Coronavirus: China approves first local neutralising antibody cocktail for high-risk patients

Brii Biosciences says its therapy shows an 80 per cent reduction in hospital admissions and death in a global phase 3 trial
HKU molecular virologist sees the therapy as an additional treatment option for China, but says it cannot replace the key role of vaccines

Coronavirus pandemic

Holly Chik

Published: 7:30pm, 9 Dec 2021

Why you can trust SCMP

China’s medical products regulator approved the use of the country’s first locally developed neutralising antibody cocktail therapy for Covid-19 on Wednesday.

Brii Biosciences said its therapy showed an 80 per cent reduction of hospital admissions and death in a global phase 3 trial with 847 non-hospitalised coronavirus patients, adding that no serious adverse events were identified.

The National Medical Products Administration granted approval for the combination of two antibodies to be used for adults who are at high risk of developing severe Covid-19, which could lead to hospital admission or death, and conditional approval for patients aged 12 to 17.

The company said lab testing data suggested that the treatment “retains activity” against major coronavirus variants, including Alpha, Beta and Delta, while tests on the highly mutated strain Omicron were continuing.

02:31

Chinese antibody cocktail a potential game changer in fight against Covid-19

It was also seeking emergency use authorisation from the Food and Drug Administration (FDA) in the United States, one of its clinical trial sites. Other trial sites were in Argentina, Brazil, Mexico, South Africa and the Philippines.

China has been fighting local outbreaks, including cases caused by the Delta variant. Nationwide, 1,190 patients are being treated, of which 24 have severe disease, according to the National Health Commission.

The company said it had donated doses for emergency use across the country since June and nearly 900 patients had been given the treatment.

Omicron better at dodging vaccine, South African study finds

The treatment, administered by infusion, combines two neutralising monoclonal antibodies. They are laboratory-made protein molecules that can act like human antibodies and are created by cloning and combining antibodies found in recovered patients in China.

Brii Bio biotechnology firm, based in the US and China, developed the therapy with Tsinghua University and the Third People’s Hospital of Shenzhen, whose team derived antibodies from recovered patients.

Lead researcher and professor at the school of medicine at Tsinghua University, Zhang Linqi, said in a video published by the university: “The treatment can fight against the coronavirus and boost immunity, which can last nine to 12 months after one dose.

06:14

Why is the Omicron variant so concerning? Virologist warns Covid strain could ‘wreak havoc’ in HK

“[The spike] protein on the coronavirus surface aims to unlock the door into our cells. Viruses can only replicate after entering cells. Our antibody therapy works by blocking the virus surface so that its keys cannot reach the locks of our cells,” the viral immunologist said.

He has previously told the South China Morning Post that “we can be sure all these existing variants, including Delta, have not escaped our antibodies”, but he also cautioned that the drug would fail if one variant escaped from the antibodies.

China has maintained a zero-tolerance policy towards coronavirus spread, rolling out mass testing, frequent contact tracing, long quarantine and strict border controls.

Abandoning zero-Covid: how long will China maintain its fortress-like approach?

Some Chinese experts have pointed to pathways for the country to fully relax its controls. Top respiratory disease expert Zhong Nanshan said those pathways included developing effective drug treatments and establishing herd immunity with a high vaccination rate.

Antibody therapies have previously been used for viral infections and the US FDA has authorised anti-Sars-CoV-2 monoclonal antibodies for patients at various stages.

Jin Dong-Yan, a molecular virologist with the University of Hong Kong, said the therapy provided an additional treatment option for China, but it could not replace the key role of vaccines in priming the immune system as part of pandemic control.

“During natural or breakthrough infection [after vaccination], antibody levels … rocket within a short period of time. Your body mobilises an army to fight the virus,” he said.

“The antibody drug is like picking up one soldier and making more of the same soldier who can only do one thing, while an army can do many, with all different weapons.

“If your body can already elicit a very strong antibody response, adding antibodies will be of no use,” Jin said, pointing to the example of Hong Kong’s first two Omicron patients.

They had received two doses of the BioNTech vaccine and developed very mild symptoms. Their antibody levels had risen at least tenfold four-to-seven days after being admitted to hospital, according to the head of HKU’s department of microbiology.