Shares of biotechnology giant Regeneron Pharmaceuticals ( REGN ) have climbed more than 4% today after Piper Jaffray analyst Ed Tenthoff upgraded from a neutral to an overweight, with an$446 price target. The bullish call, which comes just a few days after the drug maker released soft guidance for 2017, argues that “anticipated approvals and a deep pipeline should drive long-term value” for this closely-watched drug stock. Of particular importance: the atopic dermatitis drug Dupixent (dupilumab).