Thalassemia

The Company recently participated in a clinical study involving the use of umbilical cord blood to treat a devastating worldwide disease, thalassemia. Thalassemia includes a number of different forms of anemia (red blood cell deficiency), including thalassemia major or Cooley's anemia. The two main types are called alpha and beta thalassemias, depending on which part of an oxygen-carrying protein (called hemoglobin) is lacking in the red blood cells. About 150,000 babies worldwide are born with severe forms of the disease each year. Thalassemia occurs most frequently in people of Italian, Greek, Middle Eastern, Southern Asian and African ancestry. Recent publications indicate that, with modern supportive therapy, 32% of patients with thalassemia major will die by the age of 35.

After providing donated umbilical cord units to one of the leading research hospitals within Taiwan, StemCyte assisted Dr. T.H. Jiang in investigating the feasibility of using umbilical cord blood transplants from unrelated HLA mismatched donors to cure the disease. In the most recent published article, between October 2003 and November 2004, five children with b-thalassemia major received busulfan, cyclophosphamide, and antithymocyte globulin before cord blood transplantation (median dose, 8.8 x 10^7 cells per kilogram of body weight) from unrelated donors (1 or 2 of 6 HLA antigens were mismatched) and were then evaluated for engraftment, adverse effects and treatment outcome. The median times to neutrophil engraftment, red blood cell transfusion independence and platelet engraftment were 12, 34 and 46 days after transplantation, respectively. This median time of neutrophil engraftment of 12 days in this study is not only faster than that of most published studies of cord blood transplantation, but is also as fast if not faster than most bone marrow or peripheral blood transplants. None of the patients developed extensive chronic graft-versus-host disease until the date of last contact. All patients were alive at a median follow-up of 303 days after transplantation, with complete donor chimerism and transfusion independence.

The study has since been extended to 9 patients, with similar outcomes as reported in an abstract. The engraftment and survival rate of 89% in this small study has been similar to results from related bone marrow transplants for thalassemia. Moreover, autologous recovery of thalassemia has not been observed in these cases. These results are encouraging and clearly show the feasibility of unrelated mismatched umbilical cord blood transplantation in the treatment of children with beta-thalassemia major. The Company plans to expand this clinical effort and serve as a worldwide thought leader by encouraging transplant centers worldwide to introduce this therapy early in a patient's life.