Peptilogics Raises $78 Million to Advance Zaloganan Into Pivotal Trial

Zaloganan (PLG0206) enters Phase 2/3 study for treating prosthetic joint infections (PJI)

PITTSBURGH, Oct. 16, 2025 /PRNewswire/ -- Peptilogics, a clinical-stage biotechnology company developing transformative surgical therapeutics to effectively treat and prevent serious medical device infections, today announced the completion of an oversubscribed $78 million Series B2 financing round. The funding will support the company's Phase 2/3 pivotal trial of zaloganan (PLG0206), an investigational treatment for prosthetic joint infections (PJI).

Presight Capital, Thiel Bio, and Founders Fund led the round, with participation from new investors AMR Action Fund, Narya Capital, and Beyond Ventures. This brings Peptilogics' total equity funding to approximately $120 million, along with substantial grant support from CARB-X.

"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," said Peptilogics' CEO Jonathan Steckbeck, PhD. "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."

Addressing Orthopedic Surgery's Most Challenging Complication to Create a New Category of Surgical Therapeutics

Prosthetic joint infections are a devastating complication that can turn a successful joint replacement into a patient's worst nightmare. With 45,000 PJI cases each year in the U.S. and no approved therapeutics specifically indicated for this condition, patients face limited and often unsuccessful treatment options.

Current approaches force difficult choices: implant-preserving procedures such as DAIR (debridement, antibiotics, and implant retention) have reported failure rates of approximately 50% in published literature, while grueling two-stage revision procedures require multiple surgeries, extended hospitalization, and months of disability, yet still fail 15-25% of the time. The financial burden is equally staggering, with total PJI costs often reaching more than $390,000 per patient, according to a study by Hany Bedair, MD published in Clinical Orthopedics and Related Research.

"Biofilm is the common enemy and the reason why existing standard-of-care surgical interventions fail, even with systemic antibiotics," says Nick Pachuda, a former orthopedic surgeon and Peptilogics Chief Operating Officer. "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."

In Peptilogics' Phase 1b study, zaloganan irrigation administered during DAIR procedures resulted in 13 of 14 patients (93%) remaining infection-free at 12 months. These encouraging results supported the company's decision to advance into pivotal trials.

Growing Problem, Expanding Opportunity

The challenge is growing as more joint replacement surgeries are expected. Projections show that by 2030, 3.48 million knee and 572,000 hip replacements will be done each year in the U.S., each with a PJI risk that current medicine cannot fully manage.

The implications reach well beyond individual patients. Healthcare systems are under increasing pressure as PJI cases strain resources through longer hospital stays, repeat surgeries, and complex care coordination. For investors, this represents a substantial and growing market opportunity where effective treatment could deliver significant value to patients, providers, and payers alike.

Regulatory and Development Progress

Peptilogics has received multiple regulatory designations that support the development pathway for zaloganan, including:

• QIDP (Qualified Infectious Disease Product) designation, which provides 5 additional years of market exclusivity upon approval
• Orphan Drug Designation for the treatment of PJI
• Fast Track Designation to facilitate development and expedite FDA review

The upcoming Phase 2/3 randomized, placebo-controlled superiority trial will enroll 240 patients beginning in December 2025, with the primary endpoint measuring the reduction in clinical failure rates. The study will also evaluate health economics measures including hospitalization duration, readmission rates, and additional surgical procedures to quantify the cost savings that zaloganan can create for hospitals, health systems, and payers.

"Periprosthetic joint infections are a striking example of how antimicrobial resistance is rapidly undermining modern medicine," said AMR Action Fund CEO Henry Skinner, PhD. "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."

About Peptilogics

Peptilogics is developing therapeutics for orthopedic hardware-related infections. The company's lead candidate, zaloganan (PLG0206), is an investigational treatment for prosthetic joint infections currently in clinical development. For more information, visit www.peptilogics.com.

About the Investor Syndicate

The investor syndicate is a group of leading venture firms and strategic healthcare investors who share a commitment to advancing transformative technologies. These investors have backed paradigm-shifting companies including AbCellera (ABCL), Atai Life Sciences (ATAI), New Amsterdam Pharma (NAMS), Compass Pathways (CMPS), Kriya Therapeutics, and F2G. This group combines deep domain expertise with a shared commitment to advancing breakthroughs that improve patient outcomes and redefine standards of care — creating an alignment of capital, science, and purpose to accelerate meaningful change for the healthcare system.

Media Contact:
Kate Kaminsky
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SOURCE Peptilogics