CSPC PHARMA - VOLUNTARY ANNOUNCEMENT - RECOMBINANT RESPIRATORY SYNCYTIAL VIRUS VACCINE (SYS6057) OBTAINS CLINICAL TRIAL APPROVAL IN CHINA

CSPC PHARMACEUTICAL GROUP LIMITED

石藥集團有限公司

(Incorporated in Hong Kong with limited liability)

(Stock Code: 1093)

VOLUNTARY ANNOUNCEMENT

RECOMBINANT RESPIRATORY SYNCYTIAL VIRUS VACCINE (SYS6057)

OBTAINS CLINICAL TRIAL APPROVAL IN CHINA

The Board of Directors (the 'Board') of CSPC Pharmaceutical Group Limited (the 'Company', together with its subsidiaries, the 'Group') is pleased to announce that the Recombinant Respiratory Syncytial Virus ('RSV') Vaccine (SYS6057) (the 'Product') developed by the Group has obtained approval from the National Medical Products Administration of the People's Republic of China to conduct clinical trials in China.

The Product is the Group's second recombinant protein vaccine product approved for clinical trials. It utilises the RSV prefusion F (Pre-F) protein antigen, formulated with the second-generation nanoadjuvant system independently developed by the Group. Compared with previous products, the adjuvant of the Product employs a different nanocarrier, exhibiting unique physicochemical properties and immunological activity. Through optimisation of this adjuvant system, the Product can simultaneously induce high-titre neutralising antibodies and potent cellular immune responses against RSV, possessing distinctive advantages in immune protection. Preclinical studies demonstrated that the Product exhibited a favourable safety and efficacy profile.

The indication of the Product for this clinical trial approval is for the prevention of lower respiratory tract disease (LRTD) caused by RSV in individuals aged 60 and above. The clinical trial approval of the Product represents another important achievement for the Group in the field of recombinant protein vaccines, laying a solid foundation for the Group's subsequent development of recombinant protein vaccines and adjuvant products, and marking the official entry of the Group's vaccine research and development pipeline into a new stage of rapid development.

By order of the Board

CSPC Pharmaceutical Group Limited CAI Dong Chen

Chairman

Hong Kong, 31 July 2026