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The new R739×5 data set from the Non-Covalent Interactions Atlas series (www.nciatlas.org) focuses on repulsive contacts in molecular complexes, covering organic molecules, sulfur, phosphorus, halogens and noble gases. Information on the repulsive parts of the potential energy surface is crucial for the development of robust empirically parametrized computational methods. We use the new data set of highly accurate CCSD(T)/CBS interaction energies to test existing DFT and semiempirical quantum-mechanical methods. On the example of the PM6 method, we analyze the source of the error and its relation to the difficulties in the description of conformational energies, and we also devise an immediately applicable correction that fixes the most serious uncorrected issues previously encountered in practical calculations. File list (2)download file view on ChemRxiv NCIA_Repulsion_dataset_2020.pdf (1.14 MiB) download file view on ChemRxiv NCIA_Repulsion_dataset_2020_SI.zip (14.00 MiB)

Background: Staphylococcus aureus remains a common cause of ventilatorassociated pneumonia, with little change in infection rates over the past 15 years. This phase 2 study evaluated suvratoxumab, an anti-alpha-toxin monoclonal antibody, in reducing incidence of S. aureus pneumonia in intensive care unit (ICU) subjects on mechanical ventilation (MV). Methods:We did a multicenter, single-dose, randomized, placebo-controlled, doubleblind, phase 2 pilot trial in 9 countries. Eligible subjects were patients in an ICU ≥18 years of age, currently intubated and on MV, positive for S. aureus lower respiratory tract (LRT) colonization as assessed by polymerase chain reaction (PCR) of endotracheal aspirate, and with no diagnosis of new-onset pneumonia. Subjects were excluded if they had confirmed or suspected acute ongoing staphylococcal disease; had received anti-S. aureus antibiotics for >48 hours; had a CPIS ≥6, APACHE-II score ≥25, a SOFA score ≥9; or had active pulmonary disease that would impair the ability to diagnose pneumonia. Subjects were screened for S. aureus lower respiratory tract (LRT) colonization using real-time polymerase chain reaction (PCR).Colonized subjects were randomly assigned 1:1:1 to a single intravenous infusion of suvratoxumab 2000 mg, 5000 mg or placebo. Randomization was stratified by country and by whether subjects received anti-S. aureus systemic antibiotic therapy. Based on pre-defined PK criteria, the 2000 mg arm was discontinued upon the recommendation of the data monitoring committee at an interim analysis. Primary efficacy endpoint was incidence of S. aureus pneumonia, adjudicated by a blinded independent panel, through 30 days post dose in the modified intent-to-treat study population. Primary safety endpoints were Francois et al. Suvratoxumab Ph2 (NCT02296320) D3 5 treatment-emergent AEs assessed through 30 and 90 days, treatment-emergent SAEs, adverse events of special interest, and new onset chronic disease, all assessed through 190 days. Findings: PCR screening of 737 ICU subjects identified 213 with S. aureus colonization; of these, 96 were randomized to receive suvratoxumab 5000 mg and 100 to placebo. At 30 days, 17/96 (17•7%) suvratoxumab and 26/100 (26•0%) placebo subjects had developed S. aureus pneumonia (relative risk reduction, 31.9%; 90% confidence interval [CI], −7•5 to 56•8; P = 0•166). At 30 days, incidences of treatmentemergent adverse events (AEs) and serious AEs were similar in suvratoxumab and placebo groups (90•6% [87/96] vs. 90•0% [90/100] and 37•5% [36/96] vs 32•0% [32/100], respectively). At 90 and 190 days, incidence of treatment-emergent AEs was still similar in suvratoxumab and placebo groups (92.

Background Ceftolozane/tazobactam is approved for treatment of hospital-acquired/ventilator-associated bacterial pneumonia (HABP/VABP) at double the dose approved for other infection sites. Among nosocomial pneumonia subtypes, ventilated HABP (vHABP) is associated with the lowest survival. In the ASPECT-NP randomized, controlled trial, participants with vHABP treated with ceftolozane/tazobactam had lower 28-day all-cause mortality (ACM) than those receiving meropenem. We conducted a series of post hoc analyses to explore the clinical significance of this finding. Methods ASPECT-NP was a multinational, phase 3, noninferiority trial comparing ceftolozane/tazobactam with meropenem for treating vHABP and VABP; study design, efficacy, and safety results have been reported previously. The primary endpoint was 28-day ACM. The key secondary endpoint was clinical response at test-of-cure. Participants with vHABP were a prospectively defined subgroup, but subgroup analyses were not powered for noninferiority testing. We compared baseline and treatment factors, efficacy, and safety between ceftolozane/tazobactam and meropenem in participants with vHABP. We also conducted a retrospective multivariable logistic regression analysis in this subgroup to determine the impact of treatment arm on mortality when adjusted for significant prognostic factors. Results Overall, 99 participants in the ceftolozane/tazobactam and 108 in the meropenem arm had vHABP. 28-day ACM was 24.2% and 37.0%, respectively, in the intention-to-treat population (95% confidence interval [CI] for difference: 0.2, 24.8) and 18.2% and 36.6%, respectively, in the microbiologic intention-to-treat population (95% CI 2.5, 32.5). Clinical cure rates in the intention-to-treat population were 50.5% and 44.4%, respectively (95% CI − 7.4, 19.3). Baseline clinical, baseline microbiologic, and treatment factors were comparable between treatment arms. Multivariable regression identified concomitant vasopressor use and baseline bacteremia as significantly impacting ACM in ASPECT-NP; adjusting for these two factors, the odds of dying by day 28 were 2.3-fold greater when participants received meropenem instead of ceftolozane/tazobactam. Conclusions There were no underlying differences between treatment arms expected to have biased the observed survival advantage with ceftolozane/tazobactam in the vHABP subgroup. After adjusting for clinically relevant factors found to impact ACM significantly in this trial, the mortality risk in participants with vHABP was over twice as high when treated with meropenem compared with ceftolozane/tazobactam. Trial registration clinicaltrials.gov, NCT02070757. Registered 25 February, 2014, clinicaltrials.gov/ct2/show/NCT02070757.