Jupiter,
Great question. This post on that topic may help. Also, read this post on Abbvie's ABBV-744 BD-2 selective BET inhibitor for oncology. Not all BD-2 selective BET inhibitors are create equal. Plus, RVX-297 is entirely pre-clinical. Perhaps RVX-297 is not orally available like RVX-208, which would pose a challenge to clinical development.
BearDownAZ