6-membered heteroarylaminosulfonamides for treating diseases and conditions mediated by deficient cftr activity

A compound of Formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• X1 is CH or N;
• X2 is CH or N;
• X3 is CH or N;
• wherein at least one of X1, X2 or X3 is N;
• R1 is hydrogen or C1-6 alkyl;
• Ar1 is aryl or 5-6 membered heteroaryl substituted with 0-3 occurrences of R2;
• each R2 is independently halo, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, —NRaRb or 3-8 membered heterocyclyl substituted with 0-3 occurrences of R5;
• Ar2 is aryl or 5-6 membered heteroaryl substituted with 0-3 occurrences of R3;
• each R3 is independently halo, C1-6 alkyl, C1-6 alkoxy, C1-6 haloalkyl, C1-6 haloalkoxy, C3-8 cycloalkyl substituted with 0-3 occurrences of R5 or 3-8 membered heterocyclyl substituted with 0-3 occurrences of R5;
• Ar3 is aryl or 5-6 membered heteroaryl substituted with 0-3 occurrences of R4;
• each R4 is independently halo, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy or C1-6 haloalkoxy;
• Ra is H or C1-4 alkyl;
• Rb is H, C1-4 alkyl, —SO2—C1-6 alkyl, C3-8 cycloalkyl or 3-8 membered heterocyclyl substituted with 0-3 occurrences of R5;
• and
• each R5 is independently hydroxyl, CO2H, C1-4 alkyl, C1-4 alkoxy, C1-4 haloalkyl or C1-4 haloalkoxy.