23 April 2026

ONDINE BIOMEDICAL INC.
("Ondine Biomedical", "Ondine" or the "Company")

University of Ottawa Heart Institute Reduces Surgical Site Infections Following Implementation of Steriwave Nasal Photodisinfection

Ondine Biomedical Inc. (AIM: OBI), a global leader in light-activated antimicrobial therapies, announces that the University of Ottawa Heart Institute ("UOHI"), Canada's largest and foremost academic health sciences centre dedicated to cardiovascular care, found notable results in patient safety following the integration of Steriwave^® nasal decolonisation into its presurgical protocols.

In a clinical evaluation at UOHI, outcomes from a 24-month control period using mupirocin were compared with an 8-month pilot programme incorporating Steriwave. Consistent with results reported from other hospitals, the addition of Steriwave was associated with a statistically significant reduction in Surgical Site Infection ("SSI") rates among cardiac surgery patients. This marked decline has significantly impacted the Institute's infection rates, improving postoperative recovery and patient outcomes.

These findings have been submitted to an upcoming major international cardiac conference, and a detailed manuscript describing the study's methodology and comprehensive results is currently in development for submission to a peer-reviewed medical journal.

Dr. Fraser Rubens, MD, MSc, FACS, FRCSC, Professor of Cardiac Surgery at the University of Ottawa, noted:

"Achieving a marked reduction in SSIs is a monumental shift that not only saves lives but also reduces the significant strain that surgical complications place on the healthcare system. In the ongoing race against antibiotic resistance, photodisinfection therapy provides an innovative and promising strategy for enhancing patient safety."

Carolyn Cross, CEO of Ondine Biomedical, stated:

"Surgical site infections represent one of the most costly and dangerous complications in cardiac surgery, often leading to extended hospital stays, readmissions, and increased mortality. By implementing a non-antibiotic, rapid decolonisation solution, UOHI continues to lead the way in both clinical innovation and antimicrobial stewardship. We are pleased to support UOHI's efforts to protect their cardiac patients from the rise in multidrug resistance."

Nasal decolonisation is a critical step in preventing healthcare-associated infections, as the nose is a primary reservoir for pathogens like Staphylococcus aureus. Unlike traditional antibiotic ointments, which can be limited by patient compliance and rising antimicrobial resistance, Steriwave uses photodynamic disinfection to rapidly eliminate bacteria, viruses, and fungi without the risk of generating "superbugs".

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About the University of Ottawa Heart Institute

Recognized as one of Canada's most distinguished heart health centres, the Ottawa Heart Institute delivers unparalleled patient care, leads globally recognized research from bench to bedside, and plays a national leadership role in heart disease prevention. Serving communities from Eastern Ontario, Western Quebec, Nunavut and Newfoundland and Labrador, the Institute strives to ensure care, research and education support heart health for all. The Ottawa Heart Institute promise remains: Always putting patients first. For more information, visit www.ottawaheart.ca.

About Steriwave^® and its Mode of Action

Steriwave nasal photodisinfection is a non-invasive and painless treatment that uses a proprietary light-activated photosensitive agent to destroy harmful bacteria, viruses, and fungi, including antibiotic-resistant strains, in the nasal passages. The procedure takes five minutes and, unlike antibiotics, is effective immediately and allows the normal nasal microbiome to recover quickly, without fostering antimicrobial resistance.

The two-step process involves applying the Steriwave formulation in the nostrils where it electrostatically binds to microbes rather than human cells. The area is then illuminated with safe red light to activate the formulation, triggering an oxidative burst that physically destroys all manner of pathogens within minutes. This rapid and overwhelming oxidative stress makes it extremely difficult for pathogens to develop resistance, and the process stops immediately once the light is turned off. Steriwave has been used in a growing number of hospitals since 2011.

About Ondine Biomedical Inc.

Ondine Biomedical Inc. is a Canadian life sciences company and leader in light-activated antimicrobial therapies ('photodisinfection') for the prevention and treatment of infections, including those caused by multidrug-resistant organisms. Ondine has a pipeline of investigational products, based on its proprietary photodisinfection technology, in various stages of development.

Ondine's nasal photodisinfection system is CE-marked in Europe and is approved for nasal decolonisation in Canada, Australia, Mexico, and several other countries under the name Steriwave®. In the US, it has been granted Qualified Infectious Disease Product designation and Fast Track status by the FDA and is currently undergoing clinical trials for regulatory approval. Products beyond nasal photodisinfection include therapies for a variety of medical indications such as chronic sinusitis, ventilator-associated pneumonia, burns, and other indications.