Aberrant activation of calpain has been observed in various pathophysiological disorders including neurode-generative diseases such as Alzheimer's Disease. Here we describe our efforts on ketoamide-based 1-benzyl-5-oxopyrrolidine-2-carboxamides as a novel series of highly selective calpain inhibitors mitigating the metabolic liability of carbonyl reduction. The most advanced compound from this new series, namely A-1212805 (ABT-957, Alicapistat) proceeded to clinical phase I studies.