Bortezomib Injection is aimed in order to treat adult patients with multiple myeloma (also known as cancer of the plasma cells). It is also aimed to treat adult patients with mantle cell lymphoma. Bortezomib Injection is prescribed by a healthcare practitioner experienced in the use of drugs to treat cancer. It is administered by a healthcare professional as an injection into your vein (intravenously, or IV) or under your skin (subcutaneously, or SC). Bortezomib injection is never administered into the spinal fluid (intrathecally).