Theravance Inc and partner Astella Pharma won the FDA approval for their superbug-fighting drug telavancin. The drug will hit the market in the fourth quarter as a treatment for adults with complicated skin and skin structure infections caused by methicillin-resistant Staphylococcus aureus, commonly known as the superbug MRSA and other Gram-positive bacteria. The drug is the first approved specifically to target MRSA, which currently is treated largely with the antibiotic vancomycin.