Pinto, L., Liu, Z., Doan, Q., Bernal, M., Dubois, R., & Lyman, G. (2007). Comparison of pegfilgrastim with filgrastim on febrile neutropenia, grade IV neutropenia and bone pain: A meta-analysis of randomized controlled trials. Current Medical Research and Opinion, 23, 2283–2295.

The purpose of this meta-analysis and systematic review was to obtain pooled estimates of comparative efficacy of pegfilgrastim and filgrastim.

The PubMed and EMBASE databases were used.

Key words were neupogen, filgrastim, recombinant methionyl human granulocyte–colony-stimulating factor, G-CSF, CSF, longrastim, polyethylene glycol conjugated filgrastim and related terms

Studies were included if they were randomized, controlled trials (RCTs) if the patients were adults with non-myeoloid cancer, had a test of a single 6 mg dose or 100 mcg/ke of pegfilgrastim after start of chemotherapy, and a daily filgrastim comparator. Endpoints included grade 4 neutropenia, febrile neutropenia, and time to ANC recovery.

94 total references were retrieved.

• Five studies were included in the final analysis.
• The sample consisted of 617 patients, and size range across the five studies was 27–296.
• Key characteristics were breast cancer,  lymphoma, and non-Hodgkin lymphoma.

Active anti-tumor treatment

Standard mean difference (SMD) for time to ANC recovery showed mixed results across studies and pooled SMD to time to recovery was not statistically significant. There was no significant difference between drugs in rates of bone pain. Multiple different grouping and analyses of data were done to try to show differentiation of effect and when meta-analysis was limited to two phase III trials. Relative risk (RR) for febrile neutropenia for pegfilgrastim relative to filgrastim was 0.56 (95% CI [0.35, 0.89], p < 0.016).  Rates for neutropenia were not different.

Results suggest that daily filgrastim and single-dose pegfilgrastim provide essentially the same effect for time to ANC recovery, grade 4 neutropenia rates, and bone pain.

Some studies had very small samples, and heterogeneity with all studies was significant. Studies involved the use of different chemotherapy regimens which could have influenced findings here.

Both pegfilgrastim and filgrastim appear to provide similar clinical effects for prevention of neutropenia and febrile neutropenia. The side effect of bone pain was similar with both treatments. Pegfilgrastim dosing requires fewer subcutaneous injections.