NEW YORK--Neupogen, Amgen's recombinant granulocyte colony-stimulating
factor (G-CSF, 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
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.