Announcement on Voluntary Disclosure of Subsidiary YKYY026 Injection Obtained Clinical Trial Approval from the National Medical Products Administration

Securities code: 688658 Securities abbreviation: Yuekang Pharmaceutical Announcement number: 2026-025

Yuekang Pharmaceutical Group Co., Ltd.

Regarding voluntary disclosure of subsidiary YKYY026 injection obtained

Announcement of Clinical Trial Approval from the National Medical Products Administration

The company's board of directors and all directors guarantee that the contents of this announcement do not contain any false records, misleading statements or major omissions, and assume legal responsibility for the authenticity, accuracy and completeness of its contents in accordance with the law.

Beijing Yuekang Kechuang Pharmaceutical Technology Co., Ltd. (hereinafter referred to as "Yuekang Kechuang") and Hangzhou Tianlong Pharmaceutical Co., Ltd. (hereinafter referred to as "Hangzhou Tianlong"), subsidiaries of Yuekang Pharmaceutical Group Co., Ltd. (hereinafter referred to as the "Company"), have recently obtained the "Drug Clinical Trial Approval Notice" approved and issued by the National Medical Products Administration (hereinafter referred to as "NMPA") for YKYY026 injection for the prevention of herpes zoster. The company will conduct Phase I clinical trials of this product. The relevant information is now announced as follows:

1. Main contents of clinical approval documents:

1. Drug name: YKYY026 injection

2. Acceptance number: CXSL2600048

3. Notice number: 2026LP01122

4. Application indication: prevention of herpes zoster

5. Applicants: Beijing Yuekang Kechuang Pharmaceutical Technology Co., Ltd., Hangzhou Tianlong Pharmaceutical Co., Ltd.

6. Application stage: clinical trial

7. Approval conclusion: According to the "Drug Administration Law of the People's Republic of China", the "Vaccine Administration Law of the People's Republic of China" and relevant regulations, after review, the YKYY026 injection clinical trial application accepted on January 9, 2026 complies with the relevant requirements for drug registration, and it is agreed to conduct clinical trials for the prevention of herpes zoster in people aged ≥40 years.

2. Other conditions of drugs

YKYY026 injection is an mRNA vaccine encoding the gE protein antigen of varicella-zoster virus (VZV) independently developed by Yuekang Science and Technology and Hangzhou Tianlong. It is used to prevent herpes zoster.

YKYY026 injection is a new mRNA sequence designed based on gE protein. It uses a combination of mutation sites with independent intellectual property rights. It has a novel structure and strong immunogenicity. It uses an LNP delivery system based on YK-009 cationic lipids with completely independent intellectual property rights, which has high delivery efficiency and good safety. The core sequence patent has been authorized by the State Intellectual Property Office for invention patents, and the international patent application has been completed simultaneously. The company enjoys global exclusive rights. Preclinical research results show that YKYY026 injection can stimulate efficient gE-specific IgG antibodies, VZV-specific antibodies, and CD4+ T cell immune responses that are more important for the prevention of herpes zoster. The immune effect is long-lasting, and the immune response can last for more than 420 days in non-human primates, with good safety. The preclinical research results have been published in the international high-level journal "Advanced Science".

This product has been approved for clinical trials by the U.S. Food and Drug Administration (hereinafter referred to as "FDA"). For details, please refer to the "Announcement of Yuekang Pharmaceutical Group Co., Ltd. Voluntarily Disclosing Subsidiary YKYY026 Injection Obtained FDA Clinical Trial Approval" (Announcement Number: 2024-054).

3. Risk warning

1. The new drug clinical trial approved by the State Food and Drug Administration is a phased result of the company's new drug research and development. However, the drug development, clinical trial approval, and production have a long cycle, many links, and high risks. There are many uncertainties in drug review and approval time, approval results and subsequent research processes, research results, and future product market competition. Investors are advised to make prudent decisions and pay attention to preventing investment risks;

2. According to drug research and development experience, there are certain risks in clinical trial research. If the drug enters the clinical trial stage, the progress and results of the clinical trial will be affected by (including but not limited to) the trial protocol, subject recruitment, safety and/or effectiveness of the clinical trial, and other issues, and there will be uncertainty.

The company will actively promote the research and development and registration progress of the above-mentioned drugs in accordance with relevant national regulations, and timely fulfill its information disclosure obligations based on the progress of research and development.

Announcement is hereby made.

Board of Directors of Yuekang Pharmaceutical Group Co., Ltd.

April 14, 2026