MEDI4893* Promotes Survival and Extends the Antibiotic Treatment Window in a Staphylococcus aureus Immunocompromised
1Department of Infectious Disease, MedImmune, LLC, Gaithersburg, Maryland, USA.
Abstract:
Immunocompromised individuals are at increased risk of Staphylococcus aureus pneumonia. Neutralization of alpha-toxin (AT) with the monoclonal antibody (MAb) MEDI4893* protects normal mice from S. aureus pneumonia; however, the effects of the MAb in immunocompromised mice have not been reported. In this study, passive immunization with MEDI4893* increased survival rates and reduced bacterial numbers in the lungs in an immunocompromised murine S. aureus pneumonia model. Lungs from infected mice exhibited alveolar epithelial damage, protein leakage, and bacterial overgrowth, whereas lungs from mice passively immunized with MEDI4893* retained a healthy architecture, with an intact epithelial barrier. Adjunctive therapy or prophylaxis with a subtherapeutic MEDI4893* dose combined with subtherapeutic doses of vancomycin or linezolid improved survival rates, compared with the monotherapies. Furthermore, coadministration of MEDI4893* with vancomycin or linezolid extended the antibiotic treatment window. These data suggest that MAb-mediated neutralization of AT holds promise in strategies for prevention and adjunctive therapy among immunocompromised patients.
Insights
Monoclonal antibody MEDI4893* improves survival in immunocompromised mice with Staphylococcus aureus pneumonia. It shows promise as a preventative and adjunctive therapy, protecting lung tissue and enhancing antibiotic effectiveness.
Area of Science:
- Immunology
- Infectious Diseases
- Pulmonology
Background:
- Immunocompromised individuals face higher risks of Staphylococcus aureus pneumonia.
- Alpha-toxin (AT) neutralization with monoclonal antibody (MAb) MEDI4893* protects healthy mice, but its efficacy in immunocompromised models was unknown.
Purpose of the Study:
- To evaluate the efficacy of passive immunization with MEDI4893* in an immunocompromised murine model of Staphylococcus aureus pneumonia.
- To assess MEDI4893* as an adjunctive therapy with antibiotics in this model.
Main Methods:
- Passive immunization with MEDI4893* in immunocompromised mice infected with S. aureus.
- Histopathological analysis of lung tissue to assess damage and bacterial load.
- Evaluation of combined therapy with subtherapeutic doses of MEDI4893* and vancomycin or linezolid.
Main Results:
- MEDI4893* significantly increased survival rates and reduced lung bacterial counts in immunocompromised mice.
- Immunization preserved lung architecture, preventing alveolar epithelial damage and protein leakage.
- Adjunctive therapy with MEDI4893* and antibiotics improved survival and extended the treatment window compared to monotherapy.
Conclusions:
- MAb-mediated neutralization of alpha-toxin is a promising strategy for preventing and treating S. aureus pneumonia in immunocompromised patients.
- MEDI4893* demonstrates potential as an adjunctive therapy, enhancing antibiotic efficacy and broadening treatment options.
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