Paris (AFP)

Can a derivative of the well-known antimalarial chloroquine fight Covid-19? French researchers launched a large study on Tuesday to "close the debate" when a Chinese team concluded the "potential" of such treatment.

The debate on the use of hydroxychloroquine has been raging for several weeks, mobilizing up to US President Donald Trump who saw it as a possible "gift from heaven" and spurred on by French professor Didier Raoult. He published two studies confirming according to him "effectiveness" of this treatment, but whose methodology is criticized by many specialists.

To "close the debate", a French team from the University Hospital of Angers announced the launch of a study "with the highest scientific and methodological standards", involving 1,300 patients with Covid-19 and carried out "under conditions which will not leave room for doubt in the analysis of the results ", according to Pr Vincent Dubée, initiator of the project.

Called Hycovid, the study must start on Wednesday and will be conducted in a "double blind": neither the patients nor the doctors will know if the patient receives chloroquine or a placebo (half of the patients for each group). These will be patients over the age of 75 or needing oxygen without being "in acute respiratory distress".

"One of the strengths of this study is that it will include patients with a non-serious form of the disease but at high risk for an unfavorable course, such as certain elderly people. We will therefore treat people early, this which is probably a determining factor in the success of care, "said Professor Dubée. The first results should be known in "a few weeks".

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Also on Tuesday, a Chinese team released its study conducted in a hospital in Wuhan, the declared origin of the Covid-19 epidemic, concluding that "potential" of hydroxychloroquine as a treatment against the new coronavirus.

However, this study was not reviewed by a specialist reading committee of a scientific journal, leading a number of specialists to put the conclusions into perspective.

Doctors at the Wuhan People's Hospital studied 62 infected patients, 31 who received hydroxychloroquine (400 mg / day) and a control group of 31 patients who did not.

The two groups were randomized by computer with an average age of patients of 44.7 years. Presenting symptoms of pneumonia which had not degenerated, they all received "standard treatment", oxygen, antivirals, antibiotics, without further details. In addition, lung scans were performed before the start of the study, and after five full days of treatment.

At that time, patients in the hydroxychloroquine group had significantly better pneumonia results, with improvement in 80.6% of them (of which 61.3% had "noticeable improvement"), versus 54.8% for the control group. The symptoms of fever and cough had also improved more quickly.

Cautious conclusion of the authors: "the potential of hydroxychloroquine for the treatment of Covid-19 has been partially confirmed" and in the absence of "no other option currently, it seems promising to use hydroxychloroquine under surveillance", continue while wishing in particular "a wider clinical study".

Professor Didier Raoult welcomed these results on Twitter: "Despite the small number of cases, the difference is significant. This shows the effectiveness of this protocol".

But others still questioned the methodology here, without, however, "throwing away" the results. Like Florian Zores, cardiologist in Strasbourg who notes that the study does not correspond to his prior declaration which announced three different cohorts of 100 patients each with a final evaluation of virological load, while finally it is satisfied with clinical results.

The authors also do not specify "the characteristics of the patients excluded" from the study (80) and the formulation leaves doubts about the conditions for carrying out double blind.

The specialized Swiss online media Heidi.news noted "promising" results, but a study "most probably carried out in an emergency", the possibility that patients may have "received other treatments, including antiviral, which blur a little the results ", and finally" the short follow-up time ".

© 2020 AFP