Immunomodulatory Cancer Drugs

Immunomodulatory drugs modify or regulate the functioning of the immune system. They induce, or inhibit immune responses, or enhance activity of immune cells. They affect the immune system through different ways, such as, enhancing the activation of T cells, enhancing the activity of natural killer (NK) cells, enhancing production of interleukin 2 (IL-2), inhibiting tumor necrosis factor-alpha (TNF-α) and interleukin 1-beta (IL-1ß), and stimulating the production of interleukin 10 (IL-10). All these activities lead to enhanced antitumor effects.

Table 5. Immunomodulatory Cancer Drugs

Bacillus Calmette-Guerin (BCG) is used for superficial early-stage bladder cancer. It promotes proliferation of T lymphocytes and causes local, acute inflammation. The inflammation is characterized by macrophage and leukocyte infiltration into the urinary bladder wall. The immune cells that conglomerate at the infection site cause tumor regression.

Thalomid and its derivatives, Revlimid and Actimid, mediate the production of cytokines and other growth factors that are responsible for growth and survival of tumor cells. They direct the immune system to target cancer cells for destruction by NK cells and cytotoxic T lymphocytes. They also lower levels of the proangiogenenic cytokines vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF).

Interferons are a family of naturally-occurring proteins that are produced by cells of the immune system. The interferon products, Avonex (interferon beta-1a), Intron A (interferon alfa-2b), and PEG-Intron (PEG-alpha interferon) direct the immune system's attack on tumor cells.

Interleukin is a number of naturally occurring immune system proteins. Both Ontak and Proleukin are interleukin-2, which activates specialized defense cells called T cells and natural killer (NK) cells to attack and destroy tumor cells.