A phase II study of recombinant human granulocyte-colony stimulating factor (rHuG-CSF, lenograstim) in the treatment of agranulocytosis in children.

The present study evaluated the clinical efficacity and tolerability of the subcutaneous (SC) administration of lenograstim, a glycosylated form of rHuG-CSF identical to human G-CSF, in the treatment of congenital agranulocytosis. Assessment criteria included neutrophil response and response stability, incidence and severity of infection and gingivostomatitis and quality of life. Lenograstim, at induction dosages of 5 (n = 9), 10 (n = 2) or 20 (n = 1) microgram/kg/day SC, produced neutrophil recovery in all of 12 children with congenital agranulocytosis. There was a median delay of 7 days to recovery after establishment of the effective induction dose. Whereas this dosage maintained a stable neutrophil response in 7 patients, the remaining 5 required dosage increases and dose reduction during maintenance therapy was not possible in these 5 cases. Among 4 patients stabilised at a dosage of 5 micrograms/kg/day, in 2 cases a lower minimum effective dose of 2 micrograms/kg/day was attained over the maintenance phase. Administration of twice the daily dose of lenograstim on alternate days was feasible in 3 of 8 patients. Lenograstim therapy reduced the incidence of infection and hospitalisation for infection relative to the prestudy period, while in 6 of 9 cases there was complete recovery from gingivostomatitis. Only one patient discontinued treatment on account of adverse events. Finally, perceived health and disease related symptoms showed a significant (p < 0.001) amelioration in the course of the study. Thus, lenogastrim produced sustained neurotrophil recovery in patients with congenital agranulocytosis, decreased the incidence and severity of infection and improved the quality of life.