Boston, MA – July 17, 2026 – Trellis Bioscience, a pioneering biotechnology company focused on developing innovative therapies for challenging infectious diseases, today announced the successful closure of a $9 million Series C funding round. This significant capital infusion will be instrumental in propelling the company’s lead candidate, calpurbatug (TRL1068), through its pivotal Phase II clinical trial for chronic prosthetic joint infections (PJI). The successful funding round elevates Trellis Bioscience’s total equity funding to approximately $35 million, underscoring strong investor confidence in the company’s potential to address a critical unmet medical need.
The Series C financing round saw robust participation from existing investors, including New Science Ventures and Easton Capital, who continue to demonstrate their commitment to Trellis Bioscience’s mission. The round also welcomed strategic new investments from the AMR Action Fund (AMRAF), a global alliance dedicated to combating antimicrobial resistance (AMR), The Doctor Group of Dallas, Texas, and a consortium of experienced orthopedic surgeons specializing in PJI across the United States. This diverse investor base highlights the broad recognition of calpurbatug’s therapeutic promise and the significant market opportunity it addresses.
Calpurbatug is a first-in-class monoclonal antibody designed to disrupt bacterial biofilms, a critical factor in the persistence and recalcitrance of chronic infections. These biofilms act as protective shields for bacteria, rendering them highly resistant to conventional antibiotics and the body’s immune defenses. By targeting and breaking down these biofilms, calpurbatug aims to re-sensitize the underlying bacteria to antibiotic treatment and facilitate clearance by the immune system.
The ongoing Phase II clinical trial for calpurbatug is evaluating its efficacy as part of a debridement, antibiotics, and implant retention (DAIR) approach. This trial is fully enrolled, a significant milestone that allows the company to focus on data analysis and future development. Top-line results from this crucial study are anticipated in the second quarter of 2027, a date eagerly awaited by the medical community and patients suffering from PJI.
Addressing a Critical Unmet Need: The Challenge of Prosthetic Joint Infections
Prosthetic joint infections (PJI) represent a severe and debilitating complication following orthopedic implant surgery, particularly for knee and hip replacements. These infections are notoriously difficult to treat, often leading to significant patient morbidity, prolonged hospital stays, and substantial healthcare costs. The current standard of care for chronic PJI typically involves a complex and invasive two-stage surgical intervention. This process requires the removal of the infected implant, a period of antibiotic treatment, and subsequent reimplantation of a new prosthesis.
This multi-stage surgical approach, while sometimes necessary, is associated with numerous challenges. High failure rates, prolonged recovery times, and a substantial risk of increased mortality are significant concerns for patients undergoing this treatment. Furthermore, the increasing prevalence of antibiotic-resistant bacteria exacerbates the problem, making effective treatment even more challenging. The lack of approved, targeted therapies specifically for PJI highlights a critical gap in the therapeutic landscape, a gap that Trellis Bioscience aims to fill with calpurbatug.
A Strategic Funding Round: Fueling Clinical Advancement and Growth
The $9 million Series C funding round is a testament to the company’s progress and the compelling scientific rationale behind calpurbatug. This investment will primarily be allocated to advancing the Phase II clinical trial to its completion, supporting the necessary data analysis, and preparing for potential future regulatory submissions. The capital infusion will also bolster Trellis Bioscience’s operational capacity and support ongoing research and development efforts.
"We are incredibly encouraged by the strong support from both our existing and new investors, particularly the AMR Action Fund, which signifies a shared commitment to tackling the global threat of antimicrobial resistance," said Geoff Dillon, CEO of Trellis Bioscience. "This funding is crucial as we advance calpurbatug through its Phase II trial. Our goal is to fundamentally change how antibiotic-resistant infections are managed, and calpurbatug’s unique mechanism of action, targeting bacterial biofilms, positions it as a potential paradigm shift in treatment."
The strategic alignment with the AMR Action Fund is particularly noteworthy. AMRAF is a global initiative specifically designed to invest in and advance the development of novel antibiotics and other anti-infective therapies. Their investment in Trellis Bioscience underscores the significant potential of calpurbatug to address the growing challenge of antibiotic resistance.
Comprehensive Funding Landscape: Equity and Non-Dilutive Support
The $35 million in total equity funding achieved by Trellis Bioscience is further complemented by substantial non-dilutive grants. The company has secured matching funding from prestigious institutions such as the National Institute of Allergy and Infectious Disease (NIAID) and the Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator (CARB-X). This dual approach of equity investment and grant funding demonstrates a robust financial strategy that minimizes dilution for shareholders while maximizing resources for critical research and development. The parallel support from government agencies and public-private partnerships highlights the recognized importance of Trellis Bioscience’s work in addressing a major public health concern.
Strategic Partnerships and Board Expansion
In conjunction with the AMR Action Fund’s investment, Junjun Gao, Principal at AMRAF, has joined the Trellis Bioscience Board of Directors. Gao’s extensive experience in the antimicrobial space and her strategic insights will be invaluable as Trellis Bioscience navigates the complex landscape of drug development and commercialization. Her appointment signifies a deepening of the partnership and a shared vision for the future of infectious disease treatment.
"We are thrilled to welcome Junjun Gao to our Board," Dillon added. "Her expertise and the AMR Action Fund’s focus on critical anti-infective therapies are a powerful combination that will undoubtedly accelerate our progress."
The Scientific Foundation: Calpurbatug’s Journey
The clinical evaluation of calpurbatug has a solid foundation. The company previously conducted a successful Phase I trial in PJI patients under an Investigational New Drug (IND) application cleared by the U.S. Food and Drug Administration (FDA). This initial study provided crucial data on the safety profile of calpurbatug, as well as its pharmacokinetic properties and its ability to disrupt bacterial biofilms in vivo. These promising early results paved the way for the current Phase II investigation.
The unique mechanism of action of calpurbatug, its ability to disrupt bacterial biofilm, offers significant potential beyond PJI. Dillon elaborated, "By disrupting bacterial biofilm, calpurbatug represents a new class of agents with potential utility in a substantial number of antibiotic-resistant infections." This broad applicability suggests that calpurbatug could become a valuable tool in the fight against a wide spectrum of challenging bacterial infections.
Regulatory Recognition and Future Outlook
Calpurbatug has garnered significant regulatory attention, receiving multiple designations from the FDA that underscore its potential to address serious unmet medical needs. These designations include Orphan Drug, Fast Track, and Qualified Infectious Disease Product (QIDP). These labels from the FDA indicate that calpurbatug is being developed for rare diseases or conditions, has the potential to address serious and life-threatening diseases, and is intended for the treatment, diagnosis, or prevention of a serious bacterial infection, respectively. These designations often come with regulatory incentives, such as extended market exclusivity and expedited review pathways, which can accelerate the drug’s journey to patients.
The successful completion of the Phase II trial and the anticipated positive top-line results in Q2 2027 will be critical inflection points for Trellis Bioscience. These results will inform the design of potential Phase III pivotal trials and further discussions with regulatory authorities. The company’s ability to secure substantial funding, build a strong investor base, and achieve key clinical milestones positions it well for continued growth and success in the challenging but vital field of infectious disease therapeutics.
The development of calpurbatug represents a significant step forward in the ongoing battle against antibiotic resistance and the persistent challenge of chronic infections. With a robust clinical pipeline, strong financial backing, and a clear strategic vision, Trellis Bioscience is poised to make a meaningful impact on patient care and public health. The company’s commitment to innovation and its focus on addressing critical unmet medical needs offer a beacon of hope for patients suffering from the debilitating effects of chronic prosthetic joint infections and potentially other difficult-to-treat bacterial diseases.
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