Roche Holding AG announced it is buying Seragon Pharmaceuticals for up to $1.725 billion. Seragon Pharmaceuticals is a privately held U.S. biotech company that does research on breast cancer treatments. Roche has lead the industry of breast cancer with drugs such as Herceptin and won approval for Kadcyla and Perjeta, two new treatments for patients whose cancer cells have high amounts of protein known as HER2. The deal represents a response to investors who worndered how Roche would use its cash now that its a ratio of net debt assets is back within its target band of zero to 15% after paying down its debt from acquiring Genentech.