Same-day pegfilgrastim and chemotherapy

Pegylated filgrastim is a new formulation of a neutrophil colony-stimulating factor that has a long circulating half-life, permitting a single dose of filgrastim per cycle of chemotherapy. The pegylated filgrastim is recommended to be administered not less than 24 hours following chemotherapy and not less than 14 days prior to chemotherapy based on the theoretic concern that marrow suppression would be accentuated. This schedule of usage for pegylated filgrastim may compromise its application for weekly chemotherapy schedules. We have treated 80 patients with pegylated filgrastim administered on the same day as chemotherapy; the latter delivered on a weekly schedule. Twenty-four patients had non-small cell lung cancer (NSCLC) and were treated with one of two weekly chemotherapy regimens alternating triplets [AT] taxane, cisplatin, irinotecan alternating with gemcitabine, cisplatin, vinorelbine or alternating doublets [AD] taxane, cisplatin alternating with gemcitabine, vinorelbine; four of these patients also received weekly taxane and carboplatin with concomitant thoracic radiation. A consistent pattern emerged in which leukocytosis was observed at Day 8; median WBC 15,800/uL (range 7,200 to 35,000/uL); at Day 14, the median WBC was 9,300/uL (range 1,100 to 17,400/uL). Pegylated filgrastim can be given safely simultaneously with chemotherapy in weekly chemotherapy schedules. The pegfilgrastim can be administered on an every two week (fortnightly) schedule to maintain a weekly chemotherapy schedule.