Lilly Antibody Combo Therapy Reduced Viral Levels in Study

Eli Lilly and Co.’s combination antibody drug for Covid-19 reduced patients’ viral levels better than one of its components that’s already authorized for U.S. emergency use, a study found.

The component, called bamlanivimab, didn’t reduce viral load compared to placebo, according to a study published in the Journal of the American Medical Association. When combined with another antibody called etesevimab, though, there was a significant reduction compared with those who got a placebo.

The study found no difference between the monotherapy and combination in outcomes like hospitalization and deaths, a finding that should be more important to doctors than the viral load results, Lilly Chief Scientific Officer Dan Skovronsky said in an interview.

Concluding from the study that bamlanivimab shouldn’t be used as a monotherapy would be a misinterpretation, he said. “Doctors should be just as confident using mono as combo.”

Lilly fell as much as 1.6% as of 1 p.m. Thursday in New York.

While researchers are rushing to develop new drugs and policies for the public-health crisis, the understanding of both Covid-19 and therapies to prevent and treat it has been more slowly evolving. Lilly is looking for other uses for bamlanivimab, with another study showing it can prevent Covid-19 in nursing home residents and workers.

The final results from the comparative study appeared to contradict an earlier interim analysis showing that bamlanivimab alone could significantly decrease viral loads, editors for the journal wrote in a corresponding note.

Typically, an early analysis like that wouldn’t be published, but “these are not normal times,” they said. The JAMA editors also said that secondary clinical outcomes will likely matter most to patients and their families.

“Even though monoclonal antibodies likely improve clinical outcomes in selected patients,” they wrote, “the studies needed to answer remaining questions on the utility of treatment (which patients can benefit and in what circumstance) are unlikely to become available in a timely manner.”

‘We Were Wrong’

Bamlanivimab and etesivimab each mimic proteins that the body naturally makes to repel viruses. Bamlanivimab was cleared in November for treatment of non-hospitalized Covid patients at risk of severe illness because of age or chronic medical conditions, or other factors.

The study, known as BLAZE-1, followed 577 patients who had tested positive and had at least one Covid symptom. Patients on the combination therapy had a statistically significant decline in their viral levels at 11 days; those who received bamlanivimab alone didn’t. Interim results of the trial, released last fall, didn’t include results for the combination therapy.

The study was designed last spring, Skovronsky said, when it appeared that measuring viral load would be an efficient approach to testing the drug’s effectiveness.

“We were wrong,” he said. “It turns out viral load is difficult to measure, and variable within patients, and cleared quite quickly in people who had a good immune system.”

Many infectious disease specialists had believed that patients’ viral load would help predict their disease course, said Rajesh Gandhi, an infectious diseases physician at Massachusetts General Hospital and Harvard Medical School.

With Covid-19 “it’s too new,” said Gandhi, who also serves as co-chair of the Infectious Diseases Society of America’s Covid-19 treatment and management guidelines expert panel. “It’s too early to say whether lowering viral load will improve clinical outcomes.”

The combination may be an option in the event that coronavirus mutations render bamlanivimab ineffective, Skovronsky said. The drug has been able to halt variants like the highly transmissible B.1.1.7 strain that emerged in the U.K., he said.

Regulators are reviewing the combination emergency use authorization. Lilly expects use of bamlanivimab will shift toward the combination around the middle of this year, Skovronsky said.

Plagued by logistical issues, insufficient reimbursement and concerns about a lack of efficacy data, Lilly’s antibody therapy has been underused. Health-care providers should continue to administer all available supply, Skovronsky said.

“You don’t want to throw out the first antibody, which has the same benefit, because you’re waiting on the other,” he said.

Preventive Treatment

Another study of bamlanivimab also released on Thursday found that it reduced the risk of symptomatic Covid-19 by as much as 80% when used preventively for nursing home resents. The therapy also held benefits for nursing home workers.

Lilly will work with U.S. regulators to explore expanding the experimental drug’s emergency-use authorization to include prevention of the spread Covid-19 in long-term care facilities, Skovronsky said, calling it an “urgent situation.”

“Where there’s an outbreak in nursing homes and people haven’t yet received the vaccine, this could be a potential way to protect them before they get it,” he said.

©2021 Bloomberg L.P.

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