Not sure if they bought in Q4 because most of their purchase was through new shares issued by company. However, i can see many more investors coming in over the next 6 months. This is not just 1 day game. It's happening over the next 2 years.
Besides Baker Bros, the other 2 13F filings to watch for are Orbimed and/or FMR. If either of those added shares you'll want to quickly add as many shares as you can before word spreads. I check the filings multiple times each day. As of this evening Vanguard opened a new position over a million shares of IDRA. Everything else - bashers, share price, etc. is just noise right now. Keep your eye on the prize - $100 by years end.