Personalized medicine is the latest trend in companion diagnostics, and companies are teaming up to develop comprehensive tests based on a patient's biologic characteristics. Roche's ($RHHBY) Ventana Medical Systems sees potential in the field, and recently inked a deal with Merck KGaA to develop a companion diagnostic test for different cancer indications. While neither side disclosed financial details or specific genetic targets, Ventana said it plans to develop and validate the test and make sure that it clears key regulatory milestones. More