- New study data released Tuesday by Regeneron and Eli Lilly provide some of the most definitive proof to date that combinations of engineered antibody drugs can help either prevent COVID-19 or treat the disease in its earliest stages.
- In one Phase 3 study, Regeneron's antibody cocktail prevented symptomatic coronavirus infections among household contacts of COVID-19 patients. In a different late-stage trial, Lilly's combination therapy reduced hospitalization rates and deaths in COVID-19 patients at "high risk" of having their disease progress.
- Taken together, the studies help solidify the benefit of antibody therapy, drugs that could play an important role but remain significantly underutilized because of difficulty in administering them. Those barriers remain, however, and the Biden administration hasn't appeared to make antibody treatment a priority, focusing its efforts instead on the rollout of coronavirus vaccines.
On a Jan. 14 conference call with reporters, top Food and Drug Administration drug evaluator Janet Woodcock listed several reasons why COVID-19 antibody treatments from Regeneron and Eli Lilly remain significantly underutilized. First among them was that, while promising, the data supporting each drug wasn't yet conclusive.
"We don't have the kind of evidence people are used to," she said then, noting the speed at which they were developed.
The past two weeks have brought more data, however. First, Lilly last week showed its single antibody treatment, bamlanivimab, helped prevent symptomatic COVID-19 in nursing home residents and staff — the first time an antibody drug was shown to protect against contracting coronavirus disease. Now, both Regeneron and Lilly are reporting Phase 3 results that bolster the idea antibody drugs can reduce the worst outcomes of COVID-19.
Regeneron's results come from a trial in which household contacts of COVID-19 patients were given an injectable version of its antibody cocktail REGEN-COV or a placebo and monitored for infection. Ten of the 186 who got Regeneron's drug were infected, but none developed symptomatic disease.
By comparison, 23 of 223 volunteers in the placebo group were infected, and eight had symptomatic COVID-19. There were no deaths or hospitalizations among those who got Regeneron's drug, versus one of each for placebo.
Treated participants who were infected also had lower levels of virus and cleared symptoms more quickly than the infected volunteers who received placebo. Regeneron aims to confirm the findings with results from all of the roughly 2,000 study volunteers.
Lilly, meanwhile, disclosed results from a study testing its own two-drug regimen in high-risk patients recently diagnosed with COVID-19. Of 1,035 total patients, Lilly said there were 11 hospitalizations or deaths in treated patients, versus 36 in the placebo group. No treated patients died, compared to 11 placebo patients.
Taken together, the results broaden the potential utility for coronavirus antibody drugs, which the FDA authorized in November for those with mild to moderate COVID-19 and who are at high risk of hospitalization. They mark the first time, for instance, REGEN-COV was shown to prevent COVID-19. And they "should support" an emergency clearance for Lilly's two-drug regimen, wrote Mizuho Securities analyst Vamil Divan.
Lilly's bamlanivimab, a single antibody, is currently cleared for use, but not the combination.
Yet the data don't address the underlying challenges of getting the drugs — which are currently infused in a healthcare setting — to the right patients when they need them, a problem that has led to just 20% to 25% of the available supply being used.
Two weeks ago, before the inauguration of President Joe Biden, Woodcock was part of a group campaigning for broader use of antibody drugs, arguing that failing to do so would lead to "more overwhelmed hospitals and healthcare workers." She and other Operation Warp Speed officials noted the government aimed to boost supply, awareness and support for healthcare providers.
A window still exists for antibody drugs to help, with the rollout of vaccines only just starting to ramp up after a slow start and some once-promising programs faltering.
But it's unclear what type of support exists for antibody drugs under the Biden administration. Woodcock is now the acting FDA commissioner, and no longer officially part of the team that will carry Warp Speed forward under a new name. She's also recused herself from decision-making on COVID-19 therapeutics, which would include Lilly's combination. Antibodies, meanwhile, weren't directly mentioned in the COVID-19 plan President Biden released last week.
For its part, Lilly aims to solve some of the logistical problems. The company said Tuesday, for example, that low doses of the combination were similarly effective as higher doses, which could stretch supply. It's also working with the FDA to cut infusion times from an hour to 16 minutes.
Injectable formulations, rather than infusions, may make administration simpler, too.
Geoffrey Porges, an analyst at SVB Leerink, has argued that preventive use of antibodies will be "an important tool" to complement vaccines and continued social distancing.
But others are skeptical improvements in administration will make a major difference. "We continue to believe that the market opportunity here will be limited given the anticipated broad rollout of vaccines, declining case loads and complexity around administration," wrote Brian Skorney, an analyst at Baird.