Shares of Regeneron Pharamceuticals (REGN), Sanofi (SNY), and Esperion Therapeutics (ESPR) are all impacted today after an FDA advisory panel back Regeneron's and Sanofi's drug for approval but only did so for a subset of cholesterol patients. The patients that were recommended to receive Regeneron's and Sanofi's Praluent -- cholesterol-lowering drug -- were those patients with predefined genetic cholesterol problems. 

The FDA advisory panel stated that it wants to see more long term studies for Praluent to see if long-term use reduces the risks of heart attacks in patients. The advisory panel didn't have any problems with the safety or efficacy of the drug, they just want more large studies to determine if there is a big benefit for the larger population group of cholesterol patients. The FDA panel voted 13 to 3 in favor of approving Praluent for these subset of cholesterol patients with genetic cholesterol defects. 

The reason for the drop in Esperion  is because the company itself is also working on non-statin cholesterol lowering therapy drug known as ECT-1002. Because the FDA  recommended larger trials be completed to determine benefit of cholesterol-lowering drugs in a wide range of population, this means that more likely than not Esperion will also have to run larger trials. This means Esperion may be roadblocked as well for many more years of clinical trials, as we saw from yesterday's FDA advisory panel for Praluent. 

Shares of Regeneron Pharmaceuticals are down 4% trading at $505 per share

Shares of Sanofi, which had been lower all week, are flat trading at $49 per share

Shares of Esperion are down 20% trading at $81 per share