TI    Trial of TAT Antagonist as Therapy for HIV Infection Altered
 AU    National Institute of Allergy and Infectious Diseases, National     
       Institutes of Health
 SO    News from NIAID
 TX    The first U.S. multi-center study examining the safety and
       effectiveness of the drug Ro 24-7429 that in laboratory tests blocks
       replication of HIV, the virus that causes AIDS, will be modified to
       study higher doses, the National Institute of Allergy and Infectious
       Diseases (NIAID) has announced.  In addition, NIAID will halt three
       of the four treatment arms testing lower doses because the drug has
       not shown such activity in participants studied to date.

       Richard Haubrich, M.D., from the University of California at San
       Diego Medical Center is scheduled to discuss the data from the
       trial, AIDS Clinical Trials Group (ACTG) 213, during an oral
       presentation on June 10, at the IX International Conference on AIDS
       in Berlin, Germany. NIAID and Hoffmann-La Roche Inc., manufacturers
       of Ro 24-7429, collaborated on the trial.  

       Ro 24-7429, unlike the three antiretroviral drugs currently approved
       for AIDS therapy, zidovudine (AZT), dideoxyinosine (ddI) and
       dideoxycytidine (ddC), appears to halt HIV replication in cells
       chronically infected with HIV, not just preventing the initial
       infection of cells.  The drug stops HIV reproduction by interfering
       with the action of a viral regulatory protein, TAT.

       The preliminary analysis of data collected from the first
       participants to complete the 12- week Phase I-II trial has shown
       that three doses of Ro 24-7429 have not stopped viral replication
       nor have they increased the number of certain immune cells, CD4+ T
       cells, that HIV targets.  Investigators will continue to study
       patients already enrolled in a fourth arm, examining therapy using
       Ro 24-7429 in combination with AZT or ddI.  Study scientists plan to
       begin new treatment arms in ACTG 213 that would examine higher doses
       of Ro 24-7429.  Hoffmann-La Roche Inc. has other studies of Ro
       24-7429 under way.

       ACTG 213 began in November 1992, with patients randomized to receive
       for 12 weeks one of three doses of Ro 24-7429, 25 milligrams (mg),
       50 mg or 100 mg every eight hours or 200 mg of AZT every eight hours
       or a body weight-dependent dose of ddI every 12 hours.  At the end
       of 12 weeks, study scientists gave the highest dose of Ro 24-7429,
       100 mg. every eight hours, to patients receiving AZT or ddI.

       To enter, all participants had to be HIV-infected and not have taken
       any antiretroviral therapy for 28 days prior to the study beginning. 
       Also, participants had to have counts of the immune system CD4+ T
       cells ranging from 50 to 500 cells per cubic millimeter of blood. 
       ACTG 213 study sites include Case Western Reserve University in
       Cleveland, Ohio, Harvard University in Boston, Mass., The Johns
       Hopkins University in Baltimore, Md., and the University of
       California at San Diego.

       Studies sponsored by Hoffmann-La Roche, Inc., and completed at Johns
       Hopkins before ACTG 213 began found that patients tolerated Ro
       24-7429 well and the major side effect was rash.  These studies   
       compared single and multiple doses of the drug to determine the
       drug's safety and how it was processed in the body.

       By interfering with the action of the TAT protein, Ro 24-7429 halts
       the transcription of HIV's genetic material from DNA to RNA in the
       infected host cell, according to laboratory studies.  This
       transcription is a necessary step for virus replication.  Without
       TAT, the transcription is impeded, new virus is not made, fewer
       cells are infected and opportunities for HIV to mutate and develop
       drug resistance decrease.

       NIAID, a component of the National Institutes of Health, supports
       investigators and scientific studies at universities, medical
       schools, hospitals and research institutions in the United States
       and abroad aimed at preventing, diagnosing and treating such
       illnesses as AIDS, tuberculosis, allergies and asthma.  NIH is an
       agency of the U.S. Public Health Service, part of the U.S.
       Department of Health and Human Services.
 NT         1.  "A Randomized Study of Safety, Tolerance, Pharmacokinetics,
       and Activity of Oral Ro 24-7429 (Tat Antagonist) in Patients with
      HIV Infection."  R.H. Haubrich, ACTG 213 Team, University of
       California, San Diego Medical Center.
            2.  For press inquiries only, please call Marion E. Glick at
       (301) 402-1663.
 MJ    TAT antagonist. Drug therapy.  HIV infection.  ACTG.  Clinical trial
       results.  Clinical trial.
 CD    931015

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