Bortezomib, also known as Velcade, is an antineoplastic agent which is available for intravenous and subcutaneous use. Each use has 3.5 mg of the drug which acts as a sterile lyophilized powder. The drug is used to treat patients with multiple myeloma who have used other treatments. It is also used in treating patients with mantle cell lymphoma who have also used other types of medication. The drug works by killing cancer cells directly.