Prolonged HIV medications interruptions are possible! - A break for HIV-infected persons
MONTREAL, Sept. 7 /CNW Telbec/ - Prolonged HIV medications interruptions
are possible in adults infected with HIV for long periods of time by using a
complex therapeutic strategy that includes vaccination with Remune (TM) (a
therapeutic vaccine). The results of this research trial have been presented
today by Dr. Emil Toma, a microbiologist and infectious diseases specialist at
Centre Hospitalier de l'Université de Montréal (CHUM) and a clinical professor
at University of Montreal, before 1,000 researchers gathered at the AIDS
Vaccine 2005 International Conference, organised by the Canadian Network for
Vaccines and Immunotherapeutics (CANVAC). Medications interruptions diminish
drug toxicities and metabolic complications, improve quality of life and
reduce the cost of treatment.
This innovative Montreal-based study, designed by Dr. Emil Toma and
colleagues, was conducted at Hôtel-Dieu Hospital from CHUM in collaboration
with the researchers from CHUM, Ste-Justine Hospital Research Centre, McGill
University and Canadian HIV Trials Network (CTN).
The study in brief
This study, extended over five and a half years, actually tested the
hypothesis whether therapeutic vaccination with Remune(TM), initiated after
intensification of the anti-HIV therapy and the use of GM-CSF (a bone marrow
stimulant), will allow for antiretrovirals' interruptions for the extended
periods of time in the presence of vaccine boosters. This therapeutic strategy
aimed, firstly, at targeting HIV reservoirs (cells or organs where the HIV
medications are less active) and secondly, at augmenting the HIV-specific
immunity in order to allow the individual to fight off HIV without
medications, at least for certain periods of time.
The study in detail
This study, designed in 1998-1999, was initiated in March 2000 and was
continued until August 2005 involving 10 adults with chronic HIV infection,
5 of whom already suffered from an AIDS complication. It is one of the first
and the longest study that evaluated the impact of a complex therapeutic
strategy and a therapeutic vaccine on HIV medications interruptions in adults
with chronic HIV infection.
The study participants had a 6-month intensification of their anti-HIV
treatment. On the 5th month of intensified therapy, the first dose of
Remune(TM) vaccine was given. One month later, HIV medications were stopped
but the vaccine was administered every 3 months for 3 years. The HIV treatment
was resumed and again stopped according to the CD4+ T cell counts (a measure
of immunity or defence against the virus) and to HIV viral load (the amount of
HIV in the blood). For the last two years, the study participants have been
receiving intermittent individualized treatments without therapeutic vaccine.
The participants have been able to stay off HIV medications
(antiretrovirals) for a median 53 % of time since the first interruption
(between 35 % and 85 %). The viral load increased as the antiretrovirals were
stopped but significant decreases were noted at the subsequent interruptions.
The patients developed an important HIV-specific immunity and a balanced
natural immunity was assessed by their cytokines blood profiles.
These study participants have been their own controls. Changes in the
presence or absence of a therapeutic intervention have been measured, a robust
experimental approach to quantitate effects of treatment in small groups of
patients. The duration of treatment interruption correlated directly with
CD4+ T cell counts these patients had before going on triple anti-HIV therapy.
In fact, this study establishes that the novel treatment strategies (even
though complex) in conjunction with a therapeutic vaccine, might enable HIV-
infected persons to benefit from the supervised HIV medications interruptions.
The collaborators
This study involved the collaboration from several companies, i.e.,
Cangene Corporation (Winnipeg, Manitoba), Agouron Pharmaceuticals (San Diego,
California), Immune Response Corporation (Carlsbad, California), Hoffman-La-
Roche Limited (Mississauga, Ontario). The study was partially funded by CTN
(Canadian HIV Trials Network), le Fonds de recherche en santé du Québec
(FRSQ), and CANFAR. The hypothesis and the design of this study were presented
at the Second Annual Meeting of RIGHT (Research Institute for Genetic and
Human Therapy), in Washington, D.C., in April 1999.
The Centre hospitalier de l'Université de Montréal (CHUM) is a university
hospital centre that provides specialized and ultraspecialized services to a
regional and supraregional clientele. CHUM also offers general and specialized
hospital services for its immediate service area. These services, which
contribute to teaching and research and to the evaluation of health-care
technologies and intervention methods, are provided on an integrated network
basis. CHUM also contributes to the ongoing promotion of health through its
front-line services.
CHUM was formed with the merger of three Montreal hospitals: Hôtel-Dieu,
Notre-Dame and Saint-Luc. CHUM's 10,000 employees, 900 doctors, 330
researchers, 5,000 students and trainees and 800 volunteers serve more than
half a million patients every year. www.chumontreal.qc.ca |
