This study was designed to compare the efficacy, safety and cost-effectiveness analysis of two different doses of PEG-rhG-CSF for grade IV myelosuppression in Asian cancer patients. The results showed the clinical efficacy between 3 mg PEG-rhG-CSF group and 6 mg PEG-rhG-CSF group was not statistically significant. It suggests that PEG-rhG-CSF 3 mg provided a similar degree of hematopoietic support for grade IV myelosuppression compared with PEG-rhG-CSF 6 mg.
Phase II/III studies demonstrated that the efficacy and adverse reactions of once-per-cycle PEG-rhG-CSF were similar to those of repeated injection of rhG-CSF in the prevention of chemotherapy-induced neutropenia[14–16]. The single administration of PEG-rhG-CSF may allow for less injection, better compliance, convenience and potential cost-savings, reducing the burden for both health-care workers and patients[17–19].
Phase I study show PEG-rhG-CSF is a concentration-dependent drug within a certain range[20, 21]. The mean ANC remained above 10,000 /mm3 for 8-day period with doses of 30–60 ug/kg. Increasing doses of PEG-rhG-CSF beyond 60 ug/kg did not result in a further increase in the ANCmax and AUCANC . In our study, we demonstrated that PEG-rhG-CSF 3 mg provided neutrophil support and a safety profile to Chinese cancer patients in a manner similar to PEG-rhG-CSF 6 mg. When there is evidence that the safety and efficacy of a certain drug are equivalents between two therapies, the lower-cost option was given priority with the indicator of cost. Since patients already bear a heavy burden for anti-tumor treatment, the cost analysis of treatment is one of the main factors that need to be considered in current clinical practice. While 6 mg PEG-rhG-CSF cost twice of 3 mg dose, which showed that 3 mg group was more economical[13, 23]. Given the convenience and economic burden, dosage at 3 mg/cycle may be the proper option for grade IV myelosuppression after chemotherapy in the clinical practice in Asian cancer patients.
The main adverse reactions caused by PEG-rhG-CSF were skeletal muscle pain, fever, and fatigue[7, 11, 18]. The incidence of adverse reactions shows a significant difference between two groups. But the symptoms were relatively mild and tolerable. No serious adverse events were observed. Skeletal muscle pain in group B occurred more frequently than in group A but was controlled by acetaminophen at two groups. In addition to skeletal muscle pain, its incidence of fever and fatigue was less than 10%, which is similar to what is observed in other studies.
However, considering that the sample size in this study is relatively small, and the number of adverse reactions observed is limited, in addition with the influence of the patient's previous treatment on the efficacy not been considered, there are certain limitations about this study and further evaluation is needed with an expansion of sample size.
Our study shows that compared with 6 mg/cycle regimen, 3 mg/cycle may be the proper dose of PEG-rhG-CSF for grade IV myelosuppression in Asian cancer patients, considering the efficacy, safety and cost-effectiveness analysis. It is a small sample study of Real-World study and we’re looking forward to more prospective studies to verify this viewpoint clinically.