Premarket analyst action - healthcare

• Agios Pharmaceuticals (NASDAQ:AGIO) upgraded to Outperform with a price target of $75 (80% upside) by Oppenheimer. Shares up 3% premarket.
• AmerisourceBergen (NYSE:ABC) upgraded to Outperform with a $95 (13% upside) price target by Leerink Swann.
• HCA Holdings (NYSE:HCA) upgraded to Market Outperform with a $96 (22% upside) price target by Avondale Partners.
• Chiasma (NASDAQ:CHMA) downgraded to Underweight with a $2.50 (22% upside) price target by Barclays.