Strokes are characterized by the rapidly developing loss of brain function due to a significant diminution in the blood supply to the brain. Strokes are typically classified into two major categories, ischemic and hemorrhagic. Ischemic strokes result from an inadequate supply of blood and oxygen to the brain due to blockage of an artery, such as by a blood clot, while hemorrhagic strokes result from rupture of a blood vessel or an abnormal vascular structure. Ischemic strokes represent approximately 87% of all cases. Patients suffering an ischemic stroke can receive a drug called tissue plasminogen activator, or tPA, which is currently the only FDA-approved acute treatment for ischemic stroke. tPA is administered intravenously to break up clots and restore blood flow to the brain. However, it is only approved for use within three hours of the onset of symptoms, and many patients who have suffered an ischemic stroke are unable to reach a hospital for diagnosis and treatment within this period. The use of tPA can also lead to bleeding in the brain. There are no currently approved therapies for treatment of ischemic stroke after this three-hour period, which we refer to as post-acute treatment.

According to the American Heart Association, approximately 795,000 patients in the United States suffer a stroke each year. According to the Centers for Disease Control and Prevention, approximately 87% of those strokes are ischemic. In a study we commissioned, Trinity Partners estimates that approximately 30% to 40% of those ischemic strokes are moderate to severe and would be candidates for ALD-401. Trinity Partners estimates that the annual nursing home and in-home costs of the post-acute treatment of an ischemic stroke patient is approximately $30,000. According to the American Heart Association, the mean lifetime cost of ischemic stroke in the United States is estimated at $140,048. Based on an assumed patient population of 176,000, we estimate the annual market potential for ALD-401 in the United States is $3.5 billion.