Strokes are among the leading causes of death in the US, affecting nearly 800,000 Americans each year. It is the fifth leading cause of death in the U.S. and the leading cause of adult disability.
Strokes occur when blood flow to the brain is restricted due to a blood clot (ischemic stroke) or a ruptured blood vessel (hemorrhagic stroke). Both types of stroke result in reduced blood flow to the regions “behind” the clot or rupture resulting in brain tissue hypoxia, which can rapidly lead to permanent brain damage and death.
Effective stroke treatment needs to be administered soon after the onset of a stroke due to the rapid rate at which oxygen-deprived neurons perish. A current barrier to rapid treatment is that the only approved drug for treatment of acute stroke is the clot-dissolving drug tissue plasminogen activator (tPA), which can be used only in ischemic stroke; administering it to patients suffering from a hemorrhagic stroke could cause uncontrolled bleeding. So, before administering tPA, it is critical to differentiate ischemic stroke from hemorrhagic stroke, which requires the careful implementation of a stroke protocol in a healthcare setting with sophisticated diagnostic imaging equipment. This diagnostic challenge delays vital treatment in many cases.
Based upon preclinical safety and efficacy data, as well as certain clinical safety data, we believe TSC has potential applications in both ischemic and hemorrhagic stroke. These data suggest TSC could be administered to a stroke patient even before the availability of a more specific diagnosis, which could save precious time.
To evaluate the safety and effectiveness of TSC in acute stroke, we began enrolling patients in a randomized Phase 2 trial in December 2019. This trial was planned to enroll 160 patients, with 80 in the TSC treatment arm and 80 in the control arm. Patients were to receive treatment while in the ambulance to ensure all eligible patients received treatment as soon as possible after the onset of clinical symptoms. However, the COVID-19 pandemic created logistical problems for the study, including with respect to in-ambulance treatment, and enrollment in this trial has been suspended due to the pandemic and the Company’s decision to reprioritize its resources to focus on the shorter-duration COVID-19 studies.