A Phase 3, Multicenter, Randomised, Controlled, Open-Label Study to demonstrate noninferiority of temocillin (unauthorized investigational medicinal product IMP in Spain, but authorized in Belgium and UK) vs a carbapenem antibiotic (meropenem) in adults with bacteraemia due to third-generation cephalosporin-resistant Enterobacteriaceae.

The duration of treatment will be between 7 and 14 days. From the 5th day of intravenous treatment, the sequential oral treatment is permitted if the patient meets appropriate conditions.

The objective of the trial is to demonstrate the non-inferiority of temocillin (2g each 8 hours, intravenous) to carbapenems (meropenem 1g each 8 hours, intravenous) in terms of efficacy and safety in the targeted treatment of bacteraemia due to Enterobacteriaceae resistant to third-generation cephalosporins, and therefore provide evidence for the use of temocillin in these infections.

The duration of treatment will be between 7 and 14 days. From the 5th day of intravenous treatment, the sequential oral treatment is permitted if the patient meets appropriate conditions.

Inclusion Criteria:

• Adult patients with monomicrobial bacteremia due to Enterobacteriaceae showing resistance to cefotaxime, ceftriaxone (MIC >2 mg/L) and/or ceftazidime (MIC >4 mg/L), and sensible to temocillin (MIC ≤8 mg/L, except in bacteremia only of urinary origin, for which the criterion is MIC ≤16 mg/L ) and meropenem (MIC ≤2 mg/L).

Patients with polymicrobial bacteremia caused by more than one Enterobacteriaceae species may also be included, provided at least one of them is resistant to third-generation cephalosporins, and both are susceptible to meropenem and temocillin.

• Duration of intravenous treatment is planned to be at least 4 days from randomization, or 3 days if the empirical treatment prior to randomization was active.
• The patient signed informed consent form.
• Potentially fertile patients must have a negative pregnancy test.

Exclusion Criteria:

• <18 years
• Pregnancy
• Breastfeeding
• Terminal condition, with life expectancy of less than 30 days, or palliative care , such that no actions will be taken to control the source of infection if necessary. Patients receiving palliative care with a life expectancy greater than 30 days may be included if source control is not necessary or, if necessary, will be carried out.
• Allergy to betalactams
• Polymicrobial bacteraemia (except when the other microorganism is considered a contaminant, (e.g. coagulase-negative staphylococci or diphtheroids in a single blood culture, or in cases where more than one Enterobacteriaceae species is isolated, provided that at least one isolate is resistant to third-generation cephalosporins and both are susceptible to meropenem and temocillin).
• Infections typically needing prolonged >14 days of therapy (e.g., endocarditis, prosthetic joint infection, vascular graft infection, empyema, chronic prostatitis) or meningitis. Patients who initially do not have a confirmed diagnosis of these infections may be included; if the diagnosis is made subsequently, the patient may be kept in the trial at the discretion of the investigator, establishing the duration of treatment that he considers necessary.
• Active empirical treatment> 96 hours after initial blood culture extraction
• Delay in inclusion> 48 h
• Recruited in another clinical trial with active treatment
• Peritoneal dialysis or continuous hemofiltration

Planning for the study will be shared with potential sites pertaining to Spanish Network for Research in Infectious Disease (REIPI)for participation. IPD is not foreseen out of this groups due to the specific characteristics of patients and sites to be candidates for study participation.

From starting to three years of study completion planification

Spanish Network for Research in Infectious Disease investigators