Bortezomib is l-Phenylalaninamide substituted at the amide nitrogen by a 1-(dihydroxyboranyl)-3-methylbutyl group and at N(alpha) by a pyrazin-2-ylcarbonyl group. Bortezomib was first synthesized in 1995. In May 2003, bortezomib became the first anticancer proteasome inhibitor that was approved by the FDA under the trade name VELCADE. Phase I, II, III, and IV clinical trials are undergoing to investigate the therapeutic efficacy of bortezomib in leukemia, myasthenia gravis, systemic lupus erythematosus, rheumatoid arthritis, and solid tumours.