Peptilogics Enrolls First International Patient in Phase 2/3 RETAIN Trial of Zaloganan for Treatment of Prosthetic Joint Infection

UK trial sites join the pivotal study of first-in-class anti-biofilm drug candidate designed to cure medical device-related infections

PITTSBURGH & LEEDS, United Kingdom--(BUSINESS WIRE)--Peptilogics, a clinical stage biotech company dedicated to curing and preventing medical device-related infections (MDRI), today announced that the first patient has been enrolled in the U.K. at Leeds Teaching Hospitals NHS Trust and NIHR Clinical Research Facility: Leeds, in the pivotal RETAIN Phase 2/3 trial of zaloganan (PLG0206) for treatment of prosthetic joint infection (PJI). Led by Investigators Dr. Hemant Pandit, Professor of Orthopaedic Surgery at the University of Leeds and Honorary Consultant Orthopaedic Surgeon at Leeds Teaching Hospitals NHS Trust, and Dr. Jeya Palan, Consultant Orthopaedic Surgeon and Honorary Senior Clinical Lecturer, the enrollment is the first outside the U.S.

“While the vast majority of knee replacement surgeries help patients move more freely and live with less pain, prosthetic joint infection is a very serious complication that can require repeated surgeries with increased risk of mortality in the most extreme cases. The diagnosis and optimal management of PJI remains challenging to surgeons, and the condition often leaves behind permanent and life-changing effects that negatively impact the patient's limb function and overall quality of life,” said Dr. Pandit.

Five million joint replacements are performed each year across the U.S., U.K. and Europe.¹ PJI affects about two percent of joint replacements and occurs when biofilm forms on an implant, shielding bacteria from antibiotics and the immune system, and causing inflammation, tissue destruction, pain and joint loosening.² The standard of care revision surgeries typically involve removing the infected implant, attempting to clear the infection surgically, and replacing the implant.

Dr. Palan added, “PJI can be clinically challenging and can require multiple procedures and have unpredictable outcomes. Finding new clinical practices and options for successful treatment of this serious condition is vital to improving the outcome for patients.”

RETAIN is an international randomized, double-blind, placebo-controlled Phase 2/3 trial of zaloganan in patients undergoing Debridement, Antibiotics, and Implant Retention (DAIR) for PJI after total knee arthroplasty. It is designed to test superiority against standard of care, with a primary endpoint of treatment failure and a key secondary endpoint of PJI-related surgical intervention, both within 12 months. The trial plans to enroll approximately 240 patients across 50 sites in the U.S., U.K. and Australia. In an earlier open label Phase 1B study, one of 13 zaloganan-treated PJI patients (seven percent) had a recurrence of infection by 12 months.³ In contrast, a 12-month failure rate of 35 to 55 percent has been reported with current standard of care.^4,5

“Biofilm is the culprit behind device-related infections, and nothing approved today was designed to target it,” said Jonathan Steckbeck, Ph.D., Peptilogics CEO. “Zaloganan could change that. It’s the first drug shown to both penetrate biofilm and kill the persister bacteria it protects. PJI is where we began because the need is greatest, but biofilm is a shared challenge across all types of implanted devices. If RETAIN succeeds, the data would support continued development of zaloganan to treat and potentially prevent infections across a broad range of devices. It is a potentially category-defining therapeutic opportunity in a multi-billion-dollar market.”

PJI is the largest unmet need in orthopedics and the entry point to a much broader MDRI market. An estimated 220 million people worldwide live with implanted medical devices, including joint replacements, cardiovascular assist devices, spinal fusion hardware, hernia mesh, post-mastectomy breast implants, and vascular grafts.^6,7,8,9 Biofilm is the primary driver of serious infections across these categories, and no approved therapy has been designed to target it.

Zaloganan is an investigational antimicrobial peptide engineered to treat PJI and, potentially, all MDRI. It is active against a broad range of bacteria, including multi-drug-resistant pathogens, and has low resistance potential. The U.S. Food & Drug Administration (FDA) has granted zaloganan Qualified Infectious Disease Product (QIDP) and Fast Track designations for PJI, and has awarded Orphan Drug designation for zaloganan in the treatment of PJI.

The RETAIN trial is being delivered in Leeds, U.K., by world-leading clinicians and researchers at Leeds Teaching Hospitals NHS Trust and the University of Leeds, with support from the NIHR Clinical Research Facility: Leeds. The first patients at Leeds were recruited within 21 days and received treatment within 25 days. A further 14 sites in the U.K. will be part of the RETAIN trial.

More information about RETAIN is available at peptilogics.com/pipeline and on ClinicalTrials.gov (NCT07214311).

About Leeds Teaching Hospitals NHS Trust

Leeds Teaching Hospitals NHS Trust is one of the largest and busiest acute hospital trusts in the country. We are the local hospital for Leeds and provide specialist services for our local communities, the Yorkshire and Humber region and beyond.

This means that people in Leeds have access to some of the very best care in the country and benefit from a seamless provision of all services.

We play an important role in the training and education of medical, nursing and dental students, and are a centre for world-class research, innovation and pioneering new treatments.

Leeds Teaching Hospitals has a budget of more than £2.1 billion and a 20,000-strong staff. Last year, we delivered close to 1.8 million episodes of care, including 109,000 inpatient admissions, 1.3 million outpatient attendances and 359,000 attendances in our Emergency Departments.

Our care and clinical expertise is delivered from seven hospitals on five sites, and they are all joined by our vision to be the best for specialist and integrated care.

Find out more on our website: www.leedsth.nhs.uk

University of Leeds

The University of Leeds is one of the largest higher education institutions in the U.K., with more than 37,000 students from about 140 different countries. We are renowned globally for the quality of our teaching and research.

We are a values-driven university, and we harness our expertise in research and education to help shape a better future for humanity, working through collaboration to tackle inequalities, achieve societal impact and drive change.

The University is a member of the Russell Group of research-intensive universities, and is a major partner in the Alan Turing, Rosalind Franklin and Royce Institutes.

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About Peptilogics

Peptilogics is a biotech company dedicated to curing and preventing medical device-related infections (MDRI). Its lead candidate, zaloganan, is a first-in-class drug that targets biofilm, the protective bacterial matrix behind device infections across surgical categories. Zaloganan is currently in a Phase 2/3 registration trial RETAIN for prosthetic joint infection (PJI), the first of multiple potential MDRI indications. For more information visit www.peptilogics.com.

Forward-Looking Statements

This press release contains “forward-looking statements” that involve substantial risks, assumptions and uncertainties. Forward-looking statements are often identified by words such as “believe,” “estimate,” “intend,” “may,” “plan,” “potentially,” “will,” “expect,” “enable,” “likely” or the negative of these terms or other similar expressions. All statements, other than statements of historical facts, regarding management’s expectations, beliefs, goals, plans or Peptilogics, Inc. prospects should be considered forward-looking statements. Readers are cautioned that actual results may differ materially from projections or estimates due to a variety of important factors. These forward-looking statements are made as of the date of this press release, and Peptilogics, Inc. assumes no obligation to update them, or the reasons why actual results could differ from those projected, except as required by law.

References

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3. McNally, M. Ph 1b data presentation. Presented at: European Bone and Joint Infection Society (EBJIS) Annual Meeting; 2024.
4. Zhu MF, Kim K, Cavadino A, et. al. Success Rates of Debridement, Antibiotics, and Implant Retention in 230 Infected Total Knee Arthroplasties: Implications for Classification of Periprosthetic Joint Infection. J Arthroplasty, 2021 Jan;36(1):305-310.e1. doi: 10.1016/j.arth.2020.07.081.
5. Urish, K. et al. A Multicenter Study of Irrigation and Debridement in Total Knee Arthroplasty Periprosthetic Joint Infection: Treatment Failure Is High. J Arthroplasty. 2018;33:1154-1159.
6. Peptilogics internal estimate.
7. Urish, K. et al. A Multicenter Study of Irrigation and Debridement in Total Knee Arthroplasty Periprosthetic Joint Infection: Treatment Failure Is High. J Arthroplasty. 2018;33:1154-1159.
8. Wang, QF, Tang, YC, Liao, HR, et al. Prevalence of metal implants among US adults aged 40 years and older. Sci Rep 15, 584 (2025).
9. Katella, K. (October 13, 2022). A Breast Cancer Decision: What Kind of Breast Reconstruction Is Right for You? Yale Medicine.