A compound of formula I: or a pharmaceutically acceptable salt thereof, wherein: Ar 1 is a 5- to 10-membered mono- or bicyclic heteroaryl ring that contains 1-3 heteroatoms selected from the group consisting of N, O and S, wherein the 5- to 10-membered ring system is optionally substituted with 1-3 substituents independently selected from alkyl, halogen, -OH, -CN, nitro, alkoxy, -CF 3 , -O-CF 3 , -S(CH 3 ), -O-alkyl, -S-alkyl, -S(O)-alkyl, -S(O 2 )-alkyl, -S(O 2 )-aryl ,-CH 2 -aryl, heteroaryl, alkanoyl, -O-aryl, -O-CH 2 -aryl, -N(CH 3 ) 2 , cycloalkyl, heterocycloalkyl, -C(O)cycloalkyl, -C(O)heterocycloalkyl, wherein the substituents may combine to form an optionally substituted 5-7 membered fused carbacyclic or heterocyclic ring, Ar 2 is a 5- to 10-membered mono- or bicyclic aryl ring, wherein the 5- to 10-membered ring system is optionally substituted with 1-3 substituents independently selected from alkyl, -F, -Cl, -Br, -OH, -CN, nitro, alkoxy, -CF 3 , -OCF 3 , -S(CH 3 ), -OCH 3 , -S-alkyl, -S(O)-alkyl, -S(O 2 )-alkyl, -S(O 2 )-aryl, -CH 2 -aryl, heteroaryl, alkanoyl, -O-aryl, -O-CH 2 -aryl, -N(CH 3 ) 2 , cycloalkyl, heterocycloalkyl, -C(O)cycloalkyl, -C(O)-heterocycloalkyl, or substituted C 1-9 alkyl wherein the substituents may combine to form an optionally substituted 5-7 membered fused carbacyclic or heterocyclic ring; P is a heteroaryl ring selected from R 1 , R 2 and R 3 are independently selected from -H, halogen, -OH, -CN, nitro, alkyl, alkoxy, -CF 3 , -OCF 3 , -CH 2 -aryl, phenyl, heteroaryl, alkanoyl, -O-aryl, -O-CH 2 -aryl, -N(CH 3 ) 2 , -C(O)-cycloalkyl, -C(O)-heterocycloalkyl, -C(O)O-alkyl, -C(O)O-aryl, wherein the substituents may combine to form an optionally substituted 5-7 membered fused carbacyclic or heterocyclic ring. Ar 1 is a 5- to 10-membered mono- or bicyclic heteroaryl ring that contains 1-3 heteroatoms selected from the group consisting of N, O and S, wherein the 5- to 10-membered ring system is optionally substituted with 1-3 substituents independently selected from alkyl, halogen, -OH, -CN, nitro, alkoxy, -CF 3 , -O-CF 3 , -S(CH 3 ), -O-alkyl, -S-alkyl, -S(O)-alkyl, -S(O 2 )-alkyl, -S(O 2 )-aryl ,-CH 2 -aryl, heteroaryl, alkanoyl, -O-aryl, -O-CH 2 -aryl, -N(CH 3 ) 2 , cycloalkyl, heterocycloalkyl, -C(O)cycloalkyl, -C(O)heterocycloalkyl, wherein the substituents may combine to form an optionally substituted 5-7 membered fused carbacyclic or heterocyclic ring, Ar 2 is a 5- to 10-membered mono- or bicyclic aryl ring, wherein the 5- to 10-membered ring system is optionally substituted with 1-3 substituents independently selected from alkyl, -F, -Cl, -Br, -OH, -CN, nitro, alkoxy, -CF 3 , -OCF 3 , -S(CH 3 ), -OCH 3 , -S-alkyl, -S(O)-alkyl, -S(O 2 )-alkyl, -S(O 2 )-aryl, -CH 2 -aryl, heteroaryl, alkanoyl, -O-aryl, -O-CH 2 -aryl, -N(CH 3 ) 2 , cycloalkyl, heterocycloalkyl, -C(O)cycloalkyl, -C(O)-heterocycloalkyl, or substituted C 1-9 alkyl wherein the substituents may combine to form an optionally substituted 5-7 membered fused carbacyclic or heterocyclic ring; P is a heteroaryl ring selected from R 1 , R 2 and R 3 are independently selected from -H, halogen, -OH, -CN, nitro, alkyl, alkoxy, -CF 3 , -OCF 3 , -CH 2 -aryl, phenyl, heteroaryl, alkanoyl, -O-aryl, -O-CH 2 -aryl, -N(CH 3 ) 2 , -C(O)-cycloalkyl, -C(O)-heterocycloalkyl, -C(O)O-alkyl, -C(O)O-aryl, wherein the substituents may combine to form an optionally substituted 5-7 membered fused carbacyclic or heterocyclic ring. <EOS>