OBJECTIVETo investigate the efficacy and safety of pegylated recombinant human granulocyte colony stimulating factor (PEG-rhG-CSF) in the salvage therapy for the grade IV neutropenia induced by concurrent chemoradiotherapy, and to provide evidence for its clinical rational application.

METHODS114 malignant tumor patients suffered with grade IV neutropenia induced by concurrent chemoradiotherapy were treated in the following groups. In the P-50 group, 42 patients received a single subcutaneous injection of 50 µg/kg PEG-rhG-CSF. In the P-100 group, 30 patients received a single subcutaneous injection of 100 µg/kg PEG-rhG-CSF. In the P+R group, 22 patients received a single subcutaneous injection of 50 µg/kg PEG-rhG-CSF and multiple subcutaneous injections of 5 µg×kg(-1)×d(-1) rhG-CSF, until the absolute neutrophil count (ANC) ≥ 2.0×10(9)/L. In the R group, 20 patients received multiple subcutaneous injections of 5 µg×kg(-1)×d(-1) rhG-CSF, until ANC ≥ 2.0×10(9)/L. The P-50, P-100 and P+R groups were experimental groups, and the R group was defined as control group. In each group, the neutrophil proliferation rate and the neutrophil counts at different time points, the period of neutropenia symptom relief, and the rate of adverse reactions induced by above drugs were analyzed.

RESULTSBoth neutrophil proliferation rates and neutrophil counts in the patients of experimental groups at different time points were significantly higher than those in the control group. In the experimental groups the period of the clinical effect began in 12-24 hours, and the conditions of neutropenia were improved in 36 hours. In the experimental groups, the period of the symptom relief such as fever and skeletal muscle pain was (30.00 ± 7.48) hours and (30.00 ± 5.10) hours, respectively, significantly shorter than (72.00 ± 17.89) hours and (59.00 ± 11.46) hours in the control group (P < 0.05). The adverse drug reaction rate was 26.1% in the experimental groups and 25.0% in the control group (P > 0.05).

CONCLUSIONSFor the treatment of grade IV neutropenia induced by concurrent chemoradiotherapy, PEG-rhG-CSF is effective and safe. The recommend dose of this drug for the salvage therapy for those patients is a single hypodermal injection of 50 µg/kg. Usually it becomes effective in 12-24 hours.