Paris (AFP)

WHO's suspension of the hydroxychloroquine trials could have signaled the end of this possible treatment for Covid-19. But the study responsible for this decision is now under attack from all sides, relaunching the debate on the controversial molecule.

The study in question, published on May 22 in the scientific journal The Lancet, is based on approximately 96,000 patients hospitalized between December and April in 671 hospitals, and compares the condition of those who received treatment with that of patients who did not haven't had it.

Dr. Mandeep Mehra and colleagues conclude that treatment does not appear to be beneficial to hospitalized Covid-19 patients and may even be harmful. Results they maintain: "We are proud to contribute to the work on the Covid-19" in this period of "uncertainty," one of the authors, Sapan Desai, told AFP on Friday.

These results, which are in line with several other smaller studies, have had considerable impact and dramatic consequences.

Three days later, the World Health Organization (WHO) announced the precautionary suspension of clinical trials it was conducting on this molecule with its partners in several countries.

Several other clinical trials have been suspended and some countries, including France, have banned the use of hydroxychloroquine for the treatment of Covid-19, much to the chagrin of its sponsors.

The first of them, the now famous Professor Didier Raoult, immediately judged the Lancet study "messy". His own work, which concludes that hydroxychloroquine is combined with an antibiotic, azithromycin, has been criticized, with other scientists pointing to numerous methodological biases.

But even skeptical researchers on the interest of the molecule against Covid-19 have expressed their doubts about the Lancet study.

In an open letter published Thursday evening, dozens of scientists from around the world, from Harvard to Imperial College London, note that the scrutiny of the Lancet study raises "both methodological concerns and data integrity ".

- "Breaking trust" -

This data comes from Surgisphere, which presents itself as a health data analysis company, based in the United States.

The company led by Sapan Desai has assured that the agreements with partner hospitals prohibit it from sharing data, the integrity of which it defended.

But on Friday, the Lancet released a correction on deaths attributed to an Australian hospital that should have been counted in Asia.

This "underscores the need for error checking throughout the database," insist the scientists who signed the open letter, calling for the establishment, for example, by WHO of a group responsible for carrying out an independent analysis. study findings.

Dr Mehra assured AFP on Friday that an "independent academic analysis of the data" was launched.

But "the results, conclusions and interpretations of the study remain unchanged", he assured, noting however the "intermediate" nature of this observational study pending the results of clinical trials "necessary to reach a conclusion" on hydroxychloroquine.

Asked about the case on Friday, the WHO noted that the suspension of the trials involving hydroxychloroquine was "temporary" and that its experts would give their "final opinion" after examining other elements (notably the interim analyzes of the Solidarity essay), probably by mid-June.

Data should also come from the British Recovery trial, the hydroxychloroquine part of which is continuing. Based on their own mortality data, officials say there is "no compelling reason to suspend recruitment for security reasons".

The open letter, signed in particular by Pr Philippe Parola, collaborator of Pr Raoult, was immediately relayed by the latter, quoting Winston Churchill.

"+ This is not the end. It is not even the beginning of the end. But it may be the end of the beginning + ... Of the war against chloroquine," he tweeted. .

But all the signatories of the open letter are far from being defenders of hydroxychloroquine.

"I have serious doubts about the benefits of a chloroquine / hydroxychloroquine treatment for Covid-19 and I can't wait for this story to end, but I believe that the integrity of the research cannot be invoked only when an article does not go in the direction of our preconceptions ", commented on Twitter Professor François Balloux, of the University College of London.

Also, "it was with a heavy heart that I added my name to the open letter".

Signatories or not, many scientists have relayed their concerns about the impact of this case on science, sometimes with the hashtag #Lancetgate ("Lancet scandal") or #whats_with_hcq_lancet_paper ("what's going on with the study Lancet ").

"If the Lancet article is a fraud, it will shatter trust in scientists in a lasting way," said Professor Gilbert Deray of Pitié-Salpêtrière in Paris on Friday. "I await with concern the results of the investigation".

© 2020 AFP