CARLSBAD, Calif., May 29 /PRNewswire/ -- The Immune Response Corporation
(Nasdaq: IMNR) announced today the publication of data from a 15-patient,
open-label research study suggesting that treatment with REMUNE(TM)
(HIV-1 Immunogen) may increase the frequency of CD8+ T cells, which are
capable of killing virus-infected cells through molecules, called perforin, in
chronically HIV-infected patients concurrently treated with antiviral drug
therapy. Perforin expression is characteristic of activated CD8+ T cells that
can directly kill HIV-infected cells. The study appears in the May 2001 issue
of the Journal of Clinical and Experimental Immunology.
The published study involved 11 chronically HIV-infected patients taking
antiviral drug therapy with CD4 counts between 305 and 1,969 cc/mm(3) and
viral loads below 400 copies/ml at baseline. Patients received an
intramuscular injection of REMUNE at day 1 and at weeks 12, 24 and 36. Four
non-randomized HIV-infected patients who were not treated with REMUNE were
analyzed for comparison. All patients in both groups exhibited a low
frequency of CD8+ T cells expressing perforin prior to treatment.
When tested for the ability to respond to HIV and p24 (HIV protein)
antigens, the immune systems of patients treated with REMUNE appeared to
exhibit a significant increase in activated, perforin-expressing CD8+ T cell
responses compared to baseline. The increase in perforin-expressing CD8+ T
cell responses was apparent at week 24 against HIV (p=0.001) and p24 antigens
(p=0.009) and was maintained at week 36 (p<0.0001 and 0.005, respectively).
As observed in previous studies, the immune systems of patients treated
with REMUNE exhibited a statistically significant increase in
lymphoproliferative responses (LPRs) to HIV (p<0.05) when cells were examined
in vitro. LPRs, a common measure of CD4+ T helper cell activity, were also
found to correlate to the frequency of perforin-expressing CD8+ T cells when
stimulated with HIV (r=0.57, p=0.008).
"These results are consistent with interim data from a double-blind,
placebo-controlled study in Spain (Study 2101) where increased CD8+ T cell
activity (CTL's) was observed after immunization with REMUNE (13th
International AIDS Conference in Durban, South Africa -- see Company's Press
Release dated July 13, 2000)," explained Ronald Moss, M.D., Vice President,
Scientific and Medical Affairs at The Immune Response Corporation. "Recent
studies by other investigators have indicated that reduced expression of
perforin in CD8+ T cells may be related to the inability to control HIV. In
this study, we observed a significant increase in perforin expression from the
CD8+ T cells after treatment with REMUNE, indicating that these T cells were
'active' and may be able to attack HIV."
"Several previous studies have indicated that REMUNE appears to
significantly enhance CD4+ T helper cell activity, and these new data suggest
that restoration of CD4+ T helper immune responses may augment the ability of
CD8+ T cells to attack virus infected cells through the perforin pathway,"
said Dr. Moss. "These results are in accordance with what other researchers
have observed regarding the complex interactions between CD4+ T helper cells
and CD8+ T cells. Ongoing trials are being conducted with REMUNE to determine
whether or not vaccine-induced immune responses correlate with antiviral
effects."
REMUNE is currently the subject of several clinical trials, including a
Phase II trial being conducted in Spain and a Phase III trial sponsored by the
Company's partner Agouron Pharmaceuticals, Inc. (a Pfizer company) to evaluate
REMUNE's effect on viral load when administered in combination with potent
antiviral drug therapy. Impact on viral load is now a measure of efficacy
that is accepted by the Food and Drug Administration.
The Immune Response Corporation is a biopharmaceutical company based in
Carlsbad, California, developing immune-based therapies to induce specific
T-cell responses for the treatment of HIV, autoimmune diseases and cancer. In
addition, the Company is developing a targeted non-viral delivery technology
for gene therapy, which is designed to enable the delivery of genes directly
to the liver via intravenous injection.
NOTE: News releases are available through PR Newswire Company News On-Call
fax service. For a menu of available news releases or to retrieve a specific
release made by The Immune Response Corporation, please call 800-758-5804,
extension 434675. Please retain these numbers for future reference. Company
information can also be located on the Internet Web Site: http://www.imnr.com.
This news release contains forward-looking statements. Actual results
could vary materially from those expected due to a variety of risk factors,
including, but not limited to, whether preclinical data can be replicated in
clinical trials, whether if initiated clinical trials will be successfully
concluded and whether REMUNE will be approved for marketing or be successfully
commercialized. Those factors are discussed more thoroughly in The Immune
Response Corporation's SEC filings, including but not limited to its report on
Form 10-K for the year ended December 31, 2000 and subsequent Form 10-Q. The
Company undertakes no obligation to publicly release the result of any
revisions to these forward-looking statements which may be made to reflect
events or circumstances after the date hereof or to reflect the occurrence of
unanticipated events.
REMUNE(TM) is a trademark of The Immune Response Corporation.
SOURCE The Immune Response Corporation
 back to top
Related links:
http://www.imnr.com
Company News On-Call:
http://www.prnewswire.com/comp/434675.html or fax,
800-758-5804, ext. 434675
CONTACT:
investors, Kathy Lane, 760-771-2236, or
media, Laura Hansen, Ph.D., 858-860-0266, both of The Immune
Response Corporation
|
