On Mar. 9, 2020, MediciNova announced that it planned to initiate development of MN-166 (ibudilast) for severe pneumonia and acute respiratory distress syndrome (ARDS). MediciNova’s decision to pursue development of this indication was based on positive results of a recent preclinical study in an animal model of ARDS.

MediciNova’s decision to pursue development of this indication was based on positive results of a recent preclinical study in an animal model of ARDS (Med Sci Monit, 2020; 26: e922281). Results of this preclinical study showed that ibudilast treatment reversed histological changes observed in the ARDS mouse model including inflammation, hemor­rhage, alveolar congestion, and alveolar wall edema. In this study, the pulmonary edema score was used to assess the degree of lung water accumulation. Importantly, pulmo­nary edema was significantly reduced by ibudilast treatment (p<0.001).

Results of this study also showed that ibudilast significantly reduced the levels of inflammatory cytokines including TNF-alpha (p<0.001), IL-1beta (p<0.001), IL-6 (p<0.001), and MCP-1 (p<0.001) in a dose-dependent manner, indicating that ibudilast suppressed the inflammatory response. Results of this study also suggest that ibudilast protects against pulmonary in­jury by attenuating cell apoptosis in lung tissue.

Acute respiratory distress syndrome (ARDS) is a serious lung condition that causes low blood oxygen. In ARDS, fluid builds up inside the tiny air sacs of the lungs, and surfactant breaks down. Surfactant is a foamy substance that keeps the lungs fully expanded so that a person can breathe. These changes prevent the lungs from filling properly with air and moving enough oxygen into the bloodstream and throughout the body.

The lung tissue may scar and become stiff. ARDS may develop over a few days, or it can get worse very quickly. The first symptom of ARDS is usually shortness of breath. Other signs and symptoms of ARDS are low blood oxygen, rapid breathing, and clicking, bubbling, or rattling sounds in the lungs when breathing. Infections are the most common risk factors for ARDS. These infections may include the flu, coronavirus or other viruses, and sepsis. The rate of death in the hospital is approximately 40% for ARDS patients.