A Combined Analysis of Average Relative Dose Intensity in the Chemotherapy of Solid Tumors with Pegfilgrastim or Filgrastim Support

A metaanalysis of 4 clinical studies that treated adult solid tumors with standard combination chemotherapy and growth factor support was conducted to study average relative dose intensity. All studies compared pegfilgrastim with filgrastim in a randomized, doubleblinded design. A total of 564 patients were included in the analyses: 291 who received pegfilgrastim and 273 who received filgrastim. For all cycles of treatment, the mean duration of filgrastim dosing was between 10 and 11 days, compared with 1 dose per cycle of pegfilgrastim. Median average dose intensities were between 99% and 100% of planned intensity in the pegfilgrastim and filgrastim groups. Across all studies, 96% of patients receiving pegfilgrastim and 95% of patients receiving filgrastim received an average relative dose intensity of ≥ 85%. Less than 10% of patients in the pegfilgrastim and filgrastim groups experienced a dose delay, and < 5% of patients received a chemotherapy reduction. We conclude that the use of prophylactic growth factor support was associated with a high proportion of chemotherapy cycles that were delivered on schedule and at full dose.