A couple of articles were published last month that focused on the mechansim of selective bromodomain inhibition of RVX-208 and RVX-297. The two studies were done both done by Chinese groups. The first one listed below is freely available, but I don't have access to the full-text of the second one (only the abstract).  

State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau, China.

Selective inhibition mechanism of RVX-208 to the second bromodomain of bromo and extraterminal proteins: insight from microsecond molecular dynamics simulations.

School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, P. R. China

Deciphering the mechanisms of selective inhibition for the tandem BD1/BD2 in the BET-bromodomain family.