Biological therapy is known by many terms. These include immunologic therapy, immunotherapy or biotherapy. Biological therapy is a type of treatment that uses the body’s immune system to facilitate the killing of cancer cells. Types of biological therapy include interferon, interleukin, monoclonal antibodies, colony stimulating factors or cytokines and vaccines.

Trastuzumab (Herceptin) as a treatment for secondary breast cancer
Trastuzumab (also known as Herceptin®) is a newer type of treatment given to some women with advanced breast cancer. It is a type of drug known as a monoclonal antibody. It works by preventing a particular growth factor produced naturally in the body from attaching to HER2 receptors (proteins) on the cancer cells and stimulating the cells to divide.

Trastuzumab can only control a breast cancer if the breast cancer cells have a large number of the HER2 receptors on their surface. Around 1 in 5 women will have a large number of HER2 receptors – this is known as being HER2-positive. Your doctor may have your cancer cells tested for HER2 protein. Herceptin may be given along with chemotherapy at first and then may be continued on its own for as long as it is effective in controlling the cancer. Trastuzumab treatment is generally given every 3 weeks
Herceptin® (trastuzumab) is the only FDA-approved therapy for women with metastatic breast cancer whose tumors express too much HER2 protein. It is also approved for adjuvant use (treatment following primary therapy, such as surgery) in combination with paclitaxel, and as a single agent for those who have received one or more chemotherapy regimens. Herceptin is not chemotherapy. It is a monoclonal antibody (sometimes called biologic therapy).
Herceptin administration can result in the development of certain heart problems, including congestive heart failure. Severe allergic reactions, infusion reactions, and lung problems have been observed. These rarely have been fatal.