Thanks BD - very good point about the wider range of BET inhibitors in the pipeline. On top of that, I realize that my question stemmed from a mis-reading of the abstract posted about the effect of FXR on idiopathic pulmonary fibrosis (IPF), another diesase characterized by fibrosis of lung tissue.  Whereas apabetalone results in downregulation of FXR, it was the upregulation of FXR in the IPF model that decreased transcrition of factors associated with disease prgression.

And yes, orphan diseases are orphans for a reason - they are too rare and numerious to make the expense of clinical trials worthwhile.  Many promising drugs simply don't get tested for these diseases even though it is clear that they mayhave beneficial effects.  Hence the attraction of off-label prescription for these diseases.  While efficacy is unknown, at least the safety (in admittedly a different groups of patients) has been established.

P.S.  and thanks for the welcome Kelsee!