The present disclosure provides substituted 9H-pyrimido [4,5-b] indoles and 5H-pyrido [4,3-b] indoles and related analogs represented by Formula I and the pharmaceutically acceptable salts, hydrates, and solvates thereof, wherein R 1a, W, B 1, B2, G, X 1, Y1, Y2, and Y 3 are as defined as set forth in the specification. The present disclosure is also directed to the use of compounds of Formula I to treat a condition or disorder responsive to inhibition of BET bromodomains such as cancer. The present disclosure is also directed to the use of compound of Formula I as synthetic intermediates.
