Amylin

Shares of pharmaceutical companies Amylin, Alkermes, and Eli Lilly -- partners in a new diabetes drug Bydureon -- have tanked in morning trading as the U.S. Food and Drug Administration declined on Tuesday to approve the drug without additional clinical studies.

Pharmaceutical giant Roche said Friday that it would delay an FDA filing for its new diabetes drug for 12 to 18 months due to safety concerns. The beneficiary of Roche's misfortune is rival Amylin, which now jumps ahead in the race to get first approval of a once-weekly injectable type 2 diabetes drug.

Federal regulators approved Novo Nordisk's new once-daily injection for treating Type 2 diabetes Victoza, driving shares higher. Shares of Amylin Pharmaceuticals also rallied as the approval of Victoza raises hopes that Amylin's rival drug will also get the greenlight.

News that Amylin Pharmaceuticals (AMLN) inked a billion-dollar development deal with Takeda Pharmaceutical for new obesity therapies was among the favorable developments in the sector on Monday that pushed several key stocks higher. Amylin shares were up nearly 10 percent in late trading after...