obiltoxaximab

Action and Spectrum

Actions and spectrum: 

obiltoxaximab is a monoclonal antibody which binds to and neutralizes the lethal toxin of Bacillus anthracis, the bacterium that causes anthrax. It works by preventing the lethal toxin from binding to and entering cells, which can lead to cell death and tissue damage.

obiltoxaximab has been approved by the USFDA for the treatment of inhalational anthrax. It is not effective against other forms of anthrax, such as cutaneous anthrax or gastrointestinal anthrax. 

Drug Interaction

Adverse Reaction

Frequency defined 

<1% 

Anaphylaxis (0.9%)  

1-10% 

Nasal congestion (2%) 

Urticaria (2%) 

Infusion site pain (2%) 

Pain in extremity (2%) 

Cough (3%) 

Swelling at Infusion site (3%) 

punctured Vessel site (3%) 

Pruritus (4%) 

URTI (5%) 

Headache (8%)  

>10% 

Hypersensitivity (10.6%) 

Black Box Warning

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

There are no speific contraindications for obiltoxaximab. However, caution should be exercised in patients who may have a history of hypersensitivity or anaphylactic reactions to any component of the product.  

Caution: 

• Hypersensitivity reactions: obiltoxaximab may cause hypersensitivity reactions, including anaphylaxis. Therefore, it should be administered in a setting with appropriate medical support to manage such reactions. 
• Interference with diagnostic tests: obiltoxaximab may interfere with certain diagnostic tests that rely on detection of the protective antigen component of Bacillus anthracis.  
• Potential for immunogenicity: As with all therapeutic proteins, treatment with obiltoxaximab may lead to the development of antibodies against the drug, potentially reducing its efficacy. 
• Risk of infections: Patients receiving obiltoxaximab may be at an increased risk of infections, especially those caused by Bacillus anthracis strains that are not susceptible to the drug.

Comorbidities: 

There are no specific comorbidities associated with the use of obiltoxaximab. However, it should be used under caution patients with hypersensitivity reactions to obiltoxaximab or any of its components. 

Pregnancy / Lactation

Pregnancy consideration: N/A 

Lactation: N/A 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

obiltoxaximab is a monoclonal antibody that targets the protective antigen (PA) component of Bacillus anthracis. PA is required for the entry of lethal and edema toxins into the host cell, and obiltoxaximab neutralizes PA to prevent the toxins from causing tissue damage and death. The binding of obiltoxaximab to PA also enhances its clearance from the bloodstream by the reticuloendothelial system. 

obiltoxaximab has no direct antibacterial activity against Bacillus anthracis and should be used in combination with appropriate antibiotics for the treatment of anthrax infections.  

Pharmacodynamics: 

obiltoxaximab binds to PA with high affinity and prevents its binding to cellular receptors, thus blocking the formation of LT and preventing anthrax toxin-mediated cellular damage. 

In preclinical studies, obiltoxaximab has been shown to protect against the effects of anthrax toxin and to reduce the mortality associated with inhalational anthrax. It is believed that obiltoxaximab can also enhance the clearance of anthrax bacteria by the immune system, although this mechanism of action is not fully understood.  

Pharmacokinetics: 

Absorption 

obiltoxaximab is administered intravenously, which means it bypasses the gastrointestinal tract and is directly delivered to the bloodstream. 

Distribution 

The steady-state volume of distribution is 5.3 L, indicating that obiltoxaximab is largely confined to the vascular space. 

Metabolism 

The metabolism of obiltoxaximab has not been fully characterized, but it is expected to degrade by the proteolysis of small peptides and amino acids. 

Elimination and excretion 

The terminal half-life is approximately 14 days, and obiltoxaximab is primarily eliminated through proteolytic degradation and clearance by the reticuloendothelial system. 

Adminstartion

Administration: 

obiltoxaximab is administered via intravenous (IV) infusion over a period of 60 minutes. The recommended dose for adults is 16 mg/kg of body weight. It is given once as a prophylactic treatment for inhalational anthrax when alternative therapies are not available or are not appropriate. The infusion should be closely monitored, and patients should be observed for adverse reactions during and after the infusion. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: obiltoxaximab 

Pronounced: (oh-bil-tox-AX-ih-mab)  

Why do we use obiltoxaximab? 

obiltoxaximab is indicated for the treatment of inhalational anthrax in combination with appropriate antibacterial drugs. It is approved for use in adult and pediatric patients. Anthrax is a potentially life-threatening infectious disease caused by the spore-forming bacterium Bacillus anthracis. The inhalational form of anthrax is the most deadly and is associated with high mortality rates if left untreated. obiltoxaximab targets the protective antigen component of the anthrax toxin, thereby neutralizing its toxic effects.