Filgrastim (G-CSF)

SOURCE: UK SPC for Neupogen 30 MU (0.3 mg/ml) solution for injection (eMC §4.2). Therapy should only be given in collaboration with an oncology centre experienced in G-CSF treatment and haematology. A transient rise in neutrophils is typical 1–2 days after starting; do not discontinue before the expected nadir has passed. In randomised trials a subcutaneous dose of 230 micrograms/m2/day (4.0 to 8.4 micrograms/kg/day) was used. OTHER INDICATIONS (all from the same SPC §4.2): (1) MYELOABLATIVE THERAPY FOLLOWED BY BONE MARROW TRANSPLANTATION — starting dose 1.0 MU (10 micrograms)/kg/day, first dose at least 24 hours after cytotoxic chemotherapy and at least 24 hours after bone marrow infusion; given as a 30-minute or 24-hour intravenous infusion or a continuous 24-hour subcutaneous infusion, diluted in 20 ml of 5% glucose. Once the nadir has passed, titrate: if ANC greater than 1.0 x 10^9/l for 3 consecutive days reduce to 0.5 MU (5 micrograms)/kg/day; if ANC then remains greater than 1.0 x 10^9/l for 3 more consecutive days, discontinue; if ANC falls below 1.0 x 10^9/l during treatment, re-escalate. (2) PBPC MOBILISATION AFTER MYELOSUPPRESSIVE/MYELOABLATIVE THERAPY WITH AUTOLOGOUS PBPC TRANSPLANT — 1.0 MU (10 micrograms)/kg/day for 5 to 7 consecutive days when used alone (24-hour continuous subcutaneous infusion or subcutaneous injection; leukapheresis often on days 5 and 6, continue dosing until the last leukapheresis); or 0.5 MU (5 micrograms)/kg/day by subcutaneous injection from the first day after chemotherapy until the nadir is passed and the count recovers, with leukapheresis while the ANC rises from below 0.5 x 10^9/l to above 5.0 x 10^9/l. (3) PBPC MOBILISATION IN NORMAL DONORS — 1.0 MU (10 micrograms)/kg/day subcutaneously for 4 to 5 consecutive days, leukapheresis from day 5 (continued to day 6 if needed) to collect 4 x 10^6 CD34+ cells/kg recipient bodyweight. (4) SEVERE CHRONIC NEUTROPENIA — congenital neutropenia starting dose 1.2 MU (12 micrograms)/kg/day as a single or divided dose; idiopathic or cyclic neutropenia starting dose 0.5 MU (5 micrograms)/kg/day as a single or divided dose; given daily subcutaneously until the neutrophil count reaches and can be maintained above 1.5 x 10^9/l, then reduced to the minimal effective dose. After 1–2 weeks the initial dose may be doubled or halved according to response, then adjusted every 1–2 weeks to maintain the average neutrophil count between 1.5 and 10 x 10^9/l. PAEDIATRIC: the fetched §4.2 text is truncated before any paediatric section, so no paediatric regimen has been sourced here — verify against a children's formulary and the full SPC. The US label states only that in 15 paediatric neuroblastoma patients (median age 2.6 years) subcutaneous filgrastim 5, 10 or 15 micrograms/kg/day for 10 days was studied and that paediatric pharmacokinetics are similar to adults at the same weight-normalised doses; it gives no separate paediatric recommended dose. CAUTION: the fetched §4.2 is truncated (it ends mid 'Method of administration' for severe chronic neutropenia) — the HIV/other sections and any remaining special-population advice were not captured.