A rheumatoid arthritis drug, Kevzara, jointly developed by Regeneron Pharmaceuticals and Sanofi, which initially showed promise in treating severely ill coronavirus patients in a clinical trial delivered disappointing results, prompting the companies to stop testing the drug in that group on Monday. The drug failed in its clinical trial after results showed that it was not of much help in patients who were less severely affected by coronavirus.

Sanofi has been in the process of developing a potential vaccine for the deadly coronavirus but not much has been achieved yet. Kevzara is different from the new antibody cocktail that Regeneron is developing to treat coronavirus that is expected to enter clinical trials in June.

Another disappointment for vaccine researchers

Sanofi
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Sanofi and Regeneron on Monday said that they will narrow the Phase III portion of their trial of marketed rheumatoid arthritis drug Kevzara as a potential Covd-19 treatment after preliminary tests shows that the drug was effective only in patients with more advanced "critical" respiratory illness caused by the disease. Kevzara was initially thought to help in reducing the lung inflammation in patients with the most severe forms of Covid-19.

However, Kevzara was not expected to directly help cure coronavirus but to help ease the immune system's overreaction to the virus that is resulting in inflammation and fluid buildup in the lungs of many patients. This would have helped in successfully keeping many patients off ventilators or saving their lives. "When you try everything under the kitchen sink, most of the time it's not going to deliver the results that you want, no matter what the small 20-patient or 30-patient studies say," said George D. Yancopoulos, Regeneron's co-founder and chief scientific officer.

Drug still can be used

Coronavirus
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Sanofi and Regeneron started trial of Kevzara Covid-19 patients in March after a study on 21 patients in China suggested that patients were benefiting from a Roche drug, Actemra, inhibiting the same pathway, known as IL-6. Results shows on Monday that patients identified as "severe" thoserequiring low level of oxygen supplementation and those not on ventilators benefited from the drug, while appear to do worse in the Phase II study, while there was no effect on those in the Phase III study.

However, that doesn't mean Sanofi and Regeneron will completely abandon the trail of the drug. The companies will proceed with a larger trial only in critical patients, testing the higher Kevzara dosage against a placebo. The results of the trial are likely to be released in June. The Federal Drug Administration hasn't approved any drug or treatment for Covid-19. However biotechnology and pharmaceutical companies have been trying out around 70 candidates across the world to develop a vaccine for the deadly coronavirus.