Risk and benefit of treatment of severe chronic neutropenia with granulocyte colony-stimulating factor.

The Severe Chronic Neutropenia International Registry (SCNIR) was established in 1994 following four phase I/II and one phase III clinical trial on the use of filgrastim (recombinant human granulocyte colony-stimulating factor [r-metHuG-CSF]) as a treatment for severe chronic neutropenia (SCN). A primary purpose of the SCNIR is to monitor SCN patients treated with filgrastim for adverse events that might occur over time. As of December 31, 2000, 832 patients with SCN (384 congenital, 160 cyclic, 288 idiopathic) were enrolled. Clinical trial and Registry data show that filgrastim is an effective treatment for SCN; more than 90% of patients treated respond with normalization of blood neutrophil counts. The SCNIR has collected data on bone pain, splenomegaly, hepatomegaly, thrombocytopenia, osteopenia/osteoporosis, vasculitis, glomerulonephritis, growth and development, pregnancy and fertility, leukemic transformation, and mortality. Analysis of data from patients who received filgrastim for up to 11 years did not identify any adverse events associated with increased duration of treatment.