AvantGen Awarded SBIR Phase II Contract to Develop High-Affinity, Anti-Peptide Rabbit Monoclonal Antibodies for SISCAPA Assays from the NIH/NCI

September 18, 2015

AvantGen, a leader in novel antibody discovery and engineering, in collaboration with SISCAPA Assay Technologies (SAT), was awarded a SBIR Phase II contract from the National Cancer Institute (NCI) to develop high-affinity, anti-peptide rabbit monoclonal antibodies for mass-spectrometry-based cancer biomarker detection and quantification assays, or so called SISCAPA (Stable Isotope Standards and Capture by Anti-Peptide Antibodies) assays.

Antibodies with high affinity and specificity suitable for cancer biomarker measurements are essential, since there are more than 2,000 potential biomarkers that have been discovered, but only about 100 of them are currently approved by the FDA for clinical diagnostic use.

Prior to this Phase II contract, AvantGen successfully completed a Phase I contract (HHSN261201300023C) using its novel rabbit monoclonal antibody generation platform which enables AvantGen to isolate the highest affinity antibody clones from an immunized rabbit with the desired specificity for the target peptide antigen.  All of the rabbit monoclonal antibody clones developed during Phase I exhibit very high affinity (10-10 to 10-11 M) and specificity for their respective antigens.

AvantGen’s technology bypasses the low efficiency of fusion between antibody-producing cells (B cells) and myeloma used with hybridoma technologies. Fusion is particularly inefficient with rabbit myeloma lines with an estimated fusion rate of 1 in 1 million. The isolated antibodies with AvantGen’s technology will be sequenced and expressed in mammalian cell systems, therefore also overcome the instability and low antibody yield issues of rabbit monoclonal antibody cell lines

The Phase II contract (HHSN261201500044C) will support the development of novel rabbit monoclonal antibodies against 100 additional peptides derived from cancer biomarkers.  The developed antibodies will be evaluated in SISCAPA assay.

SISCAPA combines antibody-based peptide enrichment with quantitative mass spectrometry to provide accurate quantitation of target proteins. The assay requires high affinity and highly specific antibodies and enables measurements of biomarkers from biological samples with unprecedented precision and throughput.

AvantGen is also providing services to generate high quality rabbit monoclonal antibody research reagents for the research community.

AvantGen Awarded SBIR Phase II Grant to Develop High-Affinity Rabbit Monoclonal Antibodies for Neuroscience Related Antigens from the NIH/NIDA

March 1, 2015

AvantGen, a leader in novel antibody discovery and engineering, was awarded a SBIR Phase II grant from the National Institute on Drug Abuse (NIDA) of the National Institutes of Health (NIH) to develop novel rabbit monoclonal antibodies against 120 proteins related neuroscience.

Neuroscience related proteins are highly conservative and homologous among different species, making them difficult targets to generate high quality antibodies.  Therefore, novel methods that could yield antibodies against these proteins and distinguish between related family members are urgently needed.

AvantGen has developed its proprietary yeast display system and rabbit antibody libraries to discover novel antibodies for research, diagnostic and therapeutic development.

While mouse monoclonal antibodies are the most widely used reagents for detecting and quantifying proteins, a recent study showed that only about 25% of antibodies on the market are specific,  due to the vastly different characterization criteria used by different providers. In addition, the affinities for antigen of the current antibody clones on the market vary considerably, ranging from μM to sub nM.  Rabbits are known to generate much stronger immune responses than mice to antigens in general, but small peptides and haptens in particular, due to their unique use of both gene conversion and somatic hypermutation and the diversity of light chain variable regions, including germline encoded Vκ variability in CDR-3 length. It has been demonstrated that rabbit monoclonal antibodies generally exhibit 10-100 fold higher affinity for antigens than murine monoclonal antibodies.
AvantGen’s technology bypasses the low efficiency of fusion between antibody-producing cells (B cells) and myeloma used with hybridoma technologies. Fusion is particularly inefficient with rabbit myeloma lines with an estimated fusion rate of 1 in 1 million. The isolated antibodies with AvantGen’s technology will be sequenced and expressed in mammalian cell systems, therefore also overcome the instability and low antibody yield issues of rabbit monoclonal antibody cell lines.

Antibody clones developed with AvantGen’s technologies are highly specific, and can be readily selected to distinguish between related family members, different isoforms, post-translational modified variants, and different conformations.

This Phase II grant will allow AvantGen to develop highly quality rabbit or human monoclonal antibodies against such challenging targets. The developed antibodies will be fully characterized by AvantGen’s collaborators at the Mount Sinai Icahn School of Medicine.