Xencor, Inc. has received a milestone payment from Janssen R&D for the use of Xencor’s Xtend half-life extension technology in a therapeutic antibody. The companies had entered a technology license agreement in 2009. The antibody target and payment amount were not disclosed.   “There has been significant interest in Xtend technology because of the impact it has on the pharmacokinetic properties of antibodies, and we are seeing Xencor technology license agreements with partners tr...