Fused tetracyclic quinazoline derivatives as inhibitors of ERBB2

A method of treating a patient having a cancer, wherein the cancer comprises cells or cell tissue having (i) one or more disease-associated point mutation in ErbB2 or (ii) increased ErbB2 kinase activity as compared to a control, or both (i) and (ii), the method comprising administering to the patient a therapeutically effective amount of the compound of formula (I′)

• or a pharmaceutically acceptable salt thereof, wherein
• Ring A is
• E is —C(═O)—R1;
• G is —O—, —C(═O)—, —S—, —S(O)—, —S(O)2—, or —CH2—;
• V is O, S, or N—R2;
• each X1 is independently N or CH;
• X2 is O, S, or N—R3;
• is N or C—Ry, wherein Ry is —H or —F;
• Z is —H, halogen, —C≡CH, —OCH3, or C1-C2 alkyl;
• R1 is C2-C4 alkenyl or C2-C4 alkynyl, each of which is independently optionally substituted by 1-4 substituents selected from the group consisting of halogen, C1-C3 alkyl, a 3- to 7-membered carbon-linked N-heterocycloalkyl, or —NR1aR1b, wherein each R1a and R1b are independently —H, C1-C3 alkyl, or —CD3, or wherein each pair of geminal R1a and R1b may be taken together with the nitrogen atom to which they are attached to form a 3- to 6-membered N-heterocyclyl, and wherein each heterocyclic nitrogen atom, if present, is independently optionally substituted with C1-C3 alkyl;
• R2 is C1-C6 alkyl or C1-C6 cycloalkyl, each of which is independently optionally substituted by 1-4 fluorines;
• R3 is —H, C1-C6 alkyl, —CD3 or C1-C6 cycloalkyl;
• R4 is —H or halogen;
• R5 is —H or halogen;
• R6 is —H or halogen;
• R7 is —H, halogen, C1-C6 alkyl, —CD3 or C1-C6 cycloalkyl;
• n is 1 or 2;
• p is 0 or 1;
• and
• q is 1 or 2.