Shionogi to Present New Fetroja®/Fetcroja® Data at IDWeek 2026 Highlighting Early Treatment Outcomes and Activity Against Drug-Resistant Gram-Negative Bacteria
Shionogi & Co., Ltd., headquartered in Osaka, Japan, and led by Chief Executive Officer Isao Teshirogi, Ph.D., will present new clinical and surveillance findings at IDWeek 2026 highlighting the potential role of Fetroja®/Fetcroja® (cefiderocol) in treating serious infections caused by Gram-negative bacteria. The presentations will include U.S. real-world evidence on treatment outcomes in critically ill patients, global antimicrobial surveillance findings involving highly resistant Pseudomonas aeruginosa, and a systematic literature review examining cefiderocol use in infections caused by Stenotrophomonas maltophilia.
The new data address several important challenges in infectious disease management, particularly the growing prevalence of antimicrobial resistance and the limited treatment options available for patients with severe infections. The findings emphasize the importance of evaluating treatment outcomes, understanding changing bacterial susceptibility patterns, and examining available clinical evidence for infections caused by difficult-to-treat Gram-negative pathogens.
Among the key findings, a U.S. subgroup analysis from the PROVE study found that 76.7% of patients treated with cefiderocol for respiratory tract infections caused by Gram-negative bacteria achieved an overall clinical response. Clinical response rates were higher among patients who received cefiderocol before a previous antibiotic regimen failed than among those who received it following treatment failure.
Additional data from the SENTRY Antimicrobial Surveillance Program demonstrated that cefiderocol maintained high in vitro activity against P. aeruginosa isolates collected from patients with ventilator-associated pneumonia (VAP), including isolates resistant to several newer beta-lactam/beta-lactamase inhibitor (BL/BLI) combinations. Meanwhile, a systematic literature review identified published clinical outcomes supporting further consideration of cefiderocol for infections caused by S. maltophilia, an opportunistic pathogen associated with serious illness in vulnerable patients.
Fetroja is approved in the United States for adults with complicated urinary tract infections (cUTIs), including pyelonephritis, and hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP) caused by specified susceptible Gram-negative bacteria. Its approved uses and important safety information are detailed below.
PROVE Study Highlights Clinical Outcomes Associated With Earlier Cefiderocol Treatment
The PROVE study, formally known as the Retrospective Cefiderocol Chart Review, is an international, retrospective, observational medical chart review conducted between November 2020 and July 2024. The study included more than 1,000 patients in the United States and Europe and evaluated real-world experience with cefiderocol in clinical practice.
At IDWeek 2026, Shionogi will present a subgroup analysis involving 266 U.S. patients who received cefiderocol for respiratory tract infections caused by Gram-negative bacteria. Of these patients, 238, or 89.5%, had infections involving bacteria resistant to carbapenem antibiotics, highlighting the difficult-to-treat nature of the population.¹
The patient population included individuals with substantial underlying illness and considerable healthcare needs. Men accounted for 59.4% of participants, or 158 patients, while 93 patients, representing 35%, had chronic pulmonary disease. Nearly all patients, 96.6%, had at least one risk factor for infections caused by carbapenem-resistant Gram-negative bacteria.
The median hospital stay was 42 days, and 74.8% of patients were admitted to an intensive care unit. Organ support was required in 65.4% of patients, while 66.2% received mechanical ventilation. These characteristics illustrate the severity of illness among the patients included in the analysis and the challenges associated with managing respiratory infections in critically ill individuals.¹
Cefiderocol was administered for a median duration of nine days, with an interquartile range of seven to 14 days. Most patients, 72.9%, received the antibiotic after the causative pathogen and its antibiotic susceptibility profile were known.
The majority of infections, 66.5%, were monomicrobial, meaning they involved a single identified microorganism. The most frequently observed pathogens were P. aeruginosa, accounting for 34.2% of cases, or 91 patients, and Acinetobacter baumannii, accounting for 19.2%, or 51 patients. Both organisms are important causes of serious healthcare-associated infections and can present substantial treatment challenges when antimicrobial resistance limits available options.¹
Clinical response rates varied according to treatment timing
Across the 266 patients, the overall clinical response rate was 76.7%, corresponding to 204 patients. The analysis also examined outcomes according to when cefiderocol was initiated during the treatment course.
Among 194 patients who received cefiderocol after the pathogen and its susceptibility profile were known, 153 achieved a clinical response, representing 78.9%. Among 30 patients who received cefiderocol empirically, before the pathogen had been identified, 24 achieved a clinical response, corresponding to 80%.
By comparison, 26 of the 41 patients who received cefiderocol after a previous antibiotic regimen had failed achieved a clinical response, a rate of 63.4%. These findings indicate that clinical response rates were numerically higher when cefiderocol was used before a prior antibiotic regimen failed.¹
The results provide real-world information on cefiderocol use in patients with severe respiratory infections caused by carbapenem-resistant Gram-negative bacteria. However, because the analysis was retrospective and observational, the findings demonstrate an association between treatment timing and clinical response rather than establishing that earlier cefiderocol administration directly caused better outcomes.
Amy L. Carr, PharmD, BCIDP, of AdventHealth Orlando, explained that the subgroup analysis was conducted because hospital-acquired respiratory infections caused by carbapenem-resistant Gram-negative bacteria are difficult to treat and delays in appropriate antibiotic therapy can be associated with increased morbidity and mortality.
Carr noted that the findings provide important insight into treatment outcomes among critically ill patients and highlighted the higher clinical response rates observed when cefiderocol was administered earlier rather than after a previous antibiotic regimen had failed.
The findings reinforce the importance of timely assessment of suspected resistant infections, pathogen identification, and antimicrobial susceptibility testing. They also contribute to the growing body of real-world evidence examining how newer antibacterial agents are used in complex hospital settings.
SENTRY Surveillance Data Demonstrate Cefiderocol Activity Against Resistant P. aeruginosa
Shionogi will also present findings from the SENTRY Antimicrobial Surveillance Program, which monitors pathogen prevalence and antimicrobial susceptibility patterns across global healthcare settings.
Antimicrobial surveillance programs provide important information about how bacterial resistance changes over time and across geographic regions. By evaluating susceptibility among contemporary clinical isolates, these programs help researchers and healthcare professionals understand emerging resistance patterns and assess the in vitro activity of available antibacterial agents.
The IDWeek presentation will examine approximately 1,400 global P. aeruginosa isolates collected from patients with ventilator-associated pneumonia in the United States and Europe between 2020 and 2024.²
P. aeruginosa is a significant cause of VAP, a serious healthcare-associated infection that can develop in patients receiving mechanical ventilation. Treatment can become particularly challenging when isolates are resistant to multiple antibiotic classes or when resistance mechanisms compromise commonly used therapies.
The analysis compared cefiderocol with four commonly prescribed BL/BLI combinations. Cefiderocol demonstrated high in vitro susceptibility across three breakpoint interpretive criteria: 99.5% according to the Clinical and Laboratory Standards Institute (CLSI), 98.9% according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST), and 97.9% according to the U.S. Food and Drug Administration (FDA) criteria.²
The findings were also notable among more resistant bacterial subgroups. Among BL/BLI-non-susceptible isolates, cefiderocol susceptibility ranged from 91.4% to 96.0% using CLSI criteria. In comparison, the BL/BLI combinations generally demonstrated susceptibility rates ranging from 30.4% to 41.8% in the reported comparison.²
The analysis also examined isolates harboring metallo-beta-lactamase (MBL) enzymes, including Verona integron-encoded metallo-beta-lactamase (VIM), New Delhi metallo-beta-lactamase (NDM), and imipenemase (IMP). These resistance mechanisms can substantially limit the activity of several beta-lactam antibiotics and complicate treatment decisions.
Cefiderocol retained high susceptibility across the highly resistant isolate groups described in the study, while the comparator BL/BLI combinations generally demonstrated lower susceptibility. These findings suggest that cefiderocol may retain in vitro activity against some P. aeruginosa isolates for which other commonly used antibiotic combinations have limited activity.²
Christine Slover, Vice President of Medical Affairs at Shionogi Inc., said that rising resistance among P. aeruginosa isolates underscores the need for treatment options that retain activity against difficult-to-treat Gram-negative pathogens.
Slover added that the analysis provides contemporary insight into susceptibility trends among VAP isolates, including evidence of cross-resistance across commonly used BL/BLI combinations. According to the company, this type of surveillance evidence helps improve understanding of the evolving antimicrobial resistance landscape.
Although the findings support further consideration of cefiderocol’s microbiological activity against resistant isolates, in vitro susceptibility does not necessarily translate into clinical efficacy. Treatment decisions must account for the patient’s condition, infection characteristics, susceptibility results, and applicable prescribing guidance.
Systematic Literature Review Examines Cefiderocol Use in S. maltophilia Infections
A third presentation will summarize a systematic literature review examining cefiderocol use in infections caused by S. maltophilia. The review included 45 published case reports and cohort studies evaluating clinical outcomes associated with treatment.³
S. maltophilia is an opportunistic Gram-negative bacterium with intrinsic resistance to many antibiotics. It can cause serious infections in hospitalized patients, particularly those who are critically ill, immunosuppressed, or affected by underlying medical conditions.
Treatment options can be limited because the organism’s resistance characteristics make the selection of effective antibacterial therapy challenging. Infections may be associated with substantial morbidity and mortality, particularly among vulnerable patients with complex healthcare needs.
According to the review, clinical response was reported in 35 of 49 patients described in case reports, corresponding to a response rate of 71.4%. Favorable clinical and microbiological outcomes were reported across a range of invasive S. maltophilia infections.³
These findings contribute to the published evidence examining cefiderocol in infections caused by this pathogen. However, case reports and observational cohort studies have important limitations, including small patient populations, differences in infection severity, variations in treatment regimens, and the potential for publication bias. The findings therefore should not be interpreted as definitive proof of efficacy across all S. maltophilia infections.
The review is particularly relevant in the context of the 2026 antimicrobial resistance guidance issued by the Infectious Diseases Society of America (IDSA). The guidance lists cefiderocol as a preferred treatment for invasive S. maltophilia infections while noting that this preference is based largely on animal-model data because clinical outcomes evidence remains limited.¹⁰
The review and guidance together highlight the continuing need for additional clinical research into effective treatment strategies for infections caused by resistant Gram-negative organisms. They also demonstrate the importance of distinguishing between evidence derived from laboratory studies, animal models, retrospective clinical observations, and prospective clinical trials when assessing treatment options.
Significance of the IDWeek 2026 Presentations
Taken together, the three presentations address different aspects of the challenges associated with serious Gram-negative infections.
The PROVE analysis provides real-world clinical response data from critically ill U.S. patients, including individuals with respiratory infections caused by carbapenem-resistant organisms. The SENTRY analysis provides global surveillance evidence concerning cefiderocol susceptibility among P. aeruginosa VAP isolates, including highly resistant subgroups. The systematic literature review consolidates published clinical experience involving S. maltophilia, a pathogen for which treatment options can be limited.
These findings are relevant as healthcare professionals continue to address antimicrobial resistance and the need for appropriate treatment strategies in hospital settings. The data also illustrate the complementary roles of observational research, microbiological surveillance, and literature reviews in evaluating antibacterial agents.
Shionogi’s presentations will contribute additional evidence to discussions about cefiderocol and its role in the management of selected serious Gram-negative infections. The company emphasizes that the findings should be considered alongside the approved prescribing information, susceptibility testing, and the clinical circumstances of individual patients.
Fetroja: U.S. Indications and Important Safety Information
Approved indications
Fetroja (cefiderocol) is indicated for patients 18 years of age or older for the treatment of the following infections caused by susceptible Gram-negative microorganisms:
- Complicated urinary tract infections (cUTIs), including pyelonephritis: Caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Enterobacter cloacae complex.
- Hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia (HABP/VABP): Caused by Acinetobacter baumannii complex, E. coli, Enterobacter cloacae complex, K. pneumoniae, P. aeruginosa, and Serratia marcescens.
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Fetroja and other antibacterial drugs, the medicine should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.
Contraindications
Fetroja is contraindicated in patients with a known history of severe hypersensitivity to cefiderocol, other beta-lactam antibacterial drugs, or any other component of the product.
Warnings and precautions
Increased all-cause mortality in patients with carbapenem-resistant Gram-negative bacterial infections: A clinical study involving patients with nosocomial pneumonia, bloodstream infections, or sepsis caused by carbapenem-resistant Gram-negative bacteria observed increased 28-day all-cause mortality among patients treated with Fetroja compared with those receiving best available therapy (BAT). Most BAT regimens included colistin. The difference in all-cause mortality remained through Day 49, and the cause of the increase has not been established.
Deaths generally occurred among patients with Gram-negative infections, including infections caused by non-fermenting organisms such as A. baumannii complex, S. maltophilia, and P. aeruginosa. Deaths were attributed to worsening infections, infection-related complications, or underlying comorbidities. Clinicians should closely monitor clinical response in patients treated for cUTI and HABP/VABP.
Hypersensitivity reactions: Serious and occasionally fatal anaphylactic reactions and serious skin reactions have been reported with beta-lactam antibacterial drugs, including Fetroja. Healthcare professionals should review patients’ histories of hypersensitivity to cephalosporins, penicillins, and other beta-lactam antibiotics before treatment. Fetroja should be discontinued if an allergic reaction occurs.
Clostridioides difficile-associated diarrhea: This complication has been reported with nearly all systemic antibacterial agents, including Fetroja, and may occur more than two months after antibiotic administration. If C. difficile-associated diarrhea is suspected or confirmed, appropriate evaluation and treatment are necessary, and antibiotics not directed against C. difficile may need to be discontinued.
Seizures and other central nervous system reactions: Cephalosporins, including Fetroja, have been associated with central nervous system adverse reactions, including seizures. Other reported reactions include encephalopathy, coma, asterixis, and neuromuscular excitability. Risk may be greater in patients with a history of epilepsy or when recommended doses are exceeded because of renal impairment. Fetroja dosing should be adjusted according to creatinine clearance. Patients experiencing focal tremors or seizures should be evaluated to determine whether treatment should be discontinued.
Development of drug-resistant bacteria: Using Fetroja without a proven or strongly suspected bacterial infection or an appropriate prophylactic indication is unlikely to benefit the patient and may increase the risk of antimicrobial resistance.
Adverse reactions
In the cUTI clinical trial, the most common adverse reactions occurring in at least 2% of patients receiving Fetroja were diarrhea (4%), infusion-site reactions (4%), constipation (3%), rash (3%), candidiasis (2%), cough (2%), elevated liver tests (2%), headache (2%), hypokalemia (2%), nausea (2%), and vomiting (2%).
In the HABP/VABP clinical trial, the most common adverse reactions occurring in at least 4% of patients receiving Fetroja were elevated liver tests (16%), hypokalemia (11%), diarrhea (9%), hypomagnesemia (5%), and atrial fibrillation (5%).
Healthcare professionals should review the complete prescribing information before prescribing Fetroja. The full U.S. Prescribing Information is available through Shionogi’s official Fetroja prescribing information.
This article summarizes Shionogi’s announcement and the reported study findings. The clinical data described do not replace the approved prescribing information or individualized medical judgment.
About Shionogi in Infectious Disease
For more than 60 years, Shionogi has discovered and commercialized novel antibiotics. Today, our R&D story extends beyond antibiotics to include novel medications for HIV and influenza. Our global pipeline includes investigational agents to address global health challenges including antimicrobial resistance, COVID-19, influenza, rare fungal diseases and respiratory syncytial virus.
As part of our commitment to addressing unmet medical needs, Shionogi partners with several non-governmental organizations to increase equitable access to our medications worldwide. Shionogi and Global Antibiotic Research and Development Partnership (GARDP) have a license and technology transfer agreement and Shionogi and GARDP have a collaboration agreement with the Clinton Health Access Initiative (CHAI) that aim to transform the landscape of access to antibiotics in many low- and middle-income countries and select high-income countries.
Shionogi ranked #2 among large research-based pharmaceutical companies in the Access to Medicine Foundation’s 2026 Antimicrobial Resistance (AMR) Benchmark, a global assessment of how leading pharmaceutical companies are tackling antimicrobial resistance and expanding responsible access to antibiotics worldwide.
About Shionogi Inc.
Shionogi Inc. is a U.S. subsidiary of Shionogi & Co., Ltd., a global research‑driven pharmaceutical company. Since 1878, Shionogi has been developing new treatments to improve patients’ lives worldwide. Today in North America, our portfolio of FDA approved products includes an antibiotic for serious infections caused by susceptible Gram-negative bacteria, an oral antiviral for post-exposure prophylaxis of COVID-19 and a therapy for amyotrophic lateral sclerosis (ALS). Our pipeline programs include investigational treatments across infectious disease, rare disease and additional high‑need therapeutic areas. Together with our subsidiaries Qpex Biopharma Inc. and Shionogi Canada Inc., we are continuing to innovate for patients in the U.S. and worldwide. Learn more at shionogi.com.
About Shionogi & Co., Ltd.
Shionogi & Co., Ltd. is a 148-year-old global, research-driven pharmaceutical company headquartered in Osaka, Japan, that is dedicated to bringing benefits to patients based on its corporate philosophy of “supplying the best possible medicine to protect the health and wellbeing of the patients we serve.” The company currently markets products in several therapeutic areas including anti-infectives, pain and CNS disorders. Shionogi’s research and development currently targets two therapeutic areas: infectious diseases and diseases with unmet medical needs, including rare diseases, allergy/inflammation, oncology, hearing loss, and sleep apnea. For more information on Shionogi & Co., Ltd., please visit https://www.shionogi.com/global/en.