Amylin, Alkermes plunge Amylin Pharmaceuticals /quotes/comstock/15*!amln/quotes/nls/amln (AMLN 10.17, -10.32, -50.38%) and Alkermes Inc. /quotes/comstock/15*!alks/quotes/nls/alks (ALKS 10.48, -4.02, -27.72%) were in the spotlight early Wednesday, with shares of the biotech companies plunging on news that U.S. regulators have declined to approve their diabetes drug Bydureon. Shares of Amylin plunged 50% while Alkermes shares spiraled 30%. Bydureon was co-developed with Eli Lilly & Co. /quotes/comstock/13*!lly/quotes/nls/lly (LLY 35.88, -1.57, -4.19%) , shares of which were down 4% at $35.99. Bydureon's woes stoked shares of rival diabetes drug maker Novo Nordisk A/S /quotes/comstock/13*!nvo/quotes/nls/nvo (NVO 100.84, +9.85, +10.83%) ; shares of the Danish company were up 10% at $99.91. The sector's two main indexes, meanwhile, were split. The NYSE Arca Pharmaceutical Index /quotes/comstock/10t!drg.x (DRG 315.88, +3.89, +1.25%) was up 1% at 314.96. The NYSE Arca Biotechnology Index /quotes/comstock/10t!btk.x (BTK 1,150, -14.10, -1.21%) , of which Amylin is a major component, was down almost 2% at 1141.65. http://www.marketwatch.com/story/amylin-alkermes-plunge-drug-indexes-split-2010-10-20