The tedious search for the saving medicine

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The tedious search for the saving medicine


In the fight against the corona virus, medical professionals are trying out means or methods that have already proven themselves in other diseases. What the medicines can do and what the first results look like.



© CARL DE SOUZA / AFP



To say it straight away: There is still no proven drug against Sars-CoV-2. The outbreak is too young for this, the virus has only been known for a short time. Nevertheless, there are a number of medicinal products that are already used in patients – mostly in the context of clinical studies: 366 studies are currently listed in the Clinicaltrials.gov study register under the keyword Covid-19.

These include well-known methods such as plasma therapy, in which infected people are given infusions with blood plasma from those who have recovered. The antibodies it contains are said to protect against the attack of the virus. The malaria drug chloroquine also belongs to this series, as do flu and HIV drugs and a medicine for Ebola.

For the four most promising substances, the World Health Organization (WHO) launched a large series of studies under the name “Solidarity” in March, in which doctors worldwide can participate with as little bureaucratic effort as possible.

However, as urgently medications against Covid-19 are needed, it is unclear whether the remedies, some of which come from the past century, are effective against the novel virus. Scientists warn against using drugs that have not been proven to be effective too quickly and bypassing previously accepted standards.

What can the means that doctors currently give their patients as a makeshift solution? And above all: how are the first results?

Blood plasma therapy

At various clinics worldwide, doctors are testing how the administration of blood plasma from convalescents affects the course of the disease in patients. The idea behind it: It takes an average of seven days for an infected person to form their own antibodies and these are detectable in the blood. This time should bridge the antibodies donated with the plasma.

So far, the results are only case descriptions of a few patients, such as here, here and here. As a result, two elderly South Korean patients are now healthy again after plasma therapy. One was initially unsuccessfully treated with malaria medication, the other additionally with an HIV medicine. After plasma administration in combination with corticosteroids, which have long been known to reduce inflammation in the body, the patients recovered.

The reports from China sound similar: doctors there treated ten seriously ill Covid-19 patients with recovered blood plasma, but only after an average of 16 days and in combination with other antiviral agents. According to the authors, symptoms such as shortness of breath decreased within three days, oxygen saturation also improved and lung changes regressed to different extents after seven days. The doctors could no longer detect coronaviruses after the therapy, nor did they observe any serious side effects.

Based on the description of the individual case, it has not yet been proven whether the blood plasma donation was the cause of the patient’s improvement. The Chinese scientists write in the “Proceedings of the National Academy of Sciences” that plasma therapy could “possibly” improve the condition of the patient by neutralizing the viruses: “The optimal dose and the time of therapy as well as the benefits of plasma therapy must be considered larger control studies. “

The Ebola drug

The antiviral remdesivir was originally developed by the pharmaceutical company Gilead Sciences against Ebola. The drug inhibits the Replication of the genome of so-called RNA viruses, which includes the novel corona virus in addition to the Ebola virus. The WHO had named the drug as the most promising candidate among the therapy options in January. For this reason, studies have been running at numerous locations worldwide since February, some of which give hope.

Because there are now first signs of effectiveness against Sars-CoV-2, the European drug agency Ema recommended on Friday to use the drug for the seriously ill as an alternative treatment. The Federal Institute for Drugs and Medical Devices (BfArM) also allowed Remdesivir to be used in Germany on Tuesday for seriously ill corona patients.

Nevertheless: Even with Remdesivir it is still unclear whether it actually works against Sars-CoV-2. This is to be investigated in three clinical trials that have been approved by the BfArM. “All patients included in these studies are moderately to seriously ill and are treated in hospital,” writes the Federal Institute.

The antimalarial

Chloroquine, also known under the trade name Resochin, has been used to prevent infestation by parasites that trigger malaria since the 1930s. Because the pathogens developed resistance, the pharmaceutical company Bayer stopped selling in 2019. Production is now “ramping up again”, the company says, because there are first indications that chloroquine could act against Sars-CoV-2.

However, the results come mainly from cell experiments. The drug is believed to work against coronaviruses by preventing the pathogens from entering the cell. How effectively it can fight Sars-CoV-2 in the human body and at what price is still unclear. The unreflected statements of the US President in March did not change this.

Because even though chloroquine or its relative hydroxychloroquine are generally well tolerated, in rare cases it can lead to retinal changes, restlessness, sleep disorders and gastrointestinal complaints. This risk is only worthwhile if Covid-19 patients really benefit from the intake.

To check this, there are currently at least 13 studies in the Clinicaltrials.gov study register on the substances that are either planned or already being carried out. The BfArM has also approved three clinical trials with hydroxychloroquine against Covid-19. “In one of these studies, people with mild Covid-19 disease are treated on an outpatient basis,” writes the institute, “the other two studies include moderately to seriously ill inpatients.”

The drugs against HIV

The HIV drugs ritonavir and lopinavir are also hopeful in the fight against Covid-19, because there had already been indications at the Sars outbreak in 2002/2003 that the combination of active ingredients could help patients. Lopinavir is known to inhibit the production of viral proteins. Ritonavir increases this effect, so it is used in combination with lopinavir. The hope is that the substances will not only have an effect on HI viruses, but also on Sars-CoV-2. The active ingredients have the advantage that they have been used for a long time, so their possible side effects are also known.

A whole series of international studies on the substances are already underway. Sometimes the doctors also use another active ingredient, the so-called interferon beta-1b. It is a messenger substance that has an anti-inflammatory and antiviral effect and is already used in the therapy of multiple sclerosis, among other things.

However, the results of an initial clinical study in people with severe Covid-19 disease did not provide any evidence that the remedies are beneficial. Conversely, this does not mean that they do not work and may not be able to help other patients, at a different stage or with a different extent of the disease.

The flu remedy

The virustatic favipiravir (trade name Avigan) is manufactured by Fujifilm Toyama Chemical. The active substance blocks an enzyme that viruses need to reproduce. It is approved against certain strands of influenza viruses in Japan, but with restrictions, as it can be dangerous for pregnant women and the unborn child. During the Ebola outbreak, the drug was already used in healing trials; now favipiravir is also being tested against Sars-CoV-2.

In a study of 240 patients, half of whom received favipiravir and the other a substance called arbidol, which is also a hope in China, favipiravir performed better. However, the agent was administered in very high doses and given to patients who had only a moderate course. In the “NDR”, the virologist Christian Drosten pointed out that due to the side effects, one did not know whether favipiravir could be used permanently under these conditions.

The bouncer

At the very beginning there are studies on an enzyme that could prevent the Sars-CoV-2 coronaviruses from entering the cells. The pathogens apparently use the body’s own enzyme ACE (angiotensin converting enzyme) to infiltrate the cells. Scientists initially showed in cell cultures that artificially produced and added ACE-2 apparently intercepts the pathogens. Clinical trials are now to follow, and in Germany the BfArM has also given the green light for use on seriously ill Covid 19 patients.

The antibodies

Monoclonal antibodies, i.e. antibodies of a certain cell line, have been produced for therapeutic purposes in the laboratory for years and are also used in humans. For example, with numerous tumor diseases, for example lung, bladder or breast cancer. Patients already receive such antibodies in rheumatoid arthritis or multiple sclerosis. Against Sars-CoV-2, researchers are already reporting experiments with monoclonal antibodies in cell culture.

You will find all current information and recommendations from the Ministry of Health here.

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