� 1999 Medical Tribune News Service
When placing patients on highly active antiretroviral therapy (HAART),
doctors can increase the odds of therapeutic success by using drugs to
which patients previously have not been exposed, according to a new study.
The Swiss study focused on 2,674 outpatients who started HAART between
1995 and 1998. At 12 months, 81.2 percent of patients had undetectable
viral load, defined as a plasma HIV-RNA concentration of 400 copies/ml or
Among treatment-naive subjects, 90.7 percent achieved undetectable levels
of virus after 12 months, compared with 70.3 percent of pretreated
subjects who received one new agent, 74 percent of participants who
received two new drugs and 78.7 percent of pretreated patients who
received three new drugs, researchers led by Bruno Ledergerber, M.D., of
University Hospital in Zurich, reported in The Lancet (1999;353:863-868).
Findings suggest that the virus develops resistance more easily to one
drug than to three new medications, as suggested by other studies,
according to the researchers.
Triple regimens are the most popular therapy for HIV infection. These
regimens usually consist of a protease inhibitor such as indinavir
(Crixivan, Merck) or ritonavir (Norvir, Abbott) and two
nucleoside-analogue reverse-transcriptase inhibitors, such as zidovudine
(AZT, Retrovir, Glaxo Wellcome) and lamivudine (3TC, Epivir, Glaxo
Confirming results of earlier studies, the Swiss team found that subjects
whose virus was never lowered to undetectable levels were 2.5 times more
likely to die from AIDS than other patients.
Among the study patients who were naive to antiretroviral agents prior to
receiving HAART and whose viral loads sank to undetectable levels at 12
months, less than 10 percent contracted AIDS or died within the next 18
Jonathan Kaplan, M.D., of the Centers for Disease Control and Prevention
in Atlanta, called the finding �exciting news� that �confirms results
we�ve been hearing [from] all over the world.�
The death rate from AIDS in the United States has fallen by 80 percent
since the introduction of triple combination therapies, he added.
In addition, the Swiss study, which looked at patients taking four
different protease inhibitors in various combinations with other drugs,
shows that there is flexibility in antiretroviral treatment, said Oren
Cohen, M.D., an HIV researcher at the National Institute of Allergy and
Infectious Diseases. Many possible combinations of antiretroviral agents
exist, so doctors do not have to be concerned about running out of
treatment options, according to Dr. Cohen.
April 8, 1999
� 1999 Medical Tribune