Drug: Zometa
Generic: Zoledronic Acid
Company: Novartis ($NVS)
Patent expiration date: March 2, 2013
Estimated Global Sales 2012: $1.26 billion

The scoop: Zometa continues to sell in excess of $1 billion annually, and Novartis has been trying a number of strategies to fend off generic attacks on the bone-strengthening medication for cancer patients. It applied in the U.S. and Europe for a new indication to treat breast cancer, which if approved would have added three additional years of exclusivity. But Novartis dumped that effort in 2010 when a study showed that the drug not only didn't keep breast cancer at bay or prolong patients' lives, it had almost exactly the opposite effects. The same year it came to an understanding with Teva Pharmaceutical Industries ($TEVA) over the U.S. launch of a generic, with Teva agreeing to hold off until the 2013 patent expiration. European regulators have cleared Mylan ($MYL) and Teva to market copies of Zometa there, and another generics maker is making a run at the drug in the U.S. In July, Novartis sued India's Sun Pharmaceutical Industries over its application to produce copies of Zometa and Novartis' Reclast, for post-menopausal osteoporosis, which also goes off patent next year.