Infections, BacterialNCT07478471
Observational Study of Raxibacumab in Sporadic Cases of Systemic Anthrax
An observational study of Infections, Bacterial, run by Emergent BioSolutions.
Trial summary
This observational, open-label, single arm, study is designed such that it may be implemented for any individual with a lab confirmed sporadic case of systemic anthrax disease treated with raxibacumab outside of the current United States Prescribing Information (USPI). Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Infections, Bacterial
- What is being tested?
- Collection of samples
- Type of treatment
- Injection or infusion
- How many people
- 10 participants
- Where
- No sites listed yet
- Study dates
- May 2027to Dec 2030
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The population to be studied are patients with lab confirmed systemic anthrax who are treated with raxibacumab according to the USPI and distributed from the US SNS. The population may include all age categories of patients (infant, pediatric, adult [including pregnant and lactating women], and geriatric) with confirmed systemic anthrax in the US.
Who may be able to join
- Any patient (women, including pregnant and lactating women, men, and children of all ages) with lab confirmed systemic anthrax in the US treated with a dose of raxibacumab from the Strategic National Stockpile (SNS).
- Patients willing and able to adhere to the procedures stated in the protocol.
- Patients (or legally acceptable representative of minors and unconscious adults) willing and able to give written informed consent/assent (as applicable) to participate in the study.
- Note: Systemic anthrax is defined in this protocol as a clinically compatible case of gastrointestinal, injectional, or inhalational anthrax; anthrax meningitis or bacteremia; or cutaneous anthrax with systemic effects (i.e., tachycardia, tachypnea, hypotension, hyperthermia, hypothermia, leukocytosis) or with lesions that involve the head, neck or upper torso, or are large, bullous, multiple, or surrounded by significant edema; plus confirmation by one of the following: Epidemiological link to a documented anthrax environmental exposure and/or laboratory test used for confirmation of systemic anthrax diagnosis by one of the following:
- Isolation and culture of Bacillus spp. from an affected tissue or site;
- Evidence of Bacillus spp. DNA by PCR in biological samples such as blood or cerebrospinal fluid (CSF) or lesion of affected tissue (skin, pulmonary, reticuloendothelial, or gastrointestinal);
Show all 9Show fewer
- Molecular Typing by Multiple-Locus Variable number tandem repeat Analysis (MLVA); Susceptibility to lysis by γ-phage;
- QuickELISA™ Anthrax-PA Kit- Detection of anti-PA antibodies in serum, plasma, or pleural/ascitic fluid or;
- RedLine Alert™ Test- Qualitative identification of B. anthracis colonies
Who cannot join
- There are no exclusion criteria for subjects enrolling in this study.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: An Observational Clinical Study of Raxibacumab Use in Sporadic Cases of Systemic Anthrax
This observational, open-label, single arm, study is designed such that it may be implemented for any individual with a lab confirmed sporadic case of systemic anthrax disease treated with raxibacumab outside of the current United States Prescribing Information (USPI). Systemic anthrax cases may include inhalational, gastrointestinal and injectional anthrax, anthrax meningitis or bacteremia or cutaneous anthrax with systemic effects.
This study is designed to evaluate the clinical effectiveness (including course of illness and survival), safety profile and pharmacokinetic (PK) analysis of raxibacumab from patients who are treated with raxibacumab as part of their clinical care following exposure to B. anthracis. Study data, PK sample provision/collection and other investigational research will be collected prospectively to the extent possible at pre-specified time points. However, there is no reasonable way to identify prospectively the individuals likely to become eligible for participation in this study so most data in this study is anticipated to be collected retrospectively. Scavenged blood samples will be utilized where possible to maximize sample analyses and other investigational parameters. Therefore, both retrospective and prospective data collection are allowed in this protocol in order to maximize the amount of information obtained in subjects who have been administered raxibacumab. This field study will be the first opportunity to collect data on B. anthracis-exposed patients treated with raxibacumab, to better understand the clinical benefit and safety of the drug and to further inform patient care and treatment choices for management of anthrax.
Read the detailed description
The protocol is a post-marketing requirement from the FDA to evaluate the clinical benefit, safety and pharmacokinetic analysis of raxibacumab administered to patients with lab confirmed systemic anthrax disease as part of their medical care following exposure to Bacillus anthracis.
- Conditions
- Infections, Bacterial
- Being tested
- Collection of samples
- Keywords
- Raxibacumab, anthrax, anti-toxin
- Medical subject headings
- Bacterial Infections, Anthrax
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Collection of samplesBiological
Whenever possible serum samples will be collected from all subjects to determine serum raxibacumab concentrations pre-infusion, and at specific timepoints post-infusion. In the event cerebrospinal fluid (CSF), pleural, ascites, or bronchoalveolar lavage (BAL) fluid are collected for ad hoc clinical laboratory testing, any remaining excess sample will be provided to Sponsor for determination of raxibacumab concentrations.
Any available serum remaining from ad hoc clinical laboratory specimen collections prior to raxibacumab administration will be provided to Sponsor for measurement of serum PA concentrations. In addition, remaining post raxibacumab dose serum specimens may also be analyzed for lethal factor (LF) levels.
| Study group | Role | What they receive |
|---|---|---|
| Raxibacumab arm | This is an open-label, single arm study. The study will be implemented for subjects with lab confirmed systemic anthrax disease who receive FDA-approved raxibacumab as part of their clinical care.
Intervention: Sampling of subjects or use of subjects salvaged standard of care samples may be considered for the following assessments (if available/applicable): pharmacokinetics (PK) analysis of antibodies to PA (anti-PA), protective antigen (PA), and lethal factor (LF) Receives: Biological: Collection of samples |
What is being measured
The primary outcome is the main question the study is designed to answer.
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease
The primary objective is:
To evaluate the clinical benefit in patients with confirmed systemic anthrax disease, as assessed by overall mortality rate up to Day 29.
Measured: Up to Day 29
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease
The primary objective is:
To evaluate safety of raxibacumab in patients with confirmed systemic anthrax disease, as assessed by incidence of ADRs.
Measured: Up to Day 29
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease
The primary objective is:
To evaluate safety of raxibacumab in patients with confirmed systemic anthrax disease, as assessed by incidence of SAEs.
Measured: Up to Day 29
Secondary outcomes (6)
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
The secondary objective is to evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease assessed by Incidence of hospitalization
Measured: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
The secondary objective is to evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease assessed by length of hospitalization
Measured: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
The secondary objective is to evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease assessed by length of ICU stay.
Measured: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
The secondary objective is to evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease assessed by duration of mechanical ventilation
Measured: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
The secondary objective is to evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease assessed by incidence of ICU stay
Measured: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
The secondary objective is to evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease assessed by incidence of mechanical ventilation
Measured: Up to Day 29
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Mar 2026
- Study startMay 2027 (estimated)
- Primary completionMay 2030 (estimated)
- Study completionDec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Infections, BacterialStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Other
- Enrolment
- 10 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Emergent BioSolutions
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Centers for Disease Control and Prevention, Department of Health and Human Services
- Responsible party
- Sponsor
- Investigators
- Bojan Drobic, PhD, Study director, Emergent BioSolutions
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07478471
- Sponsor's protocol ID
- EBS-RAX-200137b
- Status last verified
- Mar 2026
- First submitted
- 21 Jul 2025
- Last updated
- 17 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Observational Clinical Study of Raxibacumab Use in Sporadic Cases of Systemic Anthrax
- ClinicalTrials.gov ID
- NCT07478471
- Acronym / sponsor ID
- EBS-RAX-200137b
- Conditions
- Infections, Bacterial
- Keywords
- Raxibacumab, anthrax, anti-toxin
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- Emergent BioSolutionsIndustry (pharma, biotech, devices)
- Collaborators
- Centers for Disease Control and Prevention, Department of Health and Human Services
- Study start
- May 2027 (estimated)
- Primary completion
- May 2030 (estimated)
- Study completion
- Dec 2030 (estimated)
- First posted
- 17 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This observational, open-label, single arm, study is designed such that it may be implemented for any individual with a lab confirmed sporadic case of systemic anthrax disease treated with raxibacumab outside of the current United States Prescribing Information (USPI). Systemic anthrax cases may include inhalational, gastrointestinal and injectional anthrax, anthrax meningitis or bacteremia or cutaneous anthrax with systemic effects.
This study is designed to evaluate the clinical effectiveness (including course of illness and survival), safety profile and pharmacokinetic (PK) analysis of raxibacumab from patients who are treated with raxibacumab as part of their clinical care following exposure to B. anthracis. Study data, PK sample provision/collection and other investigational research will be collected prospectively to the extent possible at pre-specified time points. However, there is no reasonable way to identify prospectively the individuals likely to become eligible for participation in this study so most data in this study is anticipated to be collected retrospectively. Scavenged blood samples will be utilized where possible to maximize sample analyses and other investigational parameters. Therefore, both retrospective and prospective data collection are allowed in this protocol in order to maximize the amount of information obtained in subjects who have been administered raxibacumab. This field study will be the first opportunity to collect data on B. anthracis-exposed patients treated with raxibacumab, to better understand the clinical benefit and safety of the drug and to further inform patient care and treatment choices for management of anthrax.
Detailed description
The protocol is a post-marketing requirement from the FDA to evaluate the clinical benefit, safety and pharmacokinetic analysis of raxibacumab administered to patients with lab confirmed systemic anthrax disease as part of their medical care following exposure to Bacillus anthracis.
Study design
- Observational model
- Case only
- Time perspective
- Other
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Raxibacumab arm | – | Biological: Collection of samplesThis is an open-label, single arm study. The study will be implemented for subjects with lab confirmed systemic anthrax disease who receive FDA-approved raxibacumab as part of their clinical care. Intervention: Sampling of subjects or use of subjects salvaged standard of care samples may be considered for the following assessments (if available/applicable): pharmacokinetics (PK) analysis of antibodies to PA (anti-PA), protective antigen (PA), and lethal factor (LF) |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The population to be studied are patients with lab confirmed systemic anthrax who are treated with raxibacumab according to the USPI and distributed from the US SNS. The population may include all age categories of patients (infant, pediatric, adult [including pregnant and lactating women], and geriatric) with confirmed systemic anthrax in the US.
Key inclusion criteria (9 listed)
- Any patient (women, including pregnant and lactating women, men, and children of all ages) with lab confirmed systemic anthrax in the US treated with a dose of raxibacumab from the Strategic National Stockpile (SNS).
- Patients willing and able to adhere to the procedures stated in the protocol.
- Patients (or legally acceptable representative of minors and unconscious adults) willing and able to give written informed consent/assent (as applicable) to participate in the study.
- Note: Systemic anthrax is defined in this protocol as a clinically compatible case of gastrointestinal, injectional, or inhalational anthrax; anthrax meningitis or bacteremia; or cutaneous anthrax with systemic effects (i.e., tachycardia, tachypnea, hypotension, hyperthermia, hypothermia, leukocytosis) or with lesions that involve the head, neck or upper torso, or are large, bullous, multiple, or surrounded by significant edema; plus confirmation by one of the following: Epidemiological link to a documented anthrax environmental exposure and/or laboratory test used for confirmation of systemic anthrax diagnosis by one of the following:
- Isolation and culture of Bacillus spp. from an affected tissue or site;
Key exclusion criteria (1 listed)
- There are no exclusion criteria for subjects enrolling in this study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Collection of samplesWhenever possible serum samples will be collected from all subjects to determine serum raxibacumab concentrations pre-infusion, and at specific timepoints post-infusion. In the event cerebrospinal fluid (CSF), pleural, ascites, or bronchoalveolar lavage (BAL) fluid are collected for ad hoc clinical laboratory testing, any remaining excess sample will be provided to Sponsor for determination of raxibacumab concentrations. Any available serum remaining from ad hoc clinical laboratory specimen collections prior to raxibacumab administration will be provided to Sponsor for measurement of serum PA concentrations. In addition, remaining post raxibacumab dose serum specimens may also be analyzed for lethal factor (LF) levels. | Biological | Raxibacumab arm |
Primary outcome
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease
Time frame: Up to Day 29
The primary objective is: To evaluate the clinical benefit in patients with confirmed systemic anthrax disease, as assessed by overall mortality rate up to Day 29.
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease
Time frame: Up to Day 29
The primary objective is: To evaluate safety of raxibacumab in patients with confirmed systemic anthrax disease, as assessed by incidence of ADRs.
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease
Time frame: Up to Day 29
The primary objective is: To evaluate safety of raxibacumab in patients with confirmed systemic anthrax disease, as assessed by incidence of SAEs.
6 secondary outcomes
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
Time frame: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
Time frame: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
Time frame: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
Time frame: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
Time frame: Up to Day 29
To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease
Time frame: Up to Day 29
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Bojan Drobic, PhD study director
Emergent BioSolutions
Questions about this trial
What is this clinical trial studying?
An observational study of Infections, Bacterial, run by Emergent BioSolutions.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Clinical Development Representative ((204) 275-4196, ct.gov@ebsi.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Clinical Benefit of Raxibacumab for Patients with Confirmed Systemic Anthrax Disease (time frame: Up to Day 29). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Mar 2026.