Interferon gamma-1b. A review of its pharmacology and therapeutic potential in chronic granulomatous disease.

Chronic granulomatous disease is a group of rare x-linked or autosomal genetic disorders of the phagocytic NADPH oxidase system involved in host defence against various microorganisms. It is manifested by a common phenotype consisting of recurrent serious, life-threatening infection and granuloma formation. Following the finding that interferon gamma-1b (IFN gamma-1b) can potentiate phagocyte activity in some other disease states as well as restoring defective phagocyte NADPH oxidase system activity in at least some patients with chronic granulomatous disease, a large-scale placebo-controlled trial was undertaken with IFN gamma-1b in patients with chronic granulomatous disease. Long term treatment with a therapeutic dosage of IFN gamma-1b produced a significant reduction in the incidence of serious clinical events necessitating hospitalisation. The relative risk of serious infection and the number of days in hospital were each reduced by about two-thirds, and the mean duration of hospital stay by about one-third in those who did experience infection. The greatest therapeutic benefit was found in patients aged less than 10 years, but all patients were improved regardless of age, sex, use of prophylactic antibiotics or genetic pattern of inheritance. The drug was well tolerated with the commonest adverse effects (e.g. fever, headache, chills, injection site erythema) usually being mild, transient, and relieved by symptomatic treatment. IFN gamma-1b therefore provides an effective and well tolerated therapy for patients with chronic granulomatous disease, offering an important clinical advance in the treatment of this rare genetic disorder by improving the prognosis of its serious and life-threatening infectious sequelae.