Eli Lilly said it is halting development of one of two phase III Alzheimer's disease drugs in its pipeline. Two studies involving semagacestat, a gamma secretase inhibitor, are being stopped because semagacestat patients did worse than placebo on clinical measures of cognition and the ability to perform activities of daily living; patients also seemed to have a higher incidence of skin cancer. Lilly said that the second drug, monoclonal antibody solanezumab, has a different mechanism of action and that clinical trials are ongoing. Two other early-stage Alzheimer's drugs are unaffected. The news, combined with Lilly's recent loss in a patent suit involving the ADHD drug Strattera, darkened the outlook for the company. Five of its biggest sellers are set to lose patent protection by 2013, including Strattera, although Lilly is seeking a court order temporarily blocking US launch of generic versions of that drug.