Is it too good to be real? Pfizer is working on tablets that have the potential to treat COVID-19-Health News, Firstpost

CDC illustration of coronavirus. Image: CDC / Unsplash

The main focus has been on vaccines, but Pfizer Try the pill treat COVID-19 (New Coronavirus Infection) .. It sounds almost too good to be true. In fact, the results are very preliminary, but this is a promising approach.

Most antivirals we tried to treat COVID-19 (New Coronavirus Infection) Pfizer pills target the inflammatory and immune responses caused by infection and directly target the virus itself, SARS-CoV-2.

Strengthen protection against viruses

Many of the illnesses associated with COVID-19 (New Coronavirus Infection) Due to severe inflammation Immune response It can occur with an infectious disease. The most successful treatments to date have targeted this enthusiastic immune response.

Inhaled corticosteroids taken early in the disease Budesonide It has been shown to reduce the incidence of more serious illnesses.

To those who were hospitalized in COVID-19 (New Coronavirus Infection) Oral corticosteroids that require oxygen Dexamethasone Reduces the chance of death.

Most Severe — COVID Patients Admitted to ICU — Anti-Inflammatory Drugs Tocilizumab Intravenous administration increases the chances of survival.

However, these treatments do not target SARS-CoV-2 itself. Only the result of infection. Targeting the virus directly has proven to be more difficult.

Target SARS-CoV-2

Viruses like SARS-CoV-2 need to invade host cells in order to propagate. It attaches to cells using spike proteins (proteins on the surface of the virus) and then invades using the proteins of the cells themselves.

Once inside the cell, SARS-CoV-2 removes the exodermis and releases viral RNA (ribonucleic acid, a type of genetic material).It acts as a template, allowing virus replication, then Infects other cells.. At any point in this life cycle, the virus can be vulnerable to intervention.

SARS-CoV-2 has an enzyme called 3C-like protease (3CLpro). Important role In the replication process. This protease is similar to the protease used by the SARS-CoV-1 (SARS) virus and is similar to the protease used by the Middle East Respiratory Virus (MERS).

Therefore, drugs that can effectively target 3CLpro and prevent viral replication may be beneficial to multiple known ones. Coronavirus es, and perhaps something that will emerge in the future.

Protease inhibitors have been successfully used to treat other viral infections, especially chronic infections such as: HIV And Hepatitis C..

They were in the early days of the pandemic, COVID-19 (New Coronavirus Infection) ..But the HIV drug lopinavir-ritonavir Two clinical trials has no effect, At the drug level Probably too low To work For SARS-CoV-2.. Higher doses may be effective, but they can also produce more side effects.

Scientists have also proposed reused antiviral drugs, Remdesivir, Originally developed to treat Ebola. Remdesivir slows the virus’s ability to replicate RNA.

initial Case report Looked promising and saw US Food and Drug Administration Approve the drug for emergency use.However, the results of randomized controlled trials in critically ill inpatients COVID-19 (New Coronavirus Infection) I was disappointed.

Although there was a decrease Period of illness For surviving patients, it did not significantly reduce a person’s chances of death.

Of course, neither of these agents was specifically designed to target SARS-CoV-2. But in 2020, Pfizer / BioNtech identified a small molecule (PF-00835231) that blocks the SARS-CoV-2 3CLpro protease. Originally designed for SARS-CoV-1, the enzymes of the two viruses are almost the same.

PF-00835231 appears to reduce various ranges of replication, alone and in combination with remdesivir. Coronavirus Including es SARS-CoV-2 In the cells of the laboratory. In addition, many animal models had reduced viral replication, which did not adversely affect safety. However, it is important to note that this study has not yet been peer-reviewed.

What now?

Pfizer / BioNtech is bringing two drugs into clinical trials COVID-19 (New Coronavirus Infection) : PF-07304814, Intravenous injection for use in severely inpatients COVID-19 (New Coronavirus Infection) And PF-07321332Oral preparations, or pills that may be used early in the disease. Both are formulations of 3CLpro inhibitors.

these Phase 1 trialBeginning in March represents the early stages of drug development. In these trials, healthy volunteers are selected and different doses of the drug are used to establish safety. They also examine whether the drug elicits a sufficient response in the body to show that the drug may be effective against SARS-CoV-2.

The next step is to try Phase 2 or 3 to see if the results improve. COVID-19 (New Coronavirus Infection) .. This process usually takes years, but as the pandemic rages around the world, Pfizer says it will do so within a few months if Phase 1 testing is successful.

Acute application of antiviral agents COVID-19 (New Coronavirus Infection) It was difficult and rewarding. The results are preliminary at this stage, but these agents by Pfizer / BioNtech are promising. They can be used early in the disease, especially in people who are not well protected by vaccination or who are not vaccinated.

They can also be used as a precautionary measure to contain the outbreak of exposed people. They should be effective against all SARS-CoV-2 variants of concern, and against other known and perhaps urgent cases. Coronavirus is.

Pfizer CEO’s recent suggestion may be that pills are available By the end of the year Probably a long shot. But the pandemic shows us what is possible in the realm of rapid scientific progress, and we look at this space with great interest.

Peter Walk, Newcastle University School of Medicine and School of Public Health Co-Professor

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