While monoclonal antibody treatment may hold promise for COVID-19, its clinical benefit has yet to be proven, said experts from the Infectious Diseases Society of America (IDSA).
In a media briefing, IDSA experts discussed that while manufacturers of monoclonal antibody treatment, Regeneron and Eli Lilly, both applied for emergency use authorization (EUA) from the FDA to treat COVID-19, the data on both so far have yet to demonstrate any impact on patient care.
Reviewing the data, Adarsh Bhimraj, MD, co-chair of the IDSA COVID-19 Treatment and Management Guidelines Expert panel, noted how the endpoints of both trials examined decreases in viral load for patients. He characterized these as surrogate endpoints, or “disease-oriented endpoints,” which are only meaningful if they translate into patient-oriented outcomes, such as preventing death or disability.
“Curing the virus is not the same thing as curing the patient and making them better,” he said.
Bhimraj even compared these antibody therapies to the saga of hydroxychloroquine, which was also shown to have “a very fast reduction in viral load” in early studies, “but randomized controlled trials did not translate into patients getting better or not dying.”
Helen Boucher, MD, member of the IDSA Board of Directors, said she wanted to support the FDA in their efforts to make evidence-based decisions about EUAs, saying they wanted to keep “everyone assured when we make recommendations, they’re believable and everyone can feel good about them.”
Bhimraj pointed to the situation with convalescent plasma, which received an EUA outside the context of a randomized clinical trial.
“We don’t have clinical trial data and it’s been used in thousands and thousands of people,” he said. “An EUA is important, but … what are the consequences … of an EUA and what are the collateral effects, especially when other therapies exist?”
He emphasized how important it was to “let science and let objectivity … determine the decision-making rather than any kind of political pressure.”
Boucher noted that the difference between having enough data for an EUA application was different than having enough data for a decision to be made. She suggested if the FDA wanted more data, it could convene an advisory committee to help in the decision-making process, “but it’s not a requirement, as far as I know.”
She added that even if an EUA is issued, that’s only half the battle, given how much manufacturers would need to scale up to meet demand.
“Any kind of authorization or approval doesn’t necessarily mean the drug is available to anyone who needs it,” Boucher said.
Using the example of 50,000 people who may be infected with COVID-19 on any particular day, even 20% of those patients ending up in the hospital would require more product than the companies are prepared to produce right now. Boucher said it would take “months” to manufacture enough to treat everyone in this country who needs it.
Cost is potentially another issue, with the other existing COVID-19 treatments potentially being much less expensive. Boucher said the steroid, dexamethasone, costs about $1 a day, while investigational antiviral remdesivir cost about $520 a day, but that “biologics … tend to be expensive, in the many, many thousands” of dollars.
In addition, the treatment was only shown to be effective in a limited population. Bhimraj pointed out the drug was effective was for patients with mild or moderate disease who were not hospitalized, and were “antibody-negative.”
“It’s not just the logistics of getting the drug, administering the drug [to] outpatients, and administering the drug in a timely manner. It’s not going to be as easy as … taking a pill.” he said, noting the drug is given as infusion therapy.
Safety is another issue, with concerns about antibody-mediated worsening of the disease, though Bhimraj said based on the data in the press releases, these drugs seem to be safe and well-tolerated.
Boucher said the current goal for COVID-19 therapies should be “if not to prevent infection, then to significantly mute it.”
“The best infection from COVID is one that never happens,” she added.