The present invention is directed to a novel trifluoromethylsulfonamide derivative which inhibits the processing of APP by the putative γ-secretase and thus is useful in the treatment or prevention of Alzheimer's disease. This compound possesses favorable pharmacokinetic properties in higher species (rhesus) and thus can be dosed on an intermittent dosing regiment (e.g., once weekly). When dosed on such a regiment the compound exhibits significant and continuous Aβ lowering without the manifestation of Notch associated gastrointestinal toxicity for extended periods, e.g., 7 days. Pharmaceutical compositions and methods of use are also included.