Covid-19: zoom on the Regeneron cocktail, now recommended by the WHO in certain cases – LCI

The World Health Organization is paving the way for a third treatment for Covid-19. But under conditions. According to an opinion of WHO experts published in the medical journal The BMJ, the synthetic antibodies of Regeneron are recommended on the one hand in “patients with non-severe forms of Covid who are at high risk of hospitalization”, like the elderly or those whose immune system is weakened by cancer or after an organ transplant, for example.

On the other hand, treatment is recommended in patients with “of a severe or critical form and who are seronegative, that is to say who have not developed their own antibody response” despite the infection. But what are these recommendations based on and how does it work? “cocktail” ? We take stock.

Designed by the biotechnology company Regeneron and marketed by the Roche laboratory under the name Ronapreve, or REGN-COV2, this treatment combines two so-called antibodies “monoclonal” made in the laboratory, casirivimab and imdevimab. Injected only in the hospital intravenously, they are supposed to support the immune system to neutralize the coronavirus. In more detail, the synthetic antibodies attack the small spikes that are on the surface of the virus.

They have already been used for years against certain cancers. The former President of the United States, Donald Trump, had also received this treatment when he had contracted the Covid in October 2020.

The new WHO recommendations for Regeneron antibodies are based on the results of several clinical trials. In the first case, these trials, the results of which have not yet been published, show that Ronapreve “probably reduces the risk of hospitalization and the duration of symptoms in patients at higher risk of severe forms” of the Covid. The second recommendation is driven by the results of the large UK Recovery trial. They show that these synthetic antibodies “probably reduce” the risk of dying and being placed on mechanical ventilation in patients who have not developed their own antibodies.

“For all other types of Covid-19 patients, the benefits of this antibody treatment are unlikely to be significant,” writes The BMJ in the press release accompanying the WHO opinion. The World Health Organization therefore calls for not giving treatment to patients who have developed antibodies, to ensure more equitable access throughout the world.

As a reminder, in France, treatment based on monoclonal antibodies has already proven its worth against Covid-19. In mid-March, temporary authorizations had thus been issued for the early treatment of adults likely to develop serious forms of the disease. More than 1,000 patients had then benefited from it, recalls the National Medicines Safety Agency (ANSM). However, one of the two drugs concerned by this first authorization in France of dual therapy based on synthetic antibodies precisely concerned the combination of casirivimab and imdevimab from the Roche laboratory co-developed by Regeneron.

In recent months, NGOs have denounced the high price of Ronapreve, which they estimated at around 2,000 dollars (1,700 euros) per dose. “Given the high cost and low availability of this treatment, (the international drug purchasing agency) Unitaid is negotiating with the Roche laboratory (…) to obtain lower prices and a fair distribution across all regions, especially low and middle income countries “, WHO highlighted in a separate statement.

WHO is also asking the laboratory to “transfer its technology to allow the manufacture of equivalent versions of this treatment, so that all patients who need it can have access”.