Regeneron advances COVID-19 antibody cocktail into late-stage trials

Monday, July 6, 2020

Source: BioPharma Dive

Dive Brief:

  • Regeneron on Monday announced the start of a Phase 3 study testing whether its experimental antibody drug cocktail can prevent coronavirus infections in people who have been exposed to a COVID-19 patient.
  • The decision to launch the trial, which will be run jointly with the U.S. government, was based on a review of data from a small safety trial. Regeneron will also begin on its own mid-stage tests of the regimen, dubbed REGN-COV2, in hospitalized and non-hospitalized COVID-19 patients, two groups that had been included in the initial study.
  • Regeneron is now the first company to begin late-stage efficacy research on an antibody-based drug, which can be used to either block infections or to prevent the virus from making patients sick. Eli Lilly is due to soon deliver initial data on an antibody treatment for COVID-19 as well.

Dive Insight:

Antibody-based drugs are designed to limit the harm of an infection with the SARS-CoV-2 virus by preventing it from entering cells and replicating, essentially giving the body's immune system an assist.

Since researchers could potentially generate supporting data for engineered antibodies relatively quickly, some experts believe these drugs could help "bridge" strained healthcare systems to the point when a vaccine is first available. Even though vaccine development is moving forward extraordinarily quickly, the large Phase 3 trials needed to prove vaccines safe and effective will still take months to run.

Regeneron's REGN-COV2 combines two antibodies that bind in two places on the new coronavirus' signature "spike" protein. A 30-patient Phase 1 trial began last month in hospitalized and non-hospitalized patients.

After a safety review by that trial's data monitoring committee, Regeneron, along with its partners at the National Institutes of Allergy and Infectious Diseases, decided to initiate a Phase 3 trial in people who have close exposure to a COVID-19 patient, such as another household member. The study will enroll about 2,000 patients at 100 sites in the U.S., with infection status as the primary endpoint.

Regeneron will also initiate two Phase 2/3 trials in hospitalized and non-hospitalized patients, which will enroll about 1,850 and 1,050 patients respectively, at 150 sites in the U.S., Brazil, Mexico and Chile. The two trials will evaluate virologic and clinical endpoints, the biotech said.

All of the trials will have an adaptive design that will adjust enrollment based on "trial progress and insights from Phase 2 studies," according to Regeneron.

In an email to BioPharma Dive, a company spokesperson said preliminary data should be available later this summer. Enrollment in the prevention study will be affected by the number of infections in the U.S., the spokesperson said.

Another planned prevention trial in healthcare workers and first responders, meanwhile, is being re-evaluated because the infection rates in those individuals has declined, the spokesperson said.

While work on Regeneron's antibody treatment is advancing quickly, the biotech and partner Sanofi announced a setback on another front last week. A trial testing the companies' rheumatoid arthritis drug Kevzara in severely ill COVID-19 patients failed to show a significant benefit, leading to the study's halt.

The hope was Kevzara, an anti-inflammatory drug, could tamp down the overactive immune response that can lead to complications and death in COVID-19 patients. Another similar therapy, Roche's Actemra, is also being tested on the same theory.

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