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Karau MJ, Mandrekar J, Lehoux D, Schuch R, Cassino C, Patel R. In vitro activity of exebacase against methicillin-resistant Staphylococcus aureus biofilms on orthopedic Kirschner wires. BMC Res Notes 2023; 16:209. [PMID: 37697424 PMCID: PMC10496330 DOI: 10.1186/s13104-023-06468-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 08/22/2023] [Indexed: 09/13/2023] Open
Abstract
Orthopedic foreign body-associated infection can be difficult to treat due to the formation of biofilms protecting microorganisms from both antimicrobials and the immune system. Exebacase is an antistaphylococcal lysin (cell wall hydrolase) under consideration for local treatment for biofilm-based infections caused by methicillin-resistant Staphylococcus aureus (MRSA). To determine the activity of exebacase, we formed MRSA biofilms on orthopedic Kirschner wires and exposed them to varying concentrations (0.098, 0.98, 9.8 mg/ml) of exebacase and/or daptomycin over 24 h. The biofilm consisted of 5.49 log10 colony forming units (cfu)/K-wire prior to treatment and remained steady throughout the experiment. Exebacase showed significant biofilm reduction at all timepoints (up to 5.78 log10 cfu/K-wire; P < 0.0495) compared to the controls at all concentrations and all time points with bactericidal activity (> 3 log10 cfu/K-wire reduction) observed for up to 12 h for the 0.098 and 0.98 mg/ml concentrations and at 24 h for 9.8 mg/ml. Daptomycin showed significant biofilm reduction, although non-bactericidal, at all time points for 0.98 and 9.8 mg/ml and at 4 and 8 h with 0.098 mg/ml (P < 0.0495). This study supports further evaluation of local administration of exebacase as a potential treatment for orthopedic implant infections.
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Affiliation(s)
- Melissa J Karau
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Jay Mandrekar
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, 55905, USA
| | | | | | - Cara Cassino
- Stony Point Life Sciences Consulting, LLC, Benson, VT, 05743, USA
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
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Giacobbe DR, Dettori S, Corcione S, Vena A, Sepulcri C, Maraolo AE, De Rosa FG, Bassetti M. Emerging Treatment Options for Acute Bacterial Skin and Skin Structure Infections and Bloodstream Infections Caused by Staphylococcus aureus: A Comprehensive Review of the Evidence. Infect Drug Resist 2022; 15:2137-2157. [PMID: 35498629 PMCID: PMC9041368 DOI: 10.2147/idr.s318322] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/07/2022] [Indexed: 12/12/2022] Open
Affiliation(s)
- Daniele Roberto Giacobbe
- Clinica Malattie Infettive, Ospedale Policlinico San Martino – IRCCS, Genoa, Italy
- Department of Health Sciences, University of Genoa, Genoa, Italy
- Correspondence: Daniele Roberto Giacobbe, Clinica Malattie Infettive, Ospedale Policlinico San Martino – IRCCS, L.go R. Benzi 10, Genoa, 16132, Italy, Tel +390105554658, Email
| | - Silvia Dettori
- Clinica Malattie Infettive, Ospedale Policlinico San Martino – IRCCS, Genoa, Italy
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | - Silvia Corcione
- Department of Medical Sciences, Division of Infectious Diseases, Azienda Ospedaliera Universitaria (A.O.U.) Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Antonio Vena
- Clinica Malattie Infettive, Ospedale Policlinico San Martino – IRCCS, Genoa, Italy
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | - Chiara Sepulcri
- Clinica Malattie Infettive, Ospedale Policlinico San Martino – IRCCS, Genoa, Italy
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | | | - Francesco Giuseppe De Rosa
- Department of Medical Sciences, Division of Infectious Diseases, Azienda Ospedaliera Universitaria (A.O.U.) Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy
| | - Matteo Bassetti
- Clinica Malattie Infettive, Ospedale Policlinico San Martino – IRCCS, Genoa, Italy
- Department of Health Sciences, University of Genoa, Genoa, Italy
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Schuch R, Cassino C, Vila-Farres X. Direct Lytic Agents: Novel, Rapidly Acting Potential Antimicrobial Treatment Modalities for Systemic Use in the Era of Rising Antibiotic Resistance. Front Microbiol 2022; 13:841905. [PMID: 35308352 PMCID: PMC8928733 DOI: 10.3389/fmicb.2022.841905] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/28/2022] [Indexed: 12/19/2022] Open
Abstract
Direct lytic agents (DLAs) are novel antimicrobial compounds with unique mechanisms of action based on rapid cell wall destabilization and bacteriolysis. DLAs include two classes of purified polypeptides—lysins (peptidoglycan hydrolase enzymes) and amurins (outer membrane targeting peptides). Their intended use is to kill bacteria in a manner that is complimentary to and synergistic with traditional antibiotics without selection for DLA resistance. Lysins were originally described as having activity against Gram-positive pathogens and of those, exebacase, is the first to have advanced into Phase 3 of clinical development. Recently, both engineered and native DLAs have now been described with potent bactericidal activity against a range of Gram-negative pathogens, including multidrug-resistant (MDR) and extensively drug-resistant (XDR) Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Importantly, novel DLAs targeting Gram-negatives, including the lysin CF-370 and the amurin peptides, are active in biological matrices (blood/serum) and, as such, offer promise for therapeutic use as systemically administered agents for the treatment of life-threatening invasive infections. In this review, DLAs are discussed as potential new classes of antimicrobial biologics that can be used to treat serious systemic infections.
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Exebacase: A Novel Approach to the Treatment of Staphylococcal Infections. Drugs R D 2022; 22:113-117. [PMID: 35175568 PMCID: PMC9167414 DOI: 10.1007/s40268-022-00383-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2022] [Indexed: 11/04/2022] Open
Abstract
Lysins are bacteriophage-derived enzymes that degrade essential components of bacteria. Exebacase (Lysin CF-301) is an attractive antimicrobial agent because it demonstrates rapid bacteriolytic activity against staphylococcal species, including Staphylococcus aureus, has a low resistance profile, eradicates biofilms, and acts synergistically with other antibiotics. Combinations including exebacase and standard of care antibiotics represent an alternative to antibiotic monotherapies currently used to treat invasive staphylococcal infections. This manuscript reviews what is known about exebacase and explores how this novel agent may be used in the future to treat human bacterial pathogens.
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Abstract
Exebacase is a lysin (cell wall hydrolase) with direct lytic activity against Staphylococcus aureus including methicillin-resistant S. aureus (MRSA). Time kill analysis experiments illustrated bactericidal activity of exebacase-daptomycin, against MRSA strains MW2 and 494. Furthermore, exebacase in addition to daptomycin (10, 6 and 4 mg/kg/d) in a two-compartment ex-vivo pharmacokinetic/pharmacodynamic simulated endocardial vegetation model with humanized doses resulted in reductions of 6.01, 4.99 and 2.81 log10 CFU/g (from initial inoculum) against MRSA strain MW2.
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Determination of MIC Quality Control Parameters for Exebacase, a Novel Lysin with Antistaphylococcal Activity. J Clin Microbiol 2021; 59:e0311720. [PMID: 33910968 PMCID: PMC8218745 DOI: 10.1128/jcm.03117-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Exebacase (CF-301), a novel, antistaphylococcal lysin (cell wall hydrolase) is the first agent of this class to enter late-stage clinical development (phase 3, NCT04160468) for the treatment of Staphylococcus aureus bacteremia, including right-sided endocarditis. A multilaboratory Clinical and Laboratory Standards Institute (CLSI) M23-defined tier 2 quality control (QC) study was conducted to establish exebacase QC ranges for a new reference broth microdilution method. S. aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 were selected as reference QC strains. Broth microdilution MIC QC ranges for exebacase spanned 4 log2 dilutions and contained 99.2% of the MIC results generated for the two reference strains. The QC ranges for exebacase were defined as 0.25 to 2 μg/ml and 8 to 64 μg/ml against S. aureus ATCC 29213 and E. faecalis ATCC 29212, respectively, and were approved by the CLSI Subcommittee on Antimicrobial Susceptibility Testing. These QC ranges established for use with the reference broth microdilution method developed for exebacase susceptibility testing will ensure the test performance and accuracy of results generated during clinical development.
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Development of a Broth Microdilution Method for Exebacase Susceptibility Testing. Antimicrob Agents Chemother 2021; 65:e0258720. [PMID: 33903102 PMCID: PMC8218677 DOI: 10.1128/aac.02587-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Exebacase (CF-301) belongs to a new class of protein-based antibacterial agents, known as lysins (peptidoglycan hydrolases). Exebacase, a novel lysin with antistaphylococcal activity, is in phase 3 of clinical development. To advance into the clinic, it was necessary to develop an accurate and reproducible method for exebacase MIC determination. The Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution (BMD) method using cation-adjusted Mueller-Hinton broth (CAMHB) produced trailing MIC endpoints, and exebacase activity was diminished when frozen BMD panels were used. A modified BMD method was developed using CAMHB supplemented with 25% horse serum and 0.5 mM dl-dithiothreitol (CAMHB-HSD). Preliminary quality control (QC) ranges for Staphylococcus aureus ATCC 29213 of 0.25 to 1 μg/ml and for Enterococcus faecalis ATCC 29212 of 16 to 64 μg/ml were determined based on the results of a CLSI M23-defined MIC QC tier 1 study. These preliminary QC ranges validated the MIC data generated from a systematic study testing a discrete S. aureus strain collection using CAMHB-HSD to investigate the impact of parameters known to influence susceptibility test results and to evaluate the exebacase MIC distribution against clinical S. aureus isolates. Presentation of these data led to the CLSI Subcommittee on Antimicrobial Susceptibility Testing (AST) approval of the use of CAMHB-HSD to determine exebacase susceptibility and commencement of a multilaboratory (tier 2) QC study. Use of a standard BMD method and concomitant QC testing provides confidence in the assessment of test performance to generate accurate and reproducible susceptibility data during antibacterial drug development.
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Fowler VG, Das AF, Lipka-Diamond J, Schuch R, Pomerantz R, Jáuregui-Peredo L, Bressler A, Evans D, Moran GJ, Rupp ME, Wise R, Corey GR, Zervos M, Douglas PS, Cassino C. Exebacase for patients with Staphylococcus aureus bloodstream infection and endocarditis. J Clin Invest 2021; 130:3750-3760. [PMID: 32271718 DOI: 10.1172/jci136577] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUNDNovel therapeutic approaches are critically needed for Staphylococcus aureus bloodstream infections (BSIs), particularly for methicillin-resistant S. aureus (MRSA). Exebacase, a first-in-class antistaphylococcal lysin, is a direct lytic agent that is rapidly bacteriolytic, eradicates biofilms, and synergizes with antibiotics.METHODSIn this superiority-design study, we randomly assigned 121 patients with S. aureus BSI/endocarditis to receive a single dose of exebacase or placebo. All patients received standard-of-care antibiotics. The primary efficacy endpoint was clinical outcome (responder rate) on day 14.RESULTSClinical responder rates on day 14 were 70.4% and 60.0% in the exebacase + antibiotics and antibiotics-alone groups, respectively (difference = 10.4, 90% CI [-6.3, 27.2], P = 0.31), and were 42.8 percentage points higher in the prespecified exploratory MRSA subgroup (74.1% vs. 31.3%, difference = 42.8, 90% CI [14.3, 71.4], ad hoc P = 0.01). Rates of adverse events (AEs) were similar in both groups. No AEs of hypersensitivity to exebacase were reported. Thirty-day all-cause mortality rates were 9.7% and 12.8% in the exebacase + antibiotics and antibiotics-alone groups, respectively, with a notable difference in MRSA patients (3.7% vs. 25.0%, difference = -21.3, 90% CI [-45.1, 2.5], ad hoc P = 0.06). Among MRSA patients in the United States, median length of stay was 4 days shorter and 30-day hospital readmission rates were 48% lower in the exebacase-treated group compared with antibiotics alone.CONCLUSIONThis study establishes proof of concept for exebacase and direct lytic agents as potential therapeutics and supports conduct of a confirmatory study focused on exebacase to treat MRSA BSIs.TRIAL REGISTRATIONClinicaltrials.gov NCT03163446.FUNDINGContraFect Corporation.
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Affiliation(s)
- Vance G Fowler
- Duke University Medical Center, Durham, North Carolina, USA.,Duke Clinical Research Institute, Durham, North Carolina, USA
| | - Anita F Das
- AD Stat Consulting, Guerneville, California, USA
| | | | | | | | | | - Adam Bressler
- Infectious Disease Specialists of Atlanta, Georgia, USA
| | - David Evans
- The Ohio State University, Columbus, Ohio, USA
| | | | - Mark E Rupp
- University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Robert Wise
- Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA
| | - G Ralph Corey
- Duke University Medical Center, Durham, North Carolina, USA
| | | | - Pamela S Douglas
- Duke University Medical Center, Durham, North Carolina, USA.,Duke Clinical Research Institute, Durham, North Carolina, USA
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Bassetti M, Del Puente F, Magnasco L, Giacobbe DR. Innovative therapies for acute bacterial skin and skin-structure infections (ABSSSI) caused by methicillin-resistant Staphylococcus aureus: advances in phase I and II trials. Expert Opin Investig Drugs 2020; 29:495-506. [PMID: 32242469 DOI: 10.1080/13543784.2020.1750595] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) is among the most frequent causative agents of acute bacterial skin and skin-structure infections (ABSSSI) and has been associated with increased risks of invasive disease and of treatment failure. AREAS COVERED In this review, we focus on those novel anti-MRSA agents currently in phase I or II of clinical development that may enrich the armamentarium against ABSSSI caused by MRSA in the future. EXPERT OPINION Promising agents belonging to either old or novel antibiotic classes are currently in early phases of clinical development and may become available in the future for the effective treatment of ABSSSI caused by MRSA. In particular, the future availability of agents belonging to novel classes will be important for guaranteeing an effective treatment and for allowing outpatient treatment/early discharge, with a consequent reduced impact on healthcare resources. However, this does not mean that we can relax our efforts directed toward improving the responsible use of already available agents. Indeed, preserving their activity in the long term is crucial for optimizing the use of healthcare resources.
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Affiliation(s)
- Matteo Bassetti
- Infectious Diseases Unit, Ospedale Policlinico San Martino - IRCCS , Genoa, Italy.,Department of Health Sciences, University of Genoa , Genoa, Italy
| | - Filippo Del Puente
- Infectious Diseases Unit, Ospedale Policlinico San Martino - IRCCS , Genoa, Italy.,Department of Health Sciences, University of Genoa , Genoa, Italy
| | - Laura Magnasco
- Infectious Diseases Unit, Ospedale Policlinico San Martino - IRCCS , Genoa, Italy.,Department of Health Sciences, University of Genoa , Genoa, Italy
| | - Daniele Roberto Giacobbe
- Infectious Diseases Unit, Ospedale Policlinico San Martino - IRCCS , Genoa, Italy.,Department of Health Sciences, University of Genoa , Genoa, Italy
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Gram-Negative Bacterial Lysins. Antibiotics (Basel) 2020; 9:antibiotics9020074. [PMID: 32054067 PMCID: PMC7168136 DOI: 10.3390/antibiotics9020074] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022] Open
Abstract
Antibiotics have had a profound impact on human society by enabling the eradication of otherwise deadly infections. Unfortunately, antibiotic use and overuse has led to the rapid spread of acquired antibiotic resistance, creating a major threat to public health. Novel therapeutic agents called bacteriophage endolysins (lysins) provide a solution to the worldwide epidemic of antibiotic resistance. Lysins are a class of enzymes produced by bacteriophages during the lytic cycle, which are capable of cleaving bonds in the bacterial cell wall, resulting in the death of the bacteria within seconds after contact. Through evolutionary selection of the phage progeny to be released and spread, these lysins target different critical components in the cell wall, making resistance to these molecules orders of magnitude less likely than conventional antibiotics. Such properties make lysins uniquely suitable for the treatment of multidrug resistant bacterial pathogens. Lysins, either naturally occurring or engineered, have the potential of being developed into fast-acting, narrow-spectrum, biofilm-disrupting antimicrobials that act synergistically with standard of care antibiotics. This review focuses on newly discovered classes of Gram-negative lysins with emphasis on prototypical enzymes that have been evaluated for efficacy against the major antibiotic resistant organisms causing nosocomial infections.
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