Genetic Therapy Inc. said Wednesday that the recombinantDNA Advisory Committee (RAC) of the National Institutes ofHealth has approved the first human gene therapy trial usingstem cells to cure a genetic disease.

The trial, targeted at adenosine deaminase deficiency, will useretroviral vectors provided by the Gaithersburg, Md., company(NASDAQ:GTII).

ADA, a rare disease that leads to severe immune systemdysfunction, is caused by the absence or malfunctioning of thegene for the ADA enzyme. The trial aims to correct thedeficiency by inserting the normal gene into retroviral vectors,which will then introduce the gene into stem cell precursorsremoved from the patient. These will then be injected into thepatient, where it is hoped they will enable the immune systemto reconstitute itself.

An ongoing ADA trial, begun in 1990 using GTI's vectors,inserts the gene into lymphocytes, but that doesn't provide apermanent cure.

GTI also announced that the RAC has approved human genetransfer trials for renal cell carcinoma and leukemia, usingGTI's vectors. The leukemia trial is designed to assess theefficacy of bone marrow transplants using GTI's gene markersin patients with acute myelogenous leukemia or acutelymphocytic leukemia. That trial has FDA approval and willbegin shortly.

The renal cell trial will use gene markers to assess the abilityof white blood cells, including tumor infiltrating lymphocytes,to seek out tumor sites and survive in patients after infusion.

GTI is preparing to submit investigational new drugapplications with the FDA for the ADA and renal carcinomatrials.

The company's shares rose 25 cents to $11.25.

-- Karen Bernstein BioWorld Staff

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