Cambridge Healthtech Institute's 9th Annual

Antibodies Against Membrane Protein Targets – Part 1

Targeting Strategies, Characterization and Screening

September 28 - 29, 2021 EDT

As the pharmaceutical and biotech industries increasingly shift attention to biologics, much more attention is being paid to the prospect of developing biotherapeutics against membrane-bound targets. For the large GPCR and ion channel target classes, biologics offer improved selectivity, an alternative for targets with known function that have not been amenable to small molecule drugs and the potential for using antibodies for the targeted delivery of therapeutics. However, for the field to advance, fundamental challenges in antigen quality and presentation, discovery methodologies, protein engineering and the pace of discovery must be resolved. This two-part meeting provides a forum in which discovery biologists and protein engineers can come together to discuss next generation strategies and technologies that will allow biologic drugs for these target families to advance into the clinic and beyond.

Monday, September 27

11:30 am Virtual Short Courses

Please visit the Short Courses page for details. Premium Package or separate registration required.

Tuesday, September 28

7:00 am Registration Open and Morning Coffee
7:55 am Organizer’s Welcome Remarks
8:00 am

Chairperson's Remarks

G. Jonah Rainey, PhD, Vice President, Antibody Engineering, AlivaMab Discovery Services

FUNCTIONAL SCREENING & CHARACTERIZATION

8:05 am

Discovery and Development of a First-in-Class Antibody against a Novel Prostate Cancer Target

Sathya Venkataramani, PhD, Associate Director, Biologics Discovery, Janssen Biotherapeutics

Explosive growth of global therapeutic mAb market is expected to generate revenue > $300 billion by 2025. Prudent choice of predictive profiling assays during discovery is pivotal for minimizing attrition in late clinical development. Here, I am sharing my perspectives on an integrated screening paradigm for the selection and characterization of a truly first-in-class high affinity antibody against a novel prostate cancer target that is a single pass transmembrane protein.

8:35 am

Development and Application of a High-Content Virion Display Human GPCR Array

Heng Zhu, PhD, Professor, Pharmacology and Molecular Sciences, Johns Hopkins Medical School

GPCRs rely on membrane for proper folding, making their biochemical properties difficult to study. By displaying GPCRs in viral envelopes, we fabricated a Virion Display (VirD) array containing 315 non-olfactory human GPCRs for functional characterization. Using this array, we found that 10 of 20 anti-GPCR mAbs were ultra-specific. We believe that the VirD-GPCR array holds great potential for high-throughput screening for small molecule drugs, affinity reagents, and ligand deorphanization.

9:05 am

Antibody Fragments as Tools to Investigate Transmembrane Receptor Signaling

Andrew C. Kruse, PhD, Professor of Biological Chemistry and Molecular Pharmacology, Harvard Medical School

Integral membrane receptors are highly dynamic proteins, adopting a wide range of structurally and functionally distinct conformations. Using a fully synthetic yeast surface-displayed library, we have developed methods to efficiently and reproducibly isolate antibody fragments targeting G protein-coupled receptors (GPCRs) and other membrane proteins. These antibody fragments allow investigation of protein structure and direct modulation of receptor signaling in vivo.

9:35 am Coffee Break in the Exhibit Hall with Poster Viewing
10:25 am

High-Throughput Functional Assays for Antibody Discovery

Jane Seagal, PhD, Research Fellow, Drug Discovery Science & Technology, AbbVie

Recent technology advances are enabling highly efficient antibody discovery campaigns resulting in the identification of diverse antigen-specific antibody panels. Introduction of functional screening assays, early in the process, may become essential for prioritization of antibodies with therapeutic potential. In this talk, high throughput functional screening assays are presented as a part of integrated screening funnel, highlighting challenges and benefits of the early implementation of functional assays.

10:55 am

Successes and Challenges of Pharmacological Characterization of Antibodies: Anti-FGFR1 Case Study

Laetitia D. Comps-Agrar, PhD, Principal Scientist, Biochemical & Cellular Pharmacology, Genentech, Inc.

Fibroblast growth factor receptor 1 (FGFR1) is a promising therapeutic target for multiple pathologies including metabolic diseases and cancer. Targeting of FGFR1 may require an agonist or antagonist depending on the indication. We investigated the mechanism of action of anti-FGFR1 antibodies reported to be agonist or antagonist and described a novel functionally distinct FGFR1 active conformation, demonstrating that modulating the geometry of FGFR1 dimers can effectively change the signaling outputs and in vivo activity.

11:25 am

Antibody-Driven Antigen Discovery in vitro and in silico

Christoph Rader, PhD, Professor, Immunology & Microbiology, The Scripps Research Institute

The limited number of suitable antigens has restricted the utility of antibody-based cancer therapy. Complementing bottom-up antigen discovery by transcriptomics and proteomics, we are pursuing top-down antigen discovery strategies based on the selection of antibody libraries against live cancer cells by phage display. Notoriously challenging due to the stickiness of phage, a new method, termed Fab biotinylation and capture (FBC), was developed. Following proof-of-concept, FBC was used for differential selection on target cells versus non-target cells followed by next-generation sequencing (NGS) and bioinformatic processing. Combining FBC and NGS was applied to antigen discovery in multiple myeloma and acute myeloid leukemia.

Joseph Rucker, VP Research & Development, Integral Molecular

Emerging data suggest that approximately 25% of therapeutic MAbs in development are polyspecific and this can result in severe adverse events. We developed the Membrane Proteome Array (MPA) to de-risk MAb safety through specificity testing across an array of 6,000 native-conformation human membrane proteins. We will discuss the importance of early stage specificity testing and present case studies for antibody and cell therapies against SARS-CoV-2 Spike and other complex therapeutic targets.  

12:25 pm Session Break
Larry Green, PhD, CEO, Ablexis
Dana Duey, Director of Antibody Discovery, AlivaMab Discovery Services

Multi-specifics and other next-generation antibody modalities bring increased challenges and complexities in discovery and development. To increase probability of success, obtaining large quantities of diverse, high-quality antibodies for reformatting into the final product is essential to achieve design goals for function and developability. In <3 months we deliver these large, molecularly diverse panels of antibodies to position our partners on the fastest and most de-risked path to success.

1:05 pm Refreshment Break in the Exhibit Hall with Poster Viewing

TARGETING WITH NANOBODIES AND SMALL PROTEINS

1:35 pm

Chairperson's Remarks

Jane Seagal, PhD, Research Fellow, Drug Discovery Science & Technology, AbbVie
1:40 pm

Monitoring Allosteric Interactions with CXCR4 Using NanoBiT Conjugated Nanobodies

Mark Soave, Research Fellow, School of Life Sciences, University of Nottingham

The small size of nanobodies enables genetic manipulation to incorporate protein tags. VUN400, a nanobody which recognizes the second extracellular loop of the chemokine CXCR4 receptor, was conjugated to the 11-amino acid HiBiT tag (VUN400-HiBiT) which complements LgBiT protein, forming full-length functional NanoLuc luciferase. Complemented luminescence was used to detect VUN400-HiBiT binding to CXCR4 expressed in HEK293 cells. VUN400-HiBiT binding to CXCR4 was prevented by orthosteric and allosteric ligands, allowing VUN400-HiBiT to be used as a probe to detect allosteric interactions with CXCR4. This demonstrated the high specificity offered by extracellular targeted nanobodies can be utilized to probe receptor pharmacology.

2:10 pm

Using Membrane Protein-Specific Nanobodies to Target AAV Vectors to Specific Cells

Friedrich Koch-Nolte, PhD, Professor, Immunology & Molecular Biology, Institute of Immunology, University Medical Center Hamburg-Eppendorf

Adenoassociated viral vectors (AAV) are used in gene therapy, oncology, and for producing therapeutic antibodies in vivo. However, the broad tissue tropism of AAV still hampers their clinical development. We demonstrate that a membrane protein-specific nanobody can readily be inserted into a surface loop of the AAV capsid. This results in a 50-500 fold increased transduction of cells expressing the target membrane protein. We have verified the efficacy of this platform for a variety of cells expressing different target proteins, using different AAV serotypes displaying nanobodies directed against GPI-anchored, singlespan, or multispan transmembrane proteins.

Moa Fransson, PhD, CEO, Genagon
John Burg, Research Investigator, OmniAb

We have characterized a novel multi-Tm protein target relevant for cancers with a high infiltration of macrophages, such as triple negative breast cancer.  Our proof-of-concept studies demonstrate that blocking target function results in reduced tumor growth or clearance.

3:10 pm Refreshment Break in the Exhibit Hall with Poster Viewing
3:40 pm

Targeting Difficult to Drug Membrane Proteins with VHH Antibodies

Priyanka Gupta, PhD, Scientist, Biotherapeutics, Boehringer Ingelheim Pharmaceuticals, Inc.

VHH antibodies and their unique properties offer an alternative approach to targeting complex membrane targets. This platform has been successfully applied to identify a potent half-life extended VHH antibody antagonist to CX3CR1, a target that has been identified as highly attractive for several therapeutic interventions. Additionally, we discuss the application of this platform to other membrane targets, the benefits and limitations of this approach, and possible future directions.

4:10 pm

Targeted Protein Stabilization Rescues Distinct Ion Channel Diseases

Henry M. Colecraft, PhD, Professor, Pharmacology, Columbia University

Impaired protein stability or membrane trafficking underlies diverse ion channelopathies and represents an unexploited unifying principle to develop common treatments for otherwise dissimilar diseases. Ubiquitination limits ion channel surface density, but targeting this pathway for basic study or therapy is challenging because of its prevalent role in proteostasis. We developed engineered deubiquitinases that enable ubiquitin chain removal selectively from target proteins to rescue functional expression of disparate mutant ion channels underlying Long QT syndrome and cystic fibrosis. This talk will focus on targeted deubiquitination as a powerful protein stabilization method to correct diverse diseases caused by impaired ion channel trafficking.

4:40 pm Interactive Discussions

Interactive Discussions are informal, moderated discussions, allowing participants to exchange ideas and experiences and develop future collaborations around a focused topic. Each discussion will be led by a facilitator who keeps the discussion on track and the group engaged. For in-person events, the facilitator will lead from the front of the room while attendees remain seated. For virtual attendees, the format will be in an online networking platform. To get the most out of this format, please come prepared to share examples from your work, be a part of a collective, problem-solving session, and participate in active idea sharing. Please visit the website's Interactive Discussions page for a complete listing of topics and descriptions.

IN-PERSON INTERACTIVE DISCUSSION: Optimization of Antibody Screening and Characterization at Early Stages of Antibody Discovery Process

Jane Seagal, PhD, Research Fellow, Drug Discovery Science & Technology, AbbVie
  • Binding specificity vs functional and analytical screens: throughput, depth, timing to enable optimal screens and data driven decisions
  • Building screening funnels without ‘perfect’ reagents
  • Multi-specific format screening: can monoclonal antibody screens guide optimal domain selections for building multi-specific biologics​
5:25 pm Welcome Reception in the Exhibit Hall with Poster Viewing
6:25 pm Close of Day

Wednesday, September 29

7:30 am Registration Open and Morning Coffee
7:55 am

Chairperson’s Remarks

Janna Bednenko, PhD, Head, Protein Expression and Genetics, TetraGenetics

OVERCOMING ANTIGEN CHALLENGES

8:00 am

Nanobody Tethering to Explore GPCR Pharmacology

Ross Cheloha, PhD, Investigator, Chemical Biology of Signaling Section, Laboratory of Bioorganic Chemistry, National Institutes of Health

Antibodies conjugated to bioactive compounds allow targeted delivery of therapeutics. We present a new type of conjugate that consists of a nanobody and a peptidic ligand for a G protein-coupled receptor (GPCR) which show biological activity superior to that of the parent fragment peptide in vitro and in mice. This approach can yield new ligands for cell surface receptors with properties superior to those previously provided by chemistry or nature.

8:30 am

Challenges and Design Considerations for Coronavirus Antigens

Xiaofeng Xin, PhD, Principal Research Scientist I, AbbVie

Evolution of SARS-CoV-2 spike was slow at the beginning of pandemic. However, now major escape variants emerge which makes antigen generation highly challenging but rewarding if we develop therapeutics targeting the SARS-CoV-2 variants and other emerging coronaviruses. Achieving these goals requires strategic design of high-quality antigens that can be used as immunogens or screening reagents. This presentation will describe the challenges and present our design strategies for our pan-coronavirus program.

Janna Bednenko, PhD, Head, Protein Expression and Genetics, Tetragenetics

At TetraGenetics, Inc., we have developed a strategy for identifying functionally modulating antibodies targeting human ion channels. High-yield production of human channels using Tetrahymena thermophila-based TetraExpress platform is combined with a multi-platform antibody discovery approach, followed by screening and characterization in mammalian cells. We describe the discovery of monoclonal antibodies that modulate the activity of voltage-gated channels Kv1.3 and Nav1.8. 

9:30 am Coffee Break in the Exhibit Hall with Poster Viewing
10:10 am

New Approaches for Conditionally Activated Antibodies and Extracellular Degraders

James A. Wells, PhD, Professor, Departments of Pharmaceutical Chemistry and Cellular & Molecular Pharmacology, University of California, San Francisco

Despite the high specificity of antibodies for protein targets, being able to target antigens specifically altered in the tumor environment has been challenging. Proteolysis is a driver of cancer and inflammation and we have developed new proteomics means to identify novel proteolytic events on cell surface proteins (Weeks et al., PNAS 2021). We have further shown it possible to target proteolytic neo-epitopes on cancer associated membrane proteins. In addition to binding membrane proteins with antibodies, we have recently shown it possible to degrade them by recruiting transmembrane E3 ligases to proteins of interest using bi-specific antibodies, a biologics technology akin to small molecule PROTACs, we call AbTACs (Cotton et al. JACS 2021).

10:40 am

Targeting Receptor Complexes for Transmembrane Proteins

David Bredt, MD, PhD

Receptors relevant to CNS disorders typically have associated proteins discretely expressed in specific neuronal pathways; these accessory proteins provide a new dimension for drug discovery. Recent studies show that targeting a TARP auxiliary subunit of AMPA receptors selectively modulates neuronal excitability in specific forebrain pathways relevant to epilepsy. Other medicinally important ion channels, gated by glutamate, GABA, and acetylcholine, also have associated proteins, which may be druggable. This emerging pharmacology of receptor-associated proteins provides a new approach for improving drug efficacy while mitigating side effects.

11:10 am Transition to Plenary Keynote

PLENARY KEYNOTE PROGRAM

11:30 am

Plenary Chairperson’s Remarks

An-Dinh Nguyen, Team Lead, Discovery on Target, Cambridge Healthtech Institute
Sunny Al-Shamma, President, Beacon Discovery a Eurofins Company
11:45 am

PLENARY: G Protein-Coupled Receptors and Beta Arrestin-Coupled Receptors: A Tale of Two Transducers

Robert J. Lefkowitz, MD, James B. Duke Professor of Medicine, Professor of Biochemistry, Duke University Medical Center; Investigator, Howard Hughes Medical Institute; 2012 Nobel Laureate in Chemistry

Beta arrestins are ubiquitous multifunctional adaptor proteins which mediate desensitization, endocytosis and signaling of most GPCRs. My lecture will cover how they were discovered as the mediators of rapid GPCR desensitization; the appreciation of their roles in endocytosis and, counterintuitively, as signal transducers in their own right; their roles in biased GPCR signaling and its therapeutic implications; and current understanding of the conformational basis of biased signaling.

12:20 pm LIVE:

Q&A Plenary Discussion

Panel Moderator:
Annette Gilchrist, PhD, Associate Professor, Pharmaceutical Sciences, Midwestern University
Panelist:
Robert J. Lefkowitz, MD, James B. Duke Professor of Medicine, Professor of Biochemistry, Duke University Medical Center; Investigator, Howard Hughes Medical Institute; 2012 Nobel Laureate in Chemistry
12:30 pm

PLENARY: Next-Generation Targeted Molecular Therapies

Alexandra Glucksmann, PhD, President & CEO, Cedilla Therapeutics

Despite decades of work, the need for small molecule-based targeted therapy in oncology is still immense. Amino-acid sequence and structure has been the primary lens to understand protein function, which has limited the reach of some key cancer targets. I highlight how we are accessing key cancer drivers that have been considered undruggable by considering the native full-length protein together with the relevant post-translational modifications, protein-protein interactions, and sub-cellular localization.

1:05 pm LIVE:

Q&A Plenary Discussion

Panel Moderator:
Joe Patel, PhD, Vice President, Structural Biology, Treeline Biosciences
Panelist:
Alexandra Glucksmann, PhD, President & CEO, Cedilla Therapeutics
1:15 pm Enjoy Lunch on Your Own
1:55 pm Refreshment Break in the Exhibit Hall with Poster Viewing
2:35 pm Close of Antibodies Against Membrane Protein Targets – Part 1 Conference
4:40 pm Roundtable Discussions