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The Antibody Society

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

Most read from mAbs, May-June 2019

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The Antibody Society is pleased  to be affiliated with mAbs, a multi-disciplinary journal dedicated to advancing the art and science of antibody research and development. We hope you enjoy these summaries based on the abstracts of the most read papers published in a recent issue.

All the articles are open access; PDFs can be freely downloaded by following the links below.

Issue 11.4 (May-June 2019)

Combining the best of two worlds: highly flexible chimeric antigen receptor adaptor molecules (CAR-adaptors) for the recruitment of chimeric antigen receptor T cells.

In this review, Darowski et al. summarize emerging approaches that aim to further evolve CAR-T cell therapy based on combinations of so-called universal or modular CAR-(modCAR-)T cells, and their respective adaptor molecules (CAR-adaptors), which mediate the crosslinking between target and effector cells. The activity of such modCAR-T cells is entirely dependent on binding of the respective CAR-adaptor to both a tumor antigen and to the CAR-expressing T cell. Contrary to conventional CAR-T cells, where the immunological synapse is established by direct interaction of CAR and membrane-bound target, modCAR-T cells provide a highly flexible and customizable development of the CAR-T cell concept and offer an additional possibility to control T cell activity.

Efficient tumor killing and minimal cytokine release with novel T-cell agonist bispecific antibodies.

Using a sequence-based discovery platform, Trinklein et al. identified new anti-CD3 antibodies from humanized rats that bind to multiple epitopes and elicit varying levels of T-cell activation. In T-BsAb format, 12 different anti-CD3 arms induce equivalent levels of tumor cell lysis by primary T-cells, but potency varies by a thousand-fold. The lead CD3-targeting arm stimulates very low levels of cytokine release, but drives robust tumor antigen-specific killing in vitro and in a mouse xenograft model. This new CD3-targeting antibody underpins a next-generation T-BsAb platform in which potent cytotoxicity is uncoupled from high levels of cytokine release, which may lead to a wider therapeutic window in the clinic.

Sym021, a promising anti-PD1 clinical candidate antibody derived from a new chicken antibody discovery platform.

In this study by Gjetting et al., the Symplex antibody discovery platform was adapted to chicken immunoglobulin genes and combined with high-throughput humanization of antibody frameworks by “mass complementarity-determining region grafting”. Wild type chickens were immunized with an immune checkpoint inhibitor programmed cell death 1 (PD1) antigen, and a repertoire of 144 antibodies was generated. The PD1 antibody repertoire was successfully humanized, and the authors found that most humanized antibodies retained affinity largely similar to that of the parental chicken antibodies. The lead antibody Sym021 blocked PD-L1 and PD-L2 ligand binding, resulting in elevated T-cell cytokine production in vitro. Detailed epitope mapping showed that the epitope recognized by Sym021 was unique compared to the clinically approved PD1 antibodies pembrolizumab and nivolumab. Moreover, Sym021 bound human PD1 with a stronger affinity (30 pM) compared to nivolumab and pembrolizumab, while also cross-reacting with cynomolgus and mouse PD1. This enabled direct testing of Sym021 in the syngeneic mouse in vivo cancer models and evaluation of preclinical toxicology in cynomolgus monkeys. Preclinical in vivo evaluation in various murine and human tumor models demonstrated a pronounced anti-tumor effect of Sym021, supporting its current evaluation in a Phase 1 clinical trial.

Anti-IL17 netakimab registered in Russia

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On May 7, 2019, BIOCAD announced the registration of netakimab (Efleira®, BCD-085) in Russia for the treatment of moderate to severe plaque psoriasis. Netakimab is a humanized IgG1 monoclonal antibody (mAb) in which the VH domain is replaced by a Lama glama VHH domain possessing a long complementarity-determining region (CDR-H3).  The mAb targets interleukin (IL)-17, a pro-inflammatory cytokine that plays a critical role in the pathogenesis of psoriasis. The registration is the first for an innovative mAb developed in Russia.

The efficacy and safety of Efleira® in psoriasis patients was confirmed in the Phase 3 BCD-085-7/PLANETA study (NCT03390101), which was conducted in 22 certified study sites in Russia and 2 study sites in the Republic of Belarus. After 12 weeks of the treatment, 83.3% of patients who received netakimab once a month after induction for the first 3 weeks achieved a 75% improvement in Psoriasis Area and Severity Index. The total duration of therapy and follow-up in this study is 3 years.

BIOCAD, which is based in Moscow, is planning to start a pivotal clinical trial of netakimab in psoriasis in Europe later in 2019.

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Student/Post-doc Poster Competition Winners Announced!

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The Antibody Society sponsors a competition for our student/postdoc members who submit posters for display at Antibody Engineering & Therapeutics Europe. Our judges select the best work based on originality, relevance and perceived impact on the field of antibody R&D.

This year, our judges selected 2 student winners who each receive complimentary registration to attend the conference and pre-conference sessions and support for travel expenses.

The winners of the contest are:

Roberta Lotti (Post-doctoral fellow, University of Modena and Reggio Emilia, Italy).
Poster title: Neutralization of soluble Fas Ligand (sFasL) blocks blister formation without immunosuppression in pemphigus: development of PC111, a new monoclonal anti-FasL antibody

Amiram Sananes (Ph.D. candidate, Ben-Gurion University, Israel).
Poster title: A selective, proteolysis-resistant inhibitor of kallikrein-related peptidase 6 (KLK6) for cancer therapy and imaging, developed by combinatorial engineering

Congratulations to our winners!

Antibody Engineering & Therapeutics Europe will be held June 11-13, 2019, at the Postillion Hotel Amsterdam, the Netherlands. We hope to see you there!

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Risankizumab-rzaa granted FDA approval

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On April 23, 2019, the US Food and Drug Administration approved risankizumab-rzaa (SKYRIZI™) for the treatment of moderate to severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy. Risankizumab is a humanized IgG1 monoclonal antibody that inhibits interleukin (IL)-23, a cytokine involved in inflammatory processes, by binding to its p19 subunit. SKYRIZI is part of a collaboration between Boehringer Ingelheim and AbbVie, with AbbVie leading development and commercialization of SKYRIZI globally.

The product’s approval is supported by data from four randomized, placebo and/or active-controlled pivotal studies, ultIMMA-1, ultIMMa-2, IMMhance and IMMvent, that evaluated the safety and efficacy of risankizumab in more than 2,000 patients with moderate-to-severe chronic plaque psoriasis. The co-primary endpoints of the studies were Psoriasis Area and Severity Index and static Physician Global Assessment [sPGA] score of clear or almost clear [sPGA 0/1] at 16 weeks versus placebo. In these four studies, all co-primary and ranked secondary outcome measures were met and no new safety signals were observed. Results of the UltIMMa-1 (NCT02684370) and UltIMMa-2 (NCT02684357) studies were reported in The Lancet. Risankizumab was previously approved in Japan and Canada, and a marketing authorization application for risankizumab is currently undergoing regulatory review in the European Union.

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The Antibody Society maintains a comprehensive table of approved mAb therapeutics and those in regulatory review in the EU or US. Please log in to access the table, which is located in the Members Only section and can be downloaded in Excel format. Information about other antibody therapeutics that may enter regulatory review in 2019 can be found in ‘Antibodies to watch in 2019’.

Most read from mAbs, April 2019

by

The Antibody Society is pleased and proud to be affiliated with mAbs, a multi-disciplinary journal dedicated to advancing the art and science of antibody research and development. We hope you enjoy these summaries based on the abstracts of the most read papers published in a recent issue. All the articles are open access; PDFs can be freely downloaded by following the links below.

Issue 11.3 (April 2019)

CH2 domain orientation of human immunoglobulin G in solution: Structural comparison of glycosylated and aglycosylated Fc regions using small-angle X-ray scattering

Yageta et al examined the small-angle X-ray scattering (SAXS) profile of the glycosylated Fc region (gFc) and aglycosylated Fc region (aFc) in solution to determine if removal of the N-linked glycan alters the CH2 domain orientation in the Fc region. For both gFc and aFc, the best-fitted SAXS profiles corresponded to ones calculated based on the crystal structure of gFc that formed a “semi-closed” CH2 domain orientation. Collectively, the data indicated that the removal of the N-linked glycan only negligibly affected the CH2 domain orientation in solution. Their findings will guide the development of methodology for the production of highly refined functional Fc variants.

Charge variants characterization and release assay development for co-formulated antibodies as a combination therapy

Characterization of co-formulated biologics can be challenging due to the high degree of similarity in the physicochemical properties of co-formulated proteins, especially at different concentrations of individual components. In this new report, Cao et al present the results of a deamidation study of one monoclonal antibody component (mAb-B) in co-formulated combination antibodies (referred to as COMBO) that contain various ratios of mAb-A and mAb-B. A single deamidation site in the complementarity-determining region of mAb-B was identified as a critical quality attribute (CQA) due to its impact on biological activity. A conventional charge-based method of monitoring mAb-B deamidation presented specificity and robustness challenges, especially when mAb-B was a minor component in the COMBO, making it unsuitable for lot release and stability testing. The authors developed and qualified a new, quality-control-friendly, single quadrupole Dalton mass detector (QDa)–based method to monitor site-specific deamidation. Their approach can be also used as a multi-attribute method for monitoring other quality attributes in COMBO. This analytical paradigm is applicable to the identification of CQAs in combination therapeutic molecules, and to the subsequent development of a highly specific, highly sensitive, and sufficiently robust method for routine monitoring CQAs for lot release test and during stability studies.

Capture and display of antibodies secreted by hybridoma cells enables fluorescent on-cell screening

Puligedda et. al describe a system in which hybridomas specifically capture and display the mAbs they secrete. Using On-Cell mAb Screening (OCMS™), monoclonal antibodies (mAbs) displayed on the cell surface can be rapidly assayed for expression level and binding specificity using fluorescent antigens with high-content (image-based) methods or flow cytometry. OCMS™ demonstrated specific mAb binding to poliovirus and rabies virus by forming a cell surface IgG “cap”, as a universal assay for anti-viral mAbs. The authors produced and characterized OCMS™-enabled hybridomas secreting mAbs that neutralize poliovirus and used fluorescence microscopy to identify and clone a human mAb specific for the human N-methyl-D-aspartate receptor. They also used OCMS™ to assess expression and antigen binding of a recombinant mAb produced in 293T cells.

Physicochemical and functional assessments demonstrating analytical similarity between rituximab biosimilar HLX01 and the MabThera®

As discussed by Xu et al, development of bio-therapeutics has exhibited exponential growth in China over the past decade. However, no biosimilar drug has been approved in China (CN) due to the lack of a national biosimilar regulatory guidance. HLX01, a rituximab biosimilar developed in China under European Medicines Agency biosimilar guidelines and requirements, was the first such drug submitted for regulatory review in China, and it is expected to receive approval there as a biosimilar product. To demonstrate the analytical similarities of HLX01, CN-rituximab (sourced in China but manufactured in Europe) and EU-rituximab (sourced and manufactured in Europe), an extensive 3-way physicochemical and functional similarity assessment using a series of orthogonal and state-of-the-art techniques was conducted, following the similarity requirement guidelines recently published by China’s Center for Drug Evaluation. The results of the similarity study showed an identical protein amino acid sequence and highly similar primary structures between HLX01 and the reference product (RP) MabThera®, along with high similarities in higher order structures, potency, integrity, purity and impurity profiles, biological and immunological binding functions, as well as degradation behaviors under stress conditions. In addition, HLX01 presented slightly lower aggregates and better photostability compared with the RP. Despite slight changes in relative abundance of glycan moieties and heavy chain C-terminal lysine modification, no differences in biological activities and immunological properties were observed between the RP and HLX01. In conclusion, HLX01 is highly similar to CN- and EU-sourced RP in terms of physicochemical properties and biological activities, suggesting similar product quality, efficacy, and safety. The regulatory requirements interpreted and applied towards the HLX01 marketing application sets a precedent for analytical similarity assessment of biosimilar products in China.

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