Paris (AFP)

The immunomodulatory drug tocilizumab has shown its effectiveness in preventing the "inflammatory storm" in Covid-19 patients in serious condition, according to a French study not yet published, the first results of which were released on Monday.

This treatment reduced "significantly" the proportion of patients who had to be transferred to intensive care or died, compared to those who received standard treatment, said the Assistance public-hospitals of Paris (AP-HP).

This is the "first comparative trial by lot" which "demonstrates a clinical benefit" of this treatment in Covid patients suffering from severe infection, said its organizers during a conference of telephone press.

These results have yet to be "consolidated" and will be published in a scientific journal in a few weeks. But the AP-HP explains that it has decided to make them public now "for reasons of public health", due to the context of the pandemic crisis, and to have communicated them to the French health authorities and to the World Health Organization ( WHO).

Tocilizumab (Actemra or RoActemra), from the Roche laboratory, belongs to the family of monoclonal antibodies - antibodies created in the laboratory, derived from a single strain of lymphocytes and designed to respond to a specific target.

Usually used in the treatment of rheumatoid arthritis, it works by blocking the receptor of a protein of the immune system which plays an important role in the inflammatory process.

Some patients with the new coronavirus experience a sudden worsening of their condition after several days, causing acute respiratory distress, a phenomenon probably linked to an excessive immune reaction of the body.

129 people hospitalized in 13 hospitals were included in the study: Covid patients suffering from "moderate to severe" pneumonia who needed oxygen assistance.

This profile corresponds "only to 5% to 10% of patients infected" by the coronavirus, but they are among those who are most at risk of being placed on artificial respiration or dying, underlined Xavier Mariette, co-investigator study coordinator, during the conference call.

Half of the participants received one or two tocilizumab injections in addition to the standard treatment (oxygen, antibiotics and anticoagulants), while the other half received only standard care.

They were then followed for 14 days to obtain these intermediate results, a follow-up which will continue to confirm the conclusions.

At this stage, the researchers did not observe more undesirable side effects in the patients who received the immunomodulator than in those who received the standard treatment, underlined Prof. Mariette.

Other teams have already reported encouraging results concerning tocilizumab, at Foch hospital in particular, but these were "open" studies, without a randomized control group, which did not bring "the same level of evidence "and" do not allow to define a standard of treatment ", underlined the researchers of the AP-HP.

The current cost of tocilizumab is around 800 euros per injection, a high price but much lower than that of a day of hospitalization in an intensive care unit, they said.

A comparable drug, sarilumab (Kevzara), developed by Sanofi and Regeneron is also being tested in the same clinical trial program, called CORIMMUNO, and the first results should be known "within the next few days", according to Pr Mariette.

© 2020 AFP