Windtree Therapeutics, Inc., a biotechnology company, announced that recently presented preclinical data at the 62nd Radiation Research Society Annual Meeting suggest that KL4 surfactant could potentially be an effective medical countermeasure to mitigate acute and chronic/late-phase radiation-induced lung injury (pneumonopathy) due to exposure from a nuclear accident or act of terrorism. The company believes that, as a possible additional application, KL4 surfactant may also mitigate radiation pneumonopathy associated with cancer radiation therapy.

"While we remain primarily focused on the rigorous and timely execution of the AEROSURF phase 2 clinical development programme for premature infants with respiratory distress syndrome (RDS), a phase I SBIR grant of $600,000 from the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH) provided us the opportunity to explore the use of KL4 surfactant to mitigate damage to lungs after radiation exposure," commented Craig Fraser, President and Chief Executive Officer. "We are very encouraged by the results of this early preclinical work and are grateful for the support provided by the NIH. Based on the results of this initial study, Windtree was awarded $3 million in additional funding from the NIAID to support the further exploration of aerosolized KL4 surfactant as a potential medical countermeasure for radiation exposure."

In this initial study, KL4 surfactant was administered via an intranasal route into the lungs of C57/BL6 mice 24-hours following exposure to a single fraction of high-dose (13.5 Gy) thoracic-targeted X-ray irradiation (XRT). Mice were evaluated for evidence of reduced blood oxygenation and lung inflammation between two to four weeks post-XRT, and lung fibrosis, chronic pneumonitis, oxidative stress and local and systemic inflammation at 18-weeks post-XRT, by assessing lung function, and analyzing bronchoalveolar fluid (BALF), serum and lung tissue.

The data from this study indicate that KL4 surfactant treatment significantly preserved blood oxygenation in irradiated mice two and four weeks post-XRT suggesting reduced acute lung injury, coupled with significantly reduced lung inflammation in irradiated mice three and 18 weeks post-XRT.  KL4 surfactant-treated irradiated mice also showed a decrease in lung fibrosis and pneumonitis at 18 weeks post-XRT, evidence of reduced chronic/late-phase radiation-induced lung injury.

"Though an early study, these data are especially encouraging as the US Department of Health and Human Services has indicated that there is an urgent and unmet need to develop medical countermeasures to prevent radiation pneumonopathy that can be efficiently administered within days, if not hours post-exposure. These data combined with our promising work to deliver aerosolized KL4 surfactant represent progress toward potentially providing an effective and efficient means to counter exposure to potential radiation lung damage under various circumstances, including potentially as a result of cancer radiation therapy," said Robert Segal, M.D., senior vice president, clinical development & academic affairs, Windtree Therapeutics, the study principle investigator, who conducted this research in collaboration with Melpo Christofidou-Solomidou, PhD, Research Professor of Medicine at the University of Pennsylvania.

Exposure to ionizing radiation (IR) from an unpredictable nuclear reactor accident, a nuclear attack, deliberate terrorist actions, including the detonation of a radiological dispersal device (RDD), and, represents a significant public health concern. Radiological and nuclear threats are complex, as the radiation source, duration and extent of exposure all contribute to the nature and effects of IR exposure. The lung is particularly susceptible to injury from IR-exposure from external radiation sources, as well as from inhaled radioactive particles from nuclear radioactive fallout as an example. Radiation pneumonopathy can manifest with acute radiation pneumonitis (ARS) and/or delayed effects of acute radiation exposure (DEARE), which may lead to progressive, often fatal, pulmonary fibrosis many months or years later, with a median survival of 2 to 4 years. This is also seen with pulmonary radiation exposure as a result of radiation therapy for certain types of cancer.

This preclinical study of KL4 surfactant as a potential medical countermeasure to mitigate acute and chronic/late-phase radiation-induced lung injury was supported, in part, by a $0.6 million Phase I Small Business Innovation Research (SBIR) grant from the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH) under award number R43AI102308.  The follow-on phase II SBIR $3.0 M grant supporting ongoing research of aerosolized KL4 surfactant as a radioprotectant is being funded under award number R44AI102308.   The content of this press release is solely the responsibility of Windtree Therapeutics, Inc. and does not necessarily represent the official views of the National Institutes of Health or the University of Pennsylvania.

Windtree Therapeutics, Inc. is a clinical-stage biotechnology company focused on developing novel surfactant therapies for respiratory diseases and other potential applications.