The present invention relates to Fused Tricyclic Heterocycle Derivatives of Formula (I): and pharmaceutically acceptable salts thereof, wherein A, B, X, Y, m, R1, R2, R3, R3, R3, R4, R5 and R9 are as defined herein. The present invention also relates to compositions comprising at least one Fused Tricyclic Heterocycle Derivative, and methods of using the Fused Tricyclic Heterocycle Derivatives for treating or preventing HIV infection in a subject.