More Minnesotans are gaining access to an experimental COVID-19 treatment that could prevent high-risk patients from being hospitalized.

Minnetonka-based United­Health Group announced Friday the launch of a large study that plans to enroll 500,000 people across 46 states, including Minnesota, and provide the new monoclonal antibody treatment to at least 5,000 patients.

Last month, Mayo Clinic became the first health system in Minnesota to begin administering the drug therapy, which is similar to treatment received earlier this year by President Donald Trump.

Hennepin Healthcare in Minneapolis is now providing the infusion treatment, and the M Health Fairview system plans to begin doing so next week.

Vaccines for COVID-19 have been getting a lot of attention in recent weeks, but the development of effective treatments remains crucial, said Ken Ehlert, chief scientific officer at UnitedHealth Group.

"In most diseases, the way these things work is, even if you have a vaccine you still need treatments that actually can help avoid the consequences of some of these diseases," Ehlert said.

The new COVID-19 drug bamlanivimab is for people with mild to moderate cases of the infectious disease.

Approved by regulators for emergency use, the treatment called bamlanivimab is manufactured by the Indiana-based drug company Eli Lilly. Patients age 65 and older receive the therapy through an hourlong infusion.

It's being offered to those with mild to moderate COVID-19 who are at high risk for getting it much worse. It's thought to work best when administered to patients early in the course of their illness.

The UnitedHealth study will let patients track their symptoms on a daily basis and get tested quickly if it appears they might have been infected by the virus. The company's division for health care services would then send a nurse to a patient's home to administer the infusion treatment.

The number of patients who might benefit from the treatment is expected to far surpass available supplies, at least initially.

Eli Lilly, which is working with UnitedHealth on the study, has a supply for research purposes. The drug is otherwise being purchased by the federal government and then allocated to states according to a formula.

The Minnesota Department of Health says it has distributed more than 4,500 doses to 70 treatment centers across the state and expects more shipments. The federal government also is distributing about 1,000 doses to a specialty pharmacy operated by Rhode Island-based CVS Health, which is providing infusions in patient homes or at long-term care centers in seven markets, including Minneapolis.

"We've had 71 sites [as of Friday] receive bamlanivimab that was allocated to us, plus the CVS location whose 80 doses are in addition to the [state] allocation," the Health Department said in a statement. Patients interested in the treatment should contact their health care provider, officials said, or seek information from the Health Department about options.

Mayo Clinic has treated 460 patients so far in Iowa, Minnesota and Wisconsin. About half the patients who've been offered the treatment at Mayo have declined it.

"We have had enough supply to date," the clinic said. "Nursing homes have limited ability to transport their patients to the infusion centers, so we are developing a plan to get the drugs to their residents at high risk."

UnitedHealth Group is the parent company of United­Healthcare, which is the nation's largest health insurer. The study announced Friday will be open to people with Medicare Advantage health plan coverage through the company, which will help identify those with a health history that puts them at greatest risk from COVID-19.

It's not yet known if the drug is safe and effective for the treatment of COVID-19, though results are encouraging. One goal of the study, Ehlert said, is to find out if there are subgroups of patients that could benefit most.

To develop the treatment, researchers from Eli Lilly and a biotech company identified "a very potent antibody that could fully neutralize the virus," said Dr. Daniel Skovronsky, Eli Lilly's chief scientific officer. Laboratory-made antibodies are designed to block the pandemic virus from attaching to and entering human cells.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck