Two doctors communicate through the glass of the ICU in a hospital with covid patients in Berlin.FABRIZIO BENSCH / Reuters
The grim reality of this pandemic is that, more than a year later, there is no cure for covid. The astonishing development of effective vaccines in record time has made the lack of treatment in hospitals, where there are thousands of already infected people who cannot be vaccinated, even more desperate. But experts believe that this situation will change in the coming months, as it is possible that several drugs in the last phases of human testing could arrive in time to save lives as the mass vaccination campaign picks up speed.
This week is have published new data on one of the most promising drugs, both in terms of its effectiveness and how it is used. It is an oral antiviral . For the first time it would not be necessary to administer it in a hospital with an intravenous injection. It also has an advantage that would make any doctor cry with joy: it could be used as a prophylactic drug. This means that it could prevent infection and transmission of the coronavirus , for example in people who have had contact with a patient. In the best of cases, this type of drug could stop the chains of infections that now go completely unnoticed by health radars.
This new drug – EIDD-2801, trade name, Molnupiravir – was developed by researchers from Emory University (EE. UU) as a broad spectrum antiviral. Its objective was to combat all strains of influenza, although in subsequent laboratory tests it has shown effectiveness against other RNA viruses, including coronaviruses.
"These are the most powerful virus inhibition results that have been observed in animal models" Víctor García-Martínez, Emory University
This drug has been shown to reduce the virus load by 25,000 times if applied 24 hours after infection in an experiment with mice grafted with human lung tissue. If rodents took the drug before coming into contact with the virus and then contagion occurs, the viral load is reduced about 100,000 times. The results are published this week in the journal Nature and complement those of another preliminary study that provides another revealing data. EIDD-2801 protected ferrets living with other infected animals from contagion.
"These are the most powerful virus inhibition results that have been observed in animal models," explains Víctor García-Martínez, an immunologist at the University from North Carolina and co-author of the study. "If these results are replicated in humans, we hope that it will make a big difference both in the prevention of contagion and in the early treatment of covid," he highlights.
This drug is in phase 2-3 of human trials in which it is will test its effectiveness. It is theoretically the last before the drug can be approved for use.
Spain is one of the countries where this molecule will be tested. "The advantage of this drug is that it can be given orally in combination with two other treatments, remdesivir and dexamethasone," explains Roger Paredes, doctor at the German Trias i Pujol hospital, in Badalona, who participates in the trials with this antiviral developed for its commercialization by the pharmaceutical companies MSD and Ridgeback.
This drug works by introducing errors in the process of copying the RNA of the virus until it annihilates it, a phenomenon known as “error catastrophe”. The drug is being tested both in hospitalized patients and in infected people without serious disease.
"Of course, it can have great potential due to the ease of administration in non-admitted patients," says Marcos López Hoyos, president of the Spanish Immunology Society. "If it really prevents covid, it would facilitate prophylaxis in case of outbreaks in closed environments, such as residences," he adds.
In any case, it is too early to know if the drug will work, warns Elena Muñez, from the Infectious Diseases Unit from the Puerta de Hierro Hospital in Madrid. "Something similar to plitidepsin happens to this drug, what has been published to date is very preliminary," he warns. The doctor refers to another promising antiviral manufactured by the Spanish Pharmamar and that has shown an effectiveness about 100 times higher than remdesivir , the only antiviral approved against SARS-CoV-2. In this case there are also no conclusive data on its effectiveness in humans.
There is more positive news from the toughest front in the fight against covid: that of seriously ill patients who are already admitted. It is in this part of the disease that some patients experience a runaway immune system reaction known as a cytokine storm, the name for inflammatory proteins that, instead of doing their job well, exacerbate inflammation in the body and can end up causing death. .
There are other very advanced and promising experimental treatments for the acute phase of the disease
This same week, it was announced that an anti-arthritis drug that reduces inflammation, tocilizumab, can reduce up to 50% of deaths in patients admitted to the ICU if it is administered together with dexamethasone. This second drug is a corticosteroid that until now was the only one that had shown power to save the lives of covid patients.
There are other very advanced and promising experimental treatments in this phase of the disease. All are based in one way or another on antibodies, the proteins that the immune system produces naturally and that are capable of binding to the virus, preventing it from entering cells and reproducing.
"This same year there will be new treatments available" Alberto Borobia, head of clinical trials in La Paz
Plasma from people who have overcome the disease, which contains these molecules, is one of the possible treatments in the queue . There are more refined variants, such as monoclonal antibodies, which are basically a dose of a single type of antibody selected from patients and reproduced in the laboratory for its high virus neutralization potency. In this same line are the hyperimmune immunoglobulins, which in this case are polyclonal, that is, they attack different parts of the coronavirus at the same time. All these treatments are being tested in Spain in clinical trials and the results of the trials are expected in the coming months.
"This same year there will be new treatments available," explains Alberto Borobia, head of clinical trials at Hospital La Paz, in Madrid . The doctor does not believe that less research has been done on treatments than on vaccines, but that there has been worse luck. "From the outset, what has been tried is to reposition drugs that were approved for other uses for COVID," he says. "We used what we had, chloroquine, azithromycin, many more things and the truth is that so far almost all have failed," he adds.
Now there is a second round of treatments to come, such as monoclonal antibodies. Some of these preparations have already been approved urgently in the United States, which show efficacy especially in the early stages of the disease, although they are very expensive. Another compound, colchicine, which has been shown to reduce COVID hospitalizations if given early, is also being tested in La Paz.There is a third drug in testing: melatonin, a compound that induces sleep and could stop replication. The best-case scenario would be to have treatments that do what vaccines might not do, Paredes adds. "Before this pandemic is over we will need new treatments, especially to stop the spread of the virus and cut the transmission chains and to reduce the mortality of already infected patients, which in some cases remains high," he details.
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