Here are some questions I may pose to try and pry out an answer:

Is your published list of Breakthrough Therapy Designations granted a complete list?  If not, what are the possible reasons why any given sponsor woud be granted a FDA Breakthrough Therapy Designation however the FDA would not list the drug on its very own published list?  

How does the FDA respond to sponsors who falsely claim the FDA has granted them a Breakthrough Therapy Designation?  (I will attach a link to the RVX Press Release).

Others?

Here's the link the FDA BTD FAQ:  https://www.fda.gov/regulatory-information/food-and-drug-administration-safety-and-innovation-act-fdasia/frequently-asked-questions-breakthrough-therapies