Patient outcomes by baseline pathogen resistance phenotype and genotype in CERTAIN-1, a Phase 3 study of cefepime-taniborbactam versus meropenem in adults with complicated urinary tract infection.

CERTAIN-1 was a Phase 3, double-blind, randomized, parallel group study of the efficacy and safety of cefepime-taniborbactam versus meropenem in the treatment of adults with complicated urinary tract infection (cUTI), including acute pyelonephritis. We determined susceptibility of Enterobacterales and Pseudomonas aeruginosa baseline pathogens to cefepime-taniborbactam and comparators and characterized ß-lactam resistance mechanisms. Microbiologic response and clinical response were assessed in patient subsets defined by baseline pathogens that were of cefepime-, multidrug-, or carbapenem-resistant phenotype or that carried ß-lactamase genes. Among Enterobacterales baseline pathogens, 26.8%, 4.1%, and 3.0% carried genes for extended-spectrum ß-lactamases (ESBLs), AmpC, and carbapenemases, respectively. Within each treatment group, while composite success rates at Test of Cure in resistant subsets by pathogen species were similar to those by pathogen overall, composite success rates in meropenem patients were numerically lower for cefepime-resistant Escherichia coli (9/19; 47.4%) and ESBL E. coli (13/25; 52.0%) compared with E. coli overall (62/100; 62.0%). Cefepime-taniborbactam achieved composite success in 7/8 (87.5%) patients with carbapenem-resistant Enterobacterales and 8/9 (88.9%) patients with Enterobacterales with a carbapenemase gene (5 OXA-48-group; 2 KPC-3; 2 NDM-1). Cefepime-taniborbactam also achieved composite success in 8/16 (50.0%) patients and clinical success in 13/16 (81.3%) patients with P. aeruginosa; corresponding rates were 4/7 (57.1%) and 6/7 (85.7%) for meropenem. Cefepime-taniborbactam demonstrated efficacy in adult cUTI patients with cefepime-, multidrug-, and carbapenem-resistant pathogens including pathogens with ESBL, AmpC, and carbapenemase genes. CLINICAL TRIALS: This study is registered with ClinicalTrials.gov as NCT03840148.

Cefepime-Taniborbactam in Complicated Urinary Tract Infection.

BACKGROUND: Carbapenem-resistant Enterobacterales species and multidrug-resistant Pseudomonas aeruginosa are global health threats. Cefepime-taniborbactam is an investigational ß-lactam and ß-lactamase inhibitor combination with activity against Enterobacterales species and P. aeruginosa expressing serine and metallo-ß-lactamases. METHODS: In this phase 3, double-blind, randomized trial, we assigned hospitalized adults with complicated urinary tract infection (UTI), including acute pyelonephritis, in a 2:1 ratio to receive intravenous cefepime-taniborbactam (2.5 g) or meropenem (1 g) every 8 hours for 7 days; this duration could be extended up to 14 days in case of bacteremia. The primary outcome was both microbiologic and clinical success (composite success) on trial days 19 to 23 in the microbiologic intention-to-treat (microITT) population (patients who had a qualifying gram-negative pathogen against which both study drugs were active). A prespecified superiority analysis of the primary outcome was performed after confirmation of noninferiority. RESULTS: Of the 661 patients who underwent randomization, 436 (66.0%) were included in the microITT population. The mean age of the patients was 56.2 years, and 38.1% were 65 years of age or older. In the microITT population, 57.8% of the patients had complicated UTI, 42.2% had acute pyelonephritis, and 13.1% had bacteremia. Composite success occurred in 207 of 293 patients (70.6%) in the cefepime-taniborbactam group and in 83 of 143 patients (58.0%) in the meropenem group. Cefepime-taniborbactam was superior to meropenem regarding the primary outcome (treatment difference, 12.6 percentage points; 95% confidence interval, 3.1 to 22.2; P = 0.009). Differences in treatment response were sustained at late follow-up (trial days 28 to 35), when cefepime-taniborbactam had higher composite success and clinical success. Adverse events occurred in 35.5% and 29.0% of patients in the cefepime-taniborbactam group and the meropenem group, respectively, with headache, diarrhea, constipation, hypertension, and nausea the most frequently reported; the frequency of serious adverse events was similar in the two groups. CONCLUSIONS: Cefepime-taniborbactam was superior to meropenem for the treatment of complicated UTI that included acute pyelonephritis, with a safety profile similar to that of meropenem. (Funded by Venatorx Pharmaceuticals and others; CERTAIN-1 ClinicalTrials.gov number, NCT03840148.).

Safety and Pharmacokinetics of Taniborbactam (VNRX-5133) with Cefepime in Subjects with Various Degrees of Renal Impairment.

Taniborbactam, an investigational ß-lactamase inhibitor that is active against both serine- and metallo-ß-lactamases, is being developed in combination with cefepime to treat serious infections caused by multidrug-resistant Gram-negative bacteria. Anticipating the use of cefepime-taniborbactam in patients with impaired renal function, an open-label, single-dose clinical study was performed to examine the pharmacokinetics of both drugs in subjects with various degrees of renal function. Hemodialysis-dependent subjects were also studied to examine the amounts of cefepime and taniborbactam dialyzed. Single intravenous infusions of 2 g cefepime and 0.5 g taniborbactam coadministered over 2 h were examined, with hemodialysis-dependent subjects receiving doses both on- and off-dialysis. No subjects experienced serious adverse events or discontinued treatment due to adverse events. The majority of adverse events observed were mild in severity, and there were no trends in the safety of cefepime-taniborbactam related to declining renal function or the timing of hemodialysis. Clinically significant and similar decreases in drug clearance with declining renal function were observed for both cefepime and taniborbactam. The respective decreases in geometric mean clearance for subjects with mild, moderate, and severe renal impairment compared to subjects with normal renal function were 18%, 63%, and 78% for cefepime and 15%, 63%, and 81% for taniborbactam, respectively. Decreases in clearance were similar for both drugs and were shown to be proportional to decreases in renal function. Both cefepime and taniborbactam were dialyzable, with similar amounts removed during 4 h of hemodialysis. This study is registered at ClinicalTrials.gov as NCT03690362.

Safety and Pharmacokinetics in Human Volunteers of Taniborbactam (VNRX-5133), a Novel Intravenous ß-Lactamase Inhibitor.

Taniborbactam (formerly VNRX-5133), an investigational ß-lactamase inhibitor active against both serine- and metallo-ß-lactamases, is being developed in combination with cefepime to treat serious infections caused by multidrug-resistant Gram-negative bacteria. This first-in-human study evaluated the safety and pharmacokinetics of single and multiple doses of taniborbactam in healthy adult subjects. Single doses of 62.5 to 1,500 mg taniborbactam and multiple doses of 250 to 750 mg taniborbactam every 8 h (q8h) for 10 days were examined; all taniborbactam doses were administered as a 2-h intravenous infusion. No subjects experienced serious adverse events or discontinued treatment due to adverse events. The most common adverse event in both placebo- and taniborbactam-treated subjects was headache. The pharmacokinetics of taniborbactam were similar to the pharmacokinetics reported for cefepime. Taniborbactam demonstrated dose-proportional pharmacokinetics with low intersubject variability. Following single doses and with extended sampling, the mean terminal elimination half-life ranged from 3.4 to 5.8 h; however, the majority of exposure was characterized by an earlier phase with a half-life of about 2 h. Following multiple dosing, there was minimal accumulation of taniborbactam in plasma. At steady-state, approximately 90% of the administered dose of taniborbactam was recovered in urine as intact drug. There was no appreciable metabolism observed in either plasma or urine samples. (This study is registered at clinicaltrials.gov under registration number NCT02955459.).

Novel targeted therapies for eosinophilic disorders.

Hypereosinophilic syndromes (HESs) are a diverse group of conditions characterized by clinical manifestations attributable to eosinophilia and eosinophilic infiltration of tissues. HESs are chronic disorders with significant morbidity and mortality. Although the availability of targeted chemotherapeutic agents, including imatinib, has improved quality of life and survival in some patients with HESs, additional agents with increased efficacy and decreased toxicity are sorely needed. The purpose of this review is to provide an overview of eosinophil biology with an emphasis on potential targets of pharmacotherapy and to provide a summary of potential eosinophil-targeting agents, including those in development, in clinical trials, or approved for other disorders.

Efficacy and safety of weekly dalbavancin therapy for catheter-related bloodstream infection caused by gram-positive pathogens.

BACKGROUND: Catheter-related bloodstream infections (CR-BSIs) are associated with substantial mortality, prolongation of hospital stay, and increased cost of care. Dalbavancin, a new glycopeptide antibiotic with unique pharmacokinetic properties that have allowed clinical development of a weekly dosing regimen, possesses excellent activity against clinically important gram-positive bacteria, suggesting utility in the treatment of patients with CR-BSIs. METHODS: A phase 2, open-label, randomized, controlled, multicenter study of 75 adult patients with CR-BSIs compared treatment with intravenous dalbavancin, administered as a single 1000-mg dose followed by a 500-mg dose 1 week later, with intravenous vancomycin, administered twice daily for 14 days. Gram-positive bacteria isolated in this study included coagulase-negative staphylococci (CoNS) and Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). RESULTS: Infected patients who received weekly dalbavancin (n=33) had an overall success rate (87.0%; 95% confidence interval [CI], 73.2%-100.0%) that was significantly higher than that of those who received vancomycin (n=34) (50.0%; 95% CI, 31.5%-68.5%). Adverse events and laboratory abnormalities were generally mild and were comparable for the 2 drugs. CONCLUSIONS: Dalbavancin thus appears to be an effective and well-tolerated treatment option for adult patients with CR-BSIs caused by CoNS and S. aureus, including MRSA.

Population pharmacokinetic analysis of anidulafungin, an echinocandin antifungal.

The objective of this analysis was to describe the pharmacokinetic characteristics of anidulafungin in patients with serious fungal disease based on pharmacokinetic data collected during four recently completed or ongoing Phase II/III clinical studies. A total of 600 anidulafungin plasma samples from 225 patients across the four studies were available for analysis. Patients received daily intravenous infusions of 50, 75, or 100 mg anidulafungin, preceded by a loading dose that was twice the daily dose. The analysis population consisted of 129 patients with esophageal candidiasis, 87 with invasive candidiasis, 7 with invasive aspergillosis, and 2 with azole refractory mucosal candidiasis. A population analysis approach was used to develop a steady-state pharmacokinetic model for anidulafungin, assess the significance of possible covariates, and determine the amount of intersubject and random residual variability. A two-compartment model with first-order elimination provided the best fit to the data. The clearance of anidulafungin was influenced by weight and gender, and subjects in the invasive candidiasis study had a typical clearance that was approximately 30% higher than subjects from other studies. Weight was determined to be a predictor of the central volume of distribution. The covariates on clearance accounted for less than 20% of the intersubject variability and therefore are deemed to be of little clinical relevance. There was no evidence that the presence of rifampin or metabolic substrates, inhibitors, or inducers of cytochrome p450 influenced the clearance of anidulafungin. This indicates that dosing adjustments are not necessary when anidulafungin is administered in the presence of medications falling into these classifications.

Once-weekly dalbavancin versus standard-of-care antimicrobial regimens for treatment of skin and soft-tissue infections.

Dalbavancin, a novel glycopeptide with a long elimination half-life ( approximately 9-12 days), was compared to standard antimicrobial therapy for skin and soft-tissue infections (SSTIs). In a randomized, controlled, open-label, phase 2 proof-of-concept trial, adults received 1100 mg of dalbavancin (as a single intravenous infusion), 1000 mg of dalbavancin intravenously and then 500 mg intravenously 1 week later, or a prospectively defined standard-of-care regimen. A gram-positive pathogen was isolated from samples obtained from 41 (66%) of 62 patients at baseline; Staphylococcus aureus was the most prevalent species (83% of pathogens). Clinical success rates at a follow-up visit (test of cure) were 94.1% among patients treated with 2 doses of dalbavancin, 61.5% among patients treated with 1 dose of dalbavancin, and 76.2% among patients treated with a standard-of-care regimen. All treatment regimens were well tolerated; drug-related adverse reaction rates were similar across the 3 groups. These findings suggest that a regimen of 2 doses of dalbavancin administered 1 week apart is effective in the treatment of complicated, gram-positive bacterial SSTIs and warrants further study.