ExplainerWhich Asian labs are working on antibody treatments in the fight against Covid-19?
- With a coronavirus vaccine or cure seemingly nowhere near, researchers are now looking closely at antibody therapy
- At least five antibody treatments are now in the works, with most of them in Asian labs, including Singapore, Japan, South Korea and mainland China
We take a look at antibody treatment and how it can help the global fight against Covid-19.
What is an antibody treatment?
When an individual catches a virus, the antigen – a toxin or foreign substance – prompts the body to produce antibodies to fight off the disease. The antibodies, which are blood proteins, would circulate throughout the body until they find and eventually attach themselves to an antigen. The antibodies can then trigger other parts of the immune system to attack the cells containing the antigen.
Scientists are hoping to harvest specific antibodies that target the coronavirus using convalescent plasma and serum from recovered patients. The antibodies, which could neutralise the virus and also stimulate other components of the immune system to respond to the invading virus, would be infused into infected patients.
Leong Hoe Nam, a Singapore-based infectious diseases physician, said researchers are also harvesting cells from recovering patients that secrete these antibodies. “If you find one or more [cell], they can be immortalised [as] an eternal living cell that continually makes neutralising antibodies, and you would have an eternal weapon against the virus,” he said.
This is akin to having a drug effective against the virus, he said, but stressed that there was an element of luck on top of “good techniques” involved in finding the right cells.
What is it commonly used for?
While reports note that antibody therapy dates back to the 19th century, when researchers used serum from the blood of infected animals to treat diphtheria, Leong said it is still a “relatively new means” of treating infections.
Besides cancer treatment, antibody therapy is also used for a range of diseases today. Leong said this includes Kawasaki disease, an illness that causes inflammation in blood vessels, or for patients with hyperinflammatory conditions. “The same goes for chickenpox, rabies or hepatitis B, where antibodies are pooled from donors,” he said.
How is it different from vaccines and other medications?
Medication and antibody treatment are two typical ways to treat diseases, said Leong, but unlike bacteria, it is hard to treat viruses – like Covid-19 – with medication as they require specific drugs to control them, akin to a “lock and key system”.
“Hence betting on medicine is rather difficult,” he said. It is also optimal to harvest antibodies for treatment as viruses including Covid-19 are controlled by specific types of antibodies.
Previously, researchers have thought of treating coronavirus patients with remdesivir, an antiviral drug used typically for Ebola treatment. “But results were not fantastic,” said Leong, adding that using antibody therapy seems like a “promise of a specific weapon against the novel coronavirus, developed quickly from survivors of the virus”.
Unlike vaccines that are aimed at generating an immune response in those who are healthy to prevent them from catching the disease, antibody treatments are only used on those who are infected with the coronavirus.
Who is in the process of developing such a treatment?
Besides China, Singapore’s defence research and development organisation DSO National Laboratories on June 17 said it had discovered five antibodies that could block the coronavirus and protect against key mutations. This came after its scientists screened hundreds of thousands of cells that produce the antibodies. It hopes to commence human trials in the coming months.
Separately, the Singapore government-linked biomedical sciences institute A*Star is working with Japanese pharmaceutical company Chugai Group on potential treatments. Even though recent developments show “high potency” in neutralising the infection, a spokesperson said the project is still in its early stages, with the team currently working on discovering and optimising a viable clinical candidate antibody.
International pharmaceutical giants are also rushing to develop such therapies. London-based multinational drug maker GSK, for example, is collaborating with biotech firm Vir Biotechnology, to use artificial intelligence, among other methods, to identify anti-coronavirus compounds.
Meanwhile, other firms that began their research earlier this year are optimistic that antibody therapies could be launched as early as this year.
Japan’s Takeda Pharmaceutical Company, which is part of the CoVIg-19 Plasma Alliance, has been collecting convalescent plasma from coronavirus survivors since mid-March and has been developing a potential hyperimmune globulin medicine for those at risk of developing serious complications from Covid-19.
“This investigational medicine is made by pooling, processing, and concentrating plasma donated by people who have recovered from Covid-19, and contains consistently high levels of antibodies to the new coronavirus,” said Julie Kim, co-leader of the alliance and president of Takeda’s Plasma-Derived Therapy Business Unit. Kim added that a global clinical trial was expected to begin in July, and that the treatment could be ready this year.
South Korean biopharmaceutical company Celltrion, which has screened 300 different antibodies since March, found 14 of them to be “powerful neutralising antibodies” against the coronavirus. The Incheon-headquartered company is now working with the Korea Centres for Disease Control and Prevention to commence the first human clinical trials in July as well.