By Joseph Walker 

Regeneron Pharmaceuticals Inc.'s experimental Covid-19 drug helped reduce virus levels and improve symptoms in nonhospitalized patients, according to a preliminary analysis of clinical trial data, the company said Tuesday.

Regeneron said the early data is an encouraging sign that its drug can help treat Covid-19 patients in earlier stages of the disease, before they are hospitalized. The company said it has begun discussing the results with regulators.

Regeneron's drug, codenamed REGN-COV2, is part of a class of medicines known as monoclonal antibodies that are designed in labs to mimic the naturally occurring antibodies that the immune system produces to fight off viruses and other foreign invaders.

The drug was most effective in treating patients who hadn't yet mounted an effective immune response, which the company measured by testing patients for antiviral antibodies before beginning treatment. The median number of days it took to alleviate symptoms in patients without antibodies was eight days among those who received the highest dose of the drug, six days in those who received the lowest dose, and 13 days in patients who were given placebos, Regeneron said.

"The greatest treatment benefit was in patients who had not mounted their own effective immune response, suggesting that REGN-COV2 could provide a therapeutic substitute for the naturally occurring immune response," George D. Yancopoulos, Regeneron president and chief scientific officer, said in a statement. "These patients were less likely to clear the virus on their own, and were at greater risk for prolonged symptoms."

The analysis looked at the first 275 patients enrolled in the first phases of an ongoing clinical trial to identify the patients most likely to benefit in later phases of the study. Because the analysis wasn't part of a preplanned analysis, the findings are merely descriptive and can't be considered statistically significant, the company said.

Write to Joseph Walker at


(END) Dow Jones Newswires

September 29, 2020 16:43 ET (20:43 GMT)

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