Pyrazinecarboxamide analog compounds for use in treating cancer

A compound of formula (I):

• or a pharmaceutically acceptable salt thereof, wherein:
• Y is —N(R3)— or
• wherein:
• * of Y indicates the point of attachment to the carbonyl of the parent structure and ** of Y indicates the point of attachment to -L1-U-L2-B;
• R1 is H or halo;
• R2 is H or C1-C6 alkyl;
• R3 is H or C1-C6 alkyl;
• A is a phenyl substituted with 1-5 halo, which may be the same or different, or an optionally substituted 5- to 12-membered heteroaryl;
• B is an optionally substituted 6- to 10-membered aryl or a 5- to 12-membered heteroaryl;
• U is —O—, —NH—, —N(R4)—, —CF2—, a 5- to 12-membered heteroaryl, or an optionally substituted 4- to 8-membered heterocyclyl, wherein:
• R4 is C1-C6 alkyl;
• L1 is optionally substituted C1-C5 alkylene or *-L3A-O-L3B-**, wherein:
• * of L1 indicates the point of attachment to the Y moiety and ** of L1 indicates the point of attachment to —U-L2-B;
• L3A and L3B are each independently optionally substituted C1-C3 alkylene or absent;
• L2 is *-L4A-O-L4B-**, *-L4C-N(R5)-L4D-**, optionally substituted C1-C3 alkylene, or absent, wherein:
• * of L2 indicates the point of attachment to the U moiety and ** of L2 indicates the point of attachment to the B moiety;
• L4A, L4B, L4C and L4D are each independently optionally substituted C1-C3 alkylene or absent;
• R5 is H or C1-C6 alkyl.