Sarilumab, Regeneron and Sanofi’s Arthritis Drug, Flops in Critically Ill COVID-19 Patients

Rheumatoid arthritis drug sarilumab was not an effective treatment for severely ill COVID-19 patients, according to the results of a phase 3 trial.

Sarilumab is manufactured by Regeneron and Sanofi and marketed as Kevzara. The companies announced the results of the trial in press releases.

The U.S.-based study was a phase 3 trial comparing 400 mg sarilumab plus best supportive care versus best supportive care alone for COVID-19 patients requiring mechanical ventilation. According to Regeneron, 80% of Kevzara patients and 77% of best supportive care patients in the primary analysis group sustained adverse events (AEs). Serious AEs documented in at least 3% of patients and were more common in the sarilumab group than the best supportive care group included multiorgan dysfunction syndrome (6% vs. 5%) and hypotension (4% vs. 3%). This study has been stopped in the 400 mg group as well as in a higher-dose cohort.

The primary analysis was a study of 194 COVID-19 patients with severe disease who needed mechanical ventilation. The main outcome was at least a one-point change from baseline on a seven-point scale consisting of:

  • death
  • hospitalized, requiring invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO)
  • hospitalized, requiring non-invasive ventilation or high-flow oxygen devices
  • hospitalized, requiring supplemental oxygen
  • hospitalized, not requiring supplemental oxygen – requiring ongoing medical care, related to COVID-19 or not
  • hospitalized, not requiring supplemental oxygen – no longer requiring ongoing medical care
  • discharged from hospital

An 800 mg dose of sarilumab was compared to best supportive care in a cohort of 27 patients.

The sarilumab trial was modeled off of a 21-person study in China of tocilizumab, which observed significant reductions in symptoms including fever and found that patients were successfully discharged from the hospital.

Sanofi is heading up a different trial that remains ongoing outside of the U.S., the companies said. This trial is also testing the drug in critical COVID-19 patients with a different dosing regimen. Results are expected in the third quarter.

The results of a phase 2 trial studying sarilumab in COVID-19 patients found the drug was not beneficial for patients hospitalized but not on ventilators.