Ligand Pharmaceuticals, Inc. has earned $1 million commercial milestone payment from Onyx Pharmaceuticals, a subsidiary of Amgen, triggered by the achievement of more than $250 million of annual product sales of Kyprolis in 2013.   Ligand receives royalties for Kyprolis and is eligible to receive additional commercial and regulatory milestones. Kyprolis is indicated to treat multiple myeloma and was received accelerated approval from FDA in July 2012....