Prescription medicine
Obiltoxaximab Brand names: Anthim
Obiltoxaximab (Anthim) is a prescription medicine with an FDA approval on record since 2016. No generic is listed in FDA's NDC Directory.
- No generic listed
- Boxed warning
Check it at the source: the obiltoxaximab FDA label on DailyMed (effective November 17, 2025, Elusys Therapeutics, Inc.); the BLA 125509 record on Drugs@FDA; every obiltoxaximab label on DailyMed.
Highlights of the record
FDA label of November 17, 2025; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026
HYPERSENSITIVITY and ANAPHYLAXIS Hypersensitivity and anaphylaxis have been reported during the intravenous infusion of ANTHIM. Due to the risk of hypersensitivity and anaphylaxis, ANTHIM should be administered in monitored settings by personnel trained and equipped to manage anaphylaxis. Monitor individuals who receive ANTHIM closely for signs and symptoms of hypersensitivity reactions throughout the infusion and for a period of time after administration. Stop ANTHIM infusion immediately and treat appropriately if hypersensitivity or anaphylaxis occurs [see Indications and Usage ( 1.2 ), Dosage and Administration ( 2.4 ) and Warnings and Precautions ( 5.1 )]. WARNING: HYPERSENSITIVITY and ANAPHYLAXIS See full prescribing information for complete boxed warning. Hypersensitivity reactions, including anaphylaxis, have been reported during ANTHIM infusion ( 5.1 ) ANTHIM should be administered in monitored settings by personnel trained and equipped to manage anaphylaxis ( 1.2 , 2.4 , 5.1 ) Stop ANTHIM infusion immediately and treat appropriately if hypersensitivity or anaphylaxis occurs
Used for
From the label: indications and usageANTHIM ® is a monoclonal antibody directed against the protective antigen of Bacillus anthracis.
Forms and strengths
- 100 mg/ml
Solution.
On the market
- Earliest approval on file
- March 18, 2016 Anthim, Elusys Therapeutics Inc; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- No generic approved
- Labelers listed (NDC)
- 1 of which 0 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- Not in the survey
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
What is obiltoxaximab used for?
From the label: indications and usageANTHIM ® is a monoclonal antibody directed against the protective antigen of Bacillus anthracis. It is indicated in adult and pediatric patients for treatment of inhalational anthrax due to B. 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 ANTHIM should only be used for prophylaxis when its benefit for prevention of inhalational anthrax outweighs the risk of hypersensitivity and anaphylaxis. ( 1.2 , 5.1 ) The effectiveness of ANTHIM is based solely on efficacy studies in animal models of inhalational anthrax. […]
FDA pharmacologic class: Anthrax Protective Antigen-directed Antibody.
Source: FDA drug label (Anthim), Elusys Therapeutics, Inc., effective November 17, 2025 (SPL set 39ad8799-00a4-4fc8-9852-c0536350c474), via openFDA; the full label on DailyMed
What does the patient leaflet for obiltoxaximab say first?
The FDA-approved Medication Guide or Patient Information that comes with the medicine, in its own words.
From the patient leaflet: What is the most important information I should know about ANTHIM?ANTHIM can cause serious side effects, including: Serious allergic reactions. Tell your healthcare provider right away if you have itching, hives, rash, throat irritation, cough, dizziness, shortness of breath or chest discomfort while receiving ANTHIM.
Source: FDA drug label (Anthim), Elusys Therapeutics, Inc., effective November 17, 2025 (SPL set 39ad8799-00a4-4fc8-9852-c0536350c474), via openFDA; the full label on DailyMed
Is there a generic for obiltoxaximab (Anthim)?
No generic obiltoxaximab is approved (Drugs@FDA, October 8, 2026).
- 2016 earliest approval on file
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What does the obiltoxaximab label say about other medicines?
The obiltoxaximab label names 2 other medicines in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Ciprofloxacin | drug interactions | DRUG INTERACTIONS 7.1 Ciprofloxacin Co-administration of 16 mg/kg ANTHIM intravenously with intravenous or oral ciprofloxacin in human subjects did not alter the PK of either ciprofloxacin or obiltoxaximab [see Clinical Pharmacology ( 12.3 )]. |
| Diphenhydramine | warnings and precautions | Premedication with diphenhydramine is recommended prior to administration of ANTHIM [see Dosage and Administration ( 2.1 ) and Adverse Reactions ( 6.1 )]. |
Source: FDA drug label (Anthim), Elusys Therapeutics, Inc., effective November 17, 2025 (SPL set 39ad8799-00a4-4fc8-9852-c0536350c474), via openFDA; the full label on DailyMed
What next?
- Other anthrax protective antigen-directed antibodys
- the pharmacologic class, with prices and generics
- Check an interaction
- what two or more labels say about each other