Combining affinity, stability, functionality & drugability on customized antibody formats
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AbCheck utilises three synergistic platforms for the discovery and generation of human antibodies:
Proprietary Phage Display libraries and Yeast Display of full-length IgG or novel formats combined into the unique AbSieve technology
Highly validated proprietary Phage Display libraries ensure fast and reliable discovery of highly specific and high affinity human antibodies for virtually every possible target protein
Track record of more than 25 successful antibody discovery projects
Three different proprietary libraries with a combined diversity of 10 10 human antibodies
In-licensed Yeast Display technology allows screening of all antibody formats and improves drugability of drug candidates
Selects improved drug candidates from a huge number of variants
Selection in the most relevant format including full-length IgGs, customer specific and novel antibody formats
Services range from antibody discovery to lead optimization
Attractive tailor-made deal structures and with no royalty obligations to its partners

Phage Display Yeast Display o Proven commercially – fast, robust and flexible o Proprietary libraries with a combined diversity of 10 10 provide a reliable source of highly specific human antibodies o Monovalent display for isolation of high affinity binders o Allows cell panning, selection of internalizing antibodies, epitope-focused selections and much more o Isolated VH/VL pairs constitute “binding units” and can be used in every antibody format from IgG to customer specific and novel formats
AbSieve o Displays functional full length IgGs , tandem scFvs , scFvs and in all probability new customer specific and novel antibody formats o Eukaryotic ER proof reading mechanism selects-out misfolded antibodies o Display efficiency correlates with expression yields and stabilities of soluble antibodies o Highest level of control by real-time, quantitative selection of antibody clones by FACS o Enables antibody engineering in the relevant antibody format
• Yeast Display of enriched AbCheck phage display libraries in two to three panning rounds
• Batch recloning of enriched pool
• Yeast Display and FACS-based selection in the most relevant format
• Expression of soluble antibodies - including full length IgGs - enables direct screening for functionality
• Apply to existing antibodies for improvement in affinity, expression, stability and functionality
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AbSieve combines the strength of highly validated phage display libraries with the advanced possibilities of yeast display to address antibody specifications beyond affinity.
Ready-to-use and highly validated phage display libraries with
10 10 different molecules are optimal tools to discover new
antibodies in minimal time.
Monovalent display on the phage allows selection of high-
affinity antibodies to monomeric, dimeric or oligomeric soluble targets or targets in their native environment on the cell surface.
Improved drugability through yeast display, selecting for enhanced soluble expression levels and stability of
antibodies.
The yeast proof reading mechanism guarantees expressability
in eukaryotic systems.
Yeast Display in combination with FACS allows real-time
monitoring and full control of the selection process.
Screening in the final drug format avoids any drop outs caused by changes in the format.
Significantly increased probability of reaching market by identifying antibodies to exact specifications
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AbCheck uses three validated distinct human libraries
Natural library derived from immune system’s antibody gene repertoire
Further info
Fully synthetic library
Further Info
Semi-synthetic library combining aspects of both natural and synthetic antibody libraries
Further info
Comprising a total of about 10 10 sequentially and structurally diverse antibodies.
Advantages
Higher probability of isolating very specific human antibodies against every target
High diversity; approximately 10 10 not only in sequence, but also in structural diversity
Antibodies tuned to best target specific properties
Validation
Track record of more than 25 successful antibody discovery projects
More than 10 antibodies from AbCheck libraries in pre-clinical programs, one in the clinic
Outstanding screening expertise including:
Several complex cell surface receptors as well as GPCR
Subnanomolar affinities
Extreme specificities
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Affinities
Monovalent binding affinities within the low nanomolar region obtained from primary screens
Low k off rates even for monovalent scFv
Transfer into bivalent IgG usually increases binding strength by orders of magnitude
Several means of affinity maturation can be applied to enhance the affinity even further
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Extreme Specificities
Efficient counter-selection strategies were successfully applied to isolate antibodies with extreme specificities:
Isoform specific antibodies:
We have isolated an antibody to the Fc g receptor CD16A (Fc g
RIIIa) that does not bind the
CD16B isoform despite 96% sequence identity between the two isoforms.
Specific binding to deletion mutants without binding to the wild type protein:
Specific targeting of deletion mutants is challenging, because the only unique epitope is at the fusion site of the fragments upstream and downstream of the deleted part.
Conformation-specific antibodies:
By depleting the libraries of binders to the non-activated platelet receptor GPIIb/IIIa we were able to isolate antibodies to the activated form of the receptor.
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Functionality
Most of the therapeutic applications require not only binding of the antibody but depend on agonistic or antagonistic activity. From our libraries we have isolated antibodies with different functions beyond binding:
Agonistic antibodies:
Binding of the anti CD16A antibody to the receptor activates NK cells and is very efficient in inducing ADCC.
Blocking antibodies:
The isolated anti GPIIb/IIIa antibody inhibits binding of fibrinogen to activated thrombocytes.
Antagonistic antibodies:
We have isolated an anti IL13R antibody that interrupts the IL13 signalling cascade.
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Diversity
Our libraries have a combined complexity of 10 10 antibodies. In the natural library all VH and VL families are included giving the maximal possible structural diversity. The synthetic library extends the diversity beyond the limits of naturally occurring antibody sequences. A combination of natural and synthetic diversity proved in further increasing the diversity.
In a typical project 5 to 10 different antibodies meet the requested specifications.
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De novo isolation of antibodies
Phage Display
Ready-to-use highly validated phage display libraries
Strong experience in panning strategies including cell panning
AbSieve
Change to final drug format during the selection process
FACS-based selections
Characterisation
Affinity and specificity
ELISA & flow cytometry titrations
Biacore
Stability
Assessed in thermofluor assays
In vitro functionality
Target specific cell-based assays
Lead Optimisation
Phage or Yeast Display
Sublibraries for lead optimisation can be created for phage or yeast display
Addressing
Affinity, expression levels, stability and functionality
Possible in different antibody formats
Yeast Display platform allows lead optimisation of
IgGs or other antibody formats
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Three discovery platforms ensure three paths to the best antibodies
AbSieve is based on highly productive and validated technologies
Drugable antibodies delivered in very competitive time frames to virtually any target
Three distinct proprietary libraries expressing about 10 10 human antibodies
Significantly increased probability of identifying antibodies to exact specifications
Proven track record of isolating more than 25 different human antibodies
Strong IP position allowing flexible, tailored deal structure
No royalty obligations to third parties
Senior team with a proven track record in the discovery and research of therapeutic antibodies
Proven, highly enabling technologies combined with attractive cost structures
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The Human antibody discovery specialist in commercially validated yeast and phage technologies
Antibody discovery for virtually all targets in all formats
Higher probability of reaching market by screening in final antibody drug format
The unique AbSieve technology delivers drugable antibodies within highly efficient timelines
Three commercially validated diversified antibody libraries
AbCheck offers tailored deals with no royalty obligations
Thank you
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Dr. Volker Lang (Managing Director)
16 years experience in the biotechnology sector, spanning basic research, industry
R&D, Business Development and Licensing, commercial operations and management
Background as scientist and project manager combined with extensive experience in the commercialization of biotechnology products
Considerable CMC/Production experience in his previous positions as Chief Business Officer
(Affimed Therapeutics AG) and Vice President Corporate Development (Scil Technology
GmbH)
Dr. Vera Molkenthin (Chief Scientist and Head of Discovery)
Many years experience in the selection of antibodies using phage display
PhD from the Faculty of Biology in Mainz with main focus on construction of a phage display library and the selection of stabilizing mutations
Head of Screening at Affimed with responsibility for the management of the screening group, with special emphasis on generation of highly diverse antibody libraries, and design and execution of the most appropriate selection procedure for a particular target
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Volker Lang, PhD
(Managing Director)
Phone: +420 378 05 1500
V.Lang@AbCheck.eu
AbCheck s.r.o.
Vedeckotechnicky park Plzen
Teslova 3
CZ-301 00 Plzen www.AbCheck.eu
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Fully human library
In vivo created diversity of antibody sequences comprising sequential as well as structural diversity
New combinations of VH and VL chains from multiple healthy donors
No bias due to amplification of the VH chains by IgM specific priming
Special assembly technology guarantees > 70% functional clones
Reliable and rapid selection of highly specific and high affinity antibodies on recombinant proteins or cells
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Back to Libraries

Synthetic library
Generated by introducing randomized sequences in the antibody binding site of selected frameworks
Ensuring reliable folding and high expression yields
Diversity generated in vitro thereby
Avoiding counter selection against anti-self antibodies
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Back to Libraries

Semi-synthetic library
Combining the advantages of the natural and synthetic library
Diversity and reliable folding and high expression
Increasing the diversity of binding molecules even further
Back to Libraries
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TM
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The SECANT™ platform is a next-generation antibody display system that can handle large and complex proteins
• First yeast system to display full-length IgG antibodies
• Proven to display tandem scFv, bispecific and proprietary scaffolds
Enables high throughput assay of 10 8 to 10 9 variants for
• De Novo Antibody Discovery
• Complex Scaffold Engineering
• Scaffold Reformatting
• Affinity Maturation
• Stability/Solubility/Folding Control
• Humanization
• The SECANT™ platform will accelerate discovery timelines by allowing faster characterization and higher throughput
• SECANT™ platform is compatible with many types of proteins and libraries
• Full length IgG and scFv, fibronectin, receptor ectodomains, superoxide dismutase, human serum albumin, vitamin D-binding protein
Source: Celexion
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1. The gene for the variant protein to be engineered (the “gene of interest“) is expressed as a fusion to a biotin acceptor peptide (BAP). A co-expressed biotin ligase attaches biotin to the BAP tag on the expressed protein.
2. Avidin is attached to the outer wall of the host cell.
Source: Celexion

3. The biotinylated protein of interest is secreted into the extracellular space where it binds to the surface-localized avidin. Approximately 10 5 proteins can be captured on the yeast surface in this manner.
4. The captured proteins can be assayed for binding, expression, or enzymatic activity by labeling with a fluorophoretagged ligand, antibody, or substrate.
Protein functionality can then be assayed and the best clones isolated by FACS.
Source: Celexion

Source: Celexion