Despite the significant therapeutic advances achieved with proteasome inhibitors 
(PIs) such as bortezomib and carfilzomib in prolonging the survival of patients 
with multiple myeloma, the development of drug resistance, peripheral 
neuropathy, and pharmacokinetic limitations continue to pose major challenges 
when using these compounds. Ixazomib is a second-generation PI with improved 
activity over other PIs. Unlike bortezomib and carfilzomib, which are 
administered by injection, ixazomib is the first oral PI approved by US Food and 
Drug Administration. This review discusses the biochemical properties, 
mechanisms of action, preclinical efficacy, and clinical trial results leading 
to the US Food and Drug Administration approval of ixazomib.