The present invention relates to compounds of Formula I, II, IA-VA, IVA1-IVA5, IIIA1-IIIA5 and their pharmaceutical uses. Particular aspects of the invention relate to the use of those compounds for the selective inhibition of one or more cysteine proteases. Also described are methods where the compounds of Formula I, II, IA-VA, IVA1-IVA5, IIIA1-IIIA5 are used in the prevention and/or treatment of various diseases and conditions in subjects, including cysteine protease-mediated diseases and/or caspase-mediated diseases such as sepsis, myocardial infarction, cancer, tissue atrophy, ischemia, ischemic stroke, spinal cord injury (SCI), traumatic brain injury (TBI) and neurodegenerative diseases such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Alzheimer's disease, Parkinson's disease, and Huntington's disease.