NEW YORK--Neupogen, Amgen's recombinant granulocyte colony-stimulating factor (G-CSF, filgrastim(Drug information on filgrastim)) has received FDA approval for use in treating severe chronic neutropenia.
In 1991, the agent was approved for use in cancer patients on various chemotherapy regimens, and in 1994 it was licensed for use in bone marrow transplants. In both settings, the growth factor reduces the duration of neutropenia and neutropenia-related clinical conditions.
Severe chronic neutropenia is said to affect some 1,000 to 2,000 children and adults in the United States. Many children with congenital forms of the condition die before adolescence. Until now, severe chronic neutropenia could only be managed episodically with regular or continuous antibiotic therapy and frequent hospitalizations, leading to debilitation and drug resistance.
In the phase III randomized multicenter trial of G-CSF in chronic neutropenia, in which 120 patients in the United States took part, 90% of patients achieved normal neutrophil levels with daily subcutaneous injections. Overall, there was a 60% reduction in infections and a 59% reduction in antibiotic use.
In addition to medical outcomes, the trial also examined quality of life issues as measured by patient's self-perceptions, and on that score as well, G-CSF was of significant benefit. Virtually all of the patients reported feeling better.
"Our findings show that nearly all people with severe chronic neutropenia can benefit substantially from this new therapy," said David Dale, MD, professor of medicine, University of Washington Medical Center, Seattle. "I think one of the remarkable things for me was that it worked with the very first patient," he said at an Amgen press conference introducing the new indication.
Dr. Dale was lead investigator of the trials in which Memorial Sloan-Kettering Cancer Center, University of Michigan, St. Jude Children's Research Hospital, and Duke University Medical Center also took part.