CLEVELAND, Jan. 6, 2011 (GLOBE NEWSWIRE) -- Athersys, Inc. (Nasdaq:ATHX) today announced that it has completed patient enrollment of the single dose arm of a clinical study involving administration of MultiStem ® to patients being treated for leukemia or other blood born cancers. The study involves administration of a single or multiple doses of MultiStem, an allogeneic cell therapy product, to patients following radiation therapy and a donor derived hematopoietic stem cell transplant. Patients receiving such transplants are typically at risk for Graft-Versus-Host Disease (GVHD), as well as other complications, such as tissue damage from the radiation and chemotherapy treatments that are conducted prior to the transplant. Initial results of safety information from the single dose arm of this trial are expected to be announced following the completion of patient evaluation periods and subsequent analysis of data. GVHD is one of the major limitations of allogeneic donor derived hematopoietic stem cell transplants. This complication is a significant cause of morbidity and mortality and is thought to be initiated by activation of donor immune cells, such as activated T-cells, that attack host cells in the transplant recipient as foreign tissue. Acute GVHD is associated with damage to the liver, skin, gastrointestinal tract and other tissues. Moderate to severe GVHD Grades II-IV occurs in 30-50% of matched related hematopoietic stem cell transplants (HSCT) and 50-70% of matched unrelated donor recipients. Severe GVHD requires treatment using intense immunosuppression with steroids and additional agents, and patients may develop severe infections as a result of such immunosuppression. An agent or cell therapy that could prevent the incidence and/or severity of GVHD without increasing relapse or infectious risk in HSCT patients would provide substantial benefits. "Despite significant advances in recent years, treatment of leukemia and other cancers of the blood and immune system is a substantial clinical challenge. Radiation and chemotherapy followed by hematopoietic stem cell transplantation remains the standard of care in many areas. Unfortunately, many patients experience complications from treatment, such as GVHD, that can be debilitating or life threatening," commented Dr. Robert Deans, Senior Vice President of Regenerative Medicine of Athersys. "Based on results from preclinical studies conducted in coordination with independent labs, we believe that MultiStem has the potential to reduce the incidence and severity of GVHD and other complications and improve patient outcomes. This Phase I safety study represents an important step in the development of MultiStem for this condition, and we look forward to evaluating the data from the trial upon completion of the appropriate follow up visits."