Astellas and CoMentis are calling it quits on their partnership in Alzheimer's disease, as the Japanese drugmaker walks away from a deal valued at up to $760 million. Through the breakup, Astellas will return all rights to CoMentis' beta-secretase (BACE) inhibitors, which are designed to slow the production of beta-amyloid proteins to treat Alzheimer's. Under the initial deal, signed in 2008, Astellas handed over $100 up front in cash and equity, promising up to $660 million more through the life of the partnership. More