Regeneron Pharmaceuticals has commenced the first clinical trial of its dual antibody cocktail, REGN-COV2, which is intended to prevent and treat Covid-19.

The REGN-COV2 clinical programme will involve hospitalised patients, non-hospitalised symptomatic patients, uninfected individuals in groups at high exposure risk, such as healthcare works, and uninfected people with close exposure to a Covid-19 patient.

Regeneron noted that the placebo-controlled trials will be performed at several sites.

The company analysed numerous fully-human antibodies generated using the company’s VelocImmune mice, along with antibodies isolated from recovered Covid-19 patients.

Based on the findings, the company chose the two most potent virus-neutralising antibodies and scaled them up for clinical use by using its in-house VelociMab and manufacturing capabilities.

According to preclinical research, the selected dual antibodies attach non-competitively to the receptor binding domain (RBD) of the virus’ spike protein.

The first two adaptive Phase I/II/III trials, REGN10933 and REGN10987, are designed to assess REGN-COV2 for the treatment of hospitalised and non-hospitalised Covid-19 patients.

The Phase I part of the trials will track virologic and safety endpoints, while the Phase II part will focus on virologic and clinical endpoints. The Phase I and Phase II results will help refine the endpoints and determine the size for the Phase III studies.

Regeneron Pharmaceuticals co-founder, president and chief scientific officer George Yancopoulos said: “We have created a unique anti-viral antibody cocktail with the potential both to prevent and treat infection, and also to preempt viral ‘escape,’ a critical precaution in the midst of an ongoing global pandemic.

“REGN-COV2 could have a major impact on public health by slowing spread of the virus and providing a needed treatment for those already sick, and could be available much sooner than a vaccine.”

The antibody cocktail is also expected to show long-term utility for elderly and immuno-compromised patients.

In March this year, Regeneron and Sanofi initiated a clinical programme of rheumatoid arthritis drug Kevzara (sarilumab) to treat hospitalised patients with severe Covid-19.