In recent months, Sanofi, the parent company of Sanofi Pasteur with a facility in Swiftwater, began working with Regeneron Pharmaceuticals Inc. on a treatment for COVID-19 using the drug sarilumab. The drug, marketed under the name Kevzara, has Federal Drug Administration approval for its use in treating rheumatoid arthritis.

Based on a small study of 21 patients in China, researchers there discovered the drug tocilizumab, which works similarly to sarilumab (Kevzara), had a positive effect on 15 of the seriously ill patients.

According to Sanofi, Kevzara is a fully human monoclonal antibody that inhibits the interleukin-6 pathway by binding and blocking the IL-6 receptor. Blocking that IL-6 may play a key role in driving the inflammatory immune response that causes acute respiratory distress syndrome in critically ill patients.

“Initial non-peer reviewed results from a single-arm, 21-patient Chinese trial found COVID-19 patients experienced rapidly reduced fevers and 75% of patients (15 out of 20) reduced their need for supplemental oxygen within days of receiving another IL-6 receptor antibody (tocilizumab),” a press release stated. “Based on these results, China recently updated its COVID-19 treatment guidelines and approved the use of that IL-6 inhibitor to treat patients with severe or critical disease.”

On March 26, tocilizumab was approved by the FDA to be used in the clinical trial for treatment of COVID-19 patients. Clinical trials using Kevzara also began in the United States and have expanded to include a federally-funded study in Boston and several in other countries including Italy, Spain, France, Denmark, Germany, Russia, Israel, Japan and Canada.

“To initiate this trial quickly, Regeneron and Sanofi have worked closely with the U.S. Food and Drug Administration and the Biomedical Advanced Research and Development Authority,” said Dr. George Yancopoulos, co-founder, president and chief scientific officer of Regeneron.

The clinical trial had three study groups: one group was given a high dose of Kevzara (400 mg), the second a low dose (200 mg), and the third a placebo. Only patients who were hospitalized with a confirmed case of COVID-19, and diagnosed as being in severe or critical condition, or having multi-organ dysfunction were accepted into the U.S. trial.

Of the 457 hospitalized patients, 28% were categorized severe, 49% were critical, and 23% had multi-system organ dysfunction in the Phase 2 trial.

Sanofi said there were no noticeable differences between patients who received the low dose of Kevzara (200 mg) and those on the placebo. Some benefit was seen in patients that were diagnosed as critical. The study found that Kevzara lowered the C-reactive protein, which is a key marker of inflammation.

For information about all clinical trials for COVID-19, go to clinicaltrials.gov.