Athersys completes patient enrollment in MultiStem Phase I study for leukemia

Athersys, Inc. 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."

The Phase I clinical trial is an open label, multi-center dose escalation trial evaluating the safety and maximum tolerated dose of a single or multiple dose administration of allogeneic MultiStem delivered intravenously following standard allogeneic hematopoietic stem cell transplant. Patients enrolled in the study receive either a low, medium or high dose of MultiStem, and are being evaluated against current standard of care. Treatment of the final patient for the single dose arm occurred December 30, 2010, consistent with the previously stated goal of completing enrollment prior to year-end, while enrollment in the multiple dose arm will continue and is intended to be completed in 2011. The study is being conducted at multiple bone marrow transplant centers in the United States, including Oregon Health & Science University Medical Center, Texas Transplant Institute, University Hospitals Case Medical Center, University of Pennsylvania, Mayo Clinic Arizona, and several other sites.  

In September 2010, Athersys received orphan drug designation from the U.S. Food and Drug Administration for the prevention of GVHD. Orphan drug designation, which is intended to encourage and facilitate drug development for products designed to treat rare diseases, also provides substantial potential benefits to the sponsor, including funding for certain clinical studies, study-design assistance, tax incentives and seven years of market exclusivity for the product upon regulatory approval.

Athersys is working in collaboration with leading independent experts and certain partners to evaluate the potential for MultiStem in a range of disease areas, including treatment of various conditions involving immune system dysfunction, as well as for treating cardiovascular disease and certain neurological conditions. In multiple preclinical models, administration of MultiStem has been shown to be non-immunogenic, even when administered without tissue matching or immune suppression, and appears to promote healing and tissue repair through multiple biological mechanisms. Results from various studies demonstrate that MultiStem has potent immunomodulatory properties that the Company and its collaborators believe could have relevance toward the treatment of various inflammatory and autoimmune disease conditions such as Inflammatory Bowel Disease (IBD). In December 2009, Athersys announced a partnership with Pfizer focused on the development of MultiStem for IBD, and in November 2010, the companies announced that they had received FDA authorization to conduct a double blind, placebo controlled Phase II clinical trial in patients with moderate to severe ulcerative colitis.