Antibody combination therapy approved to treat COVID-19

China approved on Dec 8 the use of a monoclonal neutralizing antibody cocktail for COVID-19 treatment created by Brii Biosciences, making it the first antibody combination therapy against the disease to get the green light in the country.

The medicine－a combination of the amubarvimab and romlusevimab antibodies, previously known as BRII-196 and BRII-198－has been approved to treat mild COVID-19 cases and moderate cases with a high risk of progressing to hospitalization or death, according to the National Medical Products Administration.

It can be used on adults and on minors ages 12 to 17 who weigh at least 40 kilograms. Since June, nearly 900 patients in China have undergone the treatment to quell local outbreaks from Liaoning to Guangdong province, according to the company.

Brii Biosciences has also filed an emergency use application for the medicine in the United States. The antibody cocktail was jointly developed by Brii Biosciences, Tsinghua University, and the Third People's Hospital of Shenzhen, Guangdong province.

The National Medical Products Administration approved the medicine based on positive final and interim results from phase 3 clinical trials on 847 patients sponsored by the United States National Institutes of Health, the company said.

The final results showed the therapy has a good safety profile and can reduce the risk of hospitalization and death by 80 percent. The study was conducted around the world, including in the US, Brazil, South Africa, Mexico, Argentina and the Philippines.

In vitro lab tests suggest that the antibody combination can be effective against common SARS-CoV-2 variants, including the Alpha, Beta, Delta, Lambda and Mu. Testing with the newer Omicron strain is ongoing.

Rogers Luo, Brii Biosciences president and general manager in China, called the antibody cocktail's approval an "important milestone".

"As a startup multinational biotech company co-located in China and the US, we are working to advance access to this treatment for a broad range of COVID-19 patients in China, while also scaling our effort to match the need for COVID-19 treatment options to combat the pandemic," he said.

Luo said on his social media account that the antibody cocktail represented a breakthrough in finding another therapeutic option for COVID-19. "We now have a strong weapon against the pandemic in hand, and it is only a matter of time before we can snare the dragon," he said.

Zhang Linqi, a key scientist in developing the antibody cocktail and a professor at Tsinghua University's School of Medicine, said the treatment is the only one of its kind to have confirmed clinical efficacy among patients infected by SARS-CoV-2 variants in premarket trials.

"The antibody combination provides world-class treatment for China to fight the COVID-19 epidemic," he said.

Zhang said they will continue to evaluate the treatment among the immunocompromised population as a preventive measure.

Monoclonal antibody treatment uses man-made antibodies that bind to the critical region of the spike protein of the COVID-19 virus to interfere with the pathogen's ability to attach to and enter cells, according to the World Health Organization.

The technology has the potential for large-scale production because scientists can mass produce antibodies in labs, and it can be highly effective against mild and moderate COVID-19 cases and help patients recover faster.

Given their potential as lifesaving medicine, more than 70 monoclonal antibodies were in development for the treatment and prevention of COVID-19 as of June, with support from many big pharma companies, such as Eli Lilly, AstraZeneca, Regeneron and GlaxoSmithKline.

However, monoclonal antibody cocktails are very expensive because of their limited production, and they typically must be administered intravenously in a hospital setting. In the US, a single dose of Regeneron's antibody infusion cost $1,250 as of August, prompting the WHO to encourage governments and companies to make such treatments more accessible.

Another challenge is that monoclonal antibodies tend to latch onto highly specific targets, raising the risk of the treatment losing its efficacy if the COVID-19 virus were to substantially change its spike protein through multiple mutations, such as in the Omicron variant.