- Two Oral Presentations at Prestigious Conference -
WALTHAM, Mass., March 3 /PRNewswire-FirstCall/ --
AltaRex Corp. (TSE: AXO, OTC: ALXFF) announced today that Dr. Hubert Eng and
Ms. Kate Agopsowicz, Company scientists, will present important new OvaRex(R)
in vitro results in two separate oral presentations at the Keystone Symposium
this week. The Company's laboratory data will further elucidate the mechanism
by which OvaRex(R) MAb interacts with target tumor associated antigen (TAA)
CA125 and the immune system to elicit potent T cell responses specific for
CA125 expressing tumors of ovarian origin. Additional laboratory data
addresses the observed synergy between chemotherapy and OvaRex(R) treatment by
further demonstrating the mechanism by which antibody/antigen complexes are
processed in the presence of chemotherapy-induced dying tumor cells.
(Logo: http://www.newscom.com/cgi-bin/prnh/20000831/ALTREXLOGO )
Dr. Eng's presentation tomorrow, entitled "Complexation with murine MAb-
B43.13 alters the endocytic trafficking of the mucinous tumor antigen CA125
after uptake by human dendritic cells", will be part of a Keystone Symposium
titled "Dendritic Cells: Interfaces with Immunobiology and Medicine" being
held in Keystone, Colorado. Ms. Agopsowicz will present her talk,
"Opsonization with specific antibodies enhances dendritic cell presentation of
apoptotic tumor cells and induction of CTL" on Sunday March 9th. Keystone
Symposia is a non-profit organization that attracts global scientific and
medical leaders for discussion and presentation of cutting edge technology and
therapeutic advances.
It has been generally reported that tumors generate certain circulating
TAA to which the immune system responds poorly, possibly associated with the
inability of dendritic cells to process these antigens. However Dr. Eng's
data demonstrates that when an immune complex is formed between "foreign"
OvaRex(R) monoclonal antibody and the "self" CA125 antigen, the complexed
CA125, unlike free CA125, is transported into processing compartments of
dendritic cells and as a consequence is able to stimulate presentation to and
activation of T cells. Dr. Eng was able to observe this CA125 processing
utilizing confocal microscopy to follow the passage of complexed and free
CA125 through the various compartments of the dendritic cells. The Company
thus concludes from its experiments that as a mechanism of immune escape,
tumor antigens, in particular mucinous ones like CA125, may inhibit processing
pathways in antigen-presenting cells, and the new data address this "defensive
strategy" of tumors and demonstrate its reversal by offering antigen to the
immune system in the form of immune complexes.
Ms. Agopsowicz's findings provide mechanistic rationale for previously
reported clinical data demonstrating that administering OvaRex(R) concurrent
with chemotherapy appears to enhance tumor-specific T cells and extend
progression free and overall survival more so than chemotherapy alone in
patients with relapsed or recurrent ovarian cancer. In her laboratory
findings, when OvaRex(R) is present with tumor cells killed by chemotherapy or
irradiation (particularly paclitaxel, doxorubicin, carboplatin and topotecan),
dendritic cells show enhanced capability to present the antigen source
(apoptotic or dying tumor cells) to stimulate cytolytic T cell responses. The
data suggest that in addition to the cytotoxic effect of the chemotherapy,
subsequent immune activation of killer T cells by OvaRex(R)-coated dying tumor
cells further enhances the therapeutic effect.
Taken together, the results of these two laboratory studies further
enhance the understanding of the Company's reported OvaRex(R) clinical trial
data in late stage "watchful waiting" and recurrent ovarian cancer as well as
extend the intellectual property and know-how of the Company. This latter
point is particularly important as the Company focuses on the application of
its technology to other diseases and in particular, with regard to these
laboratory findings, to allergy and chronic infectious disease.
AltaRex Corp. is focused on the research and development of antigen-
targeted monoclonal antibodies, or antibody-based immunotherapy, for the
treatment of certain late stage cancers and other diseases with significant
unmet medical needs. The Company's lead product, OvaRex(R) for advanced
ovarian cancer, is in a U.S. phase III clinical program being conducted by the
Company's licensee, Unither Pharmaceuticals, a wholly owned subsidiary of
United Therapeutics. OvaRex(R) targets the tumor associated antigen CA125 and
BrevaRex(R) targets MUC1, which has completed a phase I study. AltaRex also
has reported using its ProstaRex(TM) MAb to induce T cells in laboratory
studies to a circulating prostate cancer antigen, PSA. ProstaRex(TM) is in
preclinical development. The Company does not expect to commence further
clinical trials of BrevaRex(R) and/or ProstaRex(TM) until it obtains
additional resources.
The Company's present and limited research is focused on an early stage
disease target, human carcinoma antigen, in collaboration with Egenix, Inc.
while at the same time conducting proof of principal experiments for applying
the technology platform to allergy and infectious and autoimmune diseases as
well as altered delivery mechanisms to enhance the desired immunogenic effect.
Additional information about AltaRex research and development, news and
events can be found on its web site at http://www.altarex.com. Clinical information
can also be found at http://www.centerwatch.com and http://www.clinicaltrials.gov.
Additional information about ovarian cancer can be found at http://www.nci.nih.gov,
http://www.ovariancanada.org and at http://www.ovarian.org.
This news release contains forward-looking statements that involve risks
and uncertainties, which may cause actual results to differ materially from
the statements made. For this purpose, any statements that are contained
herein that are not statements of historical fact may be deemed to be forward-
looking statements. Without limiting the foregoing, the words "believes,"
"anticipates," "plans," "intends," "expects" and similar expressions are
intended to identify forward-looking statements. Such risks and uncertainties
include, but are not limited to our need for capital and the risk that the
Company can not raise funds on a timely basis on satisfactory terms or at all,
changing market conditions, completion of clinical trials, patient enrollment
rates, uncertainty of preclinical, retrospective and early clinical trial
results, which may not be indicative of results, including the laboratory data
referenced above, that will be obtained in ongoing or future clinical trials,
the establishment of manufacturing processes and new corporate alliances, the
timely development, regulatory approval and market acceptance of the Company's
products, uncertainty as to whether patents will issue from pending patent
applications and, if issued, as to whether such patents will be sufficiently
broad to protect the Company's technology, and other risks detailed from time-
to-time in the Company's filings with the United States Securities and
Exchange Commission and Canadian securities authorities. The Company
disclaims any obligation to update these statements.
THE TORONTO STOCK EXCHANGE HAS NOT APPROVED OR DISAPPROVED OF THE
INFORMATION CONTAINED HEREIN.
Contact:
Robert Newman
Vice President, Business Operations
(781) 672-0138 ext. 1502
bnewman@altarex.com
SOURCE AltaRex Corp.
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Related links:
http://www.altarex.com
http://www.altarex.com http://www.centerwatch.com
http://www.clinicaltrials.gov http://www.nci.nih.gov
http://www.ovariancanada.org http://www.ovarian.org
Photo Notes:
NewsCom:
http://www.newscom.com/cgi-bin/prnh/20000831/ALTREXLOGO
AP Archive: http://photoarchive.ap.org
PRN Photo Desk, 888-776-6555 or 212-782-2840
Company News On-Call:
http://www.prnewswire.com/gh/cnoc/comp/128163.html
CONTACT:
Robert Newman, Vice President, Business
Operations of AltaRex Corp., +1-781-672-0138, ext. 1502,
bnewman@altarex.com
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