Trellis Bioscience Raises $9 Million Series C to Advance Novel Biofilm-Disrupting Antibody for Prosthetic Joint Infections
Key Insights
Trellis Bioscience (search) closed a $9 million Series C financing to support completion of its Phase 2 trial of calpurbatug (TRL1068) for chronic prosthetic joint infections (search), with top-line results expected in Q2 2027.
Calpurbatug is a native human monoclonal antibody that disrupts bacterial biofilm (search), representing a new therapeutic class aimed at overcoming antibiotic resistance at its source.
Prosthetic joint infections (search) affect more than 25,000 patients annually in the U.S., with no approved therapeutic treatments and per-patient management costs exceeding $400,000.
Trellis Bioscience (search), a clinical-stage biotechnology company focused on native human monoclonal antibodies for intractable infectious diseases, announced the closing of a $9 million Series C financing on July 16, 2026. The funding will support completion of the company's Phase 2 trial of calpurbatug (TRL1068), an investigational monoclonal antibody designed to treat chronic prosthetic joint infections (search) (PJI) by disrupting bacterial biofilm (search).
The Series C round drew continued support from existing investors New Science Ventures (search) and Easton Capital (search), while attracting new investors including the AMR Action Fund (search) (AMRAF), The Doctor Group of Dallas, Texas, and orthopedic surgeons with extensive PJI expertise from centers of excellence across the United States. This brings Trellis's total equity funding to approximately $35 million, matched by a similar amount of non-dilutive grant support from NIAID and CARB-X. In conjunction with AMRAF's investment, Junjun Gao, PhD, Principal at AMRAF, has been appointed to the Trellis Board of Directors.
"We're excited to have the backing of AMRAF, the most prominent investor in the antimicrobial space, as we move ahead in our efforts to redefine how antibiotic-resistant infections are treated in the future," said Trellis CEO Geoff Dillon. "By disrupting bacterial biofilm (search), calpurbatug represents a new class of agents with potential utility in a substantial number of antibiotic-resistant infections."
The Unmet Need in Prosthetic Joint Infections (search)
Prosthetic joint infections (search) represent a debilitating and costly complication of knee and hip replacements, affecting more than 25,000 patients — roughly 1 to 2 percent of joint replacement recipients — annually in the United States alone. Currently, there are no approved therapeutic treatments for this condition. The standard of care is a two-stage surgical revision associated with significantly diminished quality of life, high failure and five-year mortality rates, and substantial healthcare expenditures. Estimates indicate that managing PJIs can exceed $400,000 per patient.
A less invasive alternative known as DAIR (debridement, antibiotics, and implant retention) offers a more patient-friendly approach but carries a substantially higher failure rate, particularly for chronic PJI. Trellis's strategy targets the root cause of antibiotic resistance in these infections by using calpurbatug to disassemble the biofilm that shields bacteria from antibiotic eradication.
"The PJI treatment challenge and financial burden are expanding as more joint replacement surgeries are expected for the aging U.S. population," said John Friedman, Chairman of Easton Capital (search).
Clinical Development and Regulatory Status
Trellis conducted its first-in-human trial of calpurbatug in PJI patients under an FDA-cleared IND application. The Phase 1 trial provided safety and pharmacokinetics data alongside early clinical evidence of biofilm-disrupting activity. The current Phase 2 trial, which tests TRL1068 in PJI patients as part of a DAIR procedure, is fully enrolled, with top-line results expected in the second quarter of 2027.
Jason Adams of The Doctor Group commented on the emerging data: "The emerging results from clinical trials for augmenting the DAIR procedure with TRL1068 suggest that this innovative drug will yield outcomes superior to two-stage revision in a range of bacterial infections. That would be a true game changer in the field — better results and less grueling for the patient."
TRL1068 has received Orphan Drug, Fast Track, and Qualified Infectious Disease Product (QIDP) designations from the FDA. These designations may facilitate development and regulatory review, and the QIDP designation provides the potential for additional market exclusivity following approval.
A Broader Platform Against Infectious Disease
Trellis developed a proprietary technology for cloning antibodies, including calpurbatug, from human white blood cells. The company notes that human antibodies have a lower failure rate due to toxicity than any other drug class. Applied to infectious diseases, the platform has enabled discovery of antibodies from patients who have recovered from the target disease. Beyond the lead biofilm disruption program, Trellis's pipeline includes antiviral antibodies — one of which is currently in a clinical trial — targeting major unmet medical needs.
Henry Skinner, PhD, CEO of AMR Action Fund (search), underscored the broader significance: "Infection is a risk with any surgical procedure, and prosthetic joint infections (search) can be devastating for patients. The growing threat of antimicrobial resistance is making these infections increasingly difficult to treat. We are pleased to support the Trellis team as they work to develop a therapy that could improve outcomes for patients and help preserve the antibiotic safety net that underpins modern surgical care."