BUZZ- Aegerion Pharmaceuticals Inc: Buys AstraZeneca's rare disease drug

** Drugmaker's shares up 13 pct at $22.91

** Agrees to buy British drugmaker AstraZeneca Plc (NYSE: AZN - news) 's rare disease drug Myalept for $325 million upfront; estimates peak net sales of $200-$250 mln

** Myalept is the only FDA-approved drug for use in generalized lipodystrophy - a skin condition characterized by an extreme scarcity of fat in subcutaneous tissue

** Companies expect transaction to close in January

** Up to Wednesday's close, stock had fallen more than 71 pct this year