azd0914 and Gonorrhea

Neisseria gonorrhoeae, the causative agent of gonorrhoea, has rapidly evolved from an exquisitely susceptible pathogen into a 'superbug' with the capacity to exhibit an extensively drug resistant (XDR) phenotype. The threat of untreatable gonorrhoea now looms on the horizon while the arsenal of effective antimicrobial agents diminishes with time. Ceftriaxone remains the mainstay of first-line therapy as a single agent or as the backbone of a dual therapy regimen. The implementation of new assays to facilitate 'precision' treatment, based on the prediction of N. gonorrhoeae susceptibility to old anti-gonococcal drugs, may enable sparing use of ceftriaxone in those countries that can afford this technology. A few existing drugs, such as ertapenem, can be repositioned to help manage multi-drug resistant and XDR gonorrhoea. Recent clinical trials involving solithromycin and delafloxacin have generated disappointing results in that both agents failed to show non-inferiority to conventional ceftriaxone-based regimens. At present, zoliflodacin and gepotidacin appear to be the most promising antimicrobial agents in clinical development. Both drugs performed well in eradicating urogenital gonorrhoea in recent Phase 2 trials; however, treatment failures were reported at the oropharyngeal site, which is an important site of infection in men who have sex with men and sex workers. Given this observation, it is unlikely that either of these new agents could be promoted for monotherapy of gonorrhoea. The pre-clinical pipeline remains relatively empty of agents likely to progress to clinical development for gonorrhoea treatment and increased investment into gonorrhoea-specific drug discovery is recommended.

Topics: Acenaphthenes; Anti-Bacterial Agents; Barbiturates; Drug Development; Drug Resistance, Multiple, Bacterial; Gonorrhea; Heterocyclic Compounds, 3-Ring; Humans; Isoxazoles; Macrolides; Morpholines; Neisseria gonorrhoeae; Oxazolidinones; Spiro Compounds; Triazoles

The emergence of high-level resistance to ceftriaxone is giving rise to serious concern about absence of effective treatment options to cure gonococcal infections. Increasing the dosage regimen can be applied to ceftriaxone and azithromycin, but the emergence of high-level resistance has already been reported. Spectinomycin is another active drug but has low efficacy in the treatment of pharyngeal gonorrhoea. Conventional antibiotics could be introduced for gonococcal treatment, but they have some limitations, such as the absence of clinical trials and breakpoint. Combining antibiotics is another promising method to cure patients and to prevent the emergence of resistance. The most important strategy to maintain the efficacy of antibiotics is rapid detection and dissemination control of novel resistant isolate.

Topics: Anti-Bacterial Agents; Azithromycin; Barbiturates; Ceftriaxone; Drug Resistance, Bacterial; Drug Therapy, Combination; Gonorrhea; Humans; Isoxazoles; Macrolides; Morpholines; Neisseria gonorrhoeae; Neisseriaceae Infections; Oxazolidinones; Pharyngitis; Spectinomycin; Spiro Compounds; Triazoles

Topics: Administration, Oral; Adult; Anti-Bacterial Agents; Cross-Over Studies; Gonorrhea; Healthy Volunteers; Humans; Oxazolidinones

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a global threat and novel treatment alternatives are imperative. Herein, susceptibility to the novel antimicrobial zoliflodacin, currently in a global Phase 3 randomized controlled clinical trial for gonorrhoea treatment, was investigated by screening for zoliflodacin GyrB target mutations in publicly available gonococcal genomes and, where feasible, determination of the associated zoliflodacin MIC.. The European Nucleotide Archive was queried using the search term 'Taxon: 485'. DNA sequences from 27 151 gonococcal isolates were analysed and gyrB, gyrA, parC and parE alleles characterized.. GyrB amino acid alterations were rare (97.0% of isolates had a wild-type GyrB sequence). GyrB V470L (2.7% of isolates) was the most prevalent alteration, followed by S467N (0.12%), N. meningitidis GyrB (0.092%), V470I (0.059%), Q468R/P (0.015%), A466T (0.0074%), L425I + L465I (0.0037%), L465I (0.0037%), G482S (0.0037%) and D429V (0.0037%). Only one isolate (0.0037%) carried a substitution in a resistance-associated GyrB codon (D429V), resulting in a zoliflodacin MIC of 8 mg/L. None of the other detected gyrB, gyrA, parC or parE mutations caused a zoliflodacin MIC outside the wild-type MIC distribution.. The zoliflodacin target GyrB was highly conserved among 27 151 global gonococcal isolates cultured in 1928-2021. The single zoliflodacin-resistant clinical isolate (0.0037%) was cultured from a male patient in Japan in 2000. Evidently, this strain has not clonally expanded nor has the gyrB zoliflodacin-resistance mutation disseminated through horizontal gene transfer to other strains. Phenotypic and genomic surveillance, including gyrB mutations, of zoliflodacin susceptibility are imperative.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; DNA Gyrase; DNA Topoisomerase IV; Drug Resistance, Bacterial; Gonorrhea; Humans; Male; Microbial Sensitivity Tests; Mutation; Neisseria gonorrhoeae

Zoliflodacin is a novel spiropyrimidinetrione antibiotic being developed as single oral dose treatment to address the growing global threat of Neisseria gonorrhoeae. To evaluate the cardiac safety of zoliflodacin, a thorough QT/QTc (TQT) study was performed in healthy subjects. In this randomized, double-blind, placebo-controlled, 4-period crossover study, 72 subjects in a fasted state received a single dose of zoliflodacin at 2 g (therapeutic), zoliflodacin at 4 g (supratherapeutic), placebo, and moxifloxacin at 400 mg as a positive comparator. Cardiac repolarization was measured by duration of the corrected QT interval by Fridericia's formula (QTcF). At each time point up to 24 h after zoliflodacin administration, the upper limit of the one-sided 95% confidence interval (CI) for the placebo-corrected change from the predose baseline in QTcF (ΔΔQTcF) was less than 10 ms, indicating an absence of a clinically meaningful increase in QT prolongation. The lower limit of the one-sided multiplicity-adjusted 95% CI of ΔΔQTcF for moxifloxacin was longer than 5 ms at four time points from 1 to 4 h after dosing, demonstrating adequate sensitivity of the QTc measurement. There were no clinically significant effects on heart rate, PR and QRS intervals, electrocardiogram (ECG) morphology, or laboratory values. Treatment-emergent adverse events (AEs) were mild or moderate in severity and transient. This was a negative TQT study according to regulatory guidelines (E14) and confirms that a single oral dose of zoliflodacin is safe and well tolerated. These findings suggest that zoliflodacin is not proarrhythmic and contribute to the favorable assessment of cardiac safety for a single oral dose of zoliflodacin. (This study has been registered at ClinicalTrials.gov under registration no. NCT03613649.).

Topics: Adult; Barbiturates; Cross-Over Studies; Dose-Response Relationship, Drug; Double-Blind Method; Electrocardiography; Fluoroquinolones; Gonorrhea; Healthy Volunteers; Heart Rate; Humans; Isoxazoles; Long QT Syndrome; Morpholines; Oxazolidinones; Spiro Compounds

Novel antimicrobials for treatment of gonorrhoea are imperative. The first-in-class spiropyrimidinetrione zoliflodacin is promising and currently in an international Phase 3 randomized controlled clinical trial (RCT) for treatment of uncomplicated gonorrhoea. We evaluated the in vitro activity of and the genetic conservation of the target (GyrB) and other potential zoliflodacin resistance determinants among 1209 consecutive clinical Neisseria gonorrhoeae isolates obtained from 25 EU/European Economic Area (EEA) countries in 2018 and compared the activity of zoliflodacin with that of therapeutic antimicrobials currently used.. MICs of zoliflodacin, ceftriaxone, cefixime, azithromycin and ciprofloxacin were determined using an agar dilution technique for zoliflodacin or using MIC gradient strip tests or an agar dilution technique for the other antimicrobials. Genome sequences were available for 96.1% of isolates.. Zoliflodacin modal MIC, MIC50, MIC90 and MIC range were 0.125, 0.125, 0.125 and ≤0.004-0.5 mg/L, respectively. The resistance was 49.9%, 6.7%, 1.6% and 0.2% to ciprofloxacin, azithromycin, cefixime and ceftriaxone, respectively. Zoliflodacin did not show any cross-resistance to other tested antimicrobials. GyrB was highly conserved and no zoliflodacin gyrB resistance mutations were found. No fluoroquinolone target GyrA or ParC resistance mutations or mutations causing overexpression of the MtrCDE efflux pump substantially affected the MICs of zoliflodacin.. The in vitro susceptibility to zoliflodacin was high and the zoliflodacin target GyrB was conserved among EU/EEA gonococcal isolates in 2018. This study supports further clinical development of zoliflodacin. However, additional zoliflodacin data regarding particularly the treatment of pharyngeal gonorrhoea, pharmacokinetics/pharmacodynamics and resistance selection, including suppression, would be valuable.

Topics: Anti-Bacterial Agents; Azithromycin; Barbiturates; Ceftriaxone; Ciprofloxacin; Drug Resistance, Bacterial; Europe; Gonorrhea; Humans; Isoxazoles; Microbial Sensitivity Tests; Morpholines; Neisseria gonorrhoeae; Oxazolidinones; Spiro Compounds

The goal of the Sexually Transmitted Infection Clinical Trial Group's Antimicrobial Resistance (AMR) in Neisseria gonorrhoeae (NG) meeting was to assemble experts from academia, government, nonprofit and industry to discuss the current state of research, gaps and challenges in research and technology and priorities and new directions to address the continued emergence of multidrug-resistant NG infections. Topics discussed at the meeting, which will be the focus of this article, include AMR NG global surveillance initiatives, the use of whole genome sequencing and bioinformatics to understand mutations associated with AMR, mechanisms of AMR, and novel antibiotics, vaccines and other methods to treat AMR NG. Key points highlighted during the meeting include: (i) US and International surveillance programs to understand AMR in NG; (ii) the US National Strategy for combating antimicrobial-resistant bacteria; (iii) surveillance needs, challenges, and novel technologies; (iv) plasmid-mediated and chromosomally mediated mechanisms of AMR in NG; (v) novel therapeutic (eg, sialic acid analogs, factor H [FH]/Fc fusion molecule, monoclonal antibodies, topoisomerase inhibitors, fluoroketolides, LpxC inhibitors) and preventative (eg, peptide mimic) strategies to combat infection. The way forward will require renewed political will, new funding initiatives, and collaborations across academic and commercial research and public health programs.

Topics: Anti-Bacterial Agents; Antimicrobial Stewardship; Bacterial Vaccines; Barbiturates; Drug Resistance, Multiple, Bacterial; Epidemiological Monitoring; Gonorrhea; Group Processes; Humans; Isoxazoles; Macrolides; Microbial Sensitivity Tests; Morpholines; Mutation; Neisseria gonorrhoeae; Oxazolidinones; Public Health; Sexually Transmitted Diseases; Spiro Compounds; Topoisomerase Inhibitors; Triazoles; World Health Organization

Antibiotic-resistant Neisseria gonorrhoeae has prompted the development of new therapies. Zoliflodacin is a new antibiotic that inhibits DNA biosynthesis. In this multicenter, phase 2 trial, zoliflodacin was evaluated for the treatment of uncomplicated gonorrhea.. We randomly assigned eligible men and women who had signs or symptoms of uncomplicated urogenital gonorrhea or untreated urogenital gonorrhea or who had had sexual contact in the preceding 14 days with a person who had gonorrhea to receive a single oral dose of zoliflodacin (2 g or 3 g) or a single 500-mg intramuscular dose of ceftriaxone in a ratio of approximately 70:70:40. A test of cure occurred within 6±2 days after treatment, followed by a safety visit 31±2 days after treatment. The primary efficacy outcome measure was the proportion of urogenital microbiologic cure in the microbiologic intention-to-treat (micro-ITT) population.. From November 2014 through December 2015, a total of 179 participants (167 men and 12 women) were enrolled. Among the 141 participants in the micro-ITT population who could be evaluated, microbiologic cure at urogenital sites was documented in 55 of 57 (96%) who received 2 g of zoliflodacin, 54 of 56 (96%) who received 3 g of zoliflodacin, and 28 of 28 (100%) who received ceftriaxone. All rectal infections were cured in all 5 participants who received 2 g of zoliflodacin and all 7 who received 3 g, and in all 3 participants in the group that received ceftriaxone. Pharyngeal infections were cured in 4 of 8 participants (50%), 9 of 11 participants (82%), and 4 of 4 participants (100%) in the groups that received 2 g of zoliflodacin, 3 g of zoliflodacin, and ceftriaxone, respectively. A total of 84 adverse events were reported: 24 in the group that received 2 g of zoliflodacin, 37 in the group that received 3 g of zoliflodacin, and 23 in the group that received ceftriaxone. According to investigators, a total of 21 adverse events were thought to be related to zoliflodacin, and most such events were gastrointestinal.. The majority of uncomplicated urogenital and rectal gonococcal infections were successfully treated with oral zoliflodacin, but this agent was less efficacious in the treatment of pharyngeal infections. (Funded by the National Institutes of Health and Entasis Therapeutics; ClinicalTrials.gov number, NCT02257918 .).

Topics: Administration, Oral; Adolescent; Adult; Anti-Bacterial Agents; Barbiturates; Ceftriaxone; Female; Female Urogenital Diseases; Gonorrhea; Humans; Injections, Intramuscular; Intention to Treat Analysis; Isoxazoles; Male; Male Urogenital Diseases; Microbial Sensitivity Tests; Middle Aged; Morpholines; Neisseria gonorrhoeae; Oxazolidinones; Pharyngeal Diseases; Rectal Diseases; Sexual Partners; Spiro Compounds; Treatment Outcome; Young Adult

With the diminishing effectiveness of current antibacterial therapies, it is critically important to discover agents that operate by a mechanism that circumvents existing resistance. ETX0914, the first of a new class of antibacterial agent targeted for the treatment of gonorrhea, operates by a novel mode-of-inhibition against bacterial type II topoisomerases. Incorporating an oxazolidinone on the scaffold mitigated toxicological issues often seen with topoisomerase inhibitors. Organisms resistant to other topoisomerase inhibitors were not cross-resistant with ETX0914 nor were spontaneous resistant mutants to ETX0914 cross-resistant with other topoisomerase inhibitor classes, including the widely used fluoroquinolone class. Preclinical evaluation of ETX0914 pharmacokinetics and pharmacodynamics showed distribution into vascular tissues and efficacy in a murine Staphylococcus aureus infection model that served as a surrogate for predicting efficacious exposures for the treatment of Neisseria gonorrhoeae infections. A wide safety margin to the efficacious exposure in toxicological evaluations supported progression to Phase 1. Dosing ETX0914 in human volunteers showed sufficient exposure and minimal adverse effects to expect a highly efficacious anti-gonorrhea therapy.

Topics: Adult; Animals; Anti-Bacterial Agents; Barbiturates; Disease Models, Animal; DNA Topoisomerases, Type II; Dogs; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Female; Fluoroquinolones; Gonorrhea; Haplorhini; Humans; Isoxazoles; Male; Mice; Microbial Sensitivity Tests; Middle Aged; Models, Molecular; Molecular Conformation; Morpholines; Mutation; Neisseria gonorrhoeae; Oxazolidinones; Rats; Spiro Compounds; Staphylococcal Infections; Staphylococcus aureus; Topoisomerase II Inhibitors; Young Adult

The aetiological bacterial agent of gonorrhoea, Neisseria gonorrhoeae, has become resistant to each of the first-line antibiotics used to treat it, including ciprofloxacin. One diagnostic approach to identify ciprofloxacin-susceptible isolates is to determine codon 91 in the gene encoding the A subunit of DNA gyrase, gyrA, where coding for the wild-type serine (gyrA. We used bacterial genetics to introduce pairwise substitutions in GyrA positions 91 (S or F) and 95 (D, G, or N), which is a second site in GyrA associated with ciprofloxacin resistance, into five clinical isolates of N gonorrhoeae. All five isolates encoded GyrA S91F, an additional substitution in GyrA at position 95, substitutions in ParC that are known to cause an increased minimum inhibitory concentration (MIC) to ciprofloxacin, and GyrB 429D, which is associated with susceptibility to zoliflodacin (a spiropyrimidinetrione-class antibiotic in phase 3 trials for treatment of gonorrhoea). We evolved these isolates to assess for the existence of pathways to ciprofloxacin resistance (MIC ≥1 μg/mL) and measured MICs for ciprofloxacin and zoliflodacin. In parallel, we searched metagenomic data for 11 355 N gonorrhoeae clinical isolates with reported ciprofloxacin MICs that were publicly available from the European Nucleotide Archive for strains that would be identified as susceptible by gyrA codon 91-based assays.. Three clinical isolates of N gonorrhoeae with substitutions in GyrA position 95 associated with resistance (G or N) maintained intermediate ciprofloxacin MICs (0·125-0·5 μg/mL), which has been associated with treatment failure, despite reversion of GyrA position 91 from phenylalanine to serine. From an in-silico analysis of the 11 355 genomes from N gonorrhoeae clinical isolates, we identified 30 isolates with gyrA codon 91 encoding a serine and a ciprofloxacin resistance-associated mutation at codon 95. The reported MICs for these isolates varied from 0·023 μg/mL to 0·25 μg/mL, including four with intermediate ciprofloxacin MICs (associated with substantially increased risk of treatment failure). Finally, through experimental evolution, one clinical isolate of N gonorrhoeae bearing GyrA 91S acquired ciprofloxacin resistance through mutations in the gene encoding for the B subunit of DNA gyrase (gyrB) that also conferred reduced susceptibility to zoliflodacin (ie, MIC ≥2 μg/mL).. Diagnostic escape from gyrA codon 91 diagnostics could occur through either reversion of the gyrA allele or expansion of circulating lineages. N gonorrhoeae genomic surveillance efforts might benefit from including gyrB, given its potential for contributing to ciprofloxacin and zoliflodacin resistance, and diagnostic strategies that reduce the likelihood of escape, such as the incorporation of multiple target sites, should be investigated. Diagnostics that guide antibiotic therapy can have unintended consequences, including novel resistance determinants and antibiotic cross-resistance.. US National Institutes of Health National Institute of Allergy and Infectious Diseases, National Institute of General Medical Sciences, and the Smith Family Foundation.

Topics: Anti-Bacterial Agents; Ciprofloxacin; DNA Gyrase; Gonorrhea; Humans; Neisseria gonorrhoeae

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is an urgent global health threat. Zoliflodacin is a novel antibiotic undergoing clinical trials for the treatment of gonorrhoea. While there are limited data regarding zoliflodacin resistance in N. gonorrhoeae, three amino acid mutations have been associated with increased MICs of zoliflodacin.. To determine the prevalence of three amino acid mutations associated with zoliflodacin resistance within a large, public database of nearly 13 000 N. gonorrhoeae genomes.. PathogenWatch is an online genomic epidemiology platform with a public database of N. gonorrhoeae genomes. That database was used to extract gyrB sequence data and a Basic Local Alignment Search Tool (BLAST) search was performed to identify any of the three amino acid mutations in GyrB that are associated with increased zoliflodacin MICs: D429N, K450N or K450T. As a control for the search methodology, all GyrA sequences were also extracted and S91F mutations were identified and compared with the PathogenWatch database.. In total, 12 493 N. gonorrhoeae genomes from the PathogenWatch database were included. Among those genomes, none was identified that harboured any of the three mutations associated with increased zoliflodacin MICs. One genome was identified to have a mutation at position 429 in GyrB (D429V).. The findings suggest that the prevalence of the three mutations associated with zoliflodacin resistance in N. gonorrhoeae is very low. However, further research into the mechanisms of zoliflodacin resistance in N. gonorrhoeae is needed. Genomic epidemiology platforms like PathogenWatch can be used to enhance the global surveillance of AMR.

Topics: Anti-Bacterial Agents; Barbiturates; Drug Resistance, Bacterial; Gonorrhea; Humans; Isoxazoles; Microbial Sensitivity Tests; Morpholines; Mutation; Neisseria gonorrhoeae; Oxazolidinones; Spiro Compounds

Topics: Anti-Bacterial Agents; Barbiturates; Gonorrhea; Humans; Isoxazoles; Morpholines; Oxazolidinones; Spiro Compounds

We tested the activity of ETX0914 against 187 Neisseria gonorrhoeae isolates from men with urethritis in Nanjing, China, in 2013. The MIC50, MIC90, and MIC range for ETX0914 were 0.03 μg/ml, 0.06 μg/ml, and ≤0.002 to 0.125 μg/ml, respectively. All isolates were resistant to ciprofloxacin, and 36.9% (69/187) were resistant to azithromycin. Of the isolates, 46.5% were penicillinase-producing N. gonorrhoeae (PPNG), 36% were tetracycline-resistant N. gonorrhoeae (TRNG), and 13% (24 isolates) had an MIC of 0.125 μg/ml for ceftriaxone. ETX0914 may be an effective treatment option for gonorrhea.

Topics: Anti-Bacterial Agents; Azithromycin; Barbiturates; Ceftriaxone; Ciprofloxacin; DNA Gyrase; Drug Resistance, Multiple, Bacterial; Gene Expression; Gonorrhea; Humans; Isoxazoles; Male; Microbial Sensitivity Tests; Morpholines; Neisseria gonorrhoeae; Oxazolidinones; Spiro Compounds; Tetracycline; Topoisomerase II Inhibitors; Urethritis

Antimicrobial resistance in Neisseria gonorrhoeae has severely limited the number of treatment options, and the emergence of extended-spectrum cephalosporin resistance threatens the effectiveness of the last remaining recommended treatment regimen. This study assessed the in vitro susceptibility of N. gonorrhoeae to ETX0914, a novel spiropyrimidinetrione that inhibits DNA biosynthesis. In vitro activity was determined by agar dilution against 100 N. gonorrhoeae isolates collected from men presenting with urethritis in the USA during 2012-2013 through the Gonococcal Isolate Surveillance Project. The minimum inhibitory concentration (MIC) that inhibited growth in 50% (MIC50) and 90% (MIC90) of isolates was calculated for each antimicrobial agent. ETX0914 demonstrated a high level of antimicrobial activity against N. gonorrhoeae, including isolates with decreased susceptibility or resistance to currently available agents. The ability of ETX0914 to inhibit the growth of N. gonorrhoeae was similar to ceftriaxone, which is currently recommended in combination with azithromycin to treat gonorrhoea. The data presented in this study strongly suggest that ETX0914 should be evaluated in a clinical trial for the treatment of N. gonorrhoeae.

Topics: Anti-Bacterial Agents; Barbiturates; Drug Resistance, Multiple, Bacterial; Gonorrhea; Humans; Isoxazoles; Male; Microbial Sensitivity Tests; Morpholines; Neisseria gonorrhoeae; Oxazolidinones; Spiro Compounds; United States; Urethritis

We evaluated the activity of the novel spiropyrimidinetrione AZD0914 (DNA gyrase inhibitor) against clinical gonococcal isolates and international reference strains (n=250), including strains with diverse multidrug resistance and extensive drug resistance. The AZD0914 MICs were substantially lower than those of most other currently or previously recommended antimicrobials. AZD0914 should be further evaluated, including in vitro selection, in vivo emergence and mechanisms of resistance, pharmacokinetics/pharmacodynamics in humans, optimal dosing, and performance, in appropriate randomized and controlled clinical trials.

Topics: Anti-Bacterial Agents; Barbiturates; DNA Gyrase; Drug Resistance, Multiple, Bacterial; Gonorrhea; Isoxazoles; Microbial Sensitivity Tests; Morpholines; Neisseria gonorrhoeae; Oxazolidinones; Spiro Compounds; Topoisomerase II Inhibitors