Along With Chloroquine, What Drugs Are Being Tested Against Coronavirus?

RIO DE JANEIRO, BRAZIL – When a crisis like the one caused by the novel coronavirus emerges, there is no time to develop specific means to tackle it. New drugs need a great deal of time to test their safety, but there is a way to skip a few steps.

The story of Viagra, created to treat angina pectoris, is well known, as it became a sales success only when it was discovered that it favored erection. Something similar is happening with the drugs for the Covid-19: drugs with other purposes are being reused, in the search for some that are effective against this virus or its effects.

Several products are being tested on patients, some in more advanced trials than others. In addition, the use of blood plasma from people who have overcome the disease and generated antibodies as treatment for the Covid-19 is currently under study.

Finally, in a longer term search, but one that may also fully prevent the disease rather than just alleviate it, as antivirals do, several potential vaccines are being tried.

As the Spanish Drug Agency recalls, “although there are numerous clinical trials underway, there is currently no evidence from controlled clinical trials to recommend a specific treatment for the SARS-CoV-2 virus”.

However, the need and lack of alternatives means that several promising products are already being offered.

Remdesivir

This drug was developed by the US pharmaceutical laboratory Gilead to treat Ebola. Although in a comparative analysis it is less effective than at least two other drugs for this purpose, its antiviral activity in experiments with the novel coronavirus has given it a second life.

It has been used with successful results in patients infected by the SARS-CoV-2 and there are already two clinical trials in China, two others in Spain and others internationally coordinated to prove its efficiency. The first results are expected in April.

Lopinavir/Ritonavir

It is part of the antiretroviral cocktail used to contain HIV. This treatment became known when it was successfully administered by doctors at the Virgen del Rocío hospital in Seville (Spain) to treat the first case of the SARS-CoV-2 infection recorded in the country.

But an individual case of success does not automatically become a proven therapy to be offered to patients in general with confidence.

In a clinical trial conducted with 200 patients in China, this antiviral therapy showed no significant beneficial effect on a control group that was given the usual course of treatment.

Nevertheless, the authors do not rule out that other studies may prove a benefit. Among other things, it is believed that the dose used to treat HIV is not sufficient for coronavirus, and that an increase could improve the results.

Chloroquine and hydroxychloroquine

Both drugs began to be used to treat malaria, but their most frequent use today is to treat autoimmune diseases such as lupus and arthritis. Its potential against the SARS-COV-2 is, on the one hand, that its ability to annihilate the viruses has been observed, but, in addition, it has anti-inflammatory effects, something that would help patients with a worse prognosis.

At the moment there are no published clinical trials proving the efficacy of any of these drugs, but there are more than 20 in progress, mainly in China, according to the Spanish Drug Agency.

“The level of evidence is still considered low and is based on pre-clinical and safety data in other indications,” they point out. In laboratory experiments, chloroquine was found to be effective against the SARS-COV-2, but it has not shown activity in animal models or in humans against the flu virus, dengue and Chikungunya.

Blood plasma

Another experimental therapy to deal with the avalanche of patients is direct blood plasma transfusion from people who have recovered from the infection. In Spain, a clinical trial is being prepared in which the efficacy of so-called hyperimmune plasma would be proven.

This strategy has already been used for the 1918 flu. In this pandemic, which killed 50 million people around the world, clinical trials at the time showed that survivors’ plasma halved the virus’ mortality potential.

Other therapies

In addition to the aforementioned, there are a dozen other compounds that have been used experimentally to halt the advance of the disease in cases with no alternatives. Tocilizumab and sarilumab, for instance, are immunosuppressants used for diseases such as rheumatoid arthritis and which prove useful in controlling inflammatory processes caused by the virus.

The vaccines

The World Health Organization (WHO) has published a list of over 40 vaccine candidates being developed by teams worldwide.

At present, only two groups have begun the first stage of clinical trials in humans to prove safety and the ability to cause an immune reaction. First, the mRNA-1273 vaccine, developed by scientists at the NIAD (National Institute for Allergies and Infectious Diseases of Spain) in cooperation with the American company Moderna.

This team, given the circumstances and in a rather unusual way, began testing its vaccine directly on humans, although standard animal trials are being conducted simultaneously.

The second project is the one developed by the Chinese company CanSino Biologics in cooperation with the Chinese Military Academy of Medical Sciences. Although there are chances that at the end of this year there will be a vaccine that shows its usefulness, it will still take months to mass produce them and reach those who need it.