The patent is not specific to RVX-208. I think Pfizer just took any and all disclosed BET inhibitors and included them in this patent, regardless of whether they were pan-BET inhibitors or selective BET inhibitors. Of course, with RVX-208 being the only selective BET inhibitor in clinical trials AND being the only BET inhibitor (regardless of class) in Phase 3, it would be the most logical choice to proceed with a frataxin/Friedreich's ataxia trial based upon its track record.

Here are the compounds mentioned in the Pfizer patent. Note, other Resverlogix and Zenith compounds are also listed. Not listed is Zenith's ZEN-3694, perhaps because the patent was filed prior to ZEN-3694 being disclosed and entering trials. 

"l-BET-762; JQ-1 ; JQ-1 (+); CPI-203; OTX-015; GW-841819X; CP-0610; CPI-232; BET-BAY-002; l-BET-151 ; RVX-208; l-BET-726; SRX-2523; N-(2-hydroxy-3-methylquinolin-6-yl)piperidine-1 -sulfonamide; N-[4-(2,4-difluorophenoxy)-3-(6-methyl-7-oxo-6,7-dihydro-1 H-pyrrolo[2,3-c]pyridin- 4-yl)phenyl]ethanesulfonamide; and N-{6-[methyl(propanoyl)amino]-3-oxo-4-[(1 S)-1^henylpropyl]-3,4-dihydropyrido[2,3 b]pyrazin-2-yl}-beta-alanine"

"Other BET-family bromodomain inhibitors which are useful for the methods disclosed herein include, but are not limited to, the following BET-family bromodomain inhibitors which have been disclosed in the public domain as being in preclinical or clinical development BMS-986158 (Bristol Myers Squibb); RVX-297 (Resverlogix); RVS-2135 (Resverlogix); ZEN-3365 (Zenith); ZEN-31 18 (Zenith); KM-601 (Kainos); SF- 2535 (Signal Rx); AU-004 (Aurigene, Orion); ABBV-075 (Abbvie); TEN-010 (Tensha Therapeutics); and BAY1238097 (Bayer)"