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Saturday, April 03, 2021
Search so far “sobering”
Doctors can’t find a cure for Covid-19
Now three corona vaccines have been approved in Europe. However, in the search for an effective drug, scientists know nothing. Research on pharmaceuticals is proceeding at full speed. An overview of the carriers of hope and failure.
The third corona wave is rolling over Germany. While several vaccines were approved at record speed, doctors still lack effective drugs to treat their patients, despite research on anti-corona drugs, which is supported by billions around the world.
About 400 different substances are currently being tested for their effectiveness against Sars-CoV-2, says Stefan Kluge, coordinator of treatment guidelines at the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI). However, so far there have been negative results in almost all studies. Recently, there has been “a bit of disappointment” with drug development, says infectologist Clemens Wendtner of the Munich Clinic.
Hopes still rest on synthetically produced antibodies that are supposed to inactivate the virus in the body. But expectations are now subdued. Several so-called antiviral substances are also being investigated. However, so far there is no agent that specifically fights the virus.
Until now, the corticosteroid dexamethasone, a long-known anti-inflammatory drug, has been used mainly in hospital patients. It is supposed to slow down an excessive immune reaction, which often occurs with Covid-19, and is one of the recommended drugs according to national guidelines. Other anti-inflammatory agents are also being investigated. The active ingredient tocilizumab, which has been used previously against rheumatoid arthritis, could be approved in the near future. Also, doctors use proven drugs that protect against certain complications, depending on the course. Clinic patients often get blood thinners because Covid-19 increases the risk of thrombosis, heart attacks, and strokes.
“Antibiotics mainly have no place in Covid-19”
Antibiotics are also often given due to the risk of additional bacterial infection. But these are ineffective against the virus and only make sense in certain cases, warns Kluge, who is also head of intensive medicine at the Hamburg University Clinic in Eppendorf. Worldwide, the use of antibiotics has increased rapidly with the pandemic; This will lead, among other things, to increased resistance. “Antibiotics mainly have no place in Covid-19. You have to look at that very critically.”
It is unlikely that a complete and effective cure for Covid-19 will be found. “We will not find anything that reduces the current death rate from 20 to 30 percent in the intensive care unit to 0 percent,” says Kluge. For influenza and other viral illnesses, direct remedies are still lacking. “There are also limited effective therapy options for other respiratory viruses,” says Christoph Spinner, senior infectious disease physician and pandemic officer at the Klinikum rechts der Isar at the Technical University of Munich (TUM).
“This is mainly due to the fact that there is only an early window for antiviral approaches in the case of respiratory diseases, whereas more immune therapies are required in the case of the later more complicated stages of the disease,” explains Spinner. Dexamethasone reduces mortality significantly, but not zero. “So preventing serious infection through vaccination just makes more sense.”
200,000 doses of bamlanivimab are in the hospital cabinets
The synthetically produced antibodies are currently being tested in several clinics in Germany: Bamlanivimab and REGN-COV2, which was also given to former President Donald Trump. Despite poor studies and a lack of recommendations, the federal government had secured 200,000 doses of both drugs for around 400 million euros.
Now they are in the closet, according to the doctors. Only one of the 100 therapeutic units of Bamlanivimab had been used at the Munich Clinic in early March, while other clinics have had similar experiences, Wendtner says. “This is not the blockbuster that is constantly being pulled out of the pharmacy cabinet.” Doctors in Germany can only administer the agent to selected patients in the clinic in the early phase. If given too late, the body may have already produced its own antibodies, Wendtner says. “The drug can trigger a serious immune reaction, including allergic shock.”
Meanwhile, in the US, authorities say that bamlanivimab should no longer be used as the sole antibody because it does not help against many corona variants. On the other hand, RKI experts recently wrote, referring to laboratory experiments, that bamlanivimab was effective in the B.1.1.7 variant, which is now dominant in Germany.
Remdesivir is rarely used
The so-called convalescent plasma, antibodies obtained from the blood of those who have recovered, is also being tested in Germany. The mechanism of action is comparable to that of synthetic antibodies. Nationwide, university hospitals asked those who had recovered from the crown for donations of blood plasma a year ago. The claims about efficacy are “mixed,” says Spinner of the Klinikum rechts der Isar.
Research is also underway on drugs that prevent the destruction of the lungs. These are the so-called mesenchymal stem cells. Obtained from umbilical cord tissue, they are precursors to various types of cells in the body, and, according to initial studies, could help severely ill corona patients. They are supposed to protect or regenerate lung tissue.
An employee of the Egyptian pharmaceutical company “Eva Pharma” is working on the production of the active ingredient remdesivir.
(Photo: Picture Alliance / dpa)
Months ago, the approval of Remdesivir, originally developed against the Ebola virus, was celebrated as a milestone. The drug is now rarely used, as doctors unanimously report. Chloroquine, an antimalarial drug, was ineffective and sometimes even contraindicated. Trump had touted this as a miracle weapon and a “gift from God” at the start of the pandemic. The FDA granted emergency approval for the drug, which was withdrawn after a few weeks.
Meanwhile, the antiparasitic drug ivermectin has also proven to be a failure. In Latin America in particular, people bought empty shelves after reports of alleged successes with the Covid treatment, but a clinical study recently found no effectiveness with Corona.
