Ligand Pharmaceuticals, Inc. has received $2 million in milestone payments from N. V. Organon, a subsidiary of Merck, through its research collaboration, which is due to expire at the end of December. “We have had a long and productive drug discovery relationship with Organon and Schering-Plough (which acquired Organon in November 2007) over the years for a range of research programs,” said John L. Higgins, president and chief executive officer of Ligand. “These activities reflect Ligand’s st...