Scientists hope to have antiviral drugs by 2022

With vaccination still far from immunizing the majority of the world’s population against COVID-19Pharmaceutical laboratories are already testing on humans Medicines that promise effective treatmentعلاج against disease.

international giants Pfizer, MSD e rush It is the most advanced. Develop Oral antivirals. me and Boehringer Ingelheim Invest in one Monoclonal antibody therapy.

In Brazil, two Soros, one of Putantan Institute and the last of Vital Institute BrazilTesting of patients should begin in the coming months. It is estimated that some of these drugs are already available to date early 2022.

The main goals of new treatments are Reducing hospitalizations and deaths from disease.

Unlike antibiotics, which can usually be used against many types of bacterial infections, drugs against one type of virus are unlikely to work against others. The difficulty in developing a broad-spectrum antiviral is that viruses are more diverse than bacteria. Furthermore, they have fewer proteins in common of their own that can be used as general drug targets.

For a drug to work, it must hit a “target” – usually, a protein. This is especially difficult with viruses. The reason is that they reproduce inside human cells. Thus, they make the cellular mechanisms work in their favour. For a drug to be effective, it must enter infected cells and attack the virus. But you should do it without destroying your host.

Targeting the virus before it enters the cell is another possible strategy. But it’s not very simple either. The virus envelope is very strong. In this way, you protect your genetic material. But destroying this circumstance and exposing this substance can be toxic to the human body. Another problem is that while drugs take a long time to develop, viruses suffer mutations Very fast. Thus they can develop drug resistance.

However, there are many effective antiviral drugs – against HIV, influenza and hepatitis C, for example. The same is now being tried against SARS-CoV-2.

Laboratories are testing antiviral pills

There are three more advanced projects, which are already in the testing phase on humans. One is MSD in association with biotech company Ridgeback Biotherapeutics. The complex is called Molnopiravir. It was initially developed against SARS and MERS. In a phase II study, the drug was well tolerated in humans. It has been taken as a tablet twice a day for five days.

The idea is that the drug works at the beginning of the infection, when the first symptoms appear. The goal is to prevent the virus from multiplying, avoiding its exacerbation and the need for hospital treatment. The third phase of testing has already begun. It will involve more than a thousand people in 18 countries, including Brazil. MSD expects to have the first results between September and October.

“The data from these studies provide convincing evidence of the antiviral activity of molnopervir,” said MSD Medical Director in Brazil, Marcia Abady. “One of our goals is to reduce hospitalizations due to illness – which is very important in Brazil because of the hospital collapse we are seeing – and also to reduce patient deaths.”

Another project is by Roche Pharmaceuticals in partnership with Atti Pharmaceuticals and the drug, also taken orally, is being tested on 1,400 people in Europe and Japan, with results also expected to be available by the end of this year, for approval by regulatory agencies. Like MSD, this medication should be taken as early as five days in the infection.

The oral drug is under development by Pfizer PF-07321322. It is a protease inhibitor (a type of enzyme) like those used against HIV. It was specially developed against SARS-CoV2. It is also already being tested in humans. The first results are expected by the end of this month. The purpose of this drug is also to prevent an exacerbation of the disease. It must be administered at the onset of infection.

Another advantage of these antivirals is that they can also be used in disease prevention. For example, by people who have been in contact with an infected person.

Currently , remdesivir, from Gilead, is the only drug approved for use in the treatment of COVID-19. It is given intravenously (injected into the bloodstream) and only in hospitalized patients. They are patients in a more serious condition, and the results are not very encouraging. Experts believe that early administration of new drugs may be necessary to prevent the progression of Covid disease.

Scientists test for both natural and synthetic antibodies

Boehringer Ingelheim tries another approach. It is the production of monoclonal antibodies (manufactured in a laboratory from living cells).

“When we think about treating a viral infection, there are two strategies: working directly on the virus, or on proteins that help the virus replicate, or preventing the virus from entering the cell,” explained Thais Gomes de Melo, Boheringer’s medical director. “In the latter case, we use a monoclonal antibody.”

Scientists have identified in the plasma of patients infected with Covid virus-specific antibodies that act on the virus’s S protein, which enters the cell. These antibodies have been synthetically copied in the laboratory to develop a treatment. In the case of a Boheringer product, management will be ready inhalation. The operation will ensure higher concentrations in the patient’s lungs. Phase III human trials begin in September in 40 countries, including Brazil.

Production in Brazil

In Brazil, the Butantan Institute in Sao Paulo, and the Bio Brazil Institute in Rio, have developed a vaccine against the new coronavirus that can also be used as soon as the patient has the first symptoms. Sera are made by isolating the antibodies that patients have developed against SARS-CoV-2 and replicating them in animal models — horses, for example.

These concentrated natural antibodies make up the serum that gives the patient weapons to fight infection. They differ from monoclonal antibodies, which are synthetic and designed to target a specific viral target. And the two institutes are preparing to start testing on humans.

Virologist Thiago Moreno, of Vicruz, explained: “What virology has taught us over the past 40 years is that with these high-fatality viruses, cocktails are often more effective than just medicine; that’s what happens with HIV and hepatitis C virus.” “. His lab is studying repositioning some of the antiviral drugs used in these cocktails to treat COVID-19. “I think it’s very difficult for a single drug to be able to treat Covid disease. But I think the ambition it can target is to reduce hospital admissions and deaths. I think that’s the big challenge in the short term.”

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