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Two companies have filed for emergency approval in the US for antibody therapies, praised by US President Donald Trump. What is behind this?
Trump announced a free COVID 19 cure. He stood in front of the Oval Office in the White House garden and spoke about a drug he took when he was caught by Corona virus. Every American should receive the same treatment as he did, said Trump. Free of charge.
For this reason he will make sure that this and another drug is approved quickly. “They call this a therapeutic,” Trump said. “For me it was much more than that. It was a cure.”
In fact, two companies, Regeneron and Eli Lilly, filed for emergency approval of antibody drugs against Sars-CoV-2 in the US on Wednesday. Trump had received one of the drugs at the beginning of his disease. Experts assess both drugs as promising. However, it has not yet been proven that they can actually help seriously ill patients. The most important facts:
How do antibody therapies work?
The therapies involve patients receiving artificially generated antibodies that dock to the coronavirus and prevent it from entering cells. Only there can the virus multiply. For this reason, antibody therapies are linked to two different hopes:
They are intended to protect infected persons from severe disease progression.
However, they may also be able to protect healthy people from infection and thus be used by doctors and nurses until proper vaccinations are available.
Studies are currently being conducted on both of these agents to determine their protective effect on healthy people. The results are still pending, however. However, initial data are available on the effect of the drugs on infected persons.
What is known about the effect of the drugs?
The first drug is the antibody cocktail that Trump received shortly after his diagnosis. It is produced by the US biotech company Regeneron. The cocktail contains two antibodies directed against a key protein of Sars-CoV-2.
Currently, the company is still working on studies that collect data on the effect and side effects of the drug. According to initial interim results, the drug can reduce the amount of virus in infected persons and shorten the duration of symptoms. Study participants whose immune system had not yet formed their own antibodies against the virus benefited particularly strongly.
It is not possible to say whether the drug helped Trump or not. In addition to the antibody cocktail, the U.S. President received two drugs that are used primarily in seriously ill patients. In principle, the effect of a drug should only be inferred from individual patient reports in absolutely exceptional cases. Instead, new drugs are usually tested on hundreds or even thousands of people.
The second, very similar product comes from the pharmaceutical company Lilly. Although the group is also researching a cocktail of two antibodies, emergency marketing authorization has only been submitted for one of the two antibodies for the time being. The application for the cocktail is expected to follow in November if further data is available. Therapy with more than one antibody is likely to reduce the risk of resistance.
Lilly, too, has so far only published interim results from an ongoing study. According to these, the antibody can also reduce the viral load in patients. In addition, the Company reported that fewer patients had to go to hospital or the emergency room compared to a placebo group. However, due to the small number of test persons affected, this statement must be viewed with caution.
The results known to date for both antibody therapies also have one major limitation: they are based solely on data from patients who had mild to moderate symptoms and did not require hospital treatment at the time of therapy. Currently, studies with seriously ill hospital patients are also underway, but the results are still pending.
It is also important to know that the published results are based on data from only a few hundred patients. The results have also not yet been published in professional journals and have not been reviewed by independent experts. However, as the studies continue, new results are expected soon. However, none of the companies has reported serious side effects so far.
What do independent experts think about the therapies?
The drugs are very promising, says Martin Landray from the University of Oxford. “Both studies show that monoclonal antibodies targeting the spike protein of the coronavirus can reduce the viral load and improve symptoms”. However, much more data is needed to assess whether the agents can effectively prevent severe courses of disease.
“We need to know whether the drugs can actually improve outcomes for patients – i.e. avoid hospital admissions, shorten hospital stays, reduce the number of artificial respirations and improve survival rates,” says Landray. In addition, he says, information is needed on how well the drugs work for example in the elderly, different ethnic groups or people with other diseases.
Stephen Evans of the London School of Hygiene & Tropical Medicine has a similar assessment of the situation. The evidence for the effectiveness of the antibodies is encouraging, but still limited. “The fact that emergency approval has been applied for in the U.S. does not mean that the companies already have sufficient data available – they hope to have it very soon.
Trump promises free treatment for all Americans. Are there enough drugs available?
The production of antibodies is complex and expensive, their quantities are limited. However, both companies have already started production regardless of the results of their studies.
“Currently, doses are available for an estimated 50,000 patients,” writes Regeneron in a statement. “However, we expect doses for a total of 300,000 patients to be available within the next few months.
Lilly has committed to delivering one million doses of its antibody in the fourth quarter, but at the lowest of the doses studied.
By comparison, in the past seven days alone, more than 300,000 people in the U.S. have been infected with sars-CoV-2, according to authorities.
Conclusion: Antibody treatments could become an important building block of Covid-19 therapy. However, it is still unclear to what extent patients will benefit from these treatments. Studies on this question are still ongoing. Antibodies are unlikely to become a “cure”, but in the best case scenario, they could protect people from infections and severe courses of disease.
— Hector Pascua, Sources: meduniwien.ac.at, spiegel.de, sciencemag.com. Picture: stockilyapp.com
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