Phase 2 Study of New Combination Antibiotics Successfully Treats Complicated UTIs Interview with:

Amanda Paschke, MD Director, Infectious Disease Clinical Research Merck Research Laboratories

Dr. Amanda Paschke

Amanda Paschke, MD
Director, Infectious Disease Clinical Research
Merck Research Laboratories What is the background for this study? What are the main findings?

Response: Relebactam is an investigational beta-lactamase inhibitor being developed as a fixed-dose combination with imipenem/cilastatin, which is a broad-spectrum antibiotic in the carbapenem class. In preclinical studies, this combination demonstrated antibacterial activity against a broad range of multidrug-resistant Gram-negative pathogens, including those producing extended-spectrum beta-lactamases such as Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae and AmpC-producing Pseudomonas aeruginosa. Many of the most concerning infections caused by “superbugs” are caused by Gram-negative bacteria. These bacteria have evolved to be resistant to commonly used antibacterials, and even to antibacterials used as “last resort” treatment, which is why finding ways to treat them has become urgent. The addition of relebactam to imipenem is designed to restore activity of imipenem against certain imipenem-resistant strains of Gram-negative bacteria known to cause serious infections among people who often have other underlying medical conditions, which complicates treatment.

This was a Phase 2, multicenter, randomized, double-blind, non-inferiority study. The study looked at the use of relebactam plus imipenem versus imipenem alone for the treatment of adult patients with complicated urinary tract infections. The primary endpoint for the trial was microbiological response at the completion of IV study therapy. The study met its primary endpoint, demonstrating that the combination of relebactam with imipenem was as at least as effective as imipenem alone for the treatment of complicated urinary tract infections. The trial also demonstrated that the combination of relebactam plus imipenem is well-tolerated, with a safety profile similar to that of imipenem alone in this patient. What should readers take away from your report?

Response: This trial confirmed the safety and efficacy of the combination of imipenem, a broad-spectrum carbapenem antibiotic, and relebactam, an investigational beta-lactamase inhibitor, in patients with complicated urinary tract infections, including Gram-negative infections. While this study was not limited to patients with multidrug-resistant pathogens, the confirmation of safety and activity of relebactam in serious bacterial infections like complicated urinary tract infections is a critical next step in the development of this combination as a potential treatment for patients with unmet medical need. What recommendations do you have for future research as a result of this study?

Response: Two pivotal Phase 3 clinical studies of relebactam in combination with imipenem/cilastatin are currently ongoing and recruiting patients. These will evaluate relebactam in combination with imipenem for use in the treatment of several complicated Gram-negative bacterial infections, with one ongoing study focusing exclusively on patients with infections caused by imipenem-resistant bacteria. Is there anything else you would like to add?

Response: New medicines are urgently needed to address the growing threat of antibiotic-resistant bacteria. The FDA has designated the combination of relebactam plus imipenem/cilastatin as a Qualified Infectious Disease Product (QIDP) with designated Fast Track status for the treatment of hospital-acquired bacterial pneumonia, ventilator-associated bacterial pneumonia, complicated intra-abdominal infections and complicated urinary tract infections. Merck’s commitment to addressing infectious diseases includes researching compounds like relebactam that have the potential to help fight multidrug-resistant “superbugs” that pose an urgent threat to global public health. Thank you for your contribution to the community.


Citation: Phase 2 Study of Relebactam (Rel) + Imipenem/Cilastatin (Imi) vs Imi Alone in Subjects with Complicated Urinary Tract Infection (cUTI) results were presented at the American Society for Microbiology’s ASM Microbe 2016 meeting in Boston, June 16-20.

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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