Dr. Nevan Krogan interview of April 13 on Bloomberg.  

https://www.bloomberg.com/news/videos/2020-04-13/do-we-already-have-the-cure-for-covid-19-video

Nothing Apabetalone specific but mentions that repurposing exiting drugs is the fastest way to find a treatment as these drugs have passed lengthy toxicity-testing trials. 

We know that although our Breakthrough Therapy Designated Apabetalone is not yet approved what is important is that it has passed years of safety trials.  IIRC pre-clinical JQ1 had toxicity issues (or was it half-life issues) so if Dr. Krogan and Dr. Shokat liked JQ1's MOA so much despite its safety limitation, how can they not like RVX-208 Apabetalone with its virtually identical MOA and stellar safety profile?