According to an Amgen Inc. (Amgen) executive, the pharma company plans to dispute a US$3.6b1 tax deficiency assessed by the Internal Revenue Service (IRS) for tax years 2010, 2011 and 2012.2 Amgen manufactures and markets the autoimmune disorder drug Enbrel, as well as the osteoporosis treatment sold as Prolia and Xgeva.Amgen disclosed in its Form 10-Q that the IRS issued a notice of deficiency of $3.6b plus interest for tax years 2010, 2011 and 2012. The IRS also proposed significant adjustments to 2013, 2014 and 2015 tax years for similar issues. Amgen stated in the Form 10-Q that any additional tax that...