Ischemic Stroke

According to the American Heart Association (AHA), approximately 800,000 individuals in the United States suffer a stroke each year and an estimated two million individuals suffer a stroke each year in the United States, Japan and major European countries, combined.  Due to an aging population, the incidence and prevalence of stroke is projected to increase by 25% in the next 20 years. Neurological injury as a result of a stroke represents one of the leading causes of death and disability in the United States and the rest of the world. Ischemic stroke, caused by a blockage in blood flow to the brain, accounts for more than 85% of all strokes according to AHA estimates. The World Health Organization estimates that approximately 16.9 million individuals suffer a stroke each year globally, resulting in 5.5 million deaths and 5 million individuals that are permanently disabled. Increasing age is one of the most significant risk factors for stroke, and with the aging baby boomer population, the AHA has projected that healthcare costs associated with stroke and cardiovascular disease will climb dramatically in the years ahead.

Recent progress toward the development of safer and more effective treatments for ischemic stroke has been disappointing. Despite the fact that stroke is a leading cause of serious disability and third leading cause of death, there has been little progress toward the development of treatments that improve the prognosis for stroke victims. The only FDA-approved drug currently available for ischemic stroke is the anti-clotting factor, tPA, which must be administered to the patient within three to four hours of the onset of the stroke. Administration of tPA beyond this time frame is not recommended, since it can cause bleeding in the brain or even death. Given this limited therapeutic window, it is estimated that less than 5% of ischemic stroke victims currently receive treatment with tPA.

MultiStem has potential as a “best-in-class” cell therapy based on its ability to deliver therapeutic benefit through multiple mechanisms of action, its ability to be delivered “off-the-shelf” like a pharmaceutical product and its consistent safety profile. MultiStem appears capable of delivering a therapeutic benefit in multiple ways, such as through the production of factors that:

  •  Protect damaged or injured neurons
  •  Reduce inflammation common in ischemic injury
  •  Promote new blood vessel formation
  •  Augment tissue repair and healing

We are developing MultiStem® cell therapy as a novel approach for the treatment of damage caused by ischemic stroke, as well as other neurological conditions. In preclinical studies, we have evaluated the safety and effectiveness of administering MultiStem intravenously at various times following a surgically-induced ischemic stroke in well-validated animal models. At the AHA International Stroke meeting in 2011, medical researchers from the University of Texas Health Science Center at Houston (UTHealth) presented data that demonstrated how MultiStem provided multiple benefits when administered in preclinical models of ischemic stroke. The study, conducted by leading researchers from the Department of Neurology at the UTHealth Medical School working in collaboration with scientists at Athersys, illustrated the potential benefits of MultiStem therapy for treating stroke. Researchers observed that intravenous administration of MultiStem one day after a stroke reduced inflammatory damage in the brain and resulted in a significant improvement in motor skills.

In previously published work, administration of MultiStem therapy in preclinical studies after a surgically-induced stroke results in substantial and long-term therapeutic benefit, as evidenced by the improvement of treated animals compared with controls in a battery of tests examining mobility, strength, fine motor skills and other aspects of neurological functional improvement. These results have been confirmed in subsequent studies that demonstrate that MultiStem treatment is well tolerated, does not require immunosuppression, and results in a robust and durable therapeutic benefit even when administered well after the initial stroke event.  Studies also demonstrate that earlier administration corresponds to improved recovery. 

In December 2015, we completed a double-blind, placebo-controlled Phase 2 clinical trial to evaluate the safety and efficacy of MultiStem administered intravenously to ischemic stroke victims. In contrast to the current standard of care, MultiStem is administered to stroke patients within approximately 18 to 36 hours following the stroke, which we believe is a clinically practical time frame for the majority of patients.  The study was conducted at leading stroke centers across the United States and included several leading stroke clinical centers in the United Kingdom.  To learn more about the trial, visit our Clinical Programs page. We believe that the potential market for a new therapy to treat stroke could be $15 to $20 billion or more, annually.