The chloroquine adopted against malaria and some autoimmune diseases, has become the first drug that has proven effective against the new coronavirus. After chloroquine comes remdesivir, which was developed for Ebola and is being tested in 761 patients in a study to be presented on April 27 . It is followed by Kaletra, which combines two drugs created against HIV and which is also expected to be effective against coronavirus.
Never before have so many treatments been tried or so quickly against a disease, indicating the level of emergency that Covid-19 represents. There are more than 100 clinical trials underway in China evaluating the potential efficacy of all kinds of treatments, from antivirals to modulators of the immune system, through stem cells, traditional Chinese medicine therapies and antibodies donated by people who have been cured.
The strategy: try everything
There are over a hundred clinical trials underway to test all kinds of therapies
All of these trials are based on treatments initially applied to other diseases . Looking to the future, researchers around the world are studying the new coronavirus called SARS-CoV-2 to obtain specific therapies against it. Not all treatments under study will be equally effective and safe, so many will be ruled out.
The first two to show efficacy in cell culture trials were chloroquine and remdesivir, researchers from the Wuhan Institute of Virology announced February 4 in the journal Cell Research .
It is inhibited by the replication of different types of viruses – including HIV and coronaviruses. In the first fifteen clinical trials conducted in China on patients hospitalized for Covid-19, it has been shown to prevent serious complications from pneumonia and to shorten the duration of the disease, according to results presented Feb. 19 in BioScience Trends .
Given these results, the authors of clinical trials have recommended that the Chinese National Health Commission include chloroquine in the Covid-19 treatment protocol.
The main candidates
In addition to chloroquine, one drug created for Ebola and another for HIV are expected to be effective.
For its part, remdesivir is a new drug that has not yet been approved for the treatment of any disease. Developed by the American biotechnology company Gilead Sciences, it acts against various types of viruses, preventing the replication of its RNA . It has shown activity against coronaviruses in mice, as well as in human lung cells infected by this type of virus.
The results of the first clinical trials with Wuhan patients are expected in late April, and if the drug proves to be effective and safe, China could approve it in May, Shibo Jiang, a virologist at Shanghai Fudan University, told the journal Nature . Gilead Sciences announced this week that in March it will start two more clinical trials of remdesivir with almost a thousand patients from other countries.
An alternative strategy is not to attack the virus directly, but to act on the immune system to mitigate the effects of the infection. With the SARS coronavirus, some of the more serious complications were found to be due to over-activation of the immune system that triggered an sometimes fatal immune reaction. Drugs like baricitinib, already approved for rheumatoid arthritis, have been proposed to reduce inflammation without compromising the ability of lymphocytes to attack the coronavirus.
Chinese medicine also provides possible treatments that are being tested in fifteen clinical trials in which more than 2,000 people participate. One of the largest, with 400 participants, evaluates shuanghuanglian , an extract from the Forsythiae fructus plant that has been used for centuries against infections.
The World Health Organization (WHO) collaborates with scientists in China to ensure that clinical trials are rigorous so that their results are useful. According to WHO’s Nature Soumya Swaminathan, “we want a scientific approach to trials of traditional medicine.”