Through its Genentech unit, Roche (RHHBY -2.01%) is testing its rheumatoid arthritis drug Actemra as a potential treatment for pneumonia in patients with COVID-19, the disease caused by the new coronavirus. Roche said the Food and Drug Administration approved the start of the company's COVACTA phase 3 clinical trial.

The idea of using a rheumatoid arthritis drug for COVID-19 isn't that far-fetched. Some doctors have already tested Actemra on COVID-19 patients with some success, although the studies didn't have a control group. And last week, Regeneron (REGN -1.02%) and Sanofi (SNY 2.88%) started a clinical trial of their interleukin-6 inhibitor Kevzara, which is also approved for rheumatoid arthritis.

Actemra works by blocking the interleukin-6 receptor, which reduces the inflammatory response in rheumatoid arthritis patients. Roche thinks it could help patients with COVID-19 because patients fighting off the infection can go through what's called a cytokine storm, wherein the immune system's positive feedback loop goes haywire and causes the immune system to ramp up higher and higher until it's attacking the patient's own cells. Interleukin-6 is one of those cytokines involved in the positive feedback loop.

Restricted area with patient and doctors

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The clinical trial, which will be run in collaboration with the U.S. government's Biomedical Advanced Research and Development Authority, will compare Actemra plus standard of care (SOC) to placebo plus SOC. The study will measure clinical status, mortality, mechanical ventilation, and intensive care unit variables over 60 days. Roche plans to conduct an interim analysis to get an early look at whether the drug has efficacy in COVID-19 patients.

Roche also announced that it plans to provide 10,000 vials of Actemra to the U.S. strategic national stockpile. The company thinks there's enough of the drug in the supply chain that the stockpiling won't affect the use in rheumatoid arthritis.