Efficacy and safety of a structured de-escalation from antipseudomonal ß-lactams in bloodstream infections due to Enterobacterales (SIMPLIFY): an open-label, multicentre, randomised trial.

BACKGROUND: De-escalation from broad-spectrum to narrow-spectrum antibiotics is considered an important measure to reduce the selective pressure of antibiotics, but a scarcity of adequate evidence is a barrier to its implementation. We aimed to determine whether de-escalation from an antipseudomonal ß-lactam to a narrower-spectrum drug was non-inferior to continuing the antipseudomonal drug in patients with Enterobacterales bacteraemia. METHODS: An open-label, pragmatic, randomised trial was performed in 21 Spanish hospitals. Patients with bacteraemia caused by Enterobacterales susceptible to one of the de-escalation options and treated empirically with an antipseudomonal ß-lactam were eligible. Patients were randomly assigned (1:1; stratified by urinary source) to de-escalate to ampicillin, trimethoprim-sulfamethoxazole (urinary tract infections only), cefuroxime, cefotaxime or ceftriaxone, amoxicillin-clavulanic acid, ciprofloxacin, or ertapenem in that order according to susceptibility (de-escalation group), or to continue with the empiric antipseudomonal ß-lactam (control group). Oral switching was allowed in both groups. The primary outcome was clinical cure 3-5 days after end of treatment in the modified intention-to-treat (mITT) population, formed of patients who received at least one dose of study drug. Safety was assessed in all participants. Non-inferiority was declared when the lower bound of the 95% CI of the absolute difference in cure rate was above the -10% non-inferiority margin. This trial is registered with EudraCT (2015-004219-19) and ClinicalTrials.gov (NCT02795949) and is complete. FINDINGS: 2030 patients were screened between Oct 5, 2016, and Jan 23, 2020, of whom 171 were randomly assigned to the de-escalation group and 173 to the control group. 164 (50%) patients in the de-escalation group and 167 (50%) in the control group were included in the mITT population. 148 (90%) patients in the de-escalation group and 148 (89%) in the control group had clinical cure (risk difference 1·6 percentage points, 95% CI -5·0 to 8·2). The number of adverse events reported was 219 in the de-escalation group and 175 in the control group, of these, 53 (24%) in the de-escalation group and 56 (32%) in the control group were considered severe. Seven (5%) of 164 patients in the de-escalation group and nine (6%) of 167 patients in the control group died during the 60-day follow-up. There were no treatment-related deaths. INTERPRETATION: De-escalation from an antipseudomonal ß-lactam in Enterobacterales bacteraemia following a predefined rule was non-inferior to continuing the empiric antipseudomonal drug. These results support de-escalation in this setting. FUNDING: Plan Nacional de I+D+i 2013-2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases; Spanish Clinical Research and Clinical Trials Platform, co-financed by the EU; European Development Regional Fund "A way to achieve Europe", Operative Program Intelligence Growth 2014-2020.

Statistical analysis plan for the multicenter, open, randomized controlled clinical trial to assess the efficacy and safety of intravenous tirofiban vs aspirin in acute ischemic stroke due to tandem lesion, undergoing recanalization therapy by endovascular treatment (ATILA trial).

RATIONALE: In-stent reocclusion after endovascular therapy has a negative impact on outcomes in acute ischemic stroke (AIS) due to tandem lesions (TL). Optimal antiplatelet therapy approach in these patients to avoid in-stent reocclusion is yet to be elucidated. AIMS: To assess efficacy and safety of intravenous tirofiban versus intravenous aspirin in patients undergoing MT plus carotid stenting in the setting of AIS due to TL. SAMPLE SIZE ESTIMATES: Two hundred forty patients will be enrolled, 120 in every treatment arm. METHODS AND DESIGN: A multicenter, prospective, randomized, controlled (aspirin group), assessor-blinded clinical trial will be conducted. Patients fulfilling the inclusion criteria will be randomized at MT onset to the experimental or control group (1:1). Intravenous aspirin will be administered at a 500-mg single dose and tirofiban at a 500-mcg bolus followed by a 200-mcg/h infusion during the first 24 h. All patients will be followed for up to 3 months. STUDY OUTCOMES: Primary efficacy outcome will be the proportion of patients with carotid in-stent thrombosis within the first 24 h after MT. Primary safety outcome will be the rate of symptomatic intracranial hemorrhage. DISCUSSION: This will be the first clinical trial to assess the best antiplatelet therapy to avoid in-stent thrombosis after MT in patients with TL. TRIAL REGISTRATION: The trial is registered as NCT05225961. February, 7th, 2022.

Randomised, open-label, non-inferiority clinical trial on the efficacy and safety of a 7-day vs 14-day course of antibiotic treatment for uncomplicated enterococcal bacteraemia: the INTENSE trial protocol.

INTRODUCTION: Enterococcus spp is responsible for 8%-15% of total bacteraemias with an associated global mortality around 23%-30%. Regarding the clinical management of enterococcal bacteraemia, the evidence on the duration of antibiotic treatment is scarce and the studies do not discriminate between complicated and uncomplicated bacteraemia. METHODS: The INTENSE study is a multicentre, open-label, randomised, pragmatic, phase-IV clinical trial to demonstrate the non-inferiority of a 7-day vs 14-day course for the treatment of uncomplicated enterococcal bacteraemia and incorporating the early switching to oral antibiotics when feasible. The primary efficacy endpoint is the clinical cure at day 30±2 after the end of the treatment. Secondary endpoints will include the rate of relapse or infective endocarditis, length of stay, duration of intravenous therapy, Clostridioides difficile infection and the evaluation of the safety of both treatment arms through the recording and analysis of adverse events. For a 6% non-inferiority margin and considering a 5% withdrawal rate, 284 patients will be included. ANALYSIS: The difference in proportions with one-sided 95% CIs will be calculated for the clinical cure rate using the control group as reference. For secondary categorical endpoints, a similar analysis will be performed and Mann-Whitney U-test will be used to compare median values of quantitative variables. A superiority analysis applying the response adjusted for days of antibiotic risk will be performed if there were incidents in recruitment; will allow obtaining results with 194 patients recruited. ETHICS AND DISSEMINATION: The study has obtained the authorisation from the Spanish Regulatory Authority, the approval of the ethics committee and the agreement of the directors of each centre. Data will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05394298.

Efficacy and safety of different antimicrobial DURATions for the treatment of Infections associated with Osteosynthesis Material implanted after long bone fractures (DURATIOM): Protocol for a randomized, pragmatic trial.

BACKGROUND: Infection associated with osteosynthesis material (IOM) is one of the most feared and challenging complications of trauma surgery and can cause significant functional loss, requiring multiple interventions and excessive consumption of antimicrobials. Evidence is needed about the best surgical procedure and the duration of antibiotic treatment according to the age of the implant or onset of infection symptoms, as it considers the biofilm formation and the state of fracture healing. There were not clinical trials evaluating the optimal duration of antibiotic therapy in IOM when implant is retained. Because there are antibiotics that have proven to be effective for the treatment of infection associated to implant, mainly in PJI, these antibiotics could be used in these infections. Investigating whether shorter duration of treatment is a priority in infectious diseases, as a way to reduce the exposure to antibiotics and help in controlling antimicrobial resistance and avoiding unnecessary adverse events and cost. We aim to describe the hypothesis, objectives, design, variables and procedures for a pragmatic randomized controlled trial comparing different durations of antibiotic treatment in IOM after long bone fractures treated with debridement and implant retention. METHODS AND DESIGN: This is a multicenter, open-label, non-inferiority, randomized, controlled, pragmatic phase 3 trial, comparing different durations of antibiotic treatment in IOM after long bone fractures treated with debridement and implant retention. Patients with microbiologically confirmed IOM will be included. Eligible patients are those older than 14 years, with early IOM (up to 2 weeks after the implant surgery) and delayed IOM (between 3 and 10 weeks after the implant surgery) with stabilized fracture and absence of bone exposure who sign the informed consent. Randomization will be 1:1 to receive a short-term antibiotic treatment (8 weeks in early IOM and 12 weeks in delayed IOM) or a long-term antibiotic treatment (12 weeks in early IOM or until fracture healing or implant removal in delayed IOM). The antibiotic treatment will be that used in routine practice by the specialist in infectious diseases. The primary outcome is the composited variable "cure" that includes clinical cure, radiological healing, and definitive soft tissue coverage, which will be evaluated in the test of cure at 12 months after the end of antibiotic therapy. Adverse events, resistance development during therapy and functional status will be collected. A total of 364 patients are needed to show a 10% non-inferiority margin, with 80% power and 5% one-sided significance level. DISCUSSION: If the hypothesis of non-inferiority of short vs. long antibiotic treatments is demonstrated, and the efficacy of antibiotics with less ecological impact in long treatments, the impact on reduction of bacterial resistance, toxicity and health costs will be observed. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov (NCT05294796) on Jan 26th 2022 and at the European Union Drug Regulating Authorities Clinical Trials (EUDRACT) (2021-003914-38) on Jul 16th 2021. The Sponsor Study Code is DURATIOM.

Safety and efficacy of tirofiban in acute ischemic stroke due to tandem lesions undergoing mechanical thrombectomy: A multicenter randomized clinical trial (ATILA) protocol.

Background: In-stent thrombosis after mechanical thrombectomy (MT) worsen outcomes in acute ischemic stroke (AIS) due to tandem lesions (TL). Although an optimal antiplatelet therapy is needed, the best approach to avoid in-stent thrombosis is yet to be elucidated. Hypothesis: Low-dose intravenous tirofiban is superior to intravenous aspirin in avoiding in-stent thrombosis in patients undergoing MT plus carotid stenting in the setting of AIS due to TL. Methods: The ATILA-trial is a multicenter, prospective, phase IV, randomized, controlled (aspirin group as control), assessor-blinded clinical trial. Patients fulfilling inclusion criteria (AIS due to TL, ASPECTS ⩾ 6, pre-stroke modified Rankin Scale ⩽2 and onset <24 h) will be randomized (1:1) at MT onset to experimental (intravenous tirofiban) or control group (intravenous aspirin). Intravenous aspirin will be administered at a 500 mg single dose and tirofiban at a 500 µg bolus followed by a 200 µg/h infusion during first 22 h. All patients will be followed up to 3 months. Sample size estimated is 240 patients. Outcomes: The primary efficacy outcome is the proportion of patients with carotid in-stent thrombosis within the first 24 h after MT. The primary safety outcome is the rate of symptomatic intracranial hemorrhage. Secondary outcomes include functional independence defined as modified Rankin Scale 0-2, proportion of patients undergoing rescue therapy due to in-stent aggregation during MT and carotid reocclusion at 30 days. Discussion: ATILA-trial will be the first clinical trial regarding the best antiplatelet therapy to avoid in-stent thrombosis after MT in patients with TL. Trial registration: NCT0522596.

Three double-dose reinforced hepatitis B revaccination scheme for patients with cirrhosis unresponsive to the standard regimen: an open-label randomised clinical trial.

OBJECTIVE: We aimed to compare the response rates between two different hepatitis B virus vaccination schedules for cirrhotic subjects who were non-responders to the first three 40 µg doses (month 0-1-2), and identify factors associated with the final response. DESIGN: A total of 120 cirrhotic patients (72.5% decompensated) were randomised at a 1:1 ratio to receive a single 40 µg booster vaccination at month 6 (classical arm) versus an additional round of three new 40 µg doses administered at monthly intervals (experimental arm). The main outcome was the rate of postvaccinal anti-hepatitis B surface antibodies levels ≥10 mIU/mL. RESULTS: Efficacy by ITT analysis was higher in the experimental arm (46.7%) than in the classical one (25%); OR 2.63, p=0.013. The experimental arm increased response rates compared with the classical one from 31% to 68% (OR 4.72; p=0.007), from 24.4% to 50% (OR 3.09; p=0.012) and from 24.4% to 53.8% (OR 3.62; p=0.007), in Child A, Model for End-Stage Liver Disease (MELD) <15 and MELD-Na<15 patients, respectively. Patients with more advanced liver disease did not benefit from the reinforced scheme. Both regimens showed similar safety profiles. Multivariable analysis showed that the experimental treatment was independently response associated when adjusted across three logistic regression models indicating equivalent cirrhosis severity. CONCLUSION: For cirrhotic patients, the revaccination of non-responders to the first three dose cycle, with three additional 40 µg doses, achieved significantly better response rates to those obtained with an isolated 40 µg booster dose. TRIAL REGISTRATION NUMBER: NCT01884415.

Clinical and Ecological Impact of an Educational Program to Optimize Antibiotic Treatments in Nursing Homes (PROA-SENIOR): A Cluster, Randomized, Controlled Trial and Interrupted Time-Series Analysis.

BACKGROUND: Antimicrobial stewardship programs (ASPs) are recommended in nursing homes (NHs), although data are limited. We aimed to determine the clinical and ecological impact of an ASP for NHs. METHODS: We performed a cluster, randomized, controlled trial and a before-after study with interrupted time-series analyses in 14 NHs for 30 consecutive months from July 2018 to December 2020 in Andalusia, Spain. Seven facilities implemented an ASP with a bundle of 5 educational measures (general ASP) and 7 added 1-to-1 educational interviews (experimental ASP). The primary outcome was the overall use of antimicrobials, calculated monthly as defined daily doses (DDD) per 1000 resident days (DRD). RESULTS: The total mean antimicrobial consumption decreased by 31.2% (-16.72 DRD; P = .045) with respect to the preintervention period; the overall use of quinolones and amoxicillin-clavulanic acid dropped by 52.2% (P = .001) and 42.5% (P = .006), respectively; and the overall prevalence of multidrug-resistant organisms (MDROs) decreased from 24.7% to 17.4% (P = .012). During the intervention period, 12.5 educational interviews per doctor were performed in the experimental ASP group; no differences were found in the total mean antimicrobial use between groups (-14.62 DRD; P = .25). Two unexpected coronavirus disease 2019 waves affected the centers increasing the overall mean use of antimicrobials by 40% (51.56 DRD; P < .0001). CONCLUSIONS: This study suggests that an ASP for NHs appears to be associated with a decrease in total consumption of antimicrobials and prevalence of MDROs. This trial did not find benefits associated with educational interviews, probably due to the coronavirus disease 2019 pandemic. Clinical Trials Registration. NCT03543605.

Study protocol for a randomized clinical trial to assess 7 versus 14-days of treatment for Pseudomonas aeruginosa bloodstream infections (SHORTEN-2 trial).

BACKGROUND: Research priorities in Antimicrobial Stewardship (AMS) have rapidly evolved in the last decade. The need for a more efficient use of antimicrobials have fueled plenty of studies to define the optimal duration for antibiotic treatments, and yet, there still are large areas of uncertainty in common clinical scenarios. Pseudomonas aeruginosa has been pointed as a priority for clinical research, but it has been unattended by most randomized trials tackling the effectiveness of short treatments. The study protocol of the SHORTEN-2 trial is presented as a practical example of new ways to approach common obstacles for clinical research in AMS. OBJECTIVE: To determine whether a 7-day course of antibiotics is superior to 14-day schemes for treating bloodstream infections by P. aeruginosa (BSI-PA). METHODS: A superiority, open-label, randomized controlled trial will be performed across 30 Spanish hospitals. Adult patients with uncomplicated BSI-PA will be randomized to receive a 7 versus 14-day course of any active antibiotic. The primary endpoint will be the probability for the 7-day group of achieving better outcomes than the control group, assessing altogether clinical effectiveness, severe adverse events, and antibiotic exposure through a DOOR/RADAR analysis. Main secondary endpoints include treatment failure, BSI-PA relapses, and mortality. A superiority design was set for the primary endpoint and non-inferiority for treatment failure, resulting in a sample size of 304 patients. CONCLUSIONS: SHORTEN-2 trial aligns with some of the priorities for clinical research in AMS. The implementation of several methodological innovations allowed overcoming common obstacles, like feasible sample sizes or measuring the clinical impact and unintended effects. TRIAL REGISTRATION: EudraCt: 2021-003847-10; ClinicalTrials.gov: NCT05210439.

Factors associated with recruitment success in the phase 2a study of aztreonam-avibactam development programme: a descriptive qualitative analysis among sites in Spain.

OBJECTIVE: Successful clinical trials are subject to recruitment. Recently, the REJUVENATE trial, a prospective phase 2a open-label, single-arm interventional clinical trial conducted within the Innovative Medicines Initiative-supported Combatting Bacterial Resistance in Europe-Carbapenem Resistance project, was published, with 85% of the recruitment performed in Spain. We analysed the recruitment success in this trial by establishing a model of recruitment practice. METHODS: A descriptive qualitative study was performed from May 2016 to October 2017 at 10 participating Spanish centres. Data were extracted from: (1) feasibility questionnaires to assess the centre's potential for patient enrolment; (2) delegation of responsibility records; (3) pre-screening records including an anonymised list of potentially eligible and (4) screening and enrolment records. A descriptive analysis of the features was performed by the participating centre. Pearson's and Spearman's correlation coefficients were calculated to determine factors of recruitment success. RESULTS: The highest recruitment rate was observed in Hospitals 3 and 6 (58.8 and 47.0 patients per month, respectively). All the study teams were multidisciplinary with a median of 15 members (range: 7-22). Only Hospitals 3, 5 and 6 had dedicated nursing staff appointed exclusively to this study. Moreover, in those three hospitals and in Hospital 9, the study coordinator performed exclusive functions as a research planner, and did not assume these functions for the other hospitals. The univariate analysis showed a significant association between recruitment success and months of recruitment (p=0.024), number of staff (p<0.001), higher number of pharmacists (p=0.005), infectious disease specialists (p<0.001), the presence of microbiologist in the research team (p=0.018) and specifically dedicated nursing staff (p=0.036). CONCLUSIONS: The existence of broad multidisciplinary teams with staff dedicated exclusively to the study as well as the implementation of a well-designed local patient assessment strategy were the essential optimisation factors for recruitment success in Spain. TRIAL REGISTRATION NUMBER: NCT02655419; EudraCT 2015-002726-39; analysis of pre-screened patients.

Effectiveness of Fosfomycin for the Treatment of Multidrug-Resistant Escherichia coli Bacteremic Urinary Tract Infections: A Randomized Clinical Trial.

Importance: The consumption of broad-spectrum drugs has increased as a consequence of the spread of multidrug-resistant (MDR) Escherichia coli. Finding alternatives for these infections is critical, for which some neglected drugs may be an option. Objective: To determine whether fosfomycin is noninferior to ceftriaxone or meropenem in the targeted treatment of bacteremic urinary tract infections (bUTIs) due to MDR E coli. Design, Setting, and Participants: This multicenter, randomized, pragmatic, open clinical trial was conducted at 22 Spanish hospitals from June 2014 to December 2018. Eligible participants were adult patients with bacteremic urinary tract infections due to MDR E coli; 161 of 1578 screened patients were randomized and followed up for 60 days. Data were analyzed in May 2021. Interventions: Patients were randomized 1 to 1 to receive intravenous fosfomycin disodium at 4 g every 6 hours (70 participants) or a comparator (ceftriaxone or meropenem if resistant; 73 participants) with the option to switch to oral fosfomycin trometamol for the fosfomycin group or an active oral drug or parenteral ertapenem for the comparator group after 4 days. Main Outcomes and Measures: The primary outcome was clinical and microbiological cure (CMC) 5 to 7 days after finalization of treatment; a noninferiority margin of 7% was considered. Results: Among 143 patients in the modified intention-to-treat population (median [IQR] age, 72 [62-81] years; 73 [51.0%] women), 48 of 70 patients (68.6%) treated with fosfomycin and 57 of 73 patients (78.1%) treated with comparators reached CMC (risk difference, -9.4 percentage points; 1-sided 95% CI, -21.5 to ∞ percentage points; P = .10). While clinical or microbiological failure occurred among 10 patients (14.3%) treated with fosfomycin and 14 patients (19.7%) treated with comparators (risk difference, -5.4 percentage points; 1-sided 95% CI, -∞ to 4.9; percentage points; P = .19), an increased rate of adverse event-related discontinuations occurred with fosfomycin vs comparators (6 discontinuations [8.5%] vs 0 discontinuations; P = .006). In an exploratory analysis among a subset of 38 patients who underwent rectal colonization studies, patients treated with fosfomycin acquired a new ceftriaxone-resistant or meropenem-resistant gram-negative bacteria at a decreased rate compared with patients treated with comparators (0 of 21 patients vs 4 of 17 patients [23.5%]; 1-sided P = .01). Conclusions and Relevance: This study found that fosfomycin did not demonstrate noninferiority to comparators as targeted treatment of bUTI from MDR E coli; this was due to an increased rate of adverse event-related discontinuations. This finding suggests that fosfomycin may be considered for selected patients with these infections. Trial Registration: ClinicalTrials.gov Identifier: NCT02142751.

Seven-versus 14-day course of antibiotics for the treatment of bloodstream infections by Enterobacterales: a randomized, controlled trial.

OBJECTIVE: To prove that 7-day courses of antibiotics for bloodstream infections caused by members of the Enterobacterales (eBSIs) allow a reduction in patients' exposure to antibiotics while achieving clinical outcomes similar to those of 14-day schemes. METHODS: A randomized trial was performed. Adult patients developing eBSI with appropriate source control were assigned to 7 or 14 days of treatment, and followed 28 days after treatment cessation; treatments could be resumed whenever necessary. The primary endpoint was days of treatment at the end of follow-up. Clinical outcomes included clinical cure, relapse of eBSI and relapse of fever. A superiority margin of 3 days was set for the primary endpoint, and a non-inferiority margin of 10% was set for clinical outcomes. Efficacy and safety were assessed together with a DOOR/RADAR (desirability of outcome ranking and response adjusted for duration of antibiotic risk) analysis. RESULTS: 248 patients were assigned to 7 (n = 119) or 14 (n = 129) days of treatment. In the intention-to-treat analysis, median days of treatment at the end of follow-up were 7 and 14 days (difference 7, 95%CI 7-7). The non-inferiority margin was also met for clinical outcomes, except for relapse of fever (-0.2%, 95%CI -10.4 to 10.1). The DOOR/RADAR showed that 7-day schemes had a 77.7% probability of achieving better results than 14-day treatments. CONCLUSIONS: 7-day schemes allowed a reduction in antibiotic exposure of patients with eBSI while achieving outcomes similar to those of 14-day schemes. The possibility of relapsing fever in a limited number of patients, without relevance to final outcomes, may not be excluded, but was overcome by the benefits of shortening treatments.

Temocillin versus meropenem for the targeted treatment of bacteraemia due to third-generation cephalosporin-resistant Enterobacterales (ASTARTÉ): protocol for a randomised, pragmatic trial.

INTRODUCTION: Alternatives to carbapenems are needed in the treatment of third-generation cephalosporin-resistant Enterobacterales (3GCR-E). Temocillin is a suitable candidate, but comparative randomised studies are lacking. The objective is to investigate if temocillin is non-inferior to carbapenems in the targeted treatment of bacteraemia due to 3GCR-E. METHODS AND ANALYSIS: Multicentre, open-label, randomised, controlled, pragmatic phase 3 trial. Patients with bacteraemia due to 3GCR-E will be randomised to receive intravenously temocillin (2 g three times a day) or carbapenem (meropenem 1 g three times a day or ertapenem 1 g once daily). The primary endpoint will be clinical success 7-10 days after end of treatment with no recurrence or death at day 28. Adverse events will be collected; serum levels of temocillin will be investigated in a subset of patients. For a 10% non-inferiority margin, 334 patients will be included (167 in each study arm). For the primary analysis, the absolute difference with one-sided 95% CI in the proportion of patients reaching the primary endpoint will be compared in the modified intention-to-treat population. ETHICS AND DISSEMINATION: The study started after approval of the Spanish Regulatory Agency and the reference institutional review board. Data will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04478721.

Combination of Tocilizumab and Steroids to Improve Mortality in Patients with Severe COVID-19 Infection: A Spanish, Multicenter, Cohort Study.

BACKGROUND: We aimed to determine the impact of tocilizumab use on severe COVID-19 (coronavirus disease 19) pneumonia mortality. METHODS: We performed a multicentre retrospective cohort study in 18 tertiary hospitals in Spain from March to April 2020. Consecutive patients admitted with severe COVID-19 treated with tocilizumab were compared to patients not treated with tocilizumab, adjusting by inverse probability of the treatment weights (IPTW). Tocilizumab's effect in patients receiving steroids during the 48 h following inclusion was analysed. RESULTS: During the study period, 506 patients with severe COVID-19 fulfilled the inclusion criteria. Among them, 268 were treated with tocilizumab and 238 patients were not. Median time to tocilizumab treatment from onset of symptoms was 11 days [interquartile range (IQR) 8-14]. Global mortality was 23.7%. Mortality was lower in patients treated with tocilizumab than in controls: 16.8% versus 31.5%, hazard ratio (HR) 0.514 [95% confidence interval (95% CI) 0.355-0.744], p < 0.001; weighted HR 0.741 (95% CI 0.619-0.887), p = 0.001. Tocilizumab treatment reduced mortality by 14.7% relative to no tocilizumab treatment [relative risk reduction (RRR) 46.7%]. We calculated a number necessary to treat of 7. Among patients treated with steroids, mortality was lower in those treated with tocilizumab than in those treated with steroids alone [10.9% versus 40.2%, HR 0.511 (95% CI 0.352-0.741), p = 0.036; weighted HR 0.6 (95% CI 0.449-0.804), p < 0.001] (interaction p = 0.094). CONCLUSIONS: These results show that survival of patients with severe COVID-19 is higher in those treated with tocilizumab than in those not treated and that tocilizumab's effect adds to that of steroids administered to non-intubated patients with COVID-19 during the first 48 h of presenting with respiratory failure despite oxygen therapy. Randomised controlled studies are needed to confirm these results. TRIAL REGISTRATION: European Union electronic Register of Post-Authorization Studies (EU PAS Register) identifier, EUPAS34415.

Quasiexperimental intervention study protocol to optimise the use of new antibiotics in Spain: the NEW_SAFE project.

INTRODUCTION: Ceftaroline, tedizolid, dalbavancin, ceftazidime-avibactam and ceftolozane-tazobactam are novel antibiotics used to treat infections caused by multidrug-resistant pathogens (MDR). Their use should be supervised and monitored as part of an antimicrobial stewardship programme (ASP). Appropriate use of the new antibiotics will be improved by including consensual indications for their use in local antibiotic guidelines, together with educational interventions providing advice to prescribers to ensure that the recommendations are clearly understood. METHODS AND ANALYSIS: This study will be implemented in two phases. First, a preliminary historical cohort (2017-2019) of patients from 13 Andalusian hospitals treated with novel antibiotics will be analysed. Second, a quasiexperimental intervention study will be developed with an interrupted time-series analysis (2020-2021). The intervention will consist of an educational interview between prescribers and ASP leaders at each hospital to reinforce the proper use of novel antibiotics. The educational intervention will be based on a consensus guideline designed and disseminated by leaders after the retrospective cohort data have been analysed. The outcomes will be acceptance of the intervention and appropriateness of prescription. Incidence of infection and colonisation with MDR organisms as well as incidence of Clostridioides difficile infection will also be analysed. Changes in prescription quality between periods and the safety profile of the antibiotics in terms of mortality rate and readmissions will also be measured. ETHICS AND DISSEMINATION: Ethical approval will be obtained from the Andalusian Coordinating Institutional Review Board. The study is being conducted in compliance with the protocol and regulatory requirements consistent with International Council of Harmonisation E6 Good Clinical Practice and the ethical principles of the latest version of the Declaration of Helsinki. The results will be published in peer-reviewed journals and disseminated at national and international conferences. TRIAL REGISTRATION NUMBER: NCT03941951; Pre-results.

Assessing the impact on intestinal microbiome and clinical outcomes of antibiotherapy optimisation strategies in haematopoietic stem cell transplant recipients: study protocol for the prospective multicentre OptimBioma study.

INTRODUCTION: Haematopoietic stem cell transplantation (HSCT) is a life-saving treatment for a number of haematological diseases. Graft versus host disease (GVHD) is its main complication and hampers survival. There is strong evidence that intestinal microbiota diversity of the recipient may increase the risk of GVHD worsening survival. Antibiotic regimens used during the early phase of the transplant may influence clinical outcomes by reducing intestinal microbiota diversity. Present guidelines of European Conference on Infections in Leukaemia exhort to optimising antibiotic use in haematological patients including HSCT recipients. The present study aims to investigate if, in HSCT recipients, the optimisation of antibacterial use may preserve intestinal microbiota composition reducing the incidence and severity of acute GVHD and improving relevant clinical outcomes. METHODS AND ANALYSIS: This is a prospective longitudinal observational study of two cohorts of HSCT recipients: (1) the intervention cohort includes patients treated in centres in which a predefined strategy of antibiotherapy optimisation is implemented, with the objective of optimising and reducing antibiotic administration according to clinical criteria and (2) the control cohort includes patients treated in centres in which a classic permissive strategy of antibiotic prophylaxis and treatment is used. Adult patient receiving a first HSCT as a treatment for any haematological condition are included. Clinical variables are prospectively recorded and up to five faecal samples are collected for microbiota characterisation at prestablished peritransplant time points. Patients are followed since the preconditioning phase throughout 1-year post-transplant and four follow-up visits are scheduled. Faecal microbiota composition and diversity will be compared between both cohorts along with acute GVHD incidence and severity, severe infections rate, mortality and overall and disease-free survival. ETHICS AND DISSEMINATION: The study was approved between 2017 and 2018 by the Ethical Committees of participant centres. Study results will be disseminated through peer-reviewed journals and national and international scientific conferences. TRIAL REGISTRATION NUMBER: NCT03727113.

Pharmacokinetics and safety of aztreonam/avibactam for the treatment of complicated intra-abdominal infections in hospitalized adults: results from the REJUVENATE study.

OBJECTIVES: To investigate pharmacokinetics (PK) and safety (primary objectives) and efficacy (secondary objective) of the investigational monobactam/ß-lactamase inhibitor combination aztreonam/avibactam in patients with complicated intra-abdominal infection (cIAI). METHODS: This Phase 2a open-label, multicentre study (NCT02655419; EudraCT 2015-002726-39) enrolled adults with cIAI into sequential cohorts for 5-14 days treatment. Cohort 1 patients received an aztreonam/avibactam loading dose of 500/137 mg (30 min infusion), followed by maintenance doses of 1500/410 mg (3 h infusions) q6h; Cohort 2 received 500/167 mg (30 min infusion), followed by 1500/500 mg (3 h infusions) q6h. Cohort 3 was an extension of exposure at the higher dose regimen. Doses were adjusted for creatinine clearance of 31-50 mL/min (Cohorts 2 + 3). All patients received IV metronidazole 500 mg q8h. PK, safety and efficacy were assessed. RESULTS: Thirty-four patients (Cohort 1, n = 16; Cohorts 2 + 3, n = 18) comprised the modified ITT (MITT) population. Mean exposures of aztreonam and avibactam in Cohorts 2 + 3 were consistent with those predicted to achieve joint PK/pharmacodynamic target attainment in >90% patients. Adverse events (AEs) were similar between cohorts. The most common AEs were hepatic enzyme increases [n = 9 (26.5%)] and diarrhoea [n = 5 (14.7%)]. Clinical cure rates at the test-of-cure visit overall were 20/34 (58.8%) (MITT) and 14/23 (60.9%) (microbiological-MITT population). CONCLUSIONS: Observed AEs were consistent with the known safety profile of aztreonam monotherapy, with no new safety concerns identified. These data support selection of the aztreonam/avibactam 500/167 mg (30 min infusion) loading dose and 1500/500 mg (3 h infusions) maintenance dose q6h regimen, in patients with creatinine clearance >50 mL/min, for the Phase 3 development programme.

Opportunities for antibiotic optimisation and outcome improvement in patients with negative blood cultures: study protocol for a cluster-randomised crossover trial, the NO-BACT study.

INTRODUCTION: Patients with negative blood cultures (BCx) represent 85%-90% of all patients with BCx taken during hospital admission. This population usually includes a heterogeneous group of patients admitted with infectious diseases or febrile syndromes that require a blood culture. There is very little evidence of the clinical characteristics and antibiotic treatment given to these patients. METHODS AND ANALYSIS: In a preliminary exploratory prospective cohort study of patients with BCx taken, the clinical/therapeutic characteristics and outcomes/antimicrobial stewardship opportunities of a population of patients with negative BCx will be analysed. In the second phase, using a cluster randomised crossover design, the implementation of an antimicrobial stewardship intervention targeting patients with negative BCx will be evaluated in terms of quality of antimicrobial use (duration and de-escalation), length of hospital stay and mortality. ETHICS AND DISSEMINATION: This study has been and registered with clinicaltrials.gov. The findings of our study may support the implementation in clinical practice of an antimicrobial stewardship intervention to optimise the use of antibiotics in patients with negative BCx. The results of this study will be published in peer-reviewed journals and disseminated at national and international conferences. TRIAL REGISTRATION NUMBER: NCT03535324.

Colistin versus meropenem in the empirical treatment of ventilator-associated pneumonia (Magic Bullet study): an investigator-driven, open-label, randomized, noninferiority controlled trial.

BACKGROUND: Colistin is recommended in the empirical treatment of ventilator-associated pneumonia (VAP) with a high prevalence of carbapenem-resistant gram-negative bacilli (CR-GNB). However, the efficacy and safety of colistin are not well defined. METHODS: A multicenter prospective randomized trial conducted in 32 European centers compared the efficacy and safety of colistin (4.5 million unit loading dose followed by a maintenance dose of 3 million units every 8 h) versus meropenem (2 g every 8 h), both in combination with levofloxacin (500 mg every 12 h) for 7-14 days in patients with late VAP. Between May 2012 and October 2015, 232 patients were randomly assigned to the 2 treatment groups. The primary endpoint was mortality at 28 days after randomization in the microbiologically modified intention-to-treat (mMITT) population. Secondary outcomes included clinical and microbiological cure, renal function at the end of the treatment, and serious adverse events. The study was interrupted after the interim analysis due to excessive nephrotoxicity in the colistin group; therefore, the sample size was not achieved. RESULTS: A total of 157 (67.7%) patients were included in the mMITT population, 36 of whom (22.9%) had VAP caused by CR-GNB. In the mMITT population, no significant difference in mortality between the colistin group (19/82, 23.2%) and the meropenem group (19/75, 25.3%) was observed, with a risk difference of - 2.16 (- 15.59 to 11.26, p = 0.377); the noninferiority of colistin was not demonstrated due to early termination and limited number of patients infected by carbapenem-resistant pathogens. Colistin plus levofloxacin increased the incidence of renal failure (40/120, 33.3%, versus 21/112, 18.8%; p = 0.012) and renal replacement therapy (11/120, 9.1%, versus 2/112, 1.8%; p = 0.015). CONCLUSIONS: This study did not demonstrate the noninferiority of colistin compared with meropenem, both combined with levofloxacin, in terms of efficacy in the empirical treatment of late VAP but demonstrated the greater nephrotoxicity of colistin. These findings do not support the empirical use of colistin for the treatment of late VAP due to early termination. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01292031. Registered 9 February 2011.

Optimisation of empirical antimicrobial therapy in patients with haematological malignancies and febrile neutropenia (How Long study): an open-label, randomised, controlled phase 4 trial.

BACKGROUND: Continuation of empirical antimicrobial therapy (EAT) for febrile neutropenia in patients with haematological malignancies until neutrophil recovery could prolong the therapy unnecessarily. We aimed to establish whether EAT discontinuation driven by a clinical approach regardless of neutrophil recovery would optimise the duration of therapy. METHODS: We did an investigator-driven, superiority, open-label, randomised, controlled phase 4 clinical trial in six academic hospitals in Spain. Eligible patients were adults with haematological malignancies or haemopoietic stem-cell transplantation recipients, with high-risk febrile neutropenia without aetiological diagnosis. An independent, computer-generated randomisation sequence was used to randomly enrol patients (1:1) to the experimental or control group. Investigators were masked to assignment only before randomisation. EAT based on an antipseudomonal ß-lactam drug as monotherapy (ceftazidime or cefepime, meropenem or imipenem, or piperacillin-tazobactam) or as combination therapy (with an aminoglycoside, fluoroquinolone, or glycopeptide) was started according to local protocols and following international guidelines and recommendations. For the experimental group, EAT was withdrawn after 72 h or more of apyrexia plus clinical recovery; for the control group, treatment was withdrawn when the neutrophil count was also 0·5 × 109 cells per L or higher. The primary efficacy endpoint was the number of EAT-free days. Primary analyses were done in the intention-to-treat population. Efficacy and safety analyses were done in the intention-to-treat population and the per-protocol population. This trial is registered with ClinicalTrials.gov, number NCT01581333. FINDINGS: Between April 10, 2012, and May 31, 2016, 157 episodes among 709 patients assessed for eligibility were included in analyses. 78 patients were randomly assigned to the experimental group and 79 to the control group. The mean number of EAT-free days was significantly higher in the experimental group than in the control group (16·1 [SD 6·3] vs 13·6 [7·2], absolute difference -2·4 [95% CI -4·6 to -0·3]; p=0·026). 636 adverse events were reported (341 in the experimental group vs 295 in the control group; p=0·057) and most (580 [91%]; 323 in the experimental group vs 257 in the control group) were considered mild or moderate (grade 1-2). The most common adverse events in the experimental versus the control group were mucositis (28 [36%] of 78 patients vs 20 [25%] of 79 patients), diarrhoea (23 [29%] of 78 vs 24 [30%] of 79), and nausea and vomiting (20 [26%] of 78 vs 22 [28%] of 79). 56 severe adverse events were reported, 18 in the experimental group and 38 in the control group. One patient died in the experimental group (from hepatic veno-occlusive disease after an allogeneic haemopoietic stem-cell transplantation) and three died in the control group (one from multiorgan failure, one from invasive pulmonary aspergillosis, and one from a post-chemotherapy intestinal perforation). INTERPRETATION: In high-risk patients with haematological malignancies and febrile neutropenia, EAT can be discontinued after 72 h of apyrexia and clinical recovery irrespective of their neutrophil count. This clinical approach reduces unnecessary exposure to antimicrobials and it is safe. FUNDING: Instituto de Salud Carlos III, Spanish Ministry of Economy (PI11/02674).

Targeted simplification versus antipseudomonal broad-spectrum beta-lactams in patients with bloodstream infections due to Enterobacteriaceae (SIMPLIFY): a study protocol for a multicentre, open-label, phase III randomised, controlled, non-inferiority clinical trial.

INTRODUCTION: Within the context of antimicrobial stewardship programmes, de-escalation of antimicrobial therapy is one of the proposed strategies for reducing the unnecessary use of broad-spectrum antibiotics (BSA). The empirical treatment of nosocomial and some healthcare-associated bloodstream infections (BSI) frequently includes a beta-lactam with antipseudomonal activity as monotherapy or in combination with other drugs, so there is a great opportunity to optimise the empirical therapy based on microbiological data. De-escalation is assumed as standard of care for experts in infectious diseases. However, it is less frequent than it would desirable. METHODS AND ANALYSIS: The SIMPLIFY trial is a multicentre, open-label, non-inferiority phase III randomised controlled clinical trial, designed as a pragmatic 'real-practice' trial. The aim of this trial is to demonstrate the non-inferiority of de-escalation from an empirical beta-lactam with antipseudomonal activity to a targeted narrow-spectrum antimicrobial in patients with BSI due to Enterobacteriaceae. The primary outcome is clinical cure, which will be assessed at the test of cure visit. It will be conducted at 19 Spanish public and university hospitals. ETHICS AND DISSEMINATION: Each participating centre has obtained the approval of the ethics review committee, the agreement of the directors of the institutions and authorisation from the Spanish Regulatory Agency (Agencia Española del Medicamento y Productos Sanitarios). Data will be presented at international conferences and published in peer-reviewed journals. DISCUSSION: Strategies to reduce the use of BSA should be a priority. Most of the studies that support de-escalation are observational, retrospective and heterogeneous. A recent Cochrane review stated that well-designed clinical trials should be conducted to assess the safety and efficacy of de-escalation. TRIAL REGISTRATION NUMBER: The European Union Clinical Trials Register: EudraCT number 2015-004219-19. Clinical trials.gov: NCT02795949. Protocol version: V.2.0, dated 16 May 2016. All items from the WHO Trial Registration Data Set are included in the registry.