1. health and fitness
2. disease
3. cancer

immunotope
Immunotope Technology
Immunotope focuses on the identification of immunotherapeutic target
proteins for the development of novel therapeutics and diagnostics for cancer,
infectious disease and autoimmune disorders. Immunotope’s antigen discovery
and immunotherapeutic development efforts are based upon the Company's
ability to identify:
• Endogenous antigenic peptides associated with class I and II major
histocompatibility complex (MHC) molecules
• Autoantibody-reactive proteins identified using serological analysis
• Membrane proteins on the surface of diseased cells that are putative targets
for novel monoclonal antibody therapeutics.
Immunotope obtains a comprehensive survey of the immunologically processed
antigens on normal and diseased cells (immunoproteomics) using a combination
of ultra-sensitive mass spectrometry, immunology and differential analysis.
Immunotope’s analytical mass spectrometry capabilities allow the identification
of individual peptides at the attomole level in complex mixtures.
Immunotope’s proprietary antigen identification technology has been developed
over the past four years by Immunotope’s scientific founder, Dr. Ramila Philip,
and the approach has been clinically validated in Phase I/II melanoma clinical
trials.
Immunotope Technology
Immunotope three methodologies to support and expand its
immunoproteomics technology platform: (1) Cytotoxic T-cell- (CTL) based
discovery using ultrasensitive techniques pioneered by Immunotope; (2) HighThroughput Peptide Sequencing (HTPS); and (3) Differential Analysis of T cell
epitopes (DATE™ analysis). Antigens present at the level of one to ten copies
(attomole level) per cell have been identified using these methods.
CTL- based Technology
When tumor-specific cytotoxic or helper T cells are available, a T cellbased methodology is employed to analyze the mixture of over 10,000 MHCassociated peptides obtained by isolation of MHC Class I and Class II epitopes
from diseased cells and to identify the peptides recognized by the CTL. Using a
combination of sophisticated immunology and high sensitivity mass
spectrometry methods, Immunotope identifies the small number of peptides that
elicit strong T cell-mediated immune responses against cancer, infectious
diseases and autoimmunity. Mounting clinical evidence has shown that
immunotherapeutic vaccines composed of defined antigens that are also
presented as MHC-associated epitopes on diseased cells are correlated with
positive clinical outcomes.
Immunotope proprietary
1
immunotope
High-Throughput Sequencing (HTS) and Differential Analysis
Immunotope uses an automated, data-dependent high throughput mass
spectrometric technique (HTS) to sequence all of the peptides extracted from
class I and II MHC molecules on a diseased cell. For each indication,
Immunotope generates a large EpiMap™ immunoproteomics database of
information about the cellular proteins that are processed into peptides and
presented to the immune system on the surfaces of the cells by MHC molecules.
Immunotope also uses novel peptide isolation, purification and mass
spectrometry technologies to determine which MHC-associated peptides and
surface-expressed proteins are differentially displayed on normal vs. diseased
cells by directly comparing the peptides or proteins from the diseased and
normal tissues. Differential analysis methodology is also applied to identify
autoantigens by screening serum autoantibodies in patients. Immunotope can
compare the MHC-associated antigens with the autoantigen database to identify
theranostic antigens that can be used for both diagnostics and therapeutics.
Disease-associated intracellular and surface proteins are also candidate targets
for drug discovery.
Diagnostics developed from novel serum biomarkers
There is substantial evidence that the serum of cancer patients contains
circulating levels of antibodies that recognize tumor-associated antigens (TAA)
even at very early stages of disease. Immunotope’s diagnostics discovery
program is focused on identification of novel serum biomarkers for early
detection and development of noninvasive serum-based diagnostics for ovarian
cancer and hepatocellular carcinoma. Tumor-reactive antibodies present in
cancer patient serum are used to identify target antigens that are present at very
early stages, before tumors are detectable by other commonly used methods,
such as imaging.
Advantages of Immunotope Technologies
Immunotope’s immunoproteomics technologies identify antigenic
proteins that are endogenously processed and presented by class I and class II
MHC-molecules. A key advantage of our methodology over competing approaches
that use predictive algorithms, or ‘reverse vaccinology’, is that prior
identification of the source protein of the presented antigen is not required. In
fact, we have identified several important peptide antigens that do not match
known binding motifs. We are able to identify post-translational modifications
(i.e., glycosylation, deamidation, cysteinylation, and phosphorylation) that can
profoundly influence peptide recognition by cytotoxic T cells. Direct
identification of endogenous MHC-associated peptides is also very powerful
because it identifies multiple “shared” antigens in the same tumor type from
several different patients as well as antigens common to different tumor types.
Immunotope proprietary
2
immunotope
Identification of autoantibody-specific natural epitopes is the first step in the
development of autoantibody-based diagnostics for early detection of cancer.
Finally, the Company’s approach enables the identification of surface proteins
and other epitopes that are differentially displayed as a consequence of changes
in gene expression or changes in protein synthesis or metabolism.
Progress in Antigen Discovery
Cancer
Class I MHC-associated peptides from ovarian cancer cells have been analyzed
by HTS to identify potential ovarian tumor antigens. An extensive database of
peptide mass spectra and protein/gene sources also has been developed. To
date, (20) candidate peptide antigens have been identified and 16 of these have
been immunologically characterized. Four of these antigens are derived from
cell surface proteins. These peptides are derived from proteins implicated in
apoptosis, tumor suppressor activity, and cell cycle regulation. Several of these
proteins are expressed in multiple tumor types from several different patients,
based on analysis of peptides extracted from several tumor samples (Figure 1).
Our therapeutic and diagnostic objectives are to identify antigen combinations
that will elicit an effective and positive immune response to kill tumors and
infected cells and/or to be reliably predictive of the disease state.
Figure 1. Representation of shared and unique
peptide
antigen
populations
mapped
by
Immunotope’s peptide analysis of ovarian tumors
from multiple patients.
In addition to the MHC class I peptide database for ovarian cancer, we have
obtained ovarian patient serum autoantigen profiles by screening serum
autoantibodies using our differential immunoproteomics technology. We have
generated a panel of autoantigens that elicit antibody responses early in the
progression of disease. These antigens are potential candidates for diagnostics
and immunotherapeutics.
Our colon cancer program has produced an EpiMap™ immunoproteomics
database of MHC class I-associated epitopes from paired tumor and normal
Immunotope proprietary
3
immunotope
tissues from the same patient, and has identified a panel of epitopes that are only
expressed in cancer cells. We have also generated a database of peptides from
colon cancer cell lines and primary tumors.
Infectious Diseases
Our infectious disease programs focus on hepatitis B/C and HIV, which are
collaborations with the Hepatitis B foundation and University of Pennsylvania
respectively. We have identified novel epitopes from HBV- and HIV-infected
cells that are naturally processed and presented by MHC class I molecules.
These epitopes are different from those reported in the literature and that were
identified using the motif prediction algorithm. We are in the process of
completing the discovery and functional characterization of these epitopes. The
identification of these novel epitopes clearly demonstrates the concept that direct
identification, rather than prediction is key to successful immunotherapy, since
the immune system only recognizes naturally processed epitopes presented by
tumor or infected cells, which cannot be reliably predicted by motif algorithms.
Business Development and Services
Immunotope is generating intellectual property by mining its large diseasespecific EpiMap™ databases of MHC class I and II-associated peptides from
normal and diseased cells, and cancer autoantigen databases based on serum
autoantibody screening. The EpiMap™ databases contain the identities of
indication-specific antigens as well as shared antigens common to multiple
indications or stages of the disease. These peptides and their proteins of origin
are excellent candidates for cancer, infectious disease and autoimmunity
immunotherapies and diagnostics. Immunotope is seeking partnerships to
expand its cancer and infectious disease programs.
We also offer a range of services that use our proprietary antigen identification
and immunoproteomics technologies to identify panels of naturally processed
MHC Class I and Class II-associated peptides for customer-specified indications.
The products of our analysis can include MHC-processed antigens for
development of immunotherapeutic vaccines, antibody targets and
diagnostics.
We have expertise in autoantigen-based antigen discovery and will screen
serum autoantibodies to identify novel diagnostic and antibody therapeutic
targets. We can also evaluate antibody responses to other forms of
immunization, including whole tumor and heat shock protein-based
immunotherapy.
Immunotope proprietary
4
immunotope
Our services also include:
Analysis of MHC processing of proteins in genetic constructs
Analysis of antigen specificity post cell based immunotherapies
Intellectual Property Strategy
The Company’s EpiMap™ and autoantigen databases provide important
information on proteins whose expression has been altered as a result of the
transformation or infection process. Immunotope has filed patents on several
MHC class I-specific peptides derived from proteins that are involved in
carcinogenesis and cellular transformation processes. Patents have also been
filed on the proteins from which these peptides were derived as immunotherapy
targets. These proteins are excellent candidates for the development of
diagnostics and immunotherapeutics, including vaccines and antibody targets.
Immunotope proprietary
5