In its many embodiments, the present invention provides certain iminothiazine dioxide compounds, including compounds Formula (I): and tautomers and stereoisomers thereof, and pharmaceutically acceptable salts of said compounds, said tautomeros and said stereoisomers, wherein the middle ring (referred to herein as “ring B”) of the tricyclic substituent is an optionally substituted 5-membered ring, and each of the remaining variables shown in the formula are as defined herein. The novel compounds of the invention are useful as BACE inhibitors and/or for the treatment and prevention of various pathologies related thereto. Pharmaceutical compositions comprising one or more such compounds (alone and in combination with one or more other active agents), and methods for their preparation and use, including Alzheimer's disease, are also disclosed.
