Securities code: 688180 Securities abbreviation: Junshi Biosciences Announcement No.: Pro 2025-009

Shanghai Junshi Biomedical Technology Co., Ltd

Voluntary Disclosure on Access to Drug Clinical Trials for JS212 for Injection

Announcement of the Notice of Approval

The board of directors and all directors of the company guarantee that there are no false records, misleading statements or material omissions in the content of this announcement, and assume legal responsibility for the authenticity, accuracy and completeness of its content in accordance with the law.

Recently, Shanghai Junshi Biomedical Technology Co., Ltd. (hereinafter referred to as the "Company") received the "Drug Clinical Trial Approval Notice" approved and issued by the National Medical Products Administration, and the clinical trial application of JS212 for injection (project code "JS212") was approved. Due to the long R&D cycle and many approval links of drugs, they are susceptible to some uncertainties, so investors are advised to make prudent decisions and pay attention to preventing investment risks. The relevant information is hereby announced as follows:

First, the basic situation of drugs

Drug name: JS212 for injection

Application matters: registration and clinical trials of domestically produced drugs

Acceptance number: CXSL2500023

Applicant: Shanghai Junshi Biomedical Technology Co., Ltd

Approval conclusion: According to the Drug Administration Law of the People's Republic of China and relevant regulations, after review, 2025

JS212 for injection, which was accepted on January 8, 2019, met the relevant requirements of drug registration, and it was agreed that this product was a single agent in an advanced stage

Clinical trials in patients with solid tumors.

2. Other relevant conditions of drugs

JS212 is a recombinant humanized anti-epidermal growth factor receptor (hereinafter referred to as "EGFR") and human epidermis

Long factor receptor 3 (HER3) bispecific antibody-drug conjugate (ADC) is mainly used for the treatment of advanced malignant solid tumors. EGFR and HER3 are highly expressed on the surface of a variety of tumor cells, such as lung cancer, breast cancer, head and neck tumors, etc. There is an interaction of signaling pathways between EGFR and HER3, which are involved in promoting the proliferation, survival, migration and angiogenesis of tumor cells, and the high expression of HER3 is one of the important mechanisms for the development of EGFR resistance in tumor tissues. Compared to single-target ADC drugs,

JS212 is able to exert tumor suppressive effects by binding to EGFR or HER3 and is expected to have a wide range of tumors

effective, and at the same time is expected to overcome the problem of drug resistance. Preclinical studies have shown that JS212 is associated with EGFR and HER3

The high-affinity, specific binding effect has demonstrated significant tumor inhibition in multiple animal models. At the same time, JS212 has good, acceptable security.

3. Risk Warning

Due to the characteristics of high-tech, high-risk and high value-added of pharmaceutical products, the pre-research and development of drugs and the cycle of products from development, clinical trial approval to production are long and linked, and they are easily affected by some uncertain factors. Investors are advised to make prudent decisions and pay attention to preventing investment risks.

The company will actively promote the above-mentioned R&D projects, and fulfill the obligation of information disclosure on the follow-up progress of the project in a timely manner in strict accordance with relevant regulations. The relevant company information is subject to the announcements published on the company's designated disclosure media, "China Securities Journal", "Shanghai Securities News", "Securities Times" and the website of the Shanghai Stock Exchange.

The announcement is hereby made.

Shanghai Junshi Biomedical Technology Co., Ltd

board of directors

March 21, 2025