Stanford Medicine researchers lead clinical trial of interferon-lambda for COVID-19

A clinical trial is underway at Stanford Medicine to determine whether a drug can keep people who’ve just tested positive for the coronavirus out of the hospital, help them recover faster and make them safer to be around in the meantime.

The researchers also want to know whether the drug stems viral shedding, which would reduce transmission to family members and the community.

The drug being looked at, interferon-lambda, is a manufactured form of a naturally occurring protein that’s been given in previous clinical trials to more than 3,000 people infected with hepatitis viruses.

“Its safety profile appears to be excellent,” said principal investigator Prasanna Jagannathan, MD, assistant professor of infectious diseases at the School of Medicine. He is co-leading the study with Upinder Singh, MD, professor of infectious diseases and of microbiology and immunology at the school.

Results in laboratory settings and in animals also suggest that lambda-interferon may be helpful in controlling viruses that cause respiratory illnesses such as influenza and SARS, an often fatal disease. It may also help snuff out other common viral infections.

Remdesivir, approved by the Food and Drug Administration for emergency use as a COVID-19 treatment, is restricted to hospitalized patients. Yet the great majority of patients with the disease — upward of 80% — are outpatients, for whom no drugs have been proven safe and effective, Singh said.

Interferon-lambda orchestrates the body’s natural defenses against infection by issuing a “call in the troops” order to constituent cells of the immune system. A closely related substance, alpha-interferon, has been used to treat hepatitis C and other viral infections, as well as cancer. But that substance has been found to be toxic to numerous organ systems. Receptors for it are present on the cells of many tissues. Receptors for interferon-lambda, however, are restricted to the linings of the lungs, intestine and liver, so it produces fewer side effects. The lungs and intestine happen to be the main places the coronavirus strikes.

The investigators are recruiting 120 participants who have just been diagnosed with cases of mild COVID-19 at Stanford Health Care and other local hospitals, emergency rooms, clinics and drive-through testing sites.

Trial participants, randomly sorted into two groups, will be given single injections under the skin of either a placebo or interferon-lambda. Then they will be monitored for 28 days for symptoms, disease severity, rates of hospitalization, and duration and quantity of viral shedding.

“Even though these individuals may not need hospitalization, infection with COVID-19 results in respiratory symptoms and lost productivity,” Singh said. “Plus — and this is important — patients with mild disease contribute to community disease transmission. Limiting viral shedding from this group would reduce transmission to family members and others, which is crucial to controlling epidemic disease spread.”

Faculty in the departments of Medicine, of Pathology, of Pediatrics and of Emergency Medicine, and at the ChEM-H Institute, are contributing to the trial.