Observational Study of Raxibacumab in Sporadic Cases of Systemic Anthrax

NCT07478471 | Not Yet Recruiting FDA Drug

• 1 other identifier: EBS-RAX-200137b
• Study Type: observational
• Target: 10
• Locations: 0 countries
• Sites: N/A

Brief 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). 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.

Conditions

Infections, Bacterial

Keywords

Raxibacumab; anthrax; anti-toxin

Outcome Measures

Primary Outcomes (3)

• 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.

  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.

  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.

  Up to Day 29

Secondary Outcomes (6)

• To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease

  Up to Day 29

• To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease

  Up to Day 29

• To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease

  Up to Day 29

• To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease

  Up to Day 29

• To evaluate the clinical course of the disease in patients with confirmed systemic anthrax disease

  Up to Day 29

Other Outcomes (6)

• Anti-PA serum concentrations

  Up to Day 29

• Anthrax toxin levels

  Up to Day 29

• Raxibacumab PK in Relation to Anthrax Toxemia

  Up to Day 29

Study Arms (1)

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)

Biological: Collection of samples

Interventions

Collection of samples BIOLOGICAL

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.

Raxibacumab arm

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

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.

You may qualify if:

• 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);
• 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

Sponsors & Collaborators

• Emergent BioSolutions: lead
• Centers for Disease Control and Prevention: collaborator
• Department of Health and Human Services: collaborator

Biospecimen

Retention: SAMPLES WITH DNA

Biological samples will be collected for PK analyses, if feasible as part of exploratory analyses. These could include whole blood, serum, pleural fluid, ascitic fluid, BAL fluid, CSF, and tissue specimens. As such, the study could enroll patients both prospectively and retrospectively, depending on enrollment logistics.

MeSH Terms

Conditions

Bacterial Infections; Anthrax

Condition Hierarchy (Ancestors)

Bacterial Infections and Mycoses; Infections; Bacillaceae Infections; Gram-Positive Bacterial Infections

Study Officials

• Bojan Drobic, PhD

  Emergent BioSolutions

  STUDY DIRECTOR

Central Study Contacts

Clinical Development Representative

CONTACT

(204) 275-4196; ct.gov@ebsi.com

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: OTHER
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 21, 2025
• First Posted: March 17, 2026
• Study Start (Estimated): May 1, 2027
• Primary Completion (Estimated): May 1, 2030
• Study Completion (Estimated): December 1, 2030
• Last Updated: March 17, 2026

Record last verified: 2026-03