AbScreen™ Platform

Accelerate therapeutic antibody discovery with our third-generation library platform engineered for diversity, affinity, and developability.

Platform Overview

AbScreen™ Platform: Next-Generation Antibody Screening Platform

Therapeutic antibody discovery has long been challenged by the need to simultaneously achieve high diversity, strong affinity, and reliable developability—goals that traditional methods often fail to balance. Protheragen addresses this gap with AbScreen™, our third-generation antibody library platform built on well-behaved therapeutic scaffolds with quality incorporated by design. By combining naturally derived CDR diversity, next-generation sequencing validation, and developability-focused scaffold engineering, AbScreen™ enables the rapid discovery of highly diverse, high-affinity antibodies that are intrinsically developable—accelerating the journey from lead to clinic.

Disruptive Technology
Excellent Team
Diversified Pipeline
Customized Solutions

Platform Core

Advanced Library Construction & Screening Technologies

At the core of AbScreen™ lies our expertise in antibody library construction and screening. When we undertake an antibody discovery campaign for you, our goal is to generate as many diverse, target-specific antibodies as possible that meet your precise requirements. Based on your needs, we offer multiple antibody formats including VHH, Fab, and scFv—with fixed light chain options available for bispecific development. Our integrated screening workflow combines three powerful technologies to ensure maximum diversity, high affinity, and comprehensive lead identification:

Phage Display: We first carry out selections from our third-generation phage display libraries to obtain an initial pool of antibody leads with maximum diversity. This broad capture of binders ensures extensive epitope coverage and access to rare clones that might be missed by conventional approaches.
Yeast Display: Yeast display is then employed to narrow down the initial pool to a diverse, high-affinity fully binding population. This step incorporates requirements for cross-reactivity, ligand antagonism, or additional specificity needs—delivering antibodies with optimized functional properties.
NGS and Analysis: Throughout library construction and downstream selection output analyses, we utilize next-generation sequencing to directly measure the diversity of each exclusive library we build, ensuring it meets our high standards. By applying NGS to selection outputs, we typically identify 100 to 1,000 different clusters. Once representative cluster sequences have been identified, gene synthesis is used to go "from sequence to clone," providing access to the most promising leads for downstream development.

Platform Advantages

Unique Advantages of the AbScreen™ Platform

Design-Embedded Developability

AbScreen™ libraries are constructed on well-behaved therapeutic scaffolds chosen specifically for their biophysical properties and absence of sequence liabilities. Unlike traditional libraries that require extensive downstream engineering, our platform delivers antibodies inherently optimized for manufacturing, stability, and formulation—significantly reducing development timelines and costs.

Verified Ultra-High Diversity

With HCDR3 diversity exceeding 10⁸ and all six CDRs incorporating naturally derived sequences, AbScreen™ ensures broad epitope recognition and comprehensive target coverage. Next-generation sequencing is employed throughout construction to directly measure—not estimate—diversity, guaranteeing that our high standards are consistently met.

Natural CDR Diversity

All diversity originates from authentic human B cell sources: HCDR3s are amplified directly from purified B cells, while remaining CDRs replicate natural sequences from extensive databases. This ensures that antibodies discovered through AbScreen™ possess physiologically relevant conformations and reduced immunogenicity risk.

Intelligent Antibody Clustering

NGS-derived sequences are analyzed by machine learning to group antibodies into clusters targeting the same epitope. This enables comprehensive epitope coverage and strategic lead selection. Our antibodies combine high affinity, developable properties, and broad diversity—accelerating lead-to-drug transition. Final deliverables include antibody panels in any format or clonotype sequence lists for in-house testing.

Integrated Affinity Maturation

Our platform uniquely combines discovery and optimization. Using a two-phase process, we replace HCDR1/2, LCDR1/2, LCDR3, and optionally HCDR3 with scaffold-matching CDRs, followed by yeast display selection. This achieves 10-200 fold affinity improvement while simultaneously purging sequence liabilities—delivering mature leads ready for development.

Platform Application

Driving Diverse Antibody Discovery Applications

Therapeutic Antibody Discovery AbScreen™ enables rapid identification of high-affinity, developable antibodies against diverse therapeutic targets. Available in VHH, scFv, and Fab formats—with fixed light chain options for bispecific development—our platform delivers panels of target-specific antibodies meeting your precise requirements for cross-reactivity, antagonism, or specificity.
Bispecific Antibody Development Fixed light chain libraries within AbScreen™ are specifically designed to streamline bispecific antibody generation. By providing common light chain partners, these libraries reduce chain mispairing issues and facilitate the development of stable, high-quality bispecific molecules with native antibody architecture.
Custom Library Construction Beyond our standard offerings, we collaborate closely with clients to create exclusive, customized libraries. From scaffold selection to CDR composition and format preferences, essential elements are optimized according to your specific needs. Each custom library remains unique and exclusive to you, providing proprietary discovery tools.

Pipeline

Research & Development Pipeline

Projects	Format	Target	Indication
ABC006	VHH	PD-L1	Solid Tumors
ABC009	scFv	TNF-α	Rheumatoid Arthritis
ABC013	Fab	VWF C-terminal CK Domain	Von Willebrand Disease
ABC018	BsAb	PD-1 / CTLA-4	Metastatic Melanoma
ABC025	BsAb	CD3 / BCMA	Multiple Myeloma

Get in Touch with Us

FAQs

Frequently Asked Questions

Q1: What makes AbScreen™ different from conventional antibody libraries? A: AbScreen™ incorporates quality by design rather than quality by testing. Libraries are built on therapeutic scaffolds pre-selected for developability, with all CDRs derived from natural human sequences. NGS verification ensures diversity is measured, not estimated, and sequence liabilities are purged from all but HCDR3.
Q2: What formats are available with AbScreen™? A: We offer libraries in scFv, Fab, and VHH formats. scFv and Fab are also available as fixed light chain libraries—ideal for bispecific antibody development. VHH libraries are based on well-behaved therapeutic VHH molecules with natural diversity from rearranged human VH3 genes.
Q3: How does AbScreen™ ensure antibody developability? A: Developability is built in by design through three mechanisms: therapeutic scaffolds selected for biophysical properties, systematic purging of sequence liabilities from all CDRs except HCDR3, and NGS-guided quality control throughout construction.
Q4: How does AbScreen™ use next-generation sequencing (NGS)? A: NGS is employed throughout library construction for quality control and diversity validation. During selection outputs, NGS combined with machine learning identifies 100-1,000 different clusters, enabling "sequence to clone" access to the most promising leads.
Q5: Do you offer custom library services? A: Absolutely. We collaborate closely with clients to create exclusive, customized libraries where essential elements—scaffolds, CDR composition, formats—are optimized to your specific needs. Each custom library is unique and exclusive to you.