The Jefferies Group downgraded Isis Pharmaceuticals (NASDAQ:ISIS) this morning from a Buy rating to an Underperform, causing shares to follow suit by 10%. Zack’s, meanwhile, maintains a #3 Short-Term Hold rating on ISIS, citing pipeline product Kynamro – partnered with Sanofi’s (NYSE:SNY) Genzyme – as a catalyst in Q1 2013. Kynamro is an antisense drug to reduce LDL Cholesterol in patients with high cardiovascular risk. The company expects approval in January (PDUFA on the 29th) of next year after four Phase III studies that have successfully met all endpoints, and an ongoing study to determine broader labeling indications and dosing. If the drug is approved, Isis stands to receive a $25M milestone from Sanofi. With strong trial results and continued testing for more option in the market space, ISIS may have been oversold today. Look for a Q2 earnings announcement soon to analyze their balance sheet and Kynamro’s potential.