Plerixafor

Therapy should be initiated and supervised by a physician experienced in oncology and/or haematology, with mobilisation and apheresis performed in collaboration with an oncology-haematology centre able to monitor haematopoietic progenitor cells. Predictors of poor mobilisation: age over 60, prior myelosuppressive or extensive chemotherapy, or a peak circulating stem cell count below 20 stem cells/microlitre. Recommended concomitant medicine: daily morning doses of G-CSF 10 micrograms/kg for 4 consecutive days prior to the first plerixafor dose and on each morning prior to apheresis. The weight used to calculate the dose should be obtained within 1 week before the first dose. In clinical studies the dose was calculated on body weight in patients up to 175% of ideal body weight; dosing above 175% of ideal body weight has not been investigated. Ideal body weight equations given in the SPC: male (kg) = 50 + 2.3 x ((height in cm x 0.394) - 60); female (kg) = 45.5 + 2.3 x ((height in cm x 0.394) - 60). Each vial delivers 1.2 mL of 20 mg/mL solution containing 24 mg plerixafor; select syringe size by patient weight (1 mL infant syringes for patients up to 45 kg; 1 mL or 2 mL syringes graduated to 0.1 mL for patients over 45 kg). Single use only; inspect visually and do not use if particulate matter or discolouration is present; use aseptic technique (preservative-free). Not recommended for haematopoietic stem cell mobilisation and harvest in patients with leukaemia (may mobilise leukaemic cells and contaminate the apheresis product). Monitor white blood cell counts (hyperleukocytosis) and platelet counts during therapy; exercise clinical judgement if peripheral blood neutrophils exceed 50 x 10^9/L. Elderly: no dose modification is necessary in elderly patients with normal renal function; adjust if creatinine clearance is 50 mL/min or less. Section 4.5 (interactions) was not captured in the source bundle — verify against the full SPC before co-prescribing.

Stated in §4.2 for the paediatric population aged 1 to less than 18 years: 'The recommended daily dose of plerixafor by subcutaneous injection (SC) is 0.24 mg/kg of body weight.' The SPC also expresses this as 240 micrograms/kg. For low weight patients up to 45 kg, 1 mL infant syringes (major graduations 0.1 mL, minor graduations 0.01 mL) are suitable to administer 240 micrograms/kg to paediatric patients of at least 9 kg body weight. Safety and efficacy in children aged 1 to less than 18 years were studied in an open-label, multicentre, controlled study. Renal impairment dose reduction (creatinine clearance 20-50 mL/min: reduce by one-third to 0.16 mg/kg/day) is stated in the SPC without a separate paediatric qualifier. Verify against a children's formulary and the local specialist mobilisation protocol before use.