Raxibacumab

Raxibacumab is a monoclonal antibody that binds the protective antigen of B. anthracis [see Microbiology ( 12.4 )] .

• Raxibacumab is indicated for the treatment of adult and pediatric patients with 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. ( 1.1 ) Limitations of Use: • The effectiveness of raxibacumab is based solely on efficacy studies in animal models of inhalational anthrax.

• None. None.contraindicated

• Premedicate with diphenhydramine. ( 2.1 , 2.2 , 5.1 ) • Dilute and administer as an intravenous infusion over 2 hours and 15 minutes. ( 2.3 ) • - Adults: 40 mg/kg raxibacumab. ( 2.1 ) • - Pediatrics greater than 40 kg: 40 mg/kg raxibacumab. ( 2.2 ) • - Pediatrics greater than 10 kg to 40 kg: 60 mg/kg raxibacumab. ( 2.2 ) • - Pediatrics 10 kg or less: 80 mg/kg raxibacumab. ( 2.2 ) 2.1 Dose and Schedule for Adults Administer raxibacumab as a single dose of 40 mg/kg intravenously over 2 hours and 15 minutes after dilution in 0.9% Sodium Chloride Injection, USP (normal saline) to a final volume of 250 mL. Administer 25 to 50 mg diphenhydramine within 1 hour prior to the raxibacumab infusion to reduce the risk of occurrence and/or the severity of an infusion reaction. Diphenhydramine route of administration (oral or intravenous) should be based on the temporal proximity to the start of the raxibacumab infusion [see Warnings and Precautions ( 5.1 ) , Adverse Reactions ( 6.1 )] . 2.2 Dose and Schedule for Pediatric Patients The recommended dose for pediatric patients is based on weight as shown in Table 1 . Table 1. Recommended Pediatric Dose Pediatric Body Weight Pediatric Dose Greater than 40 kg 40 mg/kg Greater than 10 kg to 40 kg 60 mg/kg 10 kg or less 80 mg/kg Premedicate with diphenhydramine within 1 hour prior to the raxibacumab infusion to reduce the risk of occurrence and/or the severity of an infusion reaction. Diphenhydramine route of administration (oral or intravenous) should be based on the temporal proximity to the start of the raxibacumab infusion.

Hypersensitivity and Anaphylaxis: ( Boxed Warning , 2.1 , 2.3 , 5.1 , 6.1 ) 5.1 Hypersensitivity and Anaphylaxis Hypersensitivity reactions including rash, urticaria, pruritus, chills, chest and throat tightness, lip and throat swelling, and hypotension were reported in 27 (4.5%) of 606 healthy subjects during or after the administration of raxibacumab in clinical trials. Two subjects experienced anaphylaxis during the raxibacumab infusion [see Adverse Reactions ( 6.1 )] . Some subjects with hypersensitivity or anaphylaxis required interruption or discontinuation of the raxibacumab infusion as well as additional appropriate treatment that included steroids, diphenhydramine, H2 blockers, and/or intravenous fluids [see Adverse Reactions ( 6.1 )] . Due to the risk of anaphylaxis, administer raxibacumab injection in monitored settings where appropriate equipment, medication (including epinephrine) and personnel trained to manage hypersensitivity, anaphylaxis, and shock are available. Monitor patients closely during the infusion and for a period of time after administration. If hypersensitivity reactions or anaphylaxis occur, interrupt or stop the raxibacumab infusion immediately and treat appropriately. Premedicate with diphenhydramine within 1 hour prior to administering raxibacumab to reduce the risk of occurrence and/or severity of a hypersensitivity reaction [see Dosage and Administration ( 2.1 ), Adverse Reactions ( 6.1 )] . Diphenhydramine premedication does not prevent anaphylaxis and may mask or delay the onset of symptoms of hypersensitivity.

Common adverse reactions in healthy adult subjects (≥1.5%) were injection site reaction, erythema and pain, headache, rash, pain in extremity, pruritus, and somnolence. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Emergent BioSolutions at 1-800-768-2304 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety of raxibacumab has been studied only in healthy volunteers. It has not been studied in patients with inhalational anthrax. In the three pre-licensure clinical trials (Trials 1, 2, and 3), the safety of raxibacumab was evaluated in 326 healthy subjects treated with a dose of 40 mg/kg in 3 clinical trials: a drug interaction trial with ciprofloxacin (Trial 1), a repeat-dose trial of 20 subjects with the second raxibacumab dose administered ≥4 months after the first dose (Trial 2), and a placebo-controlled trial evaluating single doses with a subset of subjects receiving 2 raxibacumab doses 14 days apart (Trial 3). Raxibacumab was administered to 86 healthy subjects in Trial 1. In Trial 3, 240 healthy subjects received raxibacumab (217 received 1 dose and 23 received 2 doses) and 80 subjects received placebo. The overall safety of raxibacumab was evaluated as an integrated summary of these 3 clinical trials.

Pediatric Use: Safety and effectiveness have not been studied in the pediatric population. ( 8.4 ) 8.1 Pregnancy Risk Summary There are no data on the use of raxibacumab in pregnant women to inform on drug-associated risk. In pregnant rabbits, intravenous administration of raxibacumab was not associated with teratogenicity or other adverse developmental outcomes at 3 times the human maximum plasma concentrations at the maximum recommended adult dose (see Data) . All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background rate of major birth defects is 2% to 4% and of miscarriage is 15% to 20% of clinically recognized pregnancies. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk: Limited data in the form of case reports of anthrax infection in pregnant women indicate that maternal infection is associated with a high risk of maternal, fetal, and neonatal deaths, particularly in the absence of treatment. Data Animal Data: A study was conducted in pregnant, healthy New Zealand White rabbits administered intravenous raxibacumab at dose levels of 40 or 120 mg/kg on Gestation Days 7 and 14.

Metabolism

The PK of raxibacumab is linear over the dose range of 1 to 40 mg/kg following single intravenous dosing in humans; raxibacumab was not tested at doses higher than 40 mg/kg in humans. Following single intravenous administration of raxibacumab 40 mg/kg in healthy male and female human subjects, the mean C max and AUC inf were 1,020.3 ± 140.6 mcg/mL and 15,845.8 ± 4,333.5 mcg•day/mL, respectively.

There is no clinical experience with overdosage of raxibacumab. In case of overdosage, monitor patients for any signs or symptoms of adverse effects.

• Dec 14, 2012BLABLA125349Human Genome Sciences Inc.

1. 1Cardiac Arrest133%
2. 2Cholecystitis133%
3. 3Off Label Use133%
4. 4Pyrexia133%

The 5 most recently updated of 5 ClinicalTrials.gov registrations naming Raxibacumab as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Observational Study of Raxibacumab in Sporadic Cases of Systemic Anthrax
  Not yet recruiting · Observational · 10 enrolled · Emergent BioSolutions
  NCT07478471updated 2026-03-17
• Clinical Benefit and Safety of Raxibacumab in Patients With Symptomatic Inhalational Anthrax in a Mass Exposure Scenario
  Not yet recruiting · Phase 4 · Interventional · 100 enrolled · Emergent BioSolutions
  NCT02177721updated 2026-02-06
• Effect of Raxibacumab on Immunogenicity of Anthrax Vaccine Adsorbed
  Completed · Phase 4 · Interventional · 573 enrolled · Emergent BioSolutions
  NCT02339155updated 2024-03-18
• An Open-label, Nonrandomized Study to Evaluate the Safety and Immunogenicity of Raxibacumab With Reinjection
  Completed · Phase 2 · Phase 3 · Interventional · 20 enrolled · Human Genome Sciences Inc.
  NCT02016963updated 2018-11-29
• A Study to Evaluate the Safety and Tolerability of Raxibacumab in Healthy Subjects
  Completed · Phase 3 · Interventional · 322 enrolled · Human Genome Sciences Inc.
  NCT00639678updated 2018-11-15

Frequently asked questions

How does Raxibacumab work?

Raxibacumab is a monoclonal antibody that binds the protective antigen of B. anthracis [see Microbiology ( 12.4 )] .

What is Raxibacumab used for?

According to FDA labeling, Raxibacumab carries indications including: Raxibacumab is indicated for the treatment of adult and pediatric patients with 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. ( 1.1 ) Limitations of Use: • The effectiveness of raxibacumab is based solely on efficacy studies in animal models of inhalational anthrax.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Raxibacumab?

Raxibacumab is classified as Antibacterial monoclonal antibodies, Anthrax Protective Antigen-directed Antibody, Anthrax Protective Antigen-directed Antibody Interactions.

What are the contraindications for Raxibacumab?

Raxibacumab labeling lists contraindications including: None. None.. Always consult the full prescribing information and a clinician.