The intramuscular administration of granulocyte colony-stimulating factor as an adjunct to chemotherapy in pretreated ovarian cancer patients: an Italian Trials in Medical Oncology (ITMO) Group pilot study.

No published data are available concerning the activity and tolerability of intramuscularly administered granulocyte colony-stimulating factor (G-CSF) in humans. To fill this gap, 19 patients with advanced ovarian cancer previously treated with at least one first-line chemotherapy cycle received the following myelosuppressive regimen: mitoxantrone (DHAD) 12 mg m-2 i.v. on day 1; ifosfamide (IFO) 4 g m-2 i.v. on days 1 and 2; mesna 800 mg m-2 i.v. t.i.d. on days 1 and 2. G-CSF (Filgrastim) was given at a dose of 5 micrograms/kg/day i.m. from day 6 to day 19, its pharmacokinetics being assessed in five patients. The neutrophil nadir was observed after a mean period of 8 days, and the neutrophil count was < 1.0 x 10(3) mm-3 for a mean of 6 days during the cycle of chemotherapy. The neutrophil count fell after the withdrawal of G-CSF on the 19th day of treatment. The difference in absolute neutrophil count between day 19 and day 21 was statistically significant (P = 0.0001); nevertheless, at day 21 no WHO grade 3-4 neutropenia was reported. DHAD and IFO were respectively given at 95% and 93% of the planned dose. The pharmacokinetics of G-CSF i.m. seems to be similar to that of the drug given subcutaneously. No evidence of cumulative myelosuppression was observed. G-CSF was well tolerated and no complications were observed at the injection sites. In conclusion, if the results obtained in this pilot study regarding the activity of i.m. G-CSF are confirmed by a randomised trial, the intramuscular administration of G-CSF could become a valid alternative for patients who dislike the subcutaneous route and who are being treated with chemotherapy that does not induce profound thrombocytopenia.