RedHill Biopharma Ltd. announced the publication of data showing that opaganib, an investigational new drug, protects against radiation-induced lung inflammation and fibrosis in an in vivo mouse model of lung damage following exposure to ionizing radiation, demonstrating its potential use as a medical countermeasure against nuclear irradiation and in cancer radiotherapy. Data from multiple experiments was published in the International Journal of Molecular Sciences.

Radiation-induced inflammation is known to occur in two phases – in an initial inflammatory response immediately after irradiation and in a delayed response that can occur weeks later. As such, one of the experiments looked specifically at longer-term survival with two treatment windows: 1-3 days post-radiation and 31-45 days post-radiation. The opaganib group treated both during the initial and delayed phases of inflammation demonstrated a highly statistically significant improvement in survival at Day 180 (60% survival compared with 10% for controls, p=0.008). Thus, treating with opaganib during both initial and delayed phases of inflammation provided the greatest improvement in survival.

“The data, when looked at collectively across multiple experiments, demonstrate that opaganib significantly improved long-term survival associated with reduced lung fibrosis, suppression of granulocyte infiltration, and reduced expression of IL-6 and TNFα in an in vivo model of lung damage following exposure to ionizing radiation,” said Dr. Lynn W. Maines, lead author of the publication and VP of Research at Apogee Biotechnology Corporation, RedHill’s development partner for opaganib. “These data further demonstrate that sphingolipid metabolism is a critical regulator of fibrogenesis, and specifically show that opaganib suppresses radiation-induced pulmonary inflammation and fibrosis.”

Opaganib is being tested as a potential treatment for Acute Radiation Syndrome (ARS), following selection by the US government National Institutes of Health’s (NIH) Radiation and Nuclear Countermeasures Program (RNCP) for its radiation medical countermeasures Product Development Program. Opaganib was also recently selected for inclusion into the BARDA/NIH Chemical Countermeasures screening program for Sulfur Mustard exposure. Opaganib, a novel, oral, small molecule pill with a five-year shelf-life, is easy to administer and distribute, supporting potential central government stockpiling for use as a medical countermeasure in the event of mass casualty nuclear radiation incidents or Sulfur Mustard attack, if approved by the US Food and Drug Administration (FDA).