Drug researchers in China are making progress on developing therapies to treat COVID-19 with several antibody drugs, which neutralize the virus, emerging as promising candidates in clinical trials.

Sunney Xie, director of the Beijing Advanced Innovation Center for Genomics at Peking University and a world-renowned biochemist, said his team has discovered a "full-spectrum neutralizing antibody" that has tackled all known emerging variants in laboratory experiments.

The antibody, known as DXP-604, is so potent that it will likely treat any mutations, he said at an academic conference in Shanghai last week.

Xie added that a new drug based on DXP-604 has demonstrated good efficacy in Phase 2 clinical trials. As of Nov 2, the medication had been administered to 14 patients with COVID-19 at Beijing Ditan Hospital through the compassionate use program, which expands access to experimental drugs for critical patients.

In the meantime, Brii Biosciences announced recently that it has filed an application for emergency use authorization with the US Food and Drug Administration for its therapy that combines two neutralizing antibodies, BRII-196 and BRII-198.

Brii Biosciences is a multinational pharmaceutical company based in China and the United States. It codeveloped the drug with Tsinghua University and the Third People's Hospital of Shenzhen.

The company said results from Phase 3 clinical trials overseas have shown that the medication can cut the risk of hospitalization and death of COVID-19 patients by 78 percent. Many participants enrolled in the trials were infected with the highly transmissible Delta variant.

Hong Zhi, chairman and CEO of the company, said that while vaccination remains the primary weapon against the novel coronavirus, antibody therapies can trigger immune responses more rapidly and are the most suitable treatment for close contacts of infected people and those who have already contracted the virus, but have not begun showing symptoms.

Brii Biosciences said in a statement on Friday it will offer the drug to Heilongjiang and Qinghai provinces for free. Both provinces are coping with local outbreaks.

Since June, nearly 700 patients in China had received the drug. Preliminary feedback from frontline medical workers suggests that the drug is safe and shows good antiviral effects on emerging variants, the statement said.

"Vaccines and antibody therapies are two weapons that complement each other," said Zhang Linqi, a professor at Tsinghua University's School of Medicine.

During an interview with thepaper.cn, a news outlet, he said highly effective and broad-spectrum antibodies can induce effects very quickly and will mainly benefit people exhibiting mild and moderate symptoms or who are at risk of developing severe illnesses.

Zhou Wenting in Shanghai contributed to this story.