Antibody Cocktail for COVID-19 Reduces Viral Load, Medical Visits

REGN-COV2 consists of 2 virus-neutralizing antibodies that bind noncompetitively to the receptor binding domain of the SARS-CoV-2 spike protein.

Positive results were announced from an ongoing phase 2/3 trial evaluating the investigational antibody cocktail, REGN-COV2 (Regeneron), plus standard of care, for the treatment of coronavirus disease 2019 (COVID-19) in an outpatient setting.

REGN-COV2 consists of 2 potent, virus-neutralizing antibodies that bind noncompetitively to the receptor binding domain of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein, thereby blocking its interaction with the host cell. The randomized, double-blind trial compared the effects of REGN-COV2 to placebo when added to standard of care in patients with laboratory-confirmed COVID-19.

Patients were randomized 1:1:1 to receive a one-time infusion of REGN-COV2 high dose (8 grams), low dose (2.4 grams), or placebo. In September 2020, a descriptive analysis of the first 275 patients showed that REGN-COV2 reduced viral load and the time to alleviate symptoms in non-hospitalized patients with COVID-19. The latest data involving an additional 524 patients confirmed earlier results demonstrating that the treatment significantly reduced viral load.

Additionally, treatment with REGN-COV2 reduced COVID-19 related medical visits by 57% through day 29 in the overall population (2.8% combined dose groups; 6.5% placebo; P =.024), and by 72% in patients with 1 or more risk factor (combined dose groups; nominal P =.0065). Findings also showed no significant difference in virologic or clinical efficacy between REGN-COV2 high dose and low dose. With regard to safety, REGN-COV2 was found to be well tolerated with numerically less frequent serious adverse events compared with placebo (0.8% high dose; 1.6% low dose; 2.3% placebo).

“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,” said George D. Yancopoulos, MD, PhD, President and Chief Scientific Officer of Regeneron.

Results from the study have been submitted to the Food and Drug Administration for review in order to obtain an Emergency Use Authorization for REGN-COV2 low dose in adults with mild to moderate COVID-19 who are at high risk for poor outcomes.

The Company will continue the phase 3 portion of the trial in non-hospitalized patients. REGN-COV2 is also being assessed in a phase 2/3 trial for the treatment of COVID-19 in hospitalized patients, a phase 3 open-label trial of hospitalized patients, and a phase 3 trial for the prevention of COVID-19 in household contacts of infected individuals.

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Regeneron’s COVID-19 outpatient trial prospectively demonstrates that REGN-COV2 antibody cocktail significantly reduced virus levels and need for further medical attention. [press release]. Tarrytown, NY: Regeneron Pharmaceuticals; October 28, 2020. 

This article originally appeared on MPR