nanobody

Nanoantibody Development Shows Momentum —Join the Dance Now Or Play Catch-up Forever

Oct 8, 2017, San Diego, CA: Last week, Belgian company Ablynx Inc. announced IPO plans based on robust results from a Phase III study with caplacizumab, the very first nanoantibody drug ready for market.

Caplacizumab targets von Willebrand factor (vWF), will benefit patients afflicted with acquired thrombotic thrombocytopenic purpura (aTTP), a life-threatening autoimmune blood clotting disorder.

The Phase III study (named as HERCULES) met the primary endpoint, namely a statistically significant reduction in time to platelet count response in patients, besides providing standard-of-care. Patients on caplacizumab were 1.5 times more likely to achieve platelet count response at any given time point, compared to placebo control. In addition, the study also met two key secondary endpoints, namely, a 74% reduction in the percentage of patients with recurrence of aTTP or related death, and absence of any major thromboembolic event during study. In addition, the proportion of patients with a recurrence of aTTP during the study period (including the 28 day follow-up period after discontinuation of the drug) was 67% lower in the caplacizumab arm compared to the placebo arm, demonstrating the sustained benefits from the treatment.

Ablynx immediately sought to capitalize the outstanding clinical benefits provided by caplacizumab. On the same day of publicizing their clinical trial results, Ablynx announced filing of a Registration Statement on Form F-1 with the U.S. Securities and Exchange Commission for a proposed stock offering (IPO in the US in the form of American Depositary Shares (“ADSs”) and private placement of ordinary shares in Europe). Ablynx plans to obtain $150 million to finance its commercialization of their new nanoantibody in the U.S. and Europe. With the new developments, the company also expects to accelerate the clinical development of other nanoantibodies, including ALX-0171 which targets respiratory syncytial virus (RSV) infection.

With these exciting news out on the market, now is a great time for the traditional players in the pharmaceutical industry to take a good look and seriously evaluate the possibility to add nanoantibody to their development portfolio. The time is now because success of the new Ablynx drug has minimized the investment risk by proving the feasibility, potential, and advantages of nanoantibodies. The time is now because the field of therapeutic nanoantibodies is still wide open, unlike other crowded, highly competitive arena of conventional antibodies. The time is now, also because with nanoantibodies just starting to get onto the map, an investment in nanoantibodies has the potential of delivering extraordinary returns.

Allele is actively involved in the preclinical development of therapeutic nanoantibody for the past several years, and has accumulated significant IP and technological know-how in this space, and a dozen or so programs ranging from oncology to inflammation. We have a high-speed new technology by which we can get dozens of new nanoantibodies per year, and a pipeline by which we routinely perform humanization, bi- or multi-valency, and expression optimization. We welcome inquiries into our development program, collaboration or joint development proposals, and in exploring investment opportunities with us.

Contact Alleleblog or the Allele nAb team: Dr. Jenny Higginbotham, jhigginbotham@allelebiotech.com; Dr. Nobuki Nakanishi, nnakanishi@allelebiotech.com

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A breakdown of your burning nAb questions

Allele Biotechnology just released its latest batch of nAbs (nano antibodies), the first wave on a long list of new antibodies to come! You might have a few questions about how these “antibodies of the future”, as we call them, can help your research:  What can I use them for?  How much should I use?  And how do they work compared to a traditional antibody? 
 
To answer these questions, we need to first discuss some antibody basics.  Conventional antibodies (your typical mouse or rabbit derived antibody) have a “Y” shape and tightly bind targeted antigens as a result of two factors.  The first is affinity between each monomer Fab fragment and the antigen.  The second is the fact that traditional antibodies are di-valent, i.e. they have two identical binding sites for each antigen, which is known as avidity. 
 
When developing a nano-antibody, we screen and select our clones to have extremely high affinity as a monomer.  This is because nAbs are mono-valent VHH fragments. The intrinsic high affinity VHHs possess for their antigens can make up for the lack of multivalency (avidity).  As a result, nAb binding is often superior to conventional antibody binding, which leads to superior performance in a variety of biological assays (immunoprecipitation, immune-staining, FACS staining, immunofluorescent imaging, etc.). 
 
Each nAb is roughly one tenth (1/10) the size of a traditional antibody.  The small size and stable conformation of nano-antibodies enable pinpointed localization of target antigens and allow access to antigen and cellular regions generally restrictive to larger antibodies. As a result of this smaller size, when measured by weight 1mg of a nAb is equivalent to 5 – 10mg of a traditional antibody (the lower end takes di-valency into account).  When substituting a nAb for a traditional antibody you can use as little as one tenth (1/10) the amount by weight. 
 
There are a couple of different ways to use nAbs.  The first is immobilizing the nano-antibody on a resin (i.e. magnetic-agarose resin) for immunoprecipitation.  The nano-antibody will not be released from the resin upon elution so you will not have contaminating bands.  The second method is direct labeling with a fluorescent dye or hapten.  nAb’s are compatible with standard NHS-ester amine chemistry binding.  This enables single or multiple fluorophore labeling per antibody.  Moving forward, additional platforms will be released that allow for a more flexible and adaptable labeling system, allowing you to harness nAbs for any biological assay you can imagine.  Have some suggestions? Don’t hesitate to let us know by emailing at nAb@allelebiotech.com. Or call 858-587-6645 and ask for a nAb expert.

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Press Release: Allele Biotech Takes Major Step into Nano Antibody Leadership Position

SAN DIEGO–(BUSINESS WIRE)–Allele Biotechnology & Pharmaceuticals Inc., a San Diego based life sciences company with a focus on novel technology development, releases the first group of a brand new class of antibodies against crucial biological targets to the research market. This week, Allele launches nano-antibodies isolated from llamas against human bFGF, P16, VEGF, and TNFa, which are all important targets in the field of cancer biology.

Nano-Antibodies (also known as nAb™, Nanobodies®, Single Domain Antibodies, Camelid Antibodies and VHH antibodies) represent the future in antibody technology of Allele’s interest. “Camelid antibodies have been an area of intense research activities at Allele because they have desirable features that no other antibody has. These tiny antibodies outperform conventional antibodies in many ways and thrive in extreme conditions, eventually they will occupy a significant portion of the antibody reagent market,” said Dr. Jiwu Wang, CEO and founder of Allele Biotechnology. This first wave of novel reagents has been meticulously tested for immunohistochemistry (IHC) in human cancer tissues; some of these antibodies also performed well in cross-species reactivity in mouse and rat while others are highly suitable for advanced applications such as flow cytometry and antigen immunoprecipitation.

This is the first release in a long-term effort to generate and commercialize hundreds of nano-antibody derived capture tools. “Our nano-antibody project is based on years of internal technology development partially funded by the National Institute of Drug Abuse of the NIH,” according to Allele’s Marketing Director, Abbas Hussain. “The nAb product line will shortly encompass a wide range of high value targets that are applicable to both basic and clinically relevant research. It will also feature cutting edge conjugation technologies that enable fluorescent imaging and electron microscopy techniques being developed at Allele.”

Since the ability to generate monoclonal antibodies was discovered in 1975, antibodies have been used in virtually every branch of biomedical research and development. In the past decade there has been a shift toward harnessing antibody technology for therapy, as illustrated by large number of antibody-based drugs on the market today. Allele’s nAb development has been one of the targets of investment from Yifang Ventures and Yuan Capital.

“Nanobodies® is a trademark of Ablynx; nAb as nano antibodies is under copyright of Allele Biotechnology, all rights reserved.”
Contacts

Allele Biotechnology & Pharmaceuticals Inc.
Abbas Hussain, 858-587-6645
Director of Sales & Marketing
6404 Nancy Ridge Dr.
San Diego, CA 92121
abbashussain@allelebiotech.com

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When Great is not Good Enough—VHH Antibodies Engineered for 10 Fold Affinity Increase

Single Domain antibodies (VHH fragments, nanobodies, or as we call them, nAbs) have been generated by injecting llamas with ligand-bound GPCR for the purpose of obtaining crystals of active-state structures. Such structural information could be critical in understanding drug functions and screening for new drugs. The unique ability of VHH fragments to fit into protein-protein complex crevices and hold proteins together was demonstrated by two Nature publications from Brian Kobilka’s group at Stanford ([1, 2], also see Allele Newsletter of Sep 4th, 2013). The nano antibody used in those studies, Nb80, showed affinity towards only the active state of the target GPCR.

However, even with an antibody as great as Nb80, the authors were only able to co-crystal GPCR beta2-adrenoceptor (b2AR) with high affinity agonists, not its natural agonists such as adrenaline. In yet another Nature paper published just now, the Kobilka lab showed that Nb80 could be further improved by 10 times in affinity, through in vitro evolution [3]. They presented Nb80 on the surface of yeast using an existing yeast display system, then applied standard limited mutagenesis and magnetic separation technologies for screening. After about 5 rounds of selection, a new version of VHH Nb6B9 was isolated that bound to ligand-loaded GPCR with a kD of 6.4 nM. For the first time, a co-crystal of b2AR-adrenoline was made.

Rasmussen et al. Nature, 2011 Structure of a nanobody-stabilized active state of the b2 adrenoceptor
Rasmussen et al. Nature, 2011 Crystal structure of the b2 adrenergic receptor–Gs protein complex
Ring et al. Nature, 2013 Adrenaline-activated structure of b2-adrenoceptor stabilized by an engineered nanobody

Update here http://www.allelebiotech.com/nab

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Camelid Antibodies

When it was discovered that animals in the camel family produce antibodies with no light chains, the idea that a single-domain fragment can bind as well as a full 4-chain antibody formed a breakthrough. So far it has been a relatively less known one.

Smaller antibody fragments have been tested for therapeutic uses because classical IgG antibodies are too bulky to penetrate tissues well, and very expensive to produce. Different combinations of antigen-binding variable regions are used, e.g. scFv, Fab, diabody, all to some degree of success. In comparison, the N-terminal domain of camelid antibodies, termed VHH domain (nanobody, VHH antibody), represents a naturally evolved, only 13-15 kD in size, fully functional target binding fragment with many advantages.

The only other known species outside camelidae family that has heavy chain antibodies is particular cartilaginous fish, nurse shark. Although the arrangement of CDRs is somewhat different between the camel and shark heavy chain variable regions, they share many characteristics such as extremely high stability (maintaining functions after100 C heat and extreme pH treatment).

Accumulating reports have demonstrated the therapeutic potentials of camelid antibody-based fragments in treating cancer, neural diseases, even use in hair dandruff preventing shampoo. For basic research, the tiny antigen binders can be used as tools for quantitative pull down with unmatched efficiency, recognizing previously inaccessible enzyme cleft as antigens, and providing libraries for binding partner selection.

Allele Biotech has been working on display antibody selection from its early days through an NIH grant, and recently carried out an NIH/NCI contract for scFv yeast display.

Check out Allele’s current Camelid antibody products: http://www.allelebiotech.com/allele3/CM.php

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