Vaccination is still far from immunizing the majority of the world population against COVID-19[female[femininePharmaceutical companies are already testing on humans Medicines that promise effective treatment علاج against disease.
international giants Pfizer, MSD e Rush It is the most advanced. Develop Oral antivirals. me and Boehringer Ingelheim Invest in a Monoclonal antibody therapy.
In Brazil, two Soros, one of Putantan Institute and the last of Vital Brazil InstitutePatient screening is expected to begin in the coming months. It is estimated that some of these drugs are already available today. early 2022.
The main objectives of the new treatments are Reduce hospitalizations and deaths from illness.
Unlike antibiotics, which can generally 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. In addition, they have fewer proteins in common that can be used as general drug targets.
For a drug to work, it must hit a “target”, usually a protein. It is especially difficult with viruses. The reason is that they reproduce inside human cells. Thus, they make cellular mechanisms work in their favor. For a drug to be effective, it must enter infected cells and attack the virus. But you should do this without destroying your host.
Another possible strategy is to target the virus before it enters the cell. But it is not very simple either. The envelope of the virus is very strong. 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 if the drugs take a long time to develop, the viruses suffer. mutation Very quickly. Thus, they can develop resistance to the drugs.
However, there are many effective antiviral drugs available – against HIV, influenza, and hepatitis C, for example. The same is currently being tried against SARS-CoV-2.
Laboratories are testing antiviral pills
There are three more advanced projects, which are already in the human test phase. One is MSD in association with the biotechnology company Ridgeback Biotherapeutics. The complex is called Molnopiravir. It was originally developed against SARS and MERS. In a phase II study, the drug was well tolerated in humans. It was taken as a tablet twice a day for five days.
The idea is that the medicine works at the start of the infection, when the first symptoms appear. The goal is to prevent the virus from multiplying, to avoid its exacerbation and the need for hospital treatment. The third test phase has already started. 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 compelling evidence for the antiviral activity of molnopervir,” said Marcia Abady, medical director of MSD in Brazil. “One of our goals is to reduce hospitalizations due to the disease – which is very important in Brazil due to the hospital collapse we are witnessing – and also to reduce patient deaths.
Another project is being carried out 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, the results should also 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 into the infection.
Oral drug is under development by Pfizer PF-07321322. It is a protease inhibitor (a type of enzyme) like those used against HIV. It has been specially developed against SARS-CoV2. It is also already tested in humans. The first results are expected by the end of the month. The purpose of this drug is also to prevent an exacerbation of the disease. It should 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 hospital patients. These 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 progression of Covid disease.
Scientists test for natural and synthetic antibodies
Boehringer Ingelheim tries another approach. It is the production of monoclonal antibodies (made in the laboratory from living cells).
“When you think of treating a viral infection, there are two strategies: working directly on the virus, or on proteins that help the virus to replicate, or preventing the virus from entering the cell,” Thais Gomes explained. de Melo, medical director of Boheringer. “In the latter case, we use a monoclonal antibody. “
Scientists have identified in the plasma of patients infected with specific antibodies to the Covid virus that act on the S protein of the virus, which enters the cell. These antibodies were 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 shows the first symptoms. The 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 constitute the serum which gives the patient the weapons to fight against the 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, from Vicruz, explained: “What virology has taught us over the past 40 years is that with these viruses with high mortality, cocktails are often more effective than just medicine; that’s what happens with HIV and the hepatitis C virus. “His lab is studying the repositioning of some of the antiviral drugs used in these cocktails to treat COVID-19.” I think it’s very difficult for one drug to be able to treat Covid disease. But I think the ambition he can aim for is to reduce hospitalizations and deaths. I think that’s the big challenge in the short term.