Bortezomib: proteasome inhibition as an effective anticancer therapy.

VELCADER (bortezomib, Millennium Pharmaceuticals, Inc., Cambridge, MA, and Johnson & Johnson Pharmaceutical Research & Development, L.L.C., Raritan, NJ) is a first-in-class proteasome inhibitor developed specifically for use as an antineoplastic agent. Inhibition of the proteasome results in disruption of homeostatic mechanisms within the cell that can lead to cell death. Bortezomib's first indication, for the treatment of relapsed myeloma in patients who have received at least two prior treatments and progressed on their previous treatment, was based in part on the magnitude of activity demonstrated in phase II trials. Bortezomib is currently indicated for patients who have received at least one prior therapy in the United States and European Union, although patients in the European Union must have already undergone bone marrow transplantation or be unsuitable for the procedure. A phase III trial demonstrated the superiority of bortezomib over high-dose dexamethasone in response rate, time to progression, and survival in patients with myeloma who had relapsed after 1-3 prior therapies. Clinical development is ongoing to investigate its activity as monotherapy and in combination regimens for the treatment of non-Hodgkin's lymphoma, solid tumors, and earlier presentations of myeloma.