CSPC PHARMA - VOLUNTARY ANNOUNCEMENT - NMPA ACCEPTS MARKETING AUTHORISATION APPLICATION FOR SECUKINUMAB INJECTION

CSPC PHARMACEUTICAL GROUP LIMITED

石藥集團有限公司

(Incorporated in Hong Kong with limited liability)

(Stock Code: 1093)

VOLUNTARY ANNOUNCEMENT

NMPA ACCEPTS MARKETING AUTHORISATION APPLICATION

FOR SECUKINUMAB INJECTION

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 marketing authorisation application for Secukinumab Injection (the 'Product') developed by CSPC Megalith Biopharmaceutical Co., Ltd (石藥集團巨石生物製藥有限公司), a subsidiary of the Company, has been accepted by the National Medical Products Administration (the 'NMPA') of the People's Republic of China. The Product has been submitted for registration as a Class 3.3 therapeutic biological product.

The Product is a fully human IgG1 monoclonal antibody that selectively binds to fully human interleukin (IL)-17A ('IL-17A'), blocking its interaction with the IL-17A receptor. IL-17A is a key cytokine in the inflammatory response and disease progression of diseases such as psoriasis, psoriatic arthritis and axial spondyloarthritis, playing a central role in their pathogenesis. As an IL-17A inhibitor, the Product can specifically neutralise IL-17A and inhibit its pro-inflammatory effects, thereby effectively alleviating disease symptoms, providing sustained improvement in disease activity, and delivering long-term clinical benefits to patients. The fully human structure of the Product results in a lower incidence of anti-drug antibodies, combining durable efficacy with a favourable safety profile.

The Product is a biosimilar of Cosentyx®. The original drug has been approved in China for the treatment of moderate-to-severe plaque psoriasis in patients aged 6 years and older who are candidates for systemic therapy or phototherapy; ankylosing spondylitis in adult patients who have had an inadequate response to conventional therapy; active psoriatic arthritis in adult patients who have had an inadequate response or intolerance to prior conventional disease-modifying antirheumatic drugs; moderate to severe hidradenitis suppurativa in adult patients; and active non-radiographic axial spondyloarthritis in adult patients who have had an inadequate response to non-steroidal antiinflammatory drugs, with objective signs of inflammation indicated by elevated C-reactive protein and/ or magnetic resonance imaging evidence.

This marketing authorisation application is based on a Phase I pharmacokinetic ('PK') similarity conducted in healthy subjects and a Phase III equivalence study conducted in patients with psoriasis. The study results demonstrated that the Product exhibited high similarity to Cosentyx® in terms of efficacy, safety, PK and immunogenicity profiles. Detailed data will be published at upcoming academic conferences and in medical journals.

By Order of the Board

CSPC Pharmaceutical Group Limited CAI Dong Chen

Chairman

Hong Kong, 18 June 2026