slipped timelines
As indicated byThera2014MJC73, there have been many slipped timelines and we are talking years not months. And that is probably one of the main reasons for the current share price. As well as missed timelines, we simply don't know yet whether this will work or not.
I know that TLT has teamed up with some great people and companies to move it forward. Patience is still needed with this stock and hopefully this treatment will be one of the few that actually makes a success once used on humans.