Description
Interferon gamma-lb, a recombinant DNA product, has orphan drug status for the
treatment of chronic granulomatous disease. It is also under investigation as a
treatment for trauma-related infections and atopic dermatitis.
Originator
Genentech (U.S.A.)
Uses
Antineoplastic; biological response modifier; immunoregulator.
General Description
Interferon gamma-1b, Actimmune, is a recombinant proteinexpressed in E. coli. IFN-γ is the cytokine that is secreted byhuman T lymphocytes and NK cells. It is a single-chain glycoproteincomposed of 140 amino acids. The crystal structure of the protein reveals several helical segments arranged toapproximate a toric shape.
Interferon gamma-1b is indicated for reducing the frequencyand severity of serious infections associated withchronic granulomatous disease, an inherited disorder characterizedby deficient phagocyte oxidase activity. In this disease,macrophages try to respond to invading organisms butlack the key oxidative enzymes to dispose of them. To compensate,additional macrophages are recruited into the infectedregion and form a granulomatous structure around thesite. IFN-γ can stimulate the oxidative burst in macrophagesand may reverse the situation.
Interferon gamma-1b is supplied as a solution in sterilewater for injection. The solution must be stored at 2°C to8°C, without freezing. The product cannot tolerate morethan 12 hours at room temperature.
Clinical Use
Adjunct to antibiotics to reduce the frequency of serious
infections in patients with chronic granulomatous disease
Drug interactions
Potentially hazardous interactions with other drugs
Avoid with vaccines.
Metabolism
The metabolism of cloned interferons falls within the
natural handling of proteins. Interferon gamma-1b
was not detected in the urine of healthy male subjects
following administration via IV, IM or SC routes. In vitro
hepatic and renal perfusion studies demonstrate that
the liver and kidneys are capable of clearing interferon
gamma-1b from perfusate.
Interferon is metabolised primarily in the kidney. It is
excreted in the urine, but is reabsorbed by the tubules
where it undergoes lysosomal degradation.
