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.

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.

Inclusion Criteria:

1. 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).
2. Patients willing and able to adhere to the procedures stated in the protocol.
3. 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

Exclusion Criteria:

• There are no exclusion criteria for subjects enrolling in this study.

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.