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Sanofi halts tests of arthritis drug for use as a COVID-19 treatment

Two rounds of testing disappointed, including one that included patients at four Boston hospitals

Sanofi is headquartered in France but has a unit in Cambridge.Marlene Awaad/Bloomberg

The drug maker Sanofi said Tuesday that it has concluded its rheumatoid arthritis medicine Kevzara will not work against COVID-19, following two disappointing rounds of testing, including one that saw the drug given to patients at four Boston hospitals.

Kevzara had been considered a potential treatment for coronavirus infection because it eases inflammation, but it now joins a growing list of unsuccessful efforts to conscript existing drugs into the battle against the pandemic.

“Although this trial did not yield the results we hoped for, we are proud of the work that was achieved by the team to further our understanding of the potential use of Kevzara for the treatment of COVID-19,” Dr. John Reed, Sanofi’s global head of research and development, said in a statement. “In times like these, commitment to properly designed, controlled clinical trials, provides the information and understanding the scientific community needs for fact-based decision making.


Massachusetts General Hospital, Brigham and Women’s Hospital, Tufts Medical Center, and Beth Israel Deaconess Medical Center were among 64 hospitals at 51 US sites where the drug had been tested starting in the spring. In July, Sanofi halted the US trial after finding that Kevzara did not sufficiently improve symptoms.

Sanofi, a French company whose Sanofi Genzyme unit is based in Cambridge, said its study involving 420 people outside of the United States did not show that the use of Kevzara significantly shortened COVID-19 patients’ hospital stays. Patients were about as likely to develop severe infections such as pneumonia and die on Kevzara as they were on a placebo. Sanofi said it did not anticipate conducting further tests.

The company previously said it wanted to see whether Kevzara lowered fever and reduced the need for supplemental oxygen to help patients breathe. But Sanofi’s chief executive had also said Kevzara was a “long shot” to work on COVID-19.


There are plenty of other candidates in play to tackle the symptoms of the coronavirus, or to reduce infections. As of Monday, there were 316 potential treatments and 207 vaccine candidates in development, according to an online tracker by the Milken Institute, a nonprofit think tank in Santa Monica, Calif.

Doctors and drug makers are scouring labs for existing treatments — from antiviral drugs to plasma from recovered patients — that could help people survive the coronavirus, and are subjecting them to stringent clinical tests. Among those that have failed are the malaria medicines chloroquine and hydroxychloroquine and Roche Holding AG’s Actemra.

The existing-treatment approach has unearthed some promising data. Gilead Sciences Inc.’s antiviral, remdesivir, and dexamethasone, an inexpensive corticosteroid used for rheumatism and asthma, both helped patients in tests. Doctors are also routinely administering heparin and other anticoagulants to prevent dangerous blood clots from forming in the veins of the critically ill.

Regeneron Pharmaceuticals Inc., a New York company that developed Kevzara with Sanofi, is also testing an antibody drug cocktail developed specifically for COVID-19.

Material from Bloomberg News was used in this report.

Andy Rosen can be reached at andrew.rosen@globe.com. Follow him on Twitter @andyrosen.