STI Hits Development Milestone with Promising Initial Data

Tucson, AZ - Jun 17, 1997

Sertoli Technologies Inc., a cellular therapy company, has successfully completed its initial stage in developing a transplant therapy using pancreatic islets and Sertoli cells for Type I, or insulin-dependent diabetes.

Recently completed studies using STI's proprietary technology have shown that islet xenografts (foreign islets) transplanted in both lower and higher animals can survive for an extended time.

"These results represent a significant milestone in cellular transplantation and should give STI a platform to accelerate development," said Shaun A. Kirkpatrick, STI vice president. "We now intend to bring in new investors and/or strategic partners to fund the next phase of development, which will include product formulation in preparation for human trials."

A recent Phase I Small Business Innovation Research grant from the National Institutes of Health supplements STI's current funding from lead investor, Research Corporation Technologies in Tucson, Ariz.

As a commercial therapy for diseases such as diabetes, cellular transplantation faces two major obstacles: destruction of the transplanted cells by the recipient's immune system and lack of sufficient human donor tissue. STI is developing a product that can solve both problems by creating local protection for transplanted tissue without immunosuppressant drugs and using tissue from nonhuman sources such as pigs.

TI uses Sertoli cells to protect transplanted tissue from immune rejection. Sertoli cells are the cells in mammalian testes that nourish and protect developing sperm. Dr. Helena P. Selawry, formerly at the University of Tennessee Medical Center and the Veterans Administration Medical Center in Memphis, found that Sertoli cells also produce substances that inhibit immune rejection. Her findings are the basis of STI's platform technology.

Selawry developed a potential treatment for Type I diabetes by co-transplanting a composite of insulin-producing islets and Sertoli cells to replace those destroyed by the disease. This landmark work showed that Sertoli cells protect islet xenografts from rejection by producing immune inhibitors directly at the graft site. Co-transplanted islets and Sertoli cells have survived indefinitely in diabetic rats, with only initial doses of immunotherapy (Cell Transplantation, 1993; 2:123-129).

Improvements on this work by STI collaborators Drs. Ray V. Rajotte and Gregory S. Korbutt at the University of Alberta in Edmonton, Canada, allow islet and Sertoli cell allografts to survive indefinitely and reverse diabetes in rodents receiving no immunosuppressants (Diabetes, 1997; 46:317-322).

Selawry also recently completed a five-year study in primates with islet allografts in the abdominal testis. Long-term survivors had functioning islets for up to five years without immunotherapy. An initial report of these results appeared in an abstract published in Diabetes (1994; 43 suppl 1:162A). STI is duplicating these results using xenografts of pig tissue.

For additional information contact Shaun A. Kirkpatrick, STI vice president, 101 N. Wilmot Rd., Suite 600, Tucson, AZ, 85711-3365, (520) 748-4470, fax (520) 748-0025, e-mail: rct2sak@aol.com.

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