Parting of the ways

SUGEN Inc. and Amgen Inc. ended their research collaboration under which AMGN had invested approximately $12 million in SUGN's signal transduction research in neurobiology and hematopoiesis since 1992.

The decision ends the four-year collaboration a year early. Both companies said their research priorities had diverged, but did not elaborate. However, during the course of the collaboration, AMGN discovered megakaryocyte growth and development factor (MGDF). The factor, also known as thrombopoietin (TPO), appears to be a potent platelet stimulator...