Velcade (bortezomib, PS-341) has recently been approved by the Food and Drug Administration (FDA) for the treatment of multiple myeloma for patients who have received at least one prior therapy. Velcade is a unique compound developed by scientists at Millennium Pharmaceuticals, Inc. Velcade enters cells and affects the way they divide. Cancer cells are particularly sensitive. Velcade interferes with the enzyme "proteasome" which is responsible for allowing cells to divide. When cancer cells cannot divide, they die. Velcade falls into the class of drugs known as "proteasome inhibitors."