Combination Cefazolin With Ertapenem for Methicillin-susceptible Staphylococcus Aureus Bacteremia (CERT)

Combination Cefazolin With Ertapenem for Methicillin-susceptible Staphylococcus Aureus Bacteremia (CERT)

There is a variety of in vitro, in vivo (animal model), and human case series data which suggests that the addition of ertapenem to cefazolin could improve outcomes in methicillin-susceptible S. aureus bacteremia. No randomized controlled trial has been performed.

Study Overview

• Status: Not yet recruiting
• Conditions: Staphylococcus Aureus Bacteremia; Staphylococcus Aureus Endocarditis; Staphylococcus Aureus Septicemia; Staphylococcal Sepsis
• Intervention / Treatment: Drug: Ertapenem; Drug: Placebo

Detailed Description

Cefazolin is licensed in Canada for the management of infections due to susceptible Staphylococcus aureus, including bacteremia. It has been commonly used for decades in this disease and, when compared in observational studies to anti-staphylococcal penicillins, has demonstrated reduced mortality.

Nevertheless, in the treatment of methicillin-susceptible S. aureus (MSSA) bacteremia, there remains significant opportunities to improve clinical outcomes. Indeed, S. aureus bacteremia kills more Canadians annually than myeloma, melanoma, renal, ovarian or stomach cancers. Overall mortality approached 18% in a recent Canadian clinical trial performed by our group (Cheng et al, 2020).

The duration of bacteremia, particularly after antibiotherapy is recognized as a major risk factor for mortality. Interventions which reduce the duration of bacteremia, without increasing the frequency of renal failure like gentamicin (Cosgrove et al, 2009) or the combination of vancomycin and flucloxacillin in MRSA (Tong et al, 2020), are among the most promising candidates for larger phase 3 studies designed to impact patient mortality.

Ertapenem is a commonly used antibiotic which has been on the Canadian market for more than 15 years. It is most commonly used in patients with infections caused by extended-spectrum beta-lactamase producing Enterobacteraciae; however, it has a broad spectrum of activity including Gram-positive bacteria such as S. aureus. Indeed, the drug is licensed in Canada for the treatment of complicated skin and soft tissue infections commonly caused by S. aureus.

In S. aureus the carbapenem antibiotics like ertapenem have exceptional affinity to the essential penicillin-binding protein (PBP), PBP1, exceeding even that of the antistaphylococcal β-lactams (Chambers et al, 1990). This complements the relative PBP2 proclivity of cefazolin (Bamberger et al, 2002).

The combination of cefazolin with ertapenem has also been shown to be synergistic in vitro (Sakoulas et al, 2016), in vivo in the mouse and rat models (Sakoulas et al, 2016; Ulloa et al, 2020), and in a small human case series (Ulloa et al, 2020).

Based on this data, there is compelling theory (attack on 2 PBPs), in vitro, in vivo, and human case evidence to support an exploratory phase 2 RCT of cefazolin-ertapenem for the treatment of MSSA bacteremia.

• Study Type: Interventional
• Enrollment (Anticipated): 60
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Sarah Elsayed; Phone Number: 23730 514-934-1934; Email: sarah.elsayed@idtrials.com

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H4A3J1
      • McGill University Health Centre (Royal Victoria Hospital and Montreal General Hospital)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 98 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Adult >=18 years old

2. S. aureus bacteremia within the past 48 hours:

   • with any unknown MRSA status (in centers with <15% prevalence of MRSA in their annual blood cultures) or known negative MRSA screening swab within 90 days OR
   • which has already been shown to be MSSA
3. Current receipt of cefazolin or where it would be clinically appropriate (according to treating ID specialist) to switch to cefazolin as the backbone therapy (open label, non-study drug).

NOTE: Up to an additional 12-24 hours of open label non-study VANCOMYCIN, LINEZOLID or DAPTOMYCIN may be allowed if there is sepsis and clinical concern for MRSA has not been excluded.

Exclusion Criteria:

Clinical:

1. At time of recruitment, the patient has already clinically improved with at least one subsequent negative culture at >24 hours incubation
2. Anaphylaxis to any beta-lactam antibiotic (and any allergy to ertapenem) Polymicrobial bacteremia (not including skin commensals)
3. Known seizure disorder
4. Any receipt of valproic acid
5. Expected mortality within 48 hours
6. Need for critical care resources but "do not resuscitate" status precludes the receipt of critical care
7. Unable to provide informed consent and no available healthcare proxy (with ethics approval for deferred consent in cases of severe illness)

Administrative:

1. Refusal to provide informed consent
2. Refusal of healthcare team to participate
3. No reliable means of outpatient contact (telephone/email/text)
4. Previously enrolled
5. Patients whose isolate is identified as MRSA post-enrollment will be subsequently excluded (see below).

Note that because MSSA is much more common than MRSA in Canada (90% of all S. aureus bacteremia at MUHC, for example, are MSSA and in the presence of a negative MRSA screening swab or unknown MRSA status, this means that the risk of MRSA is less than 5%). We believe time to combination therapy is likely linked to benefit, therefore we will recruit the patients as soon as S. aureus is identified but potentially prior to confirmation the organism is MSSA. Where possible, rapid MRSA detection techniques will be deployed; however with conventional screening this will mean approximately a 12-24 hours delay. Organisms subsequently identified as MRSA will be excluded from the intention to treat analysis and the sample size will be adjusted accordingly to ensure the total enrollment meets study goals.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ertapenem; Ertapenem 1g IV daily infused over 2 hours x 5 days	Drug: Ertapenem; Adjunctive ertapenem; Other Names: Invanz
Placebo Comparator: Placebo; Saline placebo infused daily over 2 hours x 5 days	Drug: Placebo; Saline placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical success	Composite of: Patient alive, fever resolved, blood cultures negative for S. aureus, systolic blood pressure >=90mmHg not on vasopressors	Day 5

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood culture clearance	Time between first positive and first negative blood culture	30 days
Clinical improvement	Time to clinical improvement defined as the time until fever resolved, blood cultures sterile, and systolic blood pressure >=90mmHg not on vasopressors in patients who survive to clinical improvement	30 days
Length of stay	The time from initial emergency room visit until discharge from hospital in patients discharged alive	90 days
All cause-mortality	Death from any cause	90 days
C. diff infection	Any C. difficile infection within 56 days	56 days
Gram-negative bacteremia	Any Gram-negative bacteremia within 56 days	56 days
New colonization with carbapenemase producing organisms	Newly identified colonization with carbapenemase producing organisms to day 56	56 days
Valve replacement surgery	Any valve replacement surgery occurring after the initial diagnosis	56 days
Recurrent isolation of MSSA from a sterile site	Any positive culture of MSSA from a sterile site (blood, cerebral spinal fluid, joint aspirate, bone, etc.) occurring after the end of combination therapy	Between Days 6 and 90 inclusive
Seizure	Any clinically identified seizure within 48 hours of discontinuation of combination therapy	7 days
Acute Kidney Injury	An increase in serum creatinine to ≥1.5 times baseline OR new requirement for hemodialysis at any time in the first 7 days from randomization	7 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Health-related quality of life	This will be assessed using the EQ-5D-5L questionnaire	90 days

Collaborators and Investigators

• Sponsor: Todd C. Lee MD MPH FIDSA
• Investigators: Principal Investigator: Emily G McDonald, MD MSc, Research Institute of the McGill University Health Centre; Principal Investigator: Matthew P Cheng, MD, Research Institute of the McGill University Health Centre

Publications and helpful links

General Publications

• Ulloa ER, Singh KV, Geriak M, Haddad F, Murray BE, Nizet V, Sakoulas G. Cefazolin and Ertapenem Salvage Therapy Rapidly Clears Persistent Methicillin-Susceptible Staphylococcus aureus Bacteremia. Clin Infect Dis. 2020 Sep 12;71(6):1413-1418. doi: 10.1093/cid/ciz995.
• Sakoulas G, Olson J, Yim J, Singh NB, Kumaraswamy M, Quach DT, Rybak MJ, Pogliano J, Nizet V. Cefazolin and Ertapenem, a Synergistic Combination Used To Clear Persistent Staphylococcus aureus Bacteremia. Antimicrob Agents Chemother. 2016 Oct 21;60(11):6609-6618. doi: 10.1128/AAC.01192-16. Print 2016 Nov.
• Cosgrove SE, Vigliani GA, Fowler VG Jr, Abrutyn E, Corey GR, Levine DP, Rupp ME, Chambers HF, Karchmer AW, Boucher HW. Initial low-dose gentamicin for Staphylococcus aureus bacteremia and endocarditis is nephrotoxic. Clin Infect Dis. 2009 Mar 15;48(6):713-21. doi: 10.1086/597031.
• Bamberger DM, Herndon BL, Fitch J, Florkowski A, Parkhurst V. Effects of neutrophils on cefazolin activity and penicillin-binding proteins in Staphylococcus aureus abscesses. Antimicrob Agents Chemother. 2002 Sep;46(9):2878-84. doi: 10.1128/AAC.46.9.2878-2884.2002.
• Chambers HF, Sachdeva M. Binding of beta-lactam antibiotics to penicillin-binding proteins in methicillin-resistant Staphylococcus aureus. J Infect Dis. 1990 Jun;161(6):1170-6. doi: 10.1093/infdis/161.6.1170.
• Cheng MP, Lawandi A, Butler-Laporte G, De l'Etoile-Morel S, Paquette K, Lee TC. Adjunctive Daptomycin in the Treatment of Methicillin-susceptible Staphylococcus aureus Bacteremia: A Randomized, Controlled Trial. Clin Infect Dis. 2021 May 4;72(9):e196-e203. doi: 10.1093/cid/ciaa1000.

Study record dates

Study Major Dates

• Study Start (Anticipated): July 1, 2022
• Primary Completion (Anticipated): March 1, 2023
• Study Completion (Anticipated): July 1, 2023

Study Registration Dates

• First Submitted: May 10, 2021
• First Submitted That Met QC Criteria: May 10, 2021
• First Posted (Actual): May 14, 2021

Study Record Updates

• Last Update Posted (Actual): March 9, 2022
• Last Update Submitted That Met QC Criteria: February 21, 2022
• Last Verified: February 1, 2022

More Information

Terms related to this study

• Keywords: Bacteremia; Staphylococcus aureus; Methicillin-susceptible
• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Infections; Systemic Inflammatory Response Syndrome; Inflammation; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Positive Bacterial Infections; Sepsis; Bacteremia; Endocarditis; Staphylococcal Infections; Anti-Infective Agents; Anti-Bacterial Agents; Ertapenem
• Other Study ID Numbers: 2021-7400

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No