Facing the challenge of "no medicines available", a new wave of RSV drugs in research is progressing!

Winter is here, and respiratory diseases caused by viral infections are about to stir
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Among them, there is a special type of respiratory infection, which is more dangerous than ordinary flu and almost "no medicine is available".

Another winter, the RSV threat is approaching

Respiratory syncytial virus (RSV) is a very common infectious pathogen that can cause seasonal epidemics of lower respiratory tract infections (LRTI), including bronchiolitis and pneumonia
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The initial symptoms of this type of disease are similar to colds, but if the infection is not controlled in time, the disease will rapidly develop into a life-threatening serious lower respiratory tract infection, and it may also cause subsequent asthma and bronchiolitis

Worldwide, RSV infection is an important cause of hospitalization for infants
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According to WHO estimates, 64 million children worldwide are infected with RSV each year

Although the respiratory diseases caused by RSV infection are serious, so far, there is no effective treatment and preventive vaccine specifically for respiratory syncytial virus in the world

At the same time, the development of previous RSV vaccines, antibodies and therapeutic drugs once faced huge challenges
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It is understood that due to safety issues, no breakthrough has been made in the development of respiratory syncytial virus vaccines for many years.

For most patients infected with RSV, there is still "no medicine available"
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Vaccines + innovative drugs, a new round of research and development ushered in the dawn

At present, a new round of research and development battles against respiratory syncytial virus is quietly kicking off
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Globally, there are a number of preventive vaccines and innovative drugs

For example, in October this year, Janssen, a subsidiary of Johnson & Johnson, just announced that its phase 2b clinical trial of RSV vaccine in elderly people over 65 years old reached the primary and key secondary endpoints, and its effectiveness in preventing lower respiratory tract diseases is 80%
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Based on this result, Janssen has launched a global phase 3 clinical trial

Prior to this, in September, Pfizer announced the launch of RENOIR, a phase 3 clinical trial of RSVpreF, a candidate vaccine candidate for the pre-bivalent fusion of the F subunit, to evaluate the effects of single-dose vaccination on the prevention of RSV infection in adults 60 years of age or older.
Effectiveness, immunogenicity and safety
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At the same time, Moderna's mRNA vaccine mRNA-1345, which encodes the F glycoprotein before stable fusion of the virus, is expected to start a global phase 2/3 clinical trial before the end of 2021 to test its safety and efficacy in preventing RSV
.

There is also a vaccine ADV110 from the Chinese company Ai Di Weixin, which is under development to prevent RSV infection.
It has also successfully completed the first batch of subjects in the Phase 2 clinical study in Australia
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In addition, GlaxoSmithKline also announced in October last year that its two vaccine candidates (GSK3888550A and GSK3844766A) for maternal immunity and RSV infection in the elderly showed good tolerance and high immunity in the Phase 1/2 clinical study.
Originality
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They have all obtained fast track qualifications granted by the US FDA
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In the field of RSV drug research and development, the current research products of many companies such as AstraZeneca/Sanofi, Janssen and AGCO are in the late clinical stage
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Moreover, many of the products under development have been included in breakthrough treatments in China
.

In May 2021, the RSV preventive antibody drug nirsevimab jointly developed by AstraZeneca and Sanofi reached the primary endpoint of the trial in the phase 3 clinical trial MELODY
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It uses a passive immune mechanism, and infants can quickly gain immunity to RSV through a single intramuscular injection, which is expected to be protected throughout the epidemic season
.

Janssen also has a new RSV fusion protein inhibitor JNJ-53718678, which has the potential to treat RSV infection
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It can specifically target and bind to the fusion protein on the surface of the virus, inhibit RSV fusion protein-mediated fusion with the host cell membrane, and prevent the virus from entering
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This can prevent the replication of RSV, reduce the viral load, and thereby reduce the severity of the disease
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A new RSV fusion protein inhibitor ziresovir (code name: AK0529) developed by AGCO Baifa has also attracted much attention
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It can prevent the virus from entering human cells by binding to the RSV fusion protein and prevent infection from causing diseases; at the same time, it can also enhance the antiviral effect by preventing cell-to-cell fusion
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According to reports, in the past, nucleoside antiviral drugs usually act on nucleotide replication in human cells, but ziresovir has a different antiviral mechanism and is expected to develop into a new anti-RSV drug with a new mechanism of action
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Public information shows that ziresovir has carried out 9 clinical trials around the world for pediatric and adult patients in the United States, China, Europe, Australia and other countries and regions.
Currently, phase 3 registration trials have been carried out in China
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It is reported that AGCO Baifa is expected to submit a new drug marketing application in the second half of 2022, and it may become the world's first anti-RSV small molecule therapeutic drug
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In addition, there are many other antibody drugs under development, such as Merck’s MK-1654, Enanta’s EDP-938, and Reviral’s RV520, which are also in the clinical development stage
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Looking at the entire field, the rapid progress of a large wave of products under research is expected to open up a new situation in the prevention and treatment of RSV infections
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Image source: AGCO Baifa prospectus

Solve global problems, and the performance of Chinese products under research is eye-catching

As mentioned in the previous article, some Chinese innovative companies are also involved in it, and are developing a series of innovative product pipelines to solve the global problem of RSV infection
.

Among them, AGCO Baifa is a biomedical innovation company focusing on this disease field.
In addition to the aforementioned new RSV fusion protein inhibitor ziresovir, the company also has two next-generation RSV drugs in its preclinical pipeline.

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At the same time, the company recently introduced another preclinical RSV antibody drug from the Institute of Microbiology of the Chinese Academy of Sciences for the prevention of RSV infection, further enriching its RSV research and development pipeline
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In addition to AGCO Baifa, there is also the RSV vaccine product ADV110, which is under development including Aidiweixin Biologics, which is a potential RSV protein subunit vaccine candidate containing a new adjuvant, designed to protect children from 6 months to 5 years of age.
Elderly people over 65 years old are currently in Phase 2 clinical phase; another example is TNM001, a long-acting recombinant RSV antibody TNM001 that has also been approved for clinical use in China to prevent lower respiratory tract diseases caused by RSV
.

It is worth mentioning that these developments in China are also closely related to the current attention and concern of the Chinese government and regulatory authorities
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Because the core population of patients with RSV infection is mainly children, except for the elderly and adults with impaired immune function
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In recent years, medicine for children has become the focus of China's reform and attention
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The "Drug Administration Law" promulgated by China in 2019 clearly states that it "encourages the development and innovation of drugs for children"
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The National Food and Drug Administration (NMPA) of China has also issued various guiding principles to encourage and guide drug research and development institutions to more actively and scientifically develop children's drug research and development
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In an interview with WuXi AppTec's content team, the relevant person in charge of the new Chinese innovative drug AGCO Baifa pointed out that if respiratory syncytial virus drugs can be developed, infected children will be treated in time, and the development of respiratory and lung damage can be avoided.
For asthma, asthma and chronic pneumonia, reduce organ damage and protect children's respiratory health
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At the same time, from the perspective of pharmacoeconomics, early treatment of childhood infections can avoid chronic diseases in children, thereby greatly saving treatment time and medical funds required
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Therefore, treatment for RSV infection is imperative
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We are very happy to see that breakthroughs are being made in the process of solving this worldwide problem, whether it is therapeutic small molecule drugs, antibody drugs, or preventive vaccines
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I look forward to the success of the follow-up research of these pipelines, which will benefit patients as soon as possible
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