A drug to treat rheumatoid arthritis and collaborated on by Regeneron (NASDAQ:REGN) and French-based Sanofi showed promise for treating the sickest coronavirus patients in a clinical trial but was not beneficial for patients with less-advanced disease, prompting the companies to stop testing the medicine in that group.
The drug, Kevzara, inhibits a pathway thought to contribute to the lung inflammation in patients with the most severe forms of COVID-19.
Regeneron, headquartered in Eastview, New York, and Sanofi started clinical trials of the medicine in COVID-19 patients in March after a small study from China suggested a benefit from a Roche drug, Actemra, inhibiting the same pathway, known as IL-6.
The results reported Monday showed patients characterized as "severe," (that is to say, those requiring low levels of oxygen supplementation and who weren’t on ventilators) derived no benefit from Kevzara in the trial — and in fact, appeared to do worse in the earlier, phase 2, part of the study. The phase 3 results in those patients showed the drug appeared to have no effect.
Sicker patients characterized as "critical," who required mechanical ventilation, high-flow oxygen or treatment in intensive care, did show a benefit from Kevzara compared with a placebo, particularly at a higher dose.
As a result, the companies are proceeding with a larger trial only in critical patients, testing the higher Kevzara dose against a placebo. Results from that trial are expected by June.
Regeneron shares tumbled $18.61, or 3.3%, to $547.60.
