This field study is a post-marketing requirement from the FDA to evaluate the clinical benefit (course of illness and survival), safety and pharmacokinetics of obiltoxaximab administered to patients as part of their medical care for treatment or prophylaxis of inhalational anthrax infection following exposure to Bacillus anthracis (B. anthracis). The protocol can be implemented for any individual who receives obiltoxaximab for a suspected, probable, or confirmed case of inhalational anthrax due to B. anthracis in the United States, including sporadic cases, small incidents and/or a mass event. In case of a small anthrax incident, to the extent possible, the information will be collected prospectively at prespecified time points, except where it would interfere with management of the subject's illness. However, because of the logistical complexities that would likely accompany a mass anthrax event, most data in this study are anticipated to be collected retrospectively. Both retrospective and prospective data collection are allowed to maximize information collection. This study will collect data on the use of obiltoxaximab in anthrax infected or exposed subjects and the data collected will inform the understanding of the clinical benefit and safety of obiltoxaximab.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
100
To the extent possible, blood samples will be collected from all subjects prior to infusion and at specified time points post-infusion to determine serum obiltoxaximab concentrations and ATA titers. Scavenged blood samples can be utilized, if acceptable, to maximize sample analyses for pharmacokinetic and other investigational parameters. Data on other relevant laboratory testing will only be collected and evaluated if available in the subject's record (eg, protective antigen (PA), anti-PA, anti-lethal factor (LF), anti-edema factor, IgG antibodies, anthrax lethal toxin neutralizing activity, presence of anthrax LF, incidence and duration of B. anthracis bacteremia, and demonstration of B. anthracis antigens in tissues).
Obiltoxaximab standard of care
Overall survival in suspected, probable, or confirmed cases of inhalational anthrax at Week 24
Overall survival will be summarized by frequency of subjects who completed the study at Week 24, and subjects who died before that visit. Population survival distribution function (SDF) will be estimated using the Kaplan-Meier (KM) method.
Time frame: Up to Week 24
Survival at Day 14 and Day 28
Population survival rates at 14 and 28 days will be estimated using the KM method.
Time frame: Up to Day 28
Duration of survival (to Week 24)
The KM method will be used to estimate duration of survival.
Time frame: Up to Week 24
Disease progression and associated complications rates of anthrax (meningitis, pleural effusion, ventilator support) (to Week 24)
The progression to systemic anthrax infection and complication rates will be summarized using KM estimates associated with time to disease progression and time to complication of anthrax. The population SDFs of time to progression to systemic anthrax infection and of time to complication will be estimated using the KM method. Summary statistics of subjects with disease progression and complication rates will be provided.
Time frame: Up to Week 24
Modified SOFA score (to Week 24)
Modified sequential organ failure assessment (SOFA) scores will be assessed using 5 organ systems (respiratory, liver, cardiovascular, central nervous system, renal).
Time frame: Up to Week 24
Incidence and duration of B. anthracis bacteremia
Incidence and duration of B. anthracis bacteremia will be summarized by total incidence across time points of subjects with bacteremia and time from study drug administration to onset of bacteremia.
Time frame: Up to Week 24
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