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Regeneron’s COVID-19 Antibody Cocktail Reduces Virus Levels
The COVID-19 antibody cocktail reduced coronavirus-related medical visits by 57% and related medical visits by 72% in patients with more than one risk factor.
Regeneron Pharmaceuticals recently announced positive prospective results from an ongoing Phase 2/3 clinical trial evaluating its COVID-19 antibody cocktail.
The trial found that the cocktail, REGN-COV2, met the primary and key secondary endpoints and significantly reduced viral load and patient medical visits, including hospitalizations, emergency room, urgent care visits, and physician office or telemedicine visits.
Specifically, treatment with the antibody cocktail reduced medical visits related to COVID-19 by 57 percent through Day 29 and reduced related medical visits by 72 percent in patients with one or more risk factor.
"The first job of an antiviral therapeutic drug is to lower the viral load, and our initial data in 275 patients strongly suggested that the REGN-COV2 antibody cocktail could lower viral load and thereby potentially improve clinical outcomes,” George D. Yancopoulos, MD, PhD, president and chief scientific officer of Regeneron, said in the announcement.
“Today's analysis, involving more than 500 additional patients, prospectively confirms that REGN-COV2 can indeed significantly reduce viral load and further shows that these viral reductions are associated with a significant decrease in the need for further medical attention.”
The randomized, double-blind trial is currently uncovering the effect of adding REGN-COV2 to standard of care, compared to adding a placebo to standard care.
The data from an additional 524 patients showed that the trial met all the first endpoints in the “statistical hierarchy,” Regeneron said. The hierarchy addressed virologic endpoints based on viral load, seronegative status (no antibody presence), dose group, and key clinical endpoint of COVID-19-related medical visits.
Viral load is the amount of COVID-19 that is present in an infected individual’s blood.
Patients with higher viral load at baseline or who were seronegative at baseline saw greater benefit from REGN-COV2.
On the primary endpoint, the average change in viral load through Day 7 was 0.68 log10 milliliters greater reduction with REGV-COV2 in patients with high viral load.
But in the overall patient group with detectable virus at baseline, the average daily reduction in viral load through Day 7 was a 0.36 log10 milliliters greater reduction with REGN-COV2 compared to placebo.
Additionally, researchers found a 1.08 log greater reduction with REGN-COV2 treatment by Day 5.
The overall results showed that REGN-COV2 was well tolerated in the trial, but there was no significant difference in virologic or clinical efficacy between the REGN-COV2 high dose (8 grams) and low dose (2.4 grams).
Additionally, serious adverse events occurred in more placebo patients than patients receiving REGN-COV2.
"We continue to see the strongest effects in patients who are most at risk for poor outcomes due to high viral load, ineffective antibody immune response at baseline, or pre-existing risk factors,” Yancopoulos said.
Regeneron stated that it will review potential changes to dosing in the ongoing outpatient clinical trial due to the limited supply of REGN-COV2, as well as submit detailed results from the trial to share insights with health and medical communities.
In mid-October, Regeneron first announced that REGN-COV2 reduced viral load and alleviated symptoms in non-hospitalized coronavirus patients in a Phase 1/2/3 clinical trial.
The mean time-weighted average change from baseline viral load through Day 7 in the seronegative group was a 0.60 log10 milliliters greater reduction in patients treated with high dose compared to a placebo.
Additionally, patients treated with a low dose saw a 0.51 log10 milliliters greater reduction compared to a placebo.
Overall, seropositive patients had significantly lower levels of virus at baseline and achieved viral loads nearing the lowest levels quantifiable, while seronegative patients had notably higher levels at baseline and cleared the virus more slowly with no treatment.
Researchers also found that patients with higher baseline viral levels had correspondingly greater reductions in viral load at Day 7 with REGN-COV2 treatment.
