The Antibody Society

the official website of the antibody society

An international non-profit supporting antibody-related research and development.

AIRR Community 2022 Executive Sub-committee Election

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With each major meeting interval of the AIRR Community, elections are held for leadership positions on the AIRR-C Executive Sub-committee.  This spring, per our governance, we are seeking nominations for Executive SC Chair-Elect and up to three members of the Executive SC.

To nominate an individual to serve on the AIRR-C Executive SC, the nominator as well as the nominee need to be members of the AIRR Community and the nominee must be willing to serve on the AIRR-C Executive SC.  You are welcome (but not required) to nominate as many people as you would like. You can nominate the same person to become Chair-Elect or to become a Member of the Executive SC, and if you want, you can nominate yourself!  Here is our election timeline:

Nominations open: Monday, April 4th, 2022
Nominations close:  Tuesday, April 19th, 2022 Midnight PDT
Nominees contacted by AIRR-C Executive SC Chair to determine interest: Thursday, April 21st, 2022 Midnight PDT
Deadline for nominees to provide short bios and statements of interest: Tuesday, May 3rd, 2022 Midnight PDT
Voting opens: Monday, May 16th, 2022 Noon PDT
Polls close: Wednesday, May 18th, 2022 Midnight PDT
Results announced: Thursday, May 19th, 2022 during the closing session of AIRR-C Meeting VI
Successful candidates will commence their role on the Exec SC commencing Friday, May 20th, 2022 until the next AIRR Community Meeting (interval ~18 months).

Please nominate someone today by clicking this link (AIRR Community members only – you will need to log in)

Targeting two receptors can significantly increase cell specificity

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Antibody Engineering & Therapeutics, held in December 2021, offered many opportunities to hear exciting and informative presentations by experts in the field. We are pleased to present here a summary of a lecture given in the “Immune Cell Recruitment and Redirection” session by Dr. Jonathan Davis. The summary was kindly written by Dr. Czeslaw Radziejewski.

 


Targeting two receptors can significantly increase cell specificity.
Jonathan Davis, Vice President of Innovation and Strategy, Invenra, Inc.

Jonathan Davis presented a talk detailing Invenra’s rationale for generating bispecific antibodies that target two receptors at the same cell and provided some examples of their biological activity. The platform is based on the construct in which CH1/CL domain in one arm is substituted with a domain derived from CH3. This approach produces stable constructs that are easy to purify. The presentation focused on bispecifics referred to as SNIPERs. The idea behind bispecific SNIPERs is to combine two binding arms, both of which having low affinity toward their cellular targets. When both targets are engaged with cognate targets on the cell surface, the avidity effect results in much stronger binding. This approach could potentially address undesirable binding of monospecific antibodies to healthy tissues where tumor antigen is also expressed at lower levels.

Dr. Davis discussed the concept of symmetric synergy and asymmetric synergy. In the case of symmetric synergy both targets are present at about the same density, whereas in asymmetric synergy one target is present in much greater abundance than the other. According to the speaker, for the symmetric synergy to occur the two target molecules have to be in a right orientation, so the epitopes have to be properly oriented in respect to each other, at least most of the time. This necessitates screening large number of antibodies in order to build a bispecific that demonstrates good synergy. With good geometry fit, 100- to 1000-fold increases in affinity can be reached on cells. He cited the IL-2 receptor system as an example of asymmetric synergy found in nature. High affinity IL-2 receptor is a three-part system consisting of alpha, beta, and gamma subunits. The alpha subunit is present in high concentration, but binds IL-2 with low affinity. The alpha subunit with bound IL-2 binds to beta and then to gamma subunits to form a high affinity signaling complex. This process goes in one direction: from alpha to beta and gamma and that is why it is considered asymmetric. Dr. Davis emphasized that Invenra has the ability to generate and screen large number of constructs to select the right candidate for further development.

Invenra is exploring the SNIPER approach for Treg depletion and for the agonism of co-stimulatory receptor for T cells, OX40. In this lecture, Dr. Davis discussed the anti-tumor activity of SNIPER INV721 in neuroblastoma. The marketed antibody therapeutic, dinutuximab, targets disialoganglioside GD2 that is densely expressed on neuroblastoma cells. GD2 is also expressed on melanomas, small cell lung cancers and sarcomas. Dinutuximab causes lysis of GD2-expressing cells and its mechanism of action involves ADCC and CDC. The antibody is very effective, but causes excruciating pain in patients, presumably because the ganglioside is expressed in all tissues, albeit at the much lower levels. As a second target of INV721, Invenra selected the check-point molecule B7H3 (CD276) that is present only on the tumor cells. To reduce affinity for ganglioside GD2, some residues in the existing antibody against the target were mutated, which allowed the generation of SNIPER( INV721) that bound to neuroblastoma cells only if two targets were present, but not either one alone. To test the in vivo binding affinity of the bispecific antibody, INV721 was radiolabeled with 89Zr. Mice bearing GD2/B7H3-expressing tumors were intravenously injected with 89Zr-labeled INV721 and its in vivo biodistribution was monitored via positron emission tomography imaging. 89Zr-INV721- showed elevated accumulation in the tumor with minimal uptake in normal tissues. 89Zr-radiolabeled isotype control antibody displayed significantly lower tumor uptake demonstrating the specificity of INV721. (1) Dr. Davis indicated that one potential extension of the Invenra bispecific antibodies approach would be to convert these molecules into T-cell engagers.

1. Erbe AK et al. Specific Targeting of Tumors Through Bispecific SNIPER Antibodies. J Immunol, May 1, 2020, 204 (1 Supplement) 91.2.

Join us on April 7th for our next webinar, Precision Execution of Bispecifics at Scale from Design to Delivery!

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Thursday April 7, 2022 11am ET / 5pm CET
Speaker: Dr. Lisa Prendergast, Associate Director of Expression System Sciences in Licensing at Lonza

Registration for our next webinar, “Precision Execution of Bispecifics at Scale from Design to Delivery“, is now open!

Novel therapeutic modalities such as bispecific antibodies are increasingly being explored as more effective alternatives to monoclonal antibodies for a range of diseases. Therapeutics such as bispecifics, can have a combinatorial effect by targeting two antigens,  resulting in treatments with enhanced utility, higher efficacy, fewer side effects and less resistance compared to mAbs.

Generating a bispecific antibody, which is correctly and stably paired, is a major production concern. Many solutions require significant changes to native antibody structure, which increases antibody complexity and forces adaptation of downstream processes. While a various platforms have been developed to mitigate Heavy-Light chain (HC-LC) mispairing, there are many other rate limiting steps for efficiently expressing these molecules in a CHO system. bYlok® technology is a design engineering approach that stabilise the interaction between the HC and LC, essentially removing the mispairing problem whilst retaining a more natural antibody structure.

This presentation will introduce you to a mechanistic review of the bispecific pipeline to demonstrate how a various tools and technologies can enable you execute bispecifics.  Case studies will be presented to show how the bYlok® technology can be used to stabilise and select for novel bispecifics from a panel of parental immunotherapeutic mAbs. Our data demonstrates that correct heterodimerisation can be achieved consistently and how standard downstream purification processes can be used during production.

Register here!

Clinical-stage ROR1xCD3 bispecific antibodies with potential for broad cancer specificity

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Antibody Engineering & Therapeutics, held in December 2021, offered many opportunities to hear exciting and informative presentations by experts in the field. We are pleased to present here a summary of a lecture given in the “Immune Cell Recruitment and Redirection” session by Prof. Kerry Chester. The summary was kindly written by Dr. Czeslaw Radziejewski.

Clinical-stage ROR1xCD3 bispecific antibodies with potential for broad cancer specificity.
Kerry Chester, Professor of Molecular Medicine at University College London and CSO of Novalgen.

The leading molecule of Novalgen is NVG-111, a first-in-class tandem T-cell engager in single-chain variable fragment (scFv) format. One arm of NVG-111 targets a T-cell coreceptor, CD3, while the second binds to the tumor-associated tyrosine kinase-like receptor ROR1. ROR1 was cloned in 1992 from a neuroblastoma cell line. (1) The function of ROR1 as a tyrosine kinase is still poorly understood, although some studies show evidence of its intrinsic tyrosine kinase activity. ROR1 is a cell-surface oncofetal antigen, expressed during embryogenesis and largely absent in normal adult organs, with only low-level expression on adipocytes, pancreas, and parathyroid glands. In contrast to the lack of expression in healthy tissues, ROR1 is present in a wide range of cancers and cancer initiating stem cells. It is expressed in both hematological malignancies and in solid tumors. (2)

ROR1 has three extracellular domains: Kringle, Frizzled and Ig-like domain. ROR1 sequences of extracellular domain (ECD) are highly similar between different species. For example, there is 97.6% identity between mouse and human ROR1 ECD. Many years after the initial ROR1 discovery, its ligand was identified as Wnt-5a, one of the Wnt family signaling molecules. Unlike other ROR1 clinical candidates under development, the anti-ROR1 arm of NVG-111 binds to ROR1 Frizzled domain.

Novalgen began the development of NVG-111 by immunizing rats with recombinant extracellular domain of ROR1. The majority of the resulting antibodies bound to Ig-like domain, none bound to Kringle domain, and only one clone (clone F) bound to Frizzled domain. Clone F was selected for further development. Using flow-cytometry, Novalgen demonstrated binding of clone F to a large number of human cancer cell lines. Clone F was humanized and used to format a bispecific scFv with humanized anti-CD3. NVG-111 binds to mouse and to human ROR1 with low nanomolar affinity, but the anti-CD3 arm does not bind to mouse CD3.

In preclinical studies NVG-111 was effective in in-vitro and in an in-vivo mice model of hematological malignancies, and it demonstrated the ability to kill solid tumor in an established PANC-1 mouse xenograft model of human pancreatic carcinoma. NVG-111 also demonstrated killing in models of advanced solid tumors. It eliminated CD44+/CD24- cancer stem cells in a solid tumor model of triple-negative breast cancer. It induced dose-dependent killing in chronic lymphocytic leukemia (CLL) patient samples where patient CLL cells were cocultured with autologous T cells with EC50 in the range of 4-100 pg/ml. NVG-111 showed T cell-mediated killing of mantle cell lymphoma (MCL) cells that was as effective as killing by blinatumomab, which binds CD3 and CD19, but with 2—30% lower levels of cytokine release (measured as interferon gamma) than blinatumomab, suggesting lower risk of cytokine-release syndrome. Toxicity studies performed in mice using AAV expressing NVG-111 showed lack of toxicity at levels 20- to 1000-fold of expected steady-state levels in clinical dose. Because over 90% of CLL/MCL patients are ROR1 positive, the current focus of Novalgen clinical studies are these two hematological malignancies. Importantly, ROR1 is not expressed on normal B cells, therefore risk of B cell aplasia is expected to be reduced.

1. Masiakowski P, Carroll RD. A novel family of cell surface receptors with tyrosine kinase-like domain. J Biol Chem. 1992;267(36):26181-90.

2. Yuming Zhao et al. Tyrosine kinase ROR1 as a target for anti-cancer therapies. Front. Oncol., 11:680834. doi: 10.3389/fonc.2021.680834.

FDA approves anti-LAG-3 relatlimab-rmbw as part of a combination therapy for melanoma

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On March 18, 2022, Bristol Myers Squibb announced that Opdualag a fixed-dose combination of anti-PD-1 nivolumab and relatlimab-rmbw, administered as a single intravenous infusion, was approved by the U.S. Food and Drug Administration (FDA) for the treatment of adult and pediatric patients 12 years of age or older with unresectable or metastatic melanoma.

Relatlimab (BMS-986016, ONO4482) is a human IgG4k antibody that targets LAG-3, which, like PD-1, is an immune checkpoint. Bristol Myers Squibb and Ono have a strategic collaboration agreement to jointly develop and commercialize multiple immunotherapies – as single agents and combination regimens – for patients with cancer in Japan, South Korea, and Taiwan. An marketing authorization application is undergoing evaluation by the European Medicines Agency.

FDA’s approval was based on data from the Phase 2/3 RELATIVITY-047 trial (NCT03470922), which evaluated the effects of relatlimab combined with nivolumab versus nivolumab in a total of 714 patients with previously untreated metastatic or unresectable melanoma. Patients were randomized 1:1 and administered a fixed-dose combination of 160 mg relatlimab and 480 mg nivolumab or 480 mg nivolumab by intravenous infusion every 4 weeks until disease recurrence, unacceptable toxicity or withdrawal of consent. The study’s primary endpoint, progression-free survival (PFS) by blinded independent central review, was met. The median PFS in the group that received both relatlimab and nivolumab (n=355) was significantly longer (10.1 months [95% CI, 6.4–15.7]) than in the group that received nivolumab only (4.6 months [95% CI, 3.4–5.6]; hazard ratio: 0.75 [95% CI, 0.6–0.9]; P = 0.0055). [1]

1. Tawbi HA, Schadendorf D, Lipson EJ, et al. Relatlimab and nivolumab versus nivolumab in untreated advanced melanoma. N Engl J Med. 2022;386:24-34.

Opdualag is the 4th antibody-based therapeutic granted a first approval for marketing in the EU or US in 2022. Explore our searchable table of antibody therapeutics approved in the EU or US for details.