1. Academic Validation
  2. Multiple-Ascending-Dose Phase 1 Clinical Study of the Safety, Tolerability, and Pharmacokinetics of CRS3123, a Narrow-Spectrum Agent with Minimal Disruption of Normal Gut Microbiota

Multiple-Ascending-Dose Phase 1 Clinical Study of the Safety, Tolerability, and Pharmacokinetics of CRS3123, a Narrow-Spectrum Agent with Minimal Disruption of Normal Gut Microbiota

  • Antimicrob Agents Chemother. 2019 Dec 20;64(1):e01395-19. doi: 10.1128/AAC.01395-19.
Barbara K Lomeli 1 Hal Galbraith 1 Jared Schettler 1 George A Saviolakis 2 Wael El-Amin 2 Blaire Osborn 3 Jacques Ravel 4 5 Keith Hazleton 6 Catherine A Lozupone 7 Ronald J Evans 8 Stacie J Bell 8 Urs A Ochsner 8 Thale C Jarvis 9 Shahida Baqar 3 Nebojsa Janjic 9
Affiliations

Affiliations

  • 1 Quintiles Phase One Services, Overland Park, Kansas, USA.
  • 2 DynPort Vaccine Company LLC, Frederick, Maryland, USA.
  • 3 Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
  • 4 Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA.
  • 5 Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA.
  • 6 Division of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
  • 7 Division of Biomedical Informatics and Personalized Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
  • 8 Crestone, Inc., Boulder, Colorado, USA.
  • 9 Crestone, Inc., Boulder, Colorado, USA tjarvis@crestonepharma.com njanjic@crestonepharma.com.
Abstract

CRS3123 is a novel small molecule that potently inhibits methionyl-tRNA synthetase of Clostridioides difficile, inhibiting C. difficile toxin production and spore formation. CRS3123 has been evaluated in a multiple-ascending-dose placebo-controlled phase 1 trial. Thirty healthy subjects, ages 18 to 45 years, were randomized into three cohorts of 10 subjects each, receiving either 200, 400, or 600 mg of CRS3123 (8 subjects per cohort) or placebo (2 subjects per cohort) by oral administration twice daily for 10 days. CRS3123 was generally safe and well tolerated, with no serious adverse events (SAEs) or severe treatment-emergent adverse events (TEAEs) reported. All subjects completed their assigned treatment and follow-up visits, and there were no trends in systemic, vital sign, or laboratory TEAEs. There were no QTcF interval changes or any clinically significant changes in other electrocardiogram (ECG) intervals or morphology. CRS3123 showed limited but detectable systemic uptake; although absorption increased with increasing dose, the increase was less than dose proportional. Importantly, the bulk of the oral dose was not absorbed, and fecal concentrations were substantially above the MIC90 value of 1 μg/ml at all dosages tested. Subjects receiving either of the two lower doses of CRS3123 exhibited minimal disruption of normal gut microbiota after 10 days of twice-daily dosing. CRS3123 was inactive against important commensal anaerobes, including Bacteroides, bifidobacteria, and commensal clostridia. Microbiome data showed favorable differentiation compared to other CDI therapeutics. These results support further development of CRS3123 as an oral agent for the treatment of CDI. (This study has been registered at Clinicaltrials.gov under identifier NCT02106338.).

Keywords

CRS3123; Clostridioides difficile; MAD study; antibiotic; gut microbiota; microbiome; narrow spectrum; phase 1; sporulation; toxin production.

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