China Medical System (867.HK; 8A8.SG) Signed Collaboration Agreements for Two Innovative Biologics Used for Passive Immunization Against Tetanus and Rabies

SHENZHEN, CHINA – China Medical System Holdings Limited (“CMS” or the “Group”) is pleased to announce that on 22 September 2025, the Group through its subsidiaries entered into two separate exclusive Collaboration Agreements (the “Agreements”) with Chongqing Genrix Biopharmaceutical Co., Ltd. (“Genrix Bio”) for two Class 1 therapeutic biological products, Vecantoxatug Injection (GR2001, “Vecantoxatug”) indicated for passive immunization against tetanus and Silevimig Injection (GR1801, “Silevimig”) indicated for passive immunization following suspected rabies virus exposure, respectively. In accordance with the Agreements, the Group has obtained exclusive commercialization rights for these two products in mainland China and exclusive licensing rights for the rest of the Asia-Pacific region, the Middle East and North Africa. The collaboration terms respectively extend until ten years after these two products receive their marketing approvals in Mainland China (the “Initial Term for each Product”). Unless terminated or dissolved under the terms set forth in the Agreements, the Agreements will automatically renew for successive ten-year periods upon expiration of the Initial Term for each Product.

Vecantoxatug is a passive immunization agent with an excellent safety profile, which delivers superior protection compared with human tetanus immunoglobulin (HTIG), providing rapid and durable immune defense for patients. Its Phase III clinical trial for passive immunization against tetanus successfully met the primary efficacy endpoint. In May 2024, Vecantoxatug was designated Breakthrough Therapy by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA). On 22 May 2025, its New Drug Application (NDA) was formally accepted by the CDE.

Silevimig is the world’s first recombinant, fully human bispecific antibody against rabies virus (RABV) targeting epitope I and/or epitope III of the rabies virus glycoprotein, developed in accordance with the World Health Organization (WHO) recommended “cocktail” therapeutic option targeting distinct antigenic sites. It can be manufactured at scale with standardized, and also demonstrates broad neutralization, low immunogenicity, minimal interference with vaccine-induced active immunity, and controlled production cost. On 14 January 2025, its NDA for use in adults requiring passive immunization following suspected rabies virus exposure was formally accepted by CDE. In addition, in July 2025, the NMPA approved the clinical trial application for Silevimig in children and adolescents aged 2 to <18 years requiring passive immunization following suspected rabies virus exposure. This Phase III clinical trial is currently in progress.

CMS has always been committed to deploying innovative products with clinical value and differentiated advantages. The market for tetanus and rabies passive immunization remains substantial, yet existing passive immunization products are constrained by safety and accessibility concerns. If approved, Vecantoxatug and Silevimig will provide new preventive and therapeutic options of passive immunization for patients following tetanus and rabies exposure. Additionally, they will synergize with the Group’s existing products in expert networks and market resources, bringing benefit to patients.

More information about Vecantoxatug and Tetanus

Vecantoxatug is a recombinant humanized monoclonal antibody against tetanus neurotoxin (TeNT), which is self-developed by Genrix Bio. Vecantoxatug binds to the fragment C domain of the TeNT heavy chain (TeNT-Hc).  TeNT is an about 150 kDa single-chain protein that undergoes post-translational modification to form an active toxin composed of heavy and light chains. By specifically binding TeNT-Hc, Vecantoxatug effectively blocks toxin entry into neurons, providing passive immunization. The patent for Vecantoxatug has been granted in China.

Tetanus is an acute and specifical infection caused by Clostridium tetani (C. tetani) entering the body through wounds. It affects individuals across all age groups and, in the absence of medical intervention, is almost universally fatal-particularly among infants and the elderly. Even with active treatment, global mortality remains as high as 30-50%, with an estimated 500,000 to 1,000,000 cases reported annually worldwide^[1].

C. tetani is ubiquitous in soil and the environment, and is also present in the intestines of mammals. As the pathogen invades through skin or mucosal injuries, causing the acute and specifical infection, prevention remains the most effective strategy. Currently available passive immunization agents, commonly known as tetanus shot, – tetanus antitoxin (TAT), equine-derived tetanus immunoglobulin (F(ab’)₂), and human tetanus immunoglobulin (HTIG) – face notable limitations in safety and accessibility^[2], including risks of allergic reactions, potential infectious pathogen transmission, and limited availability. Consequently, there remains a pressing clinical need for new preventive and therapeutic options. Vecantoxatug is able to provide greater protection than HTIG, while demonstrating excellent safety, tolerability, and low immunogenicity. With enhanced controllability and accessibility, Vecantoxatug has the potential to offer patients an advanced preventive and therapeutic option.

More information about Silevimig and Rabies

Silevimig is a recombinant, fully human bispecific antibody against rabies virus, which is self-developed by Genrix Bio. It targets the viral envelope glycoprotein (G protein) of RABV and blocks its interaction with host receptors by binding to epitopes I and/or III. Through this mechanism, Silevimig prevents RABV from invading neural tissue prior to the establishment of full protection by active rabies vaccination, thereby helping to prevent rabies infection. Silevimig’s molecular design is consistent with the recommendations of the WHO for anti-RABV antibody development, which emphasize the use of “cocktail” combinations of monoclonal antibodies targeting distinct antigenic sites to ensure broad effectiveness across different viral strains and genotypes. The patent for Silevimig has been granted in China.

In a Phase III clinical trial for post-exposure passive immunization in adults, Silevimig met its primary efficacy endpoint, demonstrating non-inferior protective efficacy compared with human rabies immunoglobulin (HRIG), the currently most used passive immunization product in China. The study confirmed that Silevimig provides immediate protection during the early stages of rabies virus exposure without compromising the active immune response induced by vaccination.

Rabies is an acute zoonotic disease caused by RABV, clinically characterized by hydrophobia, aerophobia, pharyngeal muscle spasms, and progressive paralysis^[3]. With a case-fatality rate approaching 100%, it is one of the deadliest diseases worldwide. At present, there is no proven treatment for rabies once clinical symptoms appear. Standardized Post-Exposure Prophylaxis (PEP), comprising wound care, vaccination, and passive immunization administered as needed, remains the most effective rabies prevention strategy^[4]. As vaccine-induced antibodies require 1–2 weeks after the first dose of vaccine injection, to reach protective levels (≥0.5 IU/mL), passive immunization provides immediate coverage during this high-risk window^[3]. According to the the National Regulation for the Rabies Exposure Prophylaxis (2023 Edition), patients with Category III exposure and those with severe immunodeficiency and Category II exposure should receive passive immunization at the same time as the first dose of rabies vaccine^[5]. In China, more than 40 million people are exposed to rabies annually, of whom approximately 40% (16 million) fall under Category III exposure^[3]. However, due to factors such as limited awareness, high cost, and restricted accessibility, only about 15% of Category III cases receive passive immunization^[3].

Currently approved passive immunization options in China include human rabies immunoglobulin (HRIG) and equine rabies antiserum (ERA), both of which provide immediate protection by preventing viral entry into neural tissue. HRIG must be sourced from repeatedly immunized healthy donors, making it difficult and costly to obtain. And it is associated with potential risks of blood-borne infections (e.g., HIV, hepatitis B, hepatitis C). ERA, being a heterologous protein, is prone to adverse reactions such as serum sickness and anaphylactic shock^[3]. Beyond HRIG and ERA, only two rabies antibody products have been approved in China to date. Silevimig is the world’s first recombinant, fully human bispecific antibody for passive immunization against rabies, which is consistent with the WHO recommended “cocktail” approach. Its approval is expected to provide patients with broad and robust protection.

About GENRIX BIO

Genrix Bio (Stock Code: 688443), founded in 2015, is an innovative biopharmaceutical company driven by advanced antibody drug discovery technology to address critical clinical needs. Genrix Bio is committed to the development of monoclonal and bispecific antibodies for autoimmune diseases, infectious diseases, and oncology. Its capabilities span across antibody molecular discovery, process development and quality research, clinical trials, and large-scale commercialization. Learn more about Genrix Bio and its products at https://www.genrixbio.com/

About CMS

CMS is a platform company linking pharmaceutical innovation and commercialization with strong product lifecycle management capability, dedicated to providing competitive products and services to meet unmet medical needs.

CMS focuses on the global first-in-class (FIC) and best-in-class (BIC) innovative products, and efficiently promotes the clinical research, development and commercialization of innovative products, enabling the continuous transformation of scientific research into clinical practices to benefit patients.

CMS deeply engages in several specialty therapeutic fields, and has developed proven commercialization capabilities, extensive networks and expert resources, resulting in leading academic and market positions for its major marketed products. CMS continues to promote the in-depth development of its advantageous specialty fields and expand business boundaries, strengthening the competitiveness of the cardio-cerebrovascular/gastroenterology/ophthalmology/ skin health businesses. Among them, the skin health business has become a leading enterprise in its field, bringing economies of scale in specialty therapeutic fields. Meanwhile, CMS continuously deepens its business development in the Southeast Asia and Middle East regions, further escorting the sustainable and healthy development.

Reference:

1. China Trauma Rescue and Treatment Association. Peking University Trauma Medicine Center. Chinese expert consensus on tetanus immunization[J]. Chinese Journal of Surgery,2018,56(3):161-167. DOI: 10.3760/cma.j.issn.0529-5815.2018.03.001
2. Members of the Emergency Surgery Committee of Chinese College of Emergency Physicians, Members of the Emergency Medicine Committee of the People’s Liberation Army, Beijing Society for Emergency Medicine, et al. Expert consensus on prophylaxis, diagnosis and management of tetanus among adults[J]. Journal of Clinical Emergency, 2018, 19(12):801-811. DOI: 10.13201/j.issn.1009-5918.2018.12.001
3. Chinese Center for Disease Control and Prevention. Technical Guidelines for Human Rabies Prevention and Control (2016). https://www.chinacdc.cn/jkyj/crb2/yl/kqb/jswj_kqb/202409/P02024090652542…
4. Yin Wenwu, Wang Chuanlin, et al. Expert consensus on rabies exposure prophylaxis[J]. Chinese Journal of Preventive Medicine, 2019,53(7):668-679. DOI:10.3760/cma.j.issn.0253-9624.2019.07.004
5. Chinese Center for Disease Control and Prevention. The National Regulation for the Rabies Exposure Prophylaxis (2023 Edition). https://www.chinacdc.cn/jkyj/crb2/yl/kqb/jswj_kqb/202409/P02024090652542…

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