Subject: Gene Therapy Test In AIDS May Begin Within Months 
Date: Published: 2/14/92 (74 lines)
Source: Wall Street Journal. Copyright Dow Jones & Co. Inc.

    Technology & Health:
    Gene Therapy Test
    In AIDS May Begin
    Within Months
    ----
    By Marilyn Chase
    Staff Reporter of The Wall Street Journal

    The first tentative test of gene therapy in acquired
 immune deficiency syndrome could get under way within a
 couple of months.
    The experiment, which received federal approval this week,
 is a collaboration between scientists from a unit of Immunex
 Corp. and the Fred Hutchinson Cancer Research Center in
 Seattle.
    Scientists envision treating between five and 15 AIDS
 patients who also are suffering from an AIDS-linked
 malignancy, B-cell lymphoma.  They will be patients slated to
 undergo a bone-marrow transplant for the treatment of their
 cancer, and shortly after that procedure doctors plan to
 insert special genetically altered cells to treat the virus.
    A test of the new treatment got a green light by the
 National Institutes of Health Recombinant DNA Advisory
 Committee, after gaining approval of the U. S. Food and Drug
 Administration in January.
    The aim of the experiment is to flood the body of these
 patients with huge numbers of killer T-cells, which are
 specifically targeted immune cells that attack and kill
 AIDS-infected cells.  In case the experiment should go awry or
 provoke toxic side effects, the killer cells will be equipped
 with a gene that acts as a so-called suicide switch, enabling
 doctors to turn off the experiment simply by giving the
 patients an antibiotic.
    The suicide gene is to be spliced into the killer cells
 using classical genetic engineering techniques.  Such
 techniques employ a mouse-tumor virus as a tool to insert a
 gene rendering the cells sensitive to the antibiotic
 ganciclovir.  Once inserted, this gene acts as a switch
 scientists can use to inactivate the killer cells, and turn
 off the experiment at will, with a dose of ganciclovir.
    Treating immune-suppressed patients with one billion
 virus-fighting cells is a delicate procedure, with some risk
 the immune reaction might become "over-exuberant," explained
 team leader Philip A. Greenberg of the Hutchinson Center.
    "We're trying to rebuild an enormous immune response in
 these patients," said Dr. Greenberg in an interview.  "But
 there's the potential that the immune response might be too
 strong, and might cause inflammation to the brain and lung.
 The suicide switch really broadens the safety margin of the
 experiment."
    So far, American scientists have used gene therapy in
 several separate tests to treat cancer patients and children
 with a hereditary immune weakness known as ADA deficiency.
 Those experiments have been led by Drs. Steven A. Rosenberg
 and W. French Anderson at the National Institutes of Health.
 A third gene therapy treatment for patients with hereditary
 high cholesterol has been approved by NIH to take place at
 the University of Michigan.
    One gene therapy pioneer, Dr. Anderson of NIH, called the
 Seattle experiment "very exciting ...a very important
 protocol."
    In a related move, Immunex announced plans to spin off its
 Targeted Genetics Corp. unit to pursue gene therapy as an
 independent company.  Following a planned private placement of
 stock, the biotech firm said it will retain a 40% stake in
 the new company.

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