KEYMED BIO-B - VOLUNTARY ANNOUNCEMENT - CM512 INCLUDED IN THE BREAKTHROUGH THERAPY DESIGNATION LIST BY THE CENTER FOR DRUG EVALUATION OF THE NATIONAL MEDICAL PRODUCTS ADMINISTRATION

Keymed Biosciences Inc. 康諾亞生物醫藥科技有限公司 (Incorporated in the Cayman Islands with limited liability) (Stock Code: 2162)

VOLUNTARY ANNOUNCEMENT － CM512 INCLUDED IN THE

BREAKTHROUGH THERAPY DESIGNATION LIST BY THE CENTER FOR DRUG EVALUATION OF THE NATIONAL MEDICAL PRODUCTS ADMINISTRATION

This announcement is made by Keymed Biosciences Inc. (the "Company", together with its subsidiaries, the "Group") on a voluntary basis to inform the shareholders and potential investors

of the Company about the latest business advancement of the Group.

The board of directors (the "Board") of the Company is pleased to announce that our key R&D product CM512 (a TSLP/IL-13 bispecific antibody) has been included in the Breakthrough Therapy Designation List by the Center for Drug Evaluation of the National Medical Products Administration for the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP).

ABOUT BREAKTHROUGH THERAPY DESIGNATION

Breakthrough Therapy Designation (BTD) is a special designation program designed to expedite the research and development and review of new drugs for the treatment of serious or life-threatening diseases. Its core objective is to enable drugs that have demonstrated significant therapeutic efficacy advantages in early-stage clinical trials to receive closer guidance and

expedited review pathways from drug regulatory authorities, thereby benefiting patients as soon as practicable.

ABOUT CM512

CM512 is a recombinant anti-thymic stromal lymphopoietin (TSLP) and anti-interleukin-13 (IL-13) bispecific antibody independently developed by the Company and is the world's first long-acting IgG-like TSLP×IL-13 dual blocker. A Phase I clinical study involving single/multiple dose-escalation in healthy subjects and adult patients with moderate-to-severe atopic dermatitis (AD) was conducted to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and immunogenicity of CM512, and to preliminarily explore its efficacy in treating patients with moderate-to-severe AD. The study achieved all endpoints in November 2025. In April 2026, West China Hospital of Sichuan University, in collaboration with the Company, published the

Phase I clinical results in the Journal of Translational Medicine.

As at the date of this announcement, a randomized, double-blinded, placebo-parallel Phase II clinical study to evaluate the safety and efficacy of CM512 injection in subjects with CRSwNP is

ongoing. The trial results will be announced as and when appropriate. In addition, we are advancing multiple Phase II clinical studies of CM512, with indications covering moderate-to-severe asthma, moderate-to-severe chronic obstructive pulmonary disease, moderate-to-severe AD in adults, chronic spontaneous urticaria, etc.

RISK WARNING

CM512 may not ultimately be successfully developed and commercialized. Shareholders and potential investors of the Company are advised to exercise caution when dealing in the securities of the Company.

By order of the Board Keymed Biosciences Inc.

Dr. Bo CHEN Chairman

Hong Kong, July 23, 2026