination of pharmacologically active agents and a pharmaceutical composition.本發明提供一種式I'化合物;或其醫藥學上可接受之鹽,其中R1、R2、R3、R4、R6、A1、A2、X1、s及m於本文中定義。本發明亦係關於一種本發明化合物之製造方法、及其醫療用途。本發明進一步提供藥理學活性劑之組合與醫藥組合物。