Mesenchymal Cells Can Be Transplanted During Bone Marrow Transplants

EMBARGOED for Release until Monday, March 1, 1999 at 5 P.M.( EST)

Contacts: Kristine Wilber, (312) 856-8818, kwilber@porternovelli.com
Deidre Malone/Jerry Chipman(901) 495- 2434/(901) 495-3306

St. Jude Researchers Prove Mesenchymal Cells Can Be Transplanted During Bone Marrow Transplants Study Describes Procedure to Improve Symptoms of Bone Diseases.

MEMPHIS, TENN, March 1, 1999 -- Researchers at St. Jude Children's Research Hospital have made a new discovery that may help patients suffering from a variety of debilitating and life-threatening bone diseases, including dwarfism, dysplasia and osteoporosis, according to a study published in the March issue of Nature Medicine.

The study involved pediatric patients suffering from osteogenesis imperfecta (OI), a genetic disorder in which osteopenia leads to deformities, excessive fragility, frequent bone fractures, short statures, and in its severe form decreased life expectancy and sometimes death.

The St. Jude research showed for the first time that mesenchymal cells, a special kind of cell found in bone marrow are actually transplanted during bone marrow transplantation. Prior to this study, scientists and physicians knew that the mesenchymal cells were present during traditional bone marrow transplants, but it had not been proven that they engrafted into the bone.

"This is an exciting new approach because for the first time mesenchymal cells have been shown to engraft in bone after marrow transplantation," said Edwin Horwitz, M.D, Ph. D., a member of the department of hematology-oncology at St. Jude and the lead researcher of this study. "We believe patients with bone disorders who are treated with this approach will ultimately have a much greater chance of enhanced quality of life since we are treating the condition that causes disorders not just treating the symptoms."

The promising results from this study give hope that bone marrow transplantation may be used to correct inherited and acquired bone disorders. "We are very hopeful that the results of this study will lead to therapies for a variety of bone disorders - including those as common as osteoporosis," said Dr. Horwitz.

Of the three patients who participated in the study, two experienced approximately 100 percent of the normal growth rate for children of the same age and sex. This is a rarity for children who have OI as well as for patients who undergo traditional bone marrow transplantation for conditions other than OI, where there is typically maintenance or slowing of growth. Additionally, there was a significant decrease in the number of fractures in the first six months following the transplant. For example, in the 13 months of life prior to the bone marrow transplant, one patient experienced 37 documented fractures, while having only three fractures in the first six months after transplant.

"We are very encouraged by these results," said Darwin Prockop, M.D., Ph.D., of MCP Hahnemann University in Philadelphia, Pennsylvania and co-author of the study. "This helps prove our original thinking that bone strength can be significantly improved and that there can be dramatic decreases in the number of bone fractures following bone marrow transplants."

"I am very pleased with what this study has done for the lives of patients we treated," said Joseph Mirro, Jr., M.D., Chief Medical Officer of St. Jude. "Dr. Horwitz and his team have opened the door to further research that will help us find even more ways of treating children - and others - with bone disorders."

St. Jude Children's Research Hospital, in Memphis, Tennessee, was founded by the late entertainer Danny Thomas. The hospital is an internationally recognized biomedical research center dedicated to finding cures for catastrophic diseases of childhood. The hospital's work is supported through funds raised by the American Lebanese Syrian Associated Charities (ALSAC). All St. Jude Hospital patients are treated regardless of their ability to pay. ALSAC covers all costs of treatment beyond those reimbursed by third party insurers, and total costs for families who have no insurance.

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