09/17/2021 at 6:53 PM CEST
A Spanish drug is giving great results to cure Covid-19
When the Covid-19 pandemic broke out, not enough tracking, isolation, quarantine and border closure measures were taken that were necessary to prevent the coronavirus from spreading around the world.
It soon became clear that humanity was unable to apply the classic epidemiological measures that could have extinguished the coronavirus shortly after it was detected, preventing its spread throughout the planet.
This failure led to the collapse of the hospital, the sick dying in absolute solitude and the corpses piling up after exceeding the capacity of the funeral services.
From medicine and science, weakened after years of cuts, it was necessary to make a huge effort in the fight against the coronavirus.
The example of whooping cough
Faced with the classic infectious diseases produced by bacteria, medicine has vaccines that largely prevent contagion and prevent us from developing serious forms of the disease.
But we also have antibiotics that allow us to effectively treat this ailment, once declared.
Let’s take an example that we all know: whooping cough.
It is an infectious disease produced by the bacterium (gram-negative) Bordetella pertussis that unleashed cruel pandemics in Europe in the 18th and 19th centuries.
It then produced a terrifying infant mortality. But today medicine has an effective vaccine developed more than 80 years ago and that they put us as babies. We sure don’t even remember.
This vaccine ended the whooping cough pandemics. The US Center for Disease Control and Prevention estimates that the pertussis vaccine saves more than 500,000 children’s lives annually.
A drug to cure Covid-19?
Despite the vaccine, some children continue to get it. They are often the children of anti-vaccines whose stupidity makes their own children suffer.
But in that case medicine has already gone one step further and has effective antibiotics to treat whooping cough once it develops.
If today we had an effective antiviral against SARS-CoV-2, we would have taken a giant step in the fight against the pandemic and could save millions of lives among those who, despite everything, end up being infected.
That is why numerous research groups dedicate an enormous effort in the attempt to develop a drug capable of curing Covid-19.
But, although we have a panoply of extremely effective antibiotics in the fight against bacterial diseases, in the case of infectious diseases caused by viruses we have very few drugs with effective antiviral activity.
This is the race to find an antibiotic
It takes many years of testing and trials to develop a drug before drug agencies will authorize its use in humans.
Therefore, against Covid-19, scientists resorted to an ingenious strategy: the repositioning against SARS-CoV-2 of existing drugs.
It is about studying and carefully analyzing whether among the thousands of drugs already authorized there is one that can be effective against Covid-19.
Ingenious molecular biology strategy
To find these possible drugs, the scientists followed a cell biology strategy.
We are going to try to explain how his intense work has been in search of a cure for Covid-19
The first step was that the sequencing of the complete SARS-CoV 2 genome allowed us to know that the coronavirus produces only 29 different viral proteins.
After much research, one study found that these 29 viral proteins only interact with 332 human cell proteins.
This fact is very important because viruses are obligate intracellular parasites. In other words, SARS-CoV-2 requires the molecular machinery of our cells to reproduce.
Specifically, the coronavirus will need some of these 332 proteins of ours with which it interacts.
Of these 332 proteins there are 69 target factors of which we know a compound that can regulate their activity.
Specifically, there are 97 drugs already authorized that regulate the activity of these 69 target factors (because in some cases there is more than one known drug that acts on the same target factor).
So the next step was to test these 97 drugs, hoping that one of them is capable of inhibiting some protein in human cells that SARS-CoV-2 needs to replicate.
Aplidin, the Spanish medicine
Now we begin to see interesting results of this strategy.
And one of the most promising is Plitidepsin, an antitumor drug developed by the Spanish company PharmaMar under the name Aplidin.
It is a compound that already exists and is licensed as a cytostatic for the treatment of cancer. That is, it is a substance capable of delaying or even stopping the growth of cells, including cancer cells, without destroying them.
In cancer matters, this drug can prevent tumors from growing and spreading, without reducing their size.
As it does?
Well, Plitidepsin works by blocking the factor eEf1A present in human cells.
And the good news now is that SARS-CoV-2 needs this factor in order to reproduce.
So when plitidepsin blocks eEf1A, the chorovirus is unable to reproduce within cells.
Spectacular results in the laboratory
The results at the laboratory level are spectacular. Doses as small as 1.7 nM (nanomole, which is equal to one billionth of a mole) inhibit 90% of virus replication.
This means that, in the laboratory, Plitidepsin is about 100 times more effective than Remdesivir, which is the best antiviral against SARS-CoV-2 available today.
But it is one thing for it to work in the laboratory and another for it to work well in patients.
First clinical trials
In early clinical trials, Plitidepsin appears to be very effective in treating patients with moderate disease who have developed pneumonia.
The administration of 2.5 mg of plitidepsin for 3 days causes 74% of these patients to be discharged from hospital in the first week.
But as usual, the first clinical trials have been conducted with a small number of patients (only 45), so it is still early to ensure that plitidepsin is finally the most effective drug in the fight against Covid-19.
In fact, there are other drugs from the same strategy (repositioning against SARS-CoV-2 of existing drugs). And even one of them, Ternatine 4, acts on exactly the same factor eEf1A on which Plitidepsin does.
It is not the moment to throw the bells to flight, but undoubtedly all this is good news.
Will a double vaccine arrive, influenza-SARS-Cov-2?
Some pharmaceutical companies already assume that in the near future we will have to re-vaccinate ourselves annually against new variants of Covid-19, in a similar way to that which occurs annually with the flu.
That is why they are beginning to prepare a strategy that includes the development of a double vaccine against influenza and coronavirus.
Everything seems to indicate that SARS-CoV-2 has come to stay with us for a long time. And in this context, research on drugs with anti-SARS-CoV-2 activity still makes a lot of sense.
Paradoxically, a drug of this type would end up saving the lives of many Covid-19 deniers and anti-vaccines.