The University of Minnesota Medical School has received $1 million to study whether a widely used generic medicine could be an effective treatment for COVID-19.

Early research suggests metformin, an inexpensive drug used for diabetes and weight loss, can help adults infected with the pandemic virus avoid serious illness. The U launched a small study of the concept late last year, and the research effort now can expand to include more than 1,000 patients.

Even as vaccines spread, doctors say the search for effective COVID-19 treatments remains important, because they don't expect the virus that causes the disease will be eradicated.

"We don't yet have accessible, available, cheap, safe, early outpatient treatment options for COVID," said Dr. Carolyn Bramante, an assistant professor of internal medicine and pediatrics at the U Medical School. "This is one of the first studies to look at that."

In December, U researchers published results showing that use of metformin was linked to significantly reduced risk of COVID-19 death in women. Their study reviewed a large set of de-identified patient data from Minnetonka-based UnitedHealth Group, and the findings supported the launch of a study with enrollment capped at 70 patients.

Other research has suggested benefits for men, as well, Bramante said.

Metformin might be helpful, she said, because it's thought to help reduce the inflammatory proteins that can kick into overdrive with serious cases of COVID-19. Also, variants of SARS-CoV-2 are emerging that could evade the protection of vaccines. Metformin is promising, she said, because it's thought to work within cells in ways that wouldn't be affected by those virus changes.

UnitedHealth Group's OptumLabs division for research and development is one of four groups providing funds to expand the study. More enrollment will help researchers demonstrate any potential benefit, Bramante said.

Beyond the $1 million received thus far, another $500,000 in support has been pledged if the study hits certain enrollment targets.

"I am excited to help further this work," Dr. Ken Cohen, executive director of translational research at OptumLabs, said in a statement. "Finding an effective, safe, low cost medication that could treat COVID-19 worldwide, particularly in countries with low healthcare resources, is a critically important endeavor."

The retrospective study published in December looked at about 6,000 patients with Type 2 diabetes or obesity who were hospitalized with COVID-19. It found that women who had filled a 90-day prescription before hospitalization had a 21 to 24% reduced likelihood of mortality compared with women in the study who weren't taking the medicine.

M Health Fairview and Hennepin Healthcare in Minneapolis are two of seven clinical trial sites across the country for the expanded study, which is open to both men and women.

Participants must enroll within three days of testing positive for COVID-19. They receive two week's worth of medicine or a placebo, which they take twice per day.

Enrollees track their symptoms and complete a survey after 14 days. The study is open to people between the ages of 30 and 85 with body mass index (BMI) readings in the overweight or obesity categories.

People with higher BMI scores tend to chronically experience at low levels the inflammatory proteins that can become a problem with severe cases of COVID-19. So those patients might be more likely to benefit from metformin's ability to decrease inflammation.

Researchers are seeking regulatory approval to further expand the trial to include two other medications. If authorized, the second expansion would occur in the near future, researchers say.

"Let's say we're in a world where we have 100% vaccination," Bramante said. "Some people will still get COVID, and it will be important to understand ways to just reduce their symptoms, even if they're at decreased risk of severe illness."

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck