- Diep, Binh An;
- Hilliard, Jamese J;
- Le, Vien TM;
- Tkaczyk, Christine;
- Le, Hoan N;
- Tran, Vuvi G;
- Rao, Renee L;
- Dip, Etyene Castro;
- Pereira-Franchi, Eliane P;
- Cha, Paulyn;
- Jacobson, Scott;
- Broome, Rosemary;
- Cheng, Lily I;
- Weiss, William;
- Prokai, Laszlo;
- Nguyen, Vien;
- Stover, C Ken;
- Sellman, Bret R
The role broad-spectrum antibiotics play in the spread of antimicrobial resistance, coupled with their effect on the healthy microbiome, has led to advances in pathogen-specific approaches for the prevention or treatment of serious bacterial infections. One approach in clinical testing is passive immunization with a monoclonal antibody (MAb) targeting alpha toxin for the prevention or treatment of Staphylococcus aureus pneumonia. Passive immunization with the human anti-alpha toxin MAb, MEDI4893*, has been shown to improve disease outcome in murine S. aureus pneumonia models. The species specificity of some S. aureus toxins necessitates testing anti-S. aureus therapeutics in alternate species. We developed a necrotizing pneumonia model in ferrets and utilized an existing rabbit pneumonia model to characterize MEDI4893* protective activity in species other than mice. MEDI4893* prophylaxis reduced disease severity in ferret and rabbit pneumonia models against both community-associated methicillin-resistant S. aureus (MRSA) and hospital-associated MRSA strains. In addition, adjunctive treatment of MEDI4893* with either vancomycin or linezolid provided enhanced protection in rabbits relative to the antibiotics alone. These results confirm that MEDI4893 is a promising candidate for immunotherapy against S. aureus pneumonia.