Shares of Vitae Pharmaceuticals ($VTAE) dropped 5% this morning after the biotech reported that Boehringer Ingelheim had decided to dump its collaboration on a new BACE program for Alzheimer's. Vitae added that it had expected to start a Phase I trial of BI-1147560/VTP-36951 after completing preclinical work that established a high rate of amyloid clearance. Merck ($MRK) is the leader in the BACE race, with a Phase III trial underway as a host of developers take a shot at the memory-wasting ailment. Eli Lilly ($LLY) is also focused on BACE with a program in-licensed from AstraZeneca ($AZN). Release