title: A combined analysis of two pivotal randomized trials of a single dose of pegfilgrastim per chemotherapy cycle and daily Filgrastim in patients with stage II-IV breast cancer.
abstract: This combined, retrospective analysis compared once-per-chemotherapy-cycle pegfilgrastim with daily Filgrastim in breast cancer patients undergoing myelosuppressive chemotherapy enrolled in two similarly designed, randomized, double-blind, pivotal trials. On day 2 of each chemotherapy cycle, a single subcutaneous (SC) injection of pegfilgrastim [either 6 mg (n=77) or 100 microg/kg (n=149)] was administered, or daily Filgrastim SC injections (5 microg/kg/day; n=222) were initiated and continued until either absolute neutrophil count (ANC) > or =10 x 10(9)/l after the expected nadir or for up to 14 days, whichever occurred first. Individually, each of these trials demonstrated that a single pegfilgrastim injection per cycle is as effective at reducing the duration of severe neutropenia as daily injections of Filgrastim. Clinical efficacy data from the two trials were combined for analysis (n=448). The risk of febrile neutropenia (FN; absolute neutrophil count <0.5 x 10(9)/l with fever > or =38.2 degrees C) was significantly lower [11% vs 19%, respectively; relative risk = 0.56 (95% confidence interval: 0.35, 0.89)] in patients receiving pegfilgrastim than for those receiving Filgrastim. Trends towards lower risks of hospitalization and intravenous anti-infective use were also observed. These observations were consistent irrespective of risk factors, including age, disease stage, performance status and prior treatment. Pegfilgrastim may offer patients more effective protection against neutropenic complications of chemotherapy with fewer injections and less disruption to their lives.
authors.affiliation: Divisione Oncologia Medica Falck, Dipartimento di Oncologia ed Ematologia, Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore 3, I-20162 Milan, Italy. ssiena@ospedaleniguarda.it
authors.forename: Salvatore
authors.initials: S
authors.lastname: Siena
authors.forename: Martine J
authors.initials: MJ
authors.lastname: Piccart
authors.forename: Frankie A
authors.initials: FA
authors.lastname: Holmes
authors.forename: John
authors.initials: J
authors.lastname: Glaspy
authors.forename: James
authors.initials: J
authors.lastname: Hackett
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Renwick
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001835:Body Weight; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology*; D004311:Double-Blind Method; D005260:Female; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D006801:Humans; D007279:Injections, Subcutaneous; D008875:Middle Aged; D009367:Neoplasm Staging; D009503:Neutropenia / Q000139:chemically induced / Q000517:prevention & control*; D011092:Polyethylene Glycols; D011994:Recombinant Proteins
chemical_list: D000970:Antineoplastic Agents; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; C455861:pegfilgrastim; D011092:Polyethylene Glycols; D000069585:Filgrastim