While the world focuses on the rollout of COVID-19 vaccines, antibody treatments that can be given to patients after they've contracted the disease haven't been in the spotlight. Regeneron's cocktail of two monoclonal antibodies synthesized to block the SARS-CoV-2 virus got plenty of press when it was given to President Trump, who subsequently recovered from COVID-19. In November 2020, Regeneron won emergency use authorization from the Food and Drug Administration for the cocktail, called REGN-COV2, in treating patients with mild to moderate cases of the disease.

100% effectiveness in preventing symptomatic disease, so far

Regeneron is conducting a trial to evaluate the usefulness of REGN-COV2 in preventing infection in the first place. This type of prevention is called "passive immunization," a process that confers short-term immunity immediately, instead of taking weeks like vaccines. The company released interim results from the trial this week. The data so far is stunning. So far, 409 patients have been evaluated. Subjects are randomized to get either REGN-COV2 or a placebo. The participants were selected from people at high risk of infection due to being exposed to a household member diagnosed with COVID-19. The antibody cocktail was administered as a simple injection, rather than via IV infusion as required in the current authorization.

None of the patients receiving the cocktail developed a symptomatic case of COVID-19, compared with eight in patients given the placebo. The incidence of asymptomatic cases was about half of that in the placebo group. What's more, the asymptomatic cases in the REGN-COV2 cohort had infections that lasted no more than a week, while 40% of the infections in the placebo group lasted three to four weeks. Analysis showed that the treated patients who became infected had significantly reduced viral loads compared to the placebo group. They were also apparently less contagious. The trial is far from over, having enrolled over 2,000 participants. That perfect record against symptomatic disease probably won't hold. Still, a successful trial could result in authorization for using the treatment to prevent the disease in people known to be exposed to the virus, potentially opening huge demand.

More good news

Regeneron is also testing the use of REGN-COV2 in hospitalized patients who aren't sick enough to need a ventilator. Data released in December was encouraging, with the treatment lowering the risk of ventilation or death by 22%. The treatment also seems to be effective against both the U.K. and South African variants.

Plenty of long-term value

Investors don't seem to be giving Regeneron much credit for its COVID-19 efforts despite the obvious success. Shares are selling for roughly the same multiple of forward earnings as they did when the pandemic began.

Media Contact|
David Paul
Managing Editor
Journal of Infectious Diseases and Diagnosis