Peptilogics, a clinical-stage biotechnology company pioneering surgical therapeutics for medical device infections, has closed an oversubscribed $78 million Series B2 financing round. The funding round was led by Presight Capital, Thiel Bio, and Founders Fund, with additional participation from AMR Action Fund, Narya Capital, and Beyond Ventures.
This brings Peptilogics’ total equity raised to approximately $120 million, alongside substantial non-dilutive grant support from CARB-X. And the investment will fund a pivotal Phase 2/3 clinical trial of its lead compound, zaloganan (PLG0206), an investigational therapy targeting prosthetic joint infections (PJI), one of the most severe complications in orthopedic surgery.
Prosthetic joint infections represent a significant unmet medical challenge, with an estimated 45,000 cases annually in the United States. These infections can turn successful joint replacements into prolonged medical crises, often requiring multiple surgeries, extended hospitalizations, and costly rehabilitation. No FDA-approved therapeutic exists specifically for PJI, leaving patients dependent on suboptimal interventions such as DAIR (debridement, antibiotics, and implant retention), which has a failure rate of roughly 50%, or two-stage revisions that can still fail in up to 25% of cases. Treatment expenses can exceed $390,000 per patient.
Zaloganan aims to address this gap by eliminating biofilm—the bacterial shield that renders most antibiotics ineffective—directly at the infection site. In a Phase 1b study, zaloganan irrigation during DAIR procedures resulted in 93% of patients (13 out of 14) remaining infection-free for 12 months, paving the way for its advancement to pivotal trials.
Peptilogics’ upcoming randomized, placebo-controlled Phase 2/3 superiority trial will enroll 240 patients beginning in December 2025. The primary endpoint will measure reductions in clinical failure rates, with secondary analyses on health economics, including hospital stays, readmissions, and surgical burden. The company holds multiple U.S. FDA regulatory designations for zaloganan, including Qualified Infectious Disease Product (QIDP), Orphan Drug, and Fast Track status, each supporting an expedited pathway to market approval and potential extended exclusivity.
As global demand for joint replacements is expected to rise sharply—projected to reach 3.48 million knee and 572,000 hip procedures annually in the U.S. by 2030—the need for effective infection management solutions continues to grow. Peptilogics’ investors see zaloganan as both a clinical breakthrough and a market-defining opportunity, capable of transforming surgical infection care and reducing healthcare system strain.
Peptilogics’ leadership describes the company’s mission as redefining surgical therapeutics for a category of infections that existing antibiotics fail to treat effectively. The company’s investor group includes firms that have previously supported leading biopharma innovators such as AbCellera, Compass Pathways, and Kriya Therapeutics—underscoring confidence in Peptilogics’ science and commercial potential.
KEY QUOTES:
“What these investors understood is that hardware-related infections like PJI are different from other common infections. We chose to focus on this huge unmet need because the lack of effective therapeutic options alters the commercial landscape that has made antibiotic development difficult. Developing treatments for these infections allows us to create a new category of surgical therapeutics for patients who currently have to undergo multiple life-changing surgeries to eliminate the infection.”
Jonathan Steckbeck, PhD, CEO, Peptilogics
“Biofilm is the common enemy and the reason why existing standard-of-care surgical interventions fail, even with systemic antibiotics. Hardware-related infections are difficult to treat because bacteria on foreign surfaces hide in drug-resistant biofilm that current antibiotics cannot eliminate. Zaloganan quickly penetrates the biofilm locally and kills the hiding bacteria.”
Nick Pachuda, Chief Operating Officer, Peptilogics
“Periprosthetic joint infections are a striking example of how antimicrobial resistance is rapidly undermining modern medicine. The financial costs, diminished quality of life, and mortality associated with such infections are frankly unacceptable, and we are pleased to support the Peptilogics team as they advance zaloganan through the clinic and toward patients in need.”
Henry Skinner, PhD, CEO, AMR Action Fund
