Dosing and uses of Raxibacumab
Adult dosage forms and strengths
intravenous solution
- 50mg/mL (1700mg/34mL single-dose vial)
- Available from CDC
Inhalational Anthrax
Indicated for treatment of inhalational anthrax due to Bacillus anthracis in combination with appropriate antibacterial drugs, and for prophylaxis of inhalational anthrax when alternative therapies are not available or are not appropriate
40 mg/kg IV as a single dose infused over 2.25 hr
Premedicate with diphenhydramine within 1 hr before infusion
Dosing Considerations
Effectiveness of raxibacumab is based solely on efficacy studies in animal models of inhalational anthrax
Raxibacumab does not cross the blood-brain barrier and does not prevent or treat meningitis; should be used in combination with appropriate antibacterial drugs
Pediatric dosage forms and strengths
intravenous solution
- 50mg/mL (1700mg/34mL single-dose vial)
- Available from CDC
Inhalational Anthrax
Indicated for treatment of inhalational anthrax due to Bacillus anthracis in combination with appropriate antibacterial drugs, and for prophylaxis of inhalational anthrax when alternative therapies are not available or are not appropriate
<15 kg: 80 mg/kg IV
≥15 to 50 kg: 60 mg/kg IV
>50 kg: 40 mg/kg IV Administer as a one-time single IV infusion over 2.25 hr
Premedicate with diphenhydramine within 1 hr before infusion
Dosing Considerations
Effectiveness of raxibacumab is based solely on efficacy studies in animal models of inhalational anthrax
There have been no studies of raxibacumab in the pediatric population; dosing in pediatric patients was derived using a population PK approach
Raxibacumab does not cross the blood-brain barrier and does not prevent or treat meningitis; should be used in combination with appropriate antibacterial drugs
Raxibacumab adverse (side) effects
1-10%
Rash (3.2%)
Pain in extremity (2.5%)
Pruritus (2.5%)
Somnolence (1.4%)
<1%
Reported at rates higher than placebo
Blood and lymphatic system: Anemia, leukopenia, lymphadenopathy
Cardiac disorders: Palpitations
Ear and labyrinth: Vertigo
General disorders and administration site: Fatigue, infusion site pain, peripheral edema
Investigations: Blood amylase increased, blood creatine phosphokinase increased, prothrombin time prolonged
Musculoskeletal and connective tissue: Back pain, muscle spasms
Nervous system: Syncope vasovagaL
Psychiatric: Insomnia
Vascular: Flushing, hypertension
Warnings
Contraindications
None
Cautions
Infusion reactions (eg, rash, urticaria, pruritus) reported in clinical trials; premedicate with diphenhydramine; slow or interrupt IV infusion and administer treatment based on severity of the reaction
Does not cross the blood-brain barrier and does not prevent or treat meningitis; use in combination with appropriate antibacterial drugs
Pregnancy and lactation
Pregnancy category: B
Lactation: Human immunoglobulins are excreted in human milk, published data suggest that neonatal consumption of human milk does not result in substantial absorption of these maternal immunoglobulins into circulation; exposure to breastfeeding infant unknown
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Raxibacumab
Mechanism of action
Recombinant human IgG1-gamma monoclonal antibody directed at the protective antigen of Bacillus anthracis
Absorption
Peak Plasma Concentration: 1020.3 mcg/mL
AUC: 15,845.8 mcg•h/mL
Distribution
Vd: 72.92 mL/kg (steady-state); suggests some tissue distribution
Elimination
Half-life: 1.76 days (alpha phase); ~22 days (beta [terminal] phase)
Renal clearance: 2.49 mL/day/kg
Excretion: Minimal in urine
Administration
IV Compatibilities
0.45% NaCL
0.9% NaCL
IV Preparation
Further dilution required before administering
- Gently invert the bag/syringe to mix the solution; do not shake
- Dilute with 0.9% or 0.45% NaCl to final volume of 250 mL for adults and children >31 kg
- For children, the final infusion volume is weight-based as described below:
- <1 kg: 7 m
- 1.1-2 kg: 15 mL
- 2.1-3 kg: 20 mL
- 3.1-4.9 kg: 25 mL
- 5-10 kg: 50 mL
- 11-30 kg: 100 mL
IV Administration
Infusion rate
- Adults and children >31 kg: 15 mL/hr IV over initial 20 min, then increase to 125 mL/hr
- For children, the final infusion rate is weight-based as described below:
- <1 kg: 7 mL total volume; 0.5 mL/hr IV over initial 20 min, then increase to 3.5 mL/hr
- 1.1-2 kg: 15 mL total volume; 1 mL/hr IV over initial 20 min, then increase to 7 mL/hr
- 2.1-3 kg: 20 mL total volume; 1.2 mL/hr IV over initial 20 min, then increase to 10 mL/hr
- 3.1-4.9 kg: 25 mL total volume; 1.5 mL/hr IV over initial 20 min, then increase to 12 mL/hr
- 5-10 kg: 50 mL total volume; 3 mL/hr IV over initial 20 min, then increase to 25 mL/hr
- 11-30 kg: 100 mL total volume; 6 mL/hr IV over initial 20 min, then increase to 50 mL/hr
- Infusion rate may be slowed or interrupted if signs of adverse reactions, including infusion-associated symptoms occur
Storage
Unopened vials
- Refrigerate at 2-8°C (36-46°F); DO NOT FREEZE
- Contains no preservative
- Protect vial from exposure to light prior to use; brief exposure to light, as with normal use, is acceptable
- Store vial in original carton until time of use
Diluted to final volume
- Prepared solution is stable for 3 hr at room temperature
