SYS6057, a recombinant respiratory syncytial virus (RSV) vaccine candidate developed by CSPC Pharmaceutical Group (HKEX: 01093), has received FDA clearance to begin clinical trials in the US, less than a month after China's National Medical Products Administration (NMPA) granted the same authorization on 30 July 2026. The back-to-back regulatory clearances give the Hong Kong-listed company a simultaneous development path in two of the world's largest markets for RSV prophylaxis in older adults.
SYS6057 combines the RSV prefusion F (Pre-F) protein antigen with a proprietary second-generation nano-adjuvant system. CSPC says the adjuvant uses a different nanocarrier compared with its earlier RSV vaccine candidate, conferring distinct physicochemical and immunological properties. Preclinical data, according to the company, showed the vaccine can simultaneously elicit high-titre neutralising antibodies and cellular immune responses — a dual-arm immune profile the company attributes to adjuvant optimization. No clinical efficacy or safety data have been disclosed.
The planned clinical development in both countries targets prevention of RSV-associated lower respiratory tract disease in adults aged 60 and older. Trial design, participant numbers, dosing, and primary endpoints have not been disclosed.