LPOXY Therapeutics Secures $28M Series A to Launch Pivotal Trial for Novel C. Difficile Prevention Therapy
Key Insights
LPOXY Therapeutics (search) has secured a $28 million Series A financing agreement with 5 Horizons Ventures (search) to fund the pivotal STOP-Cdiff trial for SIDIPREV, a first-in-class non-antibiotic therapy designed to prevent C. difficile (search) infections.
The randomized, placebo-controlled superiority study will enroll approximately 500 hospitalized patients at high risk for CDI (search) due to age and antibiotic exposure, with trial initiation planned for Q3 2026.
SIDIPREV delivers controlled oxygen release into the lower gastrointestinal tract to inhibit anaerobic pathogens (search) like C. difficile (search) while suppressing toxin production (search) and reducing inflammation.
LPOXY Therapeutics (search) has signed a term sheet with 5 Horizons Ventures (search) for a $28 million Series A financing round to advance SIDIPREV, a novel non-antibiotic therapy designed to prevent Clostridioides difficile infections (search) in high-risk hospitalized patients. The funding will support the launch of the company's registrational STOP-Cdiff clinical trial, representing a significant milestone in addressing one of healthcare's most persistent infectious disease challenges.
Addressing an Urgent Public Health Threat
C. difficile (search) remains classified by the Centers for Disease Control and Prevention (search) as an urgent public health concern, responsible for approximately 80 deaths daily in the United States. The infection disproportionately affects older adults and patients exposed to antibiotics (search), often leading to severe gastrointestinal illness, prolonged hospital stays, and increased mortality. Despite its prevalence, no therapies are currently approved to prevent primary C. difficile infections, creating a critical gap in patient care.
Novel Mechanism of Action
SIDIPREV represents a fundamentally different approach to infection prevention. The therapy is formulated as an orally administered, enteric-coated capsule that delivers a controlled release of oxygen into the lower gastrointestinal tract. This oxygen-rich environment is designed to inhibit anaerobic pathogens (search) such as C. difficile (search). Additional mechanisms include suppression of toxin production (search) and mucosal anti-inflammatory effects, offering a multi-pronged defense against infection.
Dr. Larry Sutton, CEO and co-founder of LPOXY, explained that SIDIPREV delivers oxygen into the gastrointestinal tract, a mechanism toxic to anaerobic C. difficile (search). Unlike vaccine-based approaches that did not meet efficacy endpoints in late-stage trials, SIDIPREV is designed for co-administration with antibiotics (search), the primary risk factor for CDI (search), to prevent infections before onset.
Pivotal Trial Design and Timeline
The upcoming STOP-Cdiff trial will be a randomized, placebo-controlled superiority study involving approximately 500 hospitalized patients who are considered at high risk due to age and recent antibiotic use. The trial is being designed in alignment with the FDA's Limited Population Pathway for Antibacterial and Antifungal Drugs, which provides a regulatory framework for therapies targeting serious infections in defined patient populations.
LPOXY plans to initiate the trial in the third quarter of 2026, with a regulatory filing targeted for 2029. If successful, STOP-Cdiff will serve as the registrational study for SIDIPREV, paving the way for potential approval and commercial launch.
Strategic Investment and Market Opportunity
The Series A financing will not only fund the clinical trial but also support continued development, manufacturing scale-up, and regulatory engagement. LPOXY is actively building its investment syndicate and engaging with additional institutional investors who share its vision for tackling antimicrobial resistance and improving outcomes for high-risk patients.
"5 Horizons Ventures (search)' commitment marks a major milestone for LPOXY as we move toward launching our pivotal STOP-Cdiff trial," said Dr. Sutton. "SIDIPREV represents a novel approach to infection prevention that not only addresses a deadly unmet need but also aligns with hospital economics by reducing costly complications within fixed DRG payments."
A representative from 5 Horizons Ventures (search) noted: "We're impressed by the LPOXY team, their data, and their clear-eyed strategy for succeeding where many anti-infective programs have struggled. SIDIPREV avoids the reimbursement and resistance-related hurdles that have plagued traditional antibiotics (search), making this a rare opportunity to unlock real economic value for patients, hospitals, and investors."
Building on Previous Developments
In January 2025, LPOXY strengthened its development capabilities by acquiring key assets from Xeno Biosciences (search), including regulatory filings, FDA correspondence, chemistry, manufacturing, and control data, intellectual property, and results from phase 1 and Ib studies demonstrating safety of the active pharmaceutical ingredient.
The company has indicated plans to use the Limited Population Pathway to target high-risk populations, such as older adults hospitalized with community-acquired pneumonia (search) who are treated with broad-spectrum antibiotics (search). LPOXY has also reported ongoing efforts to establish partnerships to expand hospital access and distribution once the therapy progresses through pivotal trials.