Biotechnology The world's largest independent biotech firm, Amgen (Nasdaq: AMGN), has failed to convince a Food and Drug Administration advisory panel that its Xgeva (denosumab), already approved for marketing in the USA to prevent bone pain and fractures caused by bone metastases in prostate cancer patients (The Pharma Letter November 19, 2010), should be approved to delay tumors spreading to bones in this patient population. Amgen stock declined 1.6% to $68.06 by close of trading yesterday. 9 February 2012