Double resistance arena!

With the approval of the fourth dual-antibody drug in the world, the once "quiet" dual-antibody came to the eve of the outbreak, and the track was evaluated by industry experts as "it has begun to be crowded before it has officially entered the game
.

" Why did the double antibody break out? Is he better than monoclonal antibodies? What's the good thing Who are the runners ahead? Through this article and two articles, a comprehensive understanding of double antibodies

In recent years, major monoclonal antibody drugs have accounted for more than half of the global biopharmaceutical market.
The breakthrough of PD-(L)1 immunosuppressants in the field of tumor therapy has further promoted its development
.

Based on this, innovative strategies such as bispecific/multispecific antibodies and antibody conjugates show great potential for further development

Compared with traditional monoclonal antibodies, the multi-specific antibody strategy of two or more targets has the advantages of more accurate targeting and stronger therapeutic effect, which has fully stimulated the enthusiasm of research and development
.

However, due to high R&D barriers, the number of drugs approved on the market is far less than that of monoclonal antibody drugs

However, with the development of bispecific antibody technology, more and more biotechnology companies around the world have invested in the development of bispecific antibody drugs.
Roche alone has acquired and held nearly 10 clinical-stage products through acquisitions and holdings.
Anti-biological products under research, 10 Amgen, 8 Johnson & Johnson and so on
.

Due to the heavy investment of these giants, the clinical trials of dual antibodies have surged.

In China, in about three years or so, companies researching dual antibodies have sprung up like mushrooms
.

According to incomplete statistics, as of April 30, 2021, 45 double-antibody products are under research, including 25 companies including Hengrui Pharmaceuticals, BeiGene, and Xinda Biological

01 Double antibody advantages and 7 difficulties

01 Double antibody advantages and 7 difficulties

Bispecific antibodies are antibodies that bind two different epitopes to cancer, and their synergistic effects have more advantages than monoclonal antibodies, and they can also mediate a variety of specific biological effects
.

For example: bridging immune cells and tumor cells, killing tumor cells by recruiting and activating immune cells; inhibiting or stimulating multiple signal pathways to play a coordinated effect; with the help of antibody bivalent structure, mediate the formation of protein complexes and exert biological effects, etc.

Since the double antibody does not exist in the natural state, it can only be prepared artificially
.

In the past, the first-generation dual antibodies were obtained through chemical cross-linking or hybridomas

Either method is inseparable from the technology platform
.

Whether there is a technical platform that adapts to the double antibody molecule will have an important impact on the druggability, mismatch rate and stability of the molecule

The dual antibody technology platforms currently in the research and development stage can be roughly divided into two categories: one is the full-length dual antibody against the technology platform containing the Fc fragment, and the other is the dual antibody against the technology platform without the Fc fragment
.
The advantage of the full-length dual-antibody platform is that the preparation process has good solubility and stability, and the efficacy of multiple mechanisms of action enhances the tumor killing effect, and has a longer half-life; the disadvantage is that the preparation process of some structures is more complicated, and the preparation process is likely to have higher polymerization.
Problems such as body, mismatch, and low purification yield
.
Representative products of this type of technology platform include Catumaxomab, Roche’s Crossmab/KIH, AbbVie’s DVD-Ig, Regeneron’s IgG-scFv and so on
.

The latter has the advantages of easy production, high yield, therapeutic effect only through antigen binding, low immunogenicity, lower side effects, and extremely high tissue permeability, which is conducive to the treatment of solid tumors, and the clinical dose is small
.
However, specific purification technology routes need to be developed, the molecular half-life is relatively short, frequent administration is required, and patient compliance is poor
.
This product type is representative of the technology platform Blincyto, Amgen BiTE, Sanofi Nanobody, Affimed TandAb the like
.

At this stage, the difficulties in the preparation process of the double antibody lie in seven levels:

At this stage, the difficulties in the preparation process of the double antibody lie in seven levels:

One is the choice of cell lines.
The glycoforms produced by cell lines such as NS0 and Sp2/0 are highly immunogenic, and human cell lines are susceptible to infection with exogenous and endogenous viruses
.
The lack of protein folding molecular chaperones in microbial cells may be hindered, making protein aggregation and product sequestration in inclusion bodies a common problem
.

The second is the choice of bioreactor, bioreactor type and cultivation mode, cultivation time, supply of metabolic precursors, accumulation of metabolic waste, gas concentration and cultivation temperature
.
These factors may affect product quality
.

The third is the optimization of culture conditions.
As with monoclonal antibodies, the metabolic requirements of the production cells of the double antibodies will also change during the culture process
.
It is necessary to evaluate the environment that is most conducive to cell metabolism by measuring the consumption of medium components during culture
.

The fourth is the production of polymers, and the double antibody has a tendency to form high molecular weight aggregates, which depends on the concentration
.

The fifth is that there are many impurities.
The concentration of product-related impurities produced during the production of bi/multispecific antibodies is usually higher than that during the production of monoclonal antibodies, such as aggregates and variants
.
The physical and chemical properties of these impurities may be highly similar to the product itself, such as hydrophobicity and net surface charge
.
In order to remove these impurities, it is generally necessary to add chromatography steps
.

Sixth is the choice between yield and purification difficulty.
Due to the similarity between the double antibody and its impurity molecules, the resolution of the chromatographic step is usually lower than that of the monoclonal antibody production process
.
To achieve the target purity, high yield may have to be sacrificed, and optimizing these steps may be more difficult than optimizing the monoclonal antibody process
.

The seventh is the difficulty of analysis.
Identifying product-related impurities and clarifying which molecules are in the supernatant is also crucial for the development of an effective purification process
.
Because there are many heavy and light chains, simple gel analysis is not enough
.
Therefore, mass spectrometry is an indispensable tool
.
Due to the higher therapeutic effect of the double antibody, the development of a more sensitive analytical method is also required
.
The core of these is to solve the problem of mismatch between heavy and light chains.
There are currently less than 20 platforms that can solve this problem, including Roche, Eli Lilly, AbbVie, Regeneron, Amgen and other multinational pharmaceutical companies and international companies.
Top biotechnology company
.

02 From a flash in the pan to the launch of four models

02 From a flash in the pan to the launch of four models

As early as the 1960s, in a Science paper, Nisonoff and his collaborators at the Roswell Park Memorial Institute in New York first proposed the original concept of dual antibodies
.
And using pepsin to produce a monovalent antigen-binding fragment Fab that specifically inhibits antigen precipitation, it is speculated that the new technology "attempts to prepare antibodies with two mixed specificities"
.

In 1975, Kohler and Milstein fuse mouse myeloma cells and spleen cells to obtain hybridoma cells that can secrete antibodies and proliferate immortally.
The monoclonal antibody hybridoma technology was established
.
In the 1980s, with the development of hybridoma technology, the research on double antibodies also showed an explosive growth
.

In 1983, Milstein et al.
developed the first double antibody with a complete immunoglobulin G (IgG) structure through Quadroma technology
.
In the following decades, double antibody molecules with different structures were continuously designed, and gradually moved from the laboratory to clinical trials
.

Entering the 21st century, the development of anti-biological molecules has entered a breakthrough period
.
In 2009, the European Union approved the world's first therapeutic double antibody-Catumaxomab targeting, which is a tri-functional double antibody Triomab for the treatment of malignant ascites
.

Source: E-pharmaceutical managers compiled according to public information

Data show that anti-EpCAM and anti-CD3 trifunctional antibodies combine the characteristics of classic monoclonal antibodies and bispecific molecules
.
It is produced by tetrachroma technology and is composed of mouse IgG2a and rat IgG2b
.
One specific antigen binding site binds T cells through CD3, and the other site binds tumor cells through EpCAM antigen
.
The Fc region provides a third functional binding site, which can selectively bind to and activate Fcγ receptor I, IIa or III positive helper cells
.
Catumaxomab does not bind to inhibitory Fcγ receptor type IIb helper cells, which may reduce the activation of certain types of immune cells
.
The interaction of different immune effector cells at the tumor site leads to a complex immune response, leading to the elimination of tumor cells
.
All in all, Catumaxomab enhances the patient's own activation of the tumor immune system
.

The approval of Catumaxomab has greatly promoted the development of double antibodies
.
Clarivate Analytics data show that the number of clinical trials for the development of double antibodies in 2010 doubled from the previous year
.
However, in the early development of Catumaxomab, the concept of the entire immunotherapy is not yet mature, let alone double antibodies
.
This has affected the clinical development concept of Catumaxomab.
At the same time, based on the consideration of R&D cost and speed, the product did not directly choose the indication of abdominal metastasis during clinical development, but chose the easier to develop ascites regression.
This feature makes many Doctors position it as an auxiliary drug with obvious side effects
.

The initial choice was the foreshadowing of Catumaxomab's subsequent coldness in the market
.
After the listing, because its commercial ownership company Fresenius was undergoing a strategic transformation, it did not establish a professional sales team for the product, as well as a reasonable price and marketing plan.
In the first year of listing, it was "dumb", in 2009, Catumaxomab Sales were only 1.
66 million U.
S.
dollars and did not achieve substantial growth in the next three years.
Sales from 2010 to 2012 were 3.
32 million U.
S.
dollars, 4.
43 million U.
S.
dollars, and 4.
54 million U.
S.
dollars
.
Due to poor sales, Catumaxomab bid farewell to the market for the time being in 2017
.

Due to the performance of the first bi-antibody in the market, coupled with the challenges of research and development, the growth rate of bi-antibody research temporarily stagnated
.
Data show that the number of new double-antibody clinical trials from 2011 to 2013 is far less than that in 2010
.

The turning point occurred in 2014.
Blincyto, developed by Amgen, the originator of American biologics, brought hope to the development of the dual-antibody circuit
.
This year, the US Food and Drug Administration accelerated the approval of Blincyto for the treatment of adult patients with Philadelphia chromosome-negative relapsed or refractory precursor B-cell acute lymphoblastic leukemia
.
At the end of 2015, Blincyto received accelerated approval by the European Commission for the aforementioned indications
.
According to the data of its phase II clinical study, after two cycles of Blincyto treatment, 43% of patients achieved complete remission or partial hematological resuscitation
.
This approval also makes Blincyto the world's first anti-CD19 drug and the second dual-antibody drug
.

Data show that Blincyto is a double antibody that targets both CD19 and CD3 molecules.
It can present the CD19 protein on tumor cells to the CD3 protein specifically expressed by T cells, thereby activating the immune system to recognize and kill tumor cells.
The development of the advanced bispecific T cell adapter system BiTE
.
After Blincyto was approved for listing, its market sales have also increased significantly compared to Catumaxomab
.
Sales of the drug in 2016 were US$85 million, and in 2017 it reached US$175 million
.

With this performance, the development of superposition technology once again made the research and development of the dual anti-race track hot again
.
Data show that starting from 2014, the number of new double-antibody clinical trials has resumed rapid growth
.
By 2017, when the third dual-antibody drug, Hemlibra, was launched, the global research and development of dual-antibody products was unprecedentedly hot
.
Data show that in 2017, double-antibody clinical trials increased by 50% compared with the previous year, and in 2018, it increased by 67% to reach the peak (50)
.

In November 2017, Hemlibra was approved by the US FDA for the routine preventive treatment of adults and children with hemophilia A who have produced factor VIII inhibitors in the body to prevent or reduce bleeding events
.
This is the first new drug approved by the FDA to treat hemophilia A containing factor VIII inhibitors in the body in the past 20 years
.
In 2015, the FDA granted Hemlibra priority review qualification and breakthrough therapy designation
.

Hemlibra is a humanized IgG4 monoclonal antibody with a double antibody structure.
It targets coagulation factor Ⅸa and coagulation factor Ⅹ.
It can bridge activated coagulation factors Ⅸ and Ⅹ, thereby restoring coagulation factor Ⅷ that is missing during the coagulation process Function
.

Why can Hemlibra really ignite the global enthusiasm for the development of dual-antibody drugs? On the one hand, it is related to the maturity of the dual antibody technology, on the other hand, thanks to its good curative effect, it performs well in the market
.
Data show that since Hemlibra went public, sales have increased rapidly, and its growth rate in 2019 has increased by more than 500% to 1.
704 billion US dollars
.
In 2020, even if affected by the epidemic, its sales will still reach US$2.
335 billion, ranking 61st as the only dual-antibody drug to enter the global TOP100 drug sales list
.

As the double-antibody technology becomes more and more mature, the three previously-marketed double-antibody drugs are all developing in a better direction
.
According to relevant media reports, Catumaxomab has restarted European GMP production in 2018.
The inventor of the drug, Dr.
Horst Lindhofer, believes that in addition to the approved indications, Catumaxomab also has excellent performance in advanced gastric cancer and bowel cancer, and decided to cooperate with China Cooperation
.
In 2017, Dr.
Horst Lindhofer and Dr.
Xiao Shen founded Ling Teng Pharmaceutical in Hangzhou.
According to CDE data, Catumaxomab has been approved for clinical use, and the indication is “the treatment of advanced gastric cancer with peritoneal metastasis that is not suitable for systemic therapy”
.
The company plans to apply for listing in China in 2021 and apply for additional indications in 2022
.
It is currently in the marketing authorization stage in Europe
.

In 2018, Blincyto expansion is indicated to treat children with B-cell precursor acute lymphoblastic leukemia and remission but still have minimal residual disease MRD
.
So far, Blincyto is still the only drug approved for the treatment of MRD-positive ALL patients.
The detection of residual cancer cells after complete remission is the strongest prognostic factor for assessing the recurrence of the disease
.
It has been approved in more than 50 countries around the world
.
And through the Amgen partner company BeiGene introduced into China and was approved for listing
.

On May 21, 2021, the FDA accelerated the approval of the EGFR/c-Met dual antibody Rybrevant (amivantamab-vmjw) developed by Johnson & Johnson's Janssen Pharmaceuticals for the treatment of epidermal growth factor receptors confirmed by the FDA-approved test (EGFR) exon 20 insertion mutations in locally advanced or metastatic non-small cell lung cancer (NSCLC) patients, these patients have disease progression during or after platinum-based chemotherapy.
It is the fourth dual antibody marketed in the world.
It has been 4 years since a double antibody was approved for marketing
.

03 Eve before the outbreak

03 Eve before the outbreak

In the past ten years, the number of double-antibody clinical trials newly started each year around the world has been increasing year by year, and it is currently in the rapid development stage of double-antibody drug research and development, and the next or the scenario of centralized marketing of double-antibody drugs will be ushered in
.

According to incomplete statistics, 131 dual-antibody drugs are currently in the international multi-center clinical stage
.
In terms of indications, 88% of drugs currently in the clinical stage are deployed in the tumor field, of which solid tumors account for 59% and hematomas account for 29%; followed by autoimmune diseases, accounting for 8%; from targeted cells In terms of type, cytotoxic effector cell redirecting antibodies accounted for more than half; from the perspective of whether there are Fc segments, 78% are double antibodies with Fc segments
.

With the increase in the development of double antibodies, the number of transactions excluding mergers and acquisitions has been concentrated on double antibodies in the clinical stage, resulting in an increase of 140% in the last 3 years, while the total value of the disclosed transactions has dropped by 50% from 2007 to 3.
2 billion.
Reduced to 1.
6 billion U.
S.
dollars
.

Clarivate Analytics expects that with the large-scale sales growth of Hemlibra, the drug will grow to 3.
96 billion US dollars by 2024
.
With the approval of new entrants such as faricimab, greemubamab, MCLA-117 and XmAb-14045, the double antibody market will exceed US$5.
43 billion in 2024
.

With the development of dual-antibody drug research, a new generation of anti-angiogenesis treatment methods are emerging
.
For example, AbbVie has 12 related projects under active development
.
Most projects focus on improving the anti-angiogenesis effect by jointly targeting two or even three molecules involved in angiogenesis, such as VEGF, VEGFR2, DLL4 and ANGPT2
.
Among them, Dilpacimab, which targets DLL4 and VEGF, is one of the most advanced projects in this class of drugs
.
Dilpacimab is designed to jointly inhibit DLL4 and VEGF signaling in order to obtain a more significant anti-tumor effect
.
The data show that in the presence of VEGF, Dilpacimab's ability to block the DLL4 signaling pathway is increased by 20-50 times
.

At the level of anti-tumorogenesis, anti-tumorogenesis by targeting oncogenic receptors is another well-proven anti-cancer treatment
.
Pertuzumab and trastuzumab are both drugs for the treatment of HER2 breast cancer.
In order to develop an ideal combination therapy for trastuzumab and pertuzumab, some of the two pairs in early clinical testing are currently under way.
In situ Her2 double antibody plan
.
The ZW25 introduced by BeiGene from Zymeworks is a dual-in-situ Her2 double antibody designed based on the Azymetric platform.
It is currently in clinical phase II, while Tianguangshi’s same-target products are in clinical phase I, and other advanced products.
there Merus of MCLA-128 (HER3 × HER2) , Johnson two products (EGFR × cMET) in stage ⅰ
.

In the direction of enhancing tumor immunity, it is also the direction in which double antibodies are widely used
.
The current anti-CTLA-4 and anti-PD-(L)1 drug treatments have shown encouraging effects and have completely changed the treatment of cancer
.
In order to further improve the anti-tumor efficacy and reduce the toxic and side effects of CTLA-4, scientists began to consider combining two monoclonal antibodies to achieve an additive effect
.

So far, there are more than a dozen double antibodies against multiple inhibitory immunomodulatory pathways (such as PD-1, CTLA-4, LAG-3, TIM-3, etc.
) in the clinically active development stage, and the fastest is from Two Chinese companies, namely Kangfang Bio's AK104 (PD-1×CTLA-4), according to its latest clinical display, the registration of the drug for the treatment of recurrent or metastatic cervical cancer in China has been completed.
If the follow-up progresses smoothly, it is expected to become the world's first new PD-1-based bispecific antibody drug, and this will also be the first approved bispecific antibody drug independently developed by China
.
Corning Jerry’s KN046 (PD-1×CTLA-4) was approved by the FDA in April last year for a phase II clinical trial for non-small cell lung cancer (NSCLC)
.
Currently, there are about 20 clinical trials of this product in China, the United States and Australia covering more than 10 types of tumors in multiple stages, including liver cancer, pancreatic cancer, triple-negative breast cancer, esophageal cancer and thymic cancer
.
The results of clinical trials showed that KN046 has good safety and preliminary effectiveness
.

The rest of the rapid progress is Regeneron’s REGN (PSMA×CD28), which is in clinical phase I/II, and more than a dozen products in clinical phase I, such as Eli Lilly/Cinda’s IBI-318 (PD-1 × PD-L1), F- star of PD-L1 × LAG-3, MacroGenics / re a ding pharmaceutical PD-1 × LAG-3, Xencor 's PD-1 × ICOS, MSLN × CD40 Abbvie the like
.

In summary, as a derivative of monoclonal antibodies, bispecific antibodies are regarded as prospective drugs in the treatment of tumors and autoimmune diseases.
At present, there are still certain technical difficulties in their technology and industrialization
.
However, based on global biotechnology companies' massive investment in the development of bispecific antibody drugs, it is expected to open a new route to the treatment of large-variety, multi-indication diseases
.
Domestic dual antibodies currently have a certain technical basis, and it is possible to achieve "curve overtaking" on a specific drug
.
But on the whole, whether it is the choice of target, the connection method of the dual antibodies and the indication direction, there is a big gap with the international first-class level, especially in the patent layout
.