In the following video, health care editor/analyst David Williamson discusses the recent analyst upgrade that sent shares of Keryx Pharmaceuticals soaring 30% over the last couple of trading sessions. After handing back perifosine to its partner Aeterna Zentaris, Keryx is regaining momentum after a successful phase 3 trial of its other drug candidate, Zerenex. To find out whether this newfound bullish sentiment is deserved, watch the video and Fool On.