Bristol-Myers Squibb has upgraded a long-running alliance with Prothena in Alzheimer’s disease, taking an option on a tau protein-targeting antibody in early-stage clinical development.The deal – potentially worth around $2.2 billion with a $55 million upfront payment – covers PRX005, an antibody that specifically targets the microtubule-binding region (MTBR) of tau, which Prothena thinks is […]