One of the great challenges patients receiving cancer chemotherapy and some anti-AIDS drugs face is their increased susceptibility to infections. Many of these drugs depress bone marrow, the site of blood-cell production. One of these blood cells is the neutrophil—the body’s primary defense for fighting infections caused by bacteria and some fungi—which constitutes 50–70 percent of all white blood cells.
The production of white blood cells of the granulocyte type, of which the neutrophils are the most plentiful, is controlled by granulocyte colony-stimulating factor (G-CSF). Neupogen (filgrastim), a product of recombinant DNA technology, is produced in the bacterium Escherichia coli and differs only very slightly from human G-CSF. This biologic drug is used to treat neutropenia, an abnormally low level of neutrophils in the blood. The most common causes of neutropenia are some chemotherapy drugs or radiation used for cancer treatment—for which Neupogen was first approved in 1991—and AZT, an anti-AIDS drug. Neupogen is also given to stimulate granulocyte production in individuals either receiving or donating stem cells or after receiving a bone-marrow transplant.
Additionally, Neupogen is used to treat children and adults with severe chronic neutropenia. This rare, inherited condition is associated with a very pronounced reduction in neutrophils, causing the individual to experience very frequent and severe infections, with potentially life-threatening consequences. Gum disease, with a loss of permanent teeth, is also a common problem.
Neupogen provides yet another example of a potentially lifesaving drug that spares hospitalization and associated medical expenses—at a high personal cost. Neupogen speeds up the production of granulocytes that have been depressed, and within twenty-four hours after its injection, neutrophil levels increase. This reduces the incidence of infections and the need for intravenous antibiotics, necessitating fewer hospital admissions and shorter hospitalization periods when they occur. Unfortunately, these beneficial effects are transient, and the drug must be injected on a daily basis at an annual cost of $15,000–$20,000, which may not be covered by insurance.
SEE ALSO Amethopterin and Methotrexate (1947), Chloramphenicol (1949), Biologic Drugs (1982), AZT/ Retrovir (1987).
A neutrophil (white blood cell) is defending the body by engulfing the invading anthrax bacteria.