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Pfizer Receives Positive CHMP Opinion for its Novel Antibiotic Combination for the Treatment of Patients with Multidrug-Resistant Infections and Limited Treatment Options

NEW YORK, March 22, 2024Pfizer Inc. (NYSE: PFE) today announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for EMBLAVEO® (aztreonam-avibactam) in the treatment of adult patients with complicated intra-abdominal infections (cIAI), hospital-acquired pneumonia (HAP) including ventilator-associated pneumonia (VAP), and complicated urinary tract infections (cUTI), including pyelonephritis. If approved, EMBLAVEO® will also be indicated for the treatment of infections due to aerobic Gram-negative organisms in adult patients with limited treatment options. The Marketing Authorization Application (MAA) for EMBLAVEO® was reviewed under the accelerated assessment procedure, which is used by the CHMP when a pharmaceutical product is of major interest for public health and therapeutic innovation.

“Gram-negative bacteria are often resistant to multiple drugs, leaving infected patients very ill and at high risk of severe complications, including mortality,” said James Rusnak, Senior Vice President and Chief Development Officer, Internal Medicine, Anti-Infectives and Hospital, Pfizer. “If approved, EMBLAVEO® could offer hope to adult patients with life-threatening Gram-negative bacterial infections that currently have limited treatment options. This recommendation is a positive step for patients with Gram-negative infections resistant to nearly all available antibiotics and demonstrates Pfizer’s commitment to helping address the global public health threat of antimicrobial resistance.”

Antimicrobial resistance (AMR), particularly in Gram-negative bacteria, is one of the biggest threats to global health, and developing new treatments for infections caused by these bacteria has been highlighted as a critical area of need by the World Health Organization (WHO).1,2 A continued rise in AMR could lead to 10 million deaths annually across the globe by 2050, and an estimated 1.27 million deaths globally were caused by bacterial AMR in 2019 alone.3,4 Without solutions, a continued rise of AMR could make routine medical procedures too risky to perform.1,3

The MAA for EMBLAVEO® included the positive results from the previously reported Phase 3 program comprising the REVISIT (NCT03329092) and ASSEMBLE (NCT03580044) studies evaluating the efficacy, safety, and tolerability of EMBLAVEO® in treating serious bacterial infections due to Gram-negative bacteria, including metallo-β-lactamase (MBL)-producing multidrug-resistant pathogens for which there are limited or no treatment options.5,6 Data support that EMBLAVEO® is effective and well-tolerated, with no new safety findings and a similar safety profile to aztreonam alone.7

The European Commission (EC), which grants central marketing authorizations in the European Union (EU), will review the CHMP recommendation and is expected to make a final decision in the coming months. If granted, the centralized marketing authorization of EMBLAVEO® would be valid in all 27 EU member states, as well as in Iceland, Liechtenstein, and Norway. Marketing authorization applications for EMBLAVEO® are planned for submission in other countries.

About EMBLAVEO® (aztreonam-avibactam)

If approved, EMBLAVEO® will be indicated for the treatment of adult patients with complicated intra-abdominal infections (cIAI), hospital-acquired pneumonia (HAP) including ventilator-associated pneumonia (VAP), complicated urinary tract infections (cUTI), including pyelonephritis, and infections due to aerobic Gram-negative organisms with limited treatment options. It combines aztreonam, a monobactam β-lactam, with avibactam, a recent broad-spectrum β-lactamase inhibitor.8,9 Metallo-β-lactamases (MBLs) are a class of β-lactamase enzymes which are not inhibited by current β-lactamase inhibitors and hydrolyze nearly all β-lactam antibiotics, with an exception being monobactams such as aztreonam. However, monobactams are degraded by other β-lactamases that are frequently co-produced with MBLs, limiting the clinical usefulness of aztreonam monotherapy.8

The combination of aztreonam with avibactam restores aztreonam’s activity against bacteria that co-produce MBLs and other β-lactamases and, if approved, could provide a well-tolerated and effective treatment option against multidrug-resistant Gram-negative bacteria.8 These multidrug-resistant Gram-negative bacteria include MBL-producing Enterobacterales, which have been highlighted as a critical priority pathogen by the WHO, and Stenotrophomonas maltophilia.10,11 If approved, EMBLAVEO® would be the first β-lactam/β-lactamase inhibitor combination for treating serious bacterial infections caused by multidrug-resistant Gram-negative bacteria, including MBL-producing bacteria, approved for use in the EU.

EMBLAVEO® was jointly developed with AbbVie. Pfizer holds the global rights to commercialize this investigative therapy outside of the U.S. and Canada, where the rights are held by AbbVie. Development of EMBLAVEO® was also supported by public-private partnerships between Pfizer and the U.S. Department of Health and Human Services; Administration for Strategic Preparedness and Response; Biomedical Advanced Research and Development Authority (BARDA) under OTA number HHSO100201500029C, and through the EU’s Innovative Medicines Initiative (IMI) – a partnership between the EU and the European pharmaceutical industry, under a project called COMBACTE-CARE (Combating Bacterial Resistance in Europe – Carbapenem Resistance). The COMBACTE-CARE consortium is a unique public-private collaboration that unites the knowledge and capabilities of leading drug resistant bacterial infection experts and is supported by the COMBACTE pan-European clinical and laboratory networks.

About Pfizer: Breakthroughs That Change Patients’ Lives

At Pfizer, we apply science and our global resources to bring therapies to people that extend and significantly improve their lives. We strive to set the standard for quality, safety, and value in the discovery, development, and manufacture of health care products, including innovative medicines and vaccines. Every day, Pfizer colleagues work across developed and emerging markets to advance wellness, prevention, treatments, and cures that challenge the most feared diseases of our time. Consistent with our responsibility as one of the world's premier innovative biopharmaceutical companies, we collaborate with health care providers, governments, and local communities to support and expand access to reliable, affordable health care around the world. For 175 years, we have worked to make a difference for all who rely on us. We routinely post information that may be important to investors on our website at In addition, to learn more, please visit us on and follow us on X at @Pfizer and @Pfizer_News, LinkedIn, YouTube and like us on Facebook at

Disclosure Notice

The information contained in this statement is as of March 22, 2024. Pfizer assumes no obligation to update forward-looking statements contained in this release as the result of new information or future events or developments.

This release contains forward-looking information about an investigational antibiotic, EMBLAVEO (aztreonam-avibactam), including its potential benefits, a marketing authorisation application pending with the European Commission and planned regulatory submissions in other countries, that involves substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Risks and uncertainties include, among other things, the uncertainties inherent in research and development, including the ability to meet anticipated clinical endpoints, commencement and/or completion dates for our clinical trials, regulatory submission dates, regulatory approval dates and/or launch dates, as well as the possibility of unfavorable new clinical data and further analyses of existing clinical data; the risk that clinical trial data are subject to differing interpretations and assessments by regulatory authorities; whether regulatory authorities will be satisfied with the design of and results from our clinical studies; whether and when any drug applications may be filed in any jurisdictions for EMBLAVEO; whether and when the European Commission may approve the MAA for EMBLAVEO and whether and when regulatory authorities in any such other jurisdictions where applications may be filed or pending may approve such applications, which will depend on myriad factors, including making a determination as to whether the product's benefits outweigh its known risks and determination of the product's efficacy, and, if approved, whether EMBLAVEO will be commercially successful; decisions by regulatory authorities impacting labeling, manufacturing processes, safety and/or other matters that could affect the availability or commercial potential of EMBLAVEO; the impact of COVID-19 on our business, operations and financial results; and competitive developments.

A further description of risks and uncertainties can be found in Pfizer’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 and in its subsequent reports on Form 10-Q, including in the sections thereof captioned “Risk Factors” and “Forward-Looking Information and Factors That May Affect Future Results,” as well as in its subsequent reports on Form 8-K, all of which are filed with the U.S. Securities and Exchange Commission and available at and

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3 Review on Antimicrobial Resistance. Tackling drug-resistant infections globally: final report and recommendations. May 2016. Available at Last accessed March 2024.
4 Antimicrobial Resistance Collaborators. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet. 2022;399(10325):629-655.
5 Pfizer. Phase 3 studies of Pfizer’s novel antibiotic combination offer new treatment hope for patients with multidrug-resistant infections and limited treatment options. June 2023. Available at: Last accessed March 2024.
6 Carmeli Y. Efficacy and safety of aztreonam-avibactam for the treatment of serious infections due to gram-negative bacteria, including metallo-β-lactamase-producing pathogens: phase 3 REVISIT study. Presented as oral session (abstract 2893) at IDweek 2023, Boston MA.
7 Pfizer data on file. ATM-AVI Top-Line Report C3601009.
8 Rossolini GM, Stone G, Kantecki M, et al. In vitro activity of aztreonam/avibactam against isolates of Enterobacterales collected globally from ATLAS in 2019. J Global Antimicrob Resist. 2022;30:214-221.
9 Cornely OA, Cisneros JM, Torre-Cisneros J, et al. Pharmacokinetics and safety of aztreonam/avibactam for the treatment of complicated intra-abdominal infections in hospitalized adults: results from the REJUVENATE study. J Antimicrob Chemother. 2020;75(3):618-627.
10 World Health Organization. WHO publishes list of bacteria for which new antibiotics are urgently needed. February 2017. Available at: Last accessed March 2024.
11 Boyd S, Livermore DM, Hooper DC, et al. Metallo-β-lactamases: Structure, function, epidemiology, treatment options, and the development pipeline. Antimicrob Agents and Chemother. 2020;64(10).


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