Results of Phase 2 Study of Merck’s Investigational Beta-Lactamase Inhibitor Relebactam in Combination with Imipenem/Cilastatin Presented at ASM Microbe


June 20, 2016 11:30 am ET

Pivotal Phase 3 Studies Ongoing in Treatment of Serious Bacterial Infections

Merck (NYSE:MRK), known as MSD outside the United States and Canada,
today announced that a Phase 2 study of relebactam, the company’s
investigational beta-lactamase inhibitor, in combination with
imipenem/cilastatin (an approved carbapenem antibiotic), in patients
with complicated urinary tract infections, met its primary endpoint. The
addition of relebactam is designed to restore activity of imipenem
against certain imipenem-resistant strains of Gram-negative bacteria,
including Pseudomonas aeruginosa and Klebsiella pneumoniae
carbapenemase (KPC)-producing Enterobacteriaceae.

The results were presented at the American Society for Microbiology’s
ASM Microbe 2016 meeting in Boston, June 16-20.

“New medicines are urgently needed to address the growing threat of
antibiotic-resistant bacteria,” said Dr. Amanda Paschke, director,
infectious disease clinical research, Merck Research Laboratories. “We
look forward to advancing our Phase 3 clinical program evaluating
relebactam in combination with imipenem for use in the treatment of
several complicated Gram-negative bacterial infections, and to continue
to build on Merck’s commitment to addressing infectious diseases.”

In this multicenter, double-blind Phase 2 study, 302 adult patients with
complicated urinary tract infections (51.7%) or acute pyelonephritis
(48.3%) were randomized to receive either relebactam 250mg, relebactam
125mg, or placebo, each given intravenously (IV) in combination with
imipenem/cilastatin (IMI) 500mg every six hours for 4 to 14 days.
Efficacy was evaluated at discontinuation of IV therapy (DCIV), early
follow‐up, and late follow‐up. The primary endpoint was the proportion
of microbiologically evaluable patients with a favorable microbiological
response at DCIV, assessed by non‐inferiority testing with a 15% margin.
Results were similar across treatment groups: relebactam 250mg + IMI
(95.5%) (n=67), relebactam 125mg + IMI (98.6%) (n=71), and placebo + IMI
(98.7%) (n=75). Among microbiologically evaluable patients, 10.5% (n=25)
had imipenem-resistant Gram-negative infections at baseline.

Safety analysis focused on adverse events occurring while on intravenous
study therapy or during the 14 days following the end of therapy in all
randomized patients who received at least one dose of intravenous study
therapy. The most common adverse events (headache, diarrhea and nausea)
occurred at similar rates across treatment groups: relebactam 250mg +
IMI (7.1%, 5.1%, 4.0%), relebactam 125mg + IMI (3.0%, 2.0%, 6.1%), and
placebo + IMI (4.0%, 4.0%, 4.0%), respectively.

Phase 3 Clinical Program of Relebactam/Imipenem/Cilastatin Ongoing

Two pivotal Phase 3 clinical studies of relebactam in combination with
imipenem/cilastatin are currently ongoing and recruiting patients. One
study compares treatment with imipenem/relebactam, as a fixed-dose
combination, with piperacillin/tazobactam in patients with
hospital-acquired bacterial pneumonia or ventilator-associated bacterial
pneumonia. The primary hypothesis of this study is that
imipenem/relebactam is non-inferior to piperacillin/tazobactam in the
incidence rate of all-cause mortality. (
Identifier: NCT02493764

A second study evaluates the efficacy and safety of imipenem/relebactam
versus colistimethate sodium in combination with imipenem in the
treatment of imipenem-resistant bacterial infections, including those
caused by Pseudomonas aeruginosa and KPC-producing organisms.
Infections evaluated in this study include hospital-acquired bacterial
pneumonia, ventilator-associated bacterial pneumonia, complicated
intra-abdominal infections and complicated urinary tract infections. (
Identifier: NCT02452047

About Relebactam

Relebactam is an investigational, intravenous, class A and C,
beta-lactamase inhibitor currently being evaluated in combination with
imipenem/cilastatin for the treatment of certain complicated
Gram-negative bacterial infections. In preclinical studies, relebactam
administered in combination with imipenem demonstrated antibacterial
activity against a broad range of Gram-negative and
beta-lactam-resistant pathogens. The U.S. Food and Drug Administration
(FDA) has designated this combination 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.

About Merck

For 125 years, Merck has been a global health care leader working to
help the world be well. Merck is known as MSD outside the United States
and Canada. Through our prescription medicines, vaccines, biologic
therapies, and animal health products, we work with customers and
operate in more than 140 countries to deliver innovative health
solutions. We also demonstrate our commitment to increasing access to
health care through far-reaching policies, programs and partnerships.
For more information, visit
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and LinkedIn.

Forward-Looking Statement of Merck & Co., Inc., Kenilworth, N.J., USA

This news release of Merck & Co., Inc., Kenilworth, N.J., USA (the
“company”) includes “forward-looking statements” within the meaning of
the safe harbor provisions of the U.S. Private Securities Litigation
Reform Act of 1995. These statements are based upon the current beliefs
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respect to pipeline products that the products will receive the
necessary regulatory approvals or that they will prove to be
commercially successful. If underlying assumptions prove inaccurate or
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Risks and uncertainties include but are not limited to, general industry
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including obtaining regulatory approval; the company’s ability to
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and other protections for innovative products; and the exposure to
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The company undertakes no obligation to publicly update any
forward-looking statement, whether as a result of new information,
future events or otherwise. Additional factors that could cause results
to differ materially from those described in the forward-looking
statements can be found in the company’s 2015 Annual Report on Form 10-K
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Pamela Eisele, (267) 305-3558
Robert Consalvo, (908) 295-0928
Teri Loxam, (908) 740-1986
Amy Klug, (908) 740-1898

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