- Regeneron said a lower dose of its antibody cocktail effectively protected trial participants from the worst outcomes from COVID-19 in a new study, a finding that may help the company increase supplies and reach more high-risk patients before they are hospitalized.
- The combination treatment of casirivimab and imdevimab is already available in the U.S. at a dose of 2,400 mg. The latest study found that a 1,200 mg dose had similar effects, reducing the risk of hospitalization or death in high-risk patients by 70%, compared with 71% for the higher dose.
- Regeneron will share the results with the Food and Drug Administration "immediately" and seek to add the 1,200 mg dose of the combination therapy to the emergency use authorization granted last year. Roche, which sells the treatment outside the U.S., is also working with regulators to increase its use.
Regulatory clearance for a lower dose would quickly enable Regeneron to boost the supply and, potentially, sales of an antibody cocktail whose use has yet to be maximized.
Regeneron posted drug sales of about $260 million in the first quarter, all from its contract with the U.S. government. The company expects to provide about 750,000 doses of the therapy starting next quarter under a second government deal, but could increase that number to 1.25 million with the availability of the 1,200 mg dose.
The news follows similar findings from Eli Lilly, which said lower doses of its combination of bamlanivimab and etesevimab could reduce the risk of hospitalization or death by 87%. By using two antibodies that attack the virus in different ways, both the Regeneron and Lilly combination treatments are designed to battle viral mutations more effectively than a single therapy. Both proving effective at lower doses could help open the door for therapies delivered subcutaneously, rather than via infusion in a medical setting — a logistical barrier that's slowed uptake.
That's significant as health officials seek to counter the rise of more transmissible variants capable of causing more severe disease. Riskier variants in the U.S. roughly doubled in less than a month from the end of January to the end of February, according to the latest data available from the Centers for Disease Control and Prevention. The FDA has asked Regeneron and Lilly to track new variants and potentially run new studies against them.
Regeneron said its combination treatment stands apart from the Lilly therapies because it maintains its potency against all of the most concerning variants emerging in the U.S. FDA fact sheets suggest some variants — in particular those that share a specific characteristic with B.1.351, a variant that originated in South Africa — are less susceptible to the Lilly therapies, especially when bamlanivimab is given alone.
In fact, the U.S. government stopped shipping Lilly's single antibody treatment, bamlanivimab, into California, Arizona and Nevada because it's not effective against a variant gaining speed in those states, acting FDA Commissioner Janet Woodcock said recently at a webinar hosted by the American Medical Association.
Lilly told Endpoints News that lab studies show its combination treatment can neutralize the specific "California" variant.