Abstract: The present invention relates to compounds of Formula (XI): wherein R1a, R2a, R3a, R4a, R5a, R6a, and Aa are as defined herein, and pharmaceutically acceptable salts thereof. The compounds of the present invention are inhibitors of hematopoietic prostaglandin D synthase (H-PGDS) inhibitors and can be useful in the treatment of Duchenne Muscular Dystrophy. Accordingly, the invention is further directed to pharmaceutical compositions comprising a compound of the invention. The invention is still further directed to methods of inhibiting H-PGDS activity and treatment of disorders associated therewith using a compound of the invention or a pharmaceutical composition comprising a compound of the invention.