Following this puts new work involving it at the top of your briefing, with a note saying why it is there. Links are taken from the source record, never inferred.
FDA approval of glycerol phenylbutyrate oral liquid formulation; regulatory action confirms marketability but does not report clinical trial outcomes or comparative efficacy.
FDA approval of glycerol phenylbutyrate oral liquid formulation; this is a regulatory action record without clinical trial data and does not establish efficacy or comparative benefit.