Introduction to BsAb Drugs
Bispecific antibody (BsAb) is an artificial protein that can simultaneously bind to two different antigens or two epitopes on the same antigen.
Compared to traditional monoclonal antibody that can bind only to the same epitope on the antigen, BsAbs are more capable of identifying cancer cells and binding to antigens that are expressed weakly.
On the other hand, BsAbs contain toxicity which may induce cytokine release syndrome and neurotoxicity. Besides, BsAbs are limited by drug resistance because of target loss, insufficient immune response, and higher immune checkpoints.
Overall, BsAbs can be applied to therapeutic treatment, clinical diagnostics, and medical imaging. Though relatively new among cancer therapies, BsAb drugs have a hotspot for research. Globally, more than 700 BsAb drugs are under research.
Status Quo in China
The passion of developing BsAb drugs has also been ignited in China, where over 300 BsAb drugs are being developed, among which nearly 100 have entered the clinical trial stage. By 2030, the Chinese BsAb market is expected to reach 10.8 billion USD.1
Currently, eight BsAb drugs have been approved worldwide, by the US Food and Drug Administration (FDA), European Medicines Agency (EMA), or China National Medical Products Administration (NMPA), respectively.
Among the eight products, three have been approved in China. Cadonilimab is the only one developed by a Chinese company, that is, Akeso. Priced at 13,220 yuan (about 1,847 USD) for 125mg/vial, Cadonilimab is estimated to cost no more than 198,000 yuan annually.2
BsAb Drugs with Marketing Authorization
Year of Approval
2009 (withdrawn from the market in 2017)
Acute lymphoblastic leukemia
Non-small cell lung cancer
Neovascular age-related macular degeneration; diabetic macular edema
(Kai Tan Ni)
In the future, more BsAb drugs are expected to be approved in China, as over 30 domestic pharmaceutical companies, including Hengrui, Alphamab Oncology, and BeiGene, have already developed pipelines for BsAbs.
Chinese Market: Opportunities and Challenges
China's overall regulatory environment is favorable for BsAb drug's R&D. To develop and market BsAb drugs in China, companies are recommended to apply for expedited approval programs that China grants to clinically significant drugs. Companies should also refer to official guidelines such as Technical Guidelines on Clinical Development of Bispecific Antibody Drugs for Cancer during R&D.
In addition, companies need to consider pricing. As commercial medical insurance in China are not very mature, companies may choose to negotiate with the National Healthcare Security Administration (NHSA) to make the drug included into the National Reimbursement Drug List, a list of drugs reimbursed by social healthcare insurance. Under such a circumstance, price cut would be a necessity.