Atossa Therapeutics, Inc. (Nasdaq: ATOS), a clinical stage biopharmaceutical company seeking to discover and develop innovative medicines in areas of significant unmet medical need in oncology and infectious diseases with a current focus on breast cancer and COVID-19, today announces it has received regulatory approval from HREC (Human Research Ethics Committee) to open a clinical study of AT-H201 in Australia. The nebulized formulation, AT-H201, is being developed as an inhalation therapy for moderately to severely-ill hospitalized COVID-19 patients and for “long-haul” patients with post-infection pulmonary disease.

“The COVID-19 pandemic continues to be an urgent health crisis with many regions reporting low vaccination rates combined with new SARS-CoV-2 variants proving more infectious and more deadly,” said Steven Quay, M.D., Ph.D., Atossa’s CEO and President. “If the initial parts of the study are successful we will study the efficacy of our proprietary AT-H201 on moderately ill COVID-19 patients who can be treated via a nebulizer. Our goal in developing nebulized AT-H201 is to improve lung function in patients with active disease, which may reduce the number of patients requiring ventilators and in “long-haul” patients who have residual pulmonary function damage. Up to one third of hospitalized patients have pulmonary function changes 60 days or more after recovering from COVID. The portability of nebulizers, already routinely used for other chronic lung disease, allows for treatment at home.”

The Phase 1/2a placebo-controlled study will enroll a total of 60 healthy participants and moderately-ill hospitalized COVID-19 patients. The study has 4 parts: a single ascending dose part, a multiple ascending dose part, a combination part in healthy individuals and a combination in COVID-19 infected patients and will be conducted with Avance Clinical Pty Ltd., a leading Australian clinical research organization.

AT-H201 is a proprietary combination of two drugs previously approved by the FDA to treat other diseases and by other administration routes. AT-H201 is intended to be inhaled via a nebulizer to improve compromised lung function for moderate to severely ill, hospitalized COVID-19 patients and for “long-haul” patients with post-infection pulmonary disease. In May 2020, we completed in vitro testing of AT-H201 which showed that the components of AT-H201 inhibit SARS-CoV-2 infectivity of VERO cells, which is a standard cell type being used to study infectivity of the coronavirus. The AT-H201 components were found to be at least four times more potent than Remdesivir and at least 20 times more potent than Hydroxychloroquine. Potency was measured by microscopic examination of the cytopathic effect caused by SARS-CoV-2 in VERO cells.

The Phase 1/2a study in Australia and other clinical studies must be successfully completed and regulatory approvals must be obtained before AT-H201 may be commercialized. No assurance can be given than studies will be successful or that regulatory approvals will be obtained.