Stock code: 688180 Stock abbreviation: Junshi Biological Announcement No.: Pro 2024-041.

SHANGHAI JUNSHI BIOPHARMACEUTICAL TECHNOLOGY CO., LTD

Voluntary Disclosure About Treplimab in Advanced Triple Negative Breast Cancer

Announcement on Approval of Application for Marketing of New Indications for First-line Treatment

the company's board of directors and all directors to ensure that the contents of this announcement does not exist any false records, misleading statements or major omissions, and the authenticity, accuracy and completeness of the contents of the legal responsibility.

Recently, Shanghai Junshi Biomedical Technology Co., Ltd. (hereinafter referred to as the "Company") received the "Drug Registration Certificate" approved and issued by the State Drug Administration?, product code: JS001) The new indication for first-line treatment of recurrent or metastatic triple negative breast cancer (TNBC) with fully verified detection and evaluation of PD-L1 positive (CPS≥ 1) combined with paclitaxel (albumin binding type) for injection has been approved, which is the 10th indication approved for teripilimumab in mainland China. As the commercialization of drugs after being approved for marketing is easily affected by some uncertain factors, investors are advised to make cautious decisions and pay attention to preventing investment risks. The relevant information is hereby announced as follows:

Basic information of 1. drugs

Drug Name: Triplimab Injection

Application: Drug Registration (Domestic Production)

Acceptance number: CXSS2300036, CXSS2300037

Certificate No.: 2024S01291, 2024S01292

Listing Permit Holder: Shanghai Junshi Biomedical Technology Co., Ltd.

Approval Conclusion: According to the "the People's Republic of China Drug Administration Law" and relevant regulations, after examination, this product meets the relevant requirements of drug registration and is approved to add indications. Specifically, this product is combined with paclitaxel for injection (albumin binding type) for first-line treatment of recurrent or metastatic triple negative breast cancer (TNBC) with fully verified detection and evaluation of PD-L1 positive (CPS≥ 1).

Other information related to 2. drugs

According to data released by GLOBOCAN 2022, annual new cases of breast cancer worldwide in 2022

The number of cases reached 2.31 million, the number of deaths reached 670000, the highest incidence of cancer in women in the world. In China, the number of new breast cancer cases will reach 357000 and the number of deaths will reach 75000 in 2022, accounting for 15.5 and 11.2 per cent of global cases, respectively. Among them, triple negative breast cancer accounts for about 10% to 15% of all breast cancers, which has the characteristics of strong invasion, high recurrence rate and poor prognosis. Triple-negative breast cancer is not sensitive to targeted therapy and endocrine therapy, and lacks specific treatment. The current treatment of advanced triple-negative breast cancer in China is still chemotherapy.

However, no matter single drug or combination chemotherapy are ineffective, the median survival time is about 9 to 12 months, 5 years

The survival rate is less than 30%.

The approval of this new indication is mainly based on the TORCHLIGHT study (NCT04085276), which is a randomized, double-blind, placebo-controlled, multi-center phase III clinical study, which is jointly carried out in 56 centers across the country by the vice chairman and secretary-general of the Chinese Society of Clinical Oncology (CSCO) and Professor Jiang Zefei from the Department of Oncology of the PLA General Hospital. In February 2023, the Independent Data Monitoring Committee (IDMC) determined in an interim analysis that the primary endpoint of the TORCHLIGHT study reached the pre-programmed excellence boundary value, making TORCHLIGHT study the first Phase III registration study in China to achieve positive results in the field of immunotherapy for advanced triple-negative breast cancer.

In January 2024, the top international medical journal Nature-Medicine (Nature Medicine, influence factors

Sub: 58.7) published the results of TORCHLIGHT interim studies. The results showed that compared with paclitaxel for injection (albumin-bound), teripilimumab combined with paclitaxel for injection (albumin-bound) for patients with first diagnosed stage IV or recurrent and metastatic triple-negative breast cancer can significantly prolong the progression-free survival (hereinafter referred to as "PFS") of PD-L1-positive patients, and the overall survival (hereinafter referred to as "OS") has also reached a benefit trend, achieving a zero breakthrough in immunotherapy for advanced triple-negative breast cancer in China. Among them, the median PFS in the teripilimab group was 8.4 months, and the risk of disease progression or death was reduced by 35%(P = 0.0102). The median OS in the teripilimab group was prolonged by 13.3 months (32.8 months vs 19.5 months), and the risk of death was reduced by 38%(P = 0.0148). The safety data of teripilimab were consistent with the known risks, and no new safety signals were found.

Treprolizumab injection is the first domestic monoclonal antibody drug with PD-1 as the target approved for marketing in China. It has won the highest national patent award "China Patent Gold Award". So far, it has been carried out in the world (including China, the United States, Southeast Asia and Europe) more than 40 clinical studies initiated by the company covering more than 15 indications. Ongoing or completed pivotal registry clinical studies have evaluated the safety and efficacy of teripilimumab in multiple tumor species. As of the disclosure date of this announcement, 10 indications for Treplimab have been approved in Mainland China. In December 2020, Treplimab injections passed the national health care negotiations for the first time, and currently

Six approved indications have been included in the National Health Insurance Catalogue (2023), which is the only one in the National Health Insurance Catalogue.

Anti-PD-1 mAb drugs for the treatment of melanoma. April 2024, Drug Office, Department of Health, Hong Kong

(DO) Accepted applications for marketing authorization for treprozumab plus cisplatin/gemcitabine as first-line therapy in adult patients with metastatic or recurrent locally advanced nasopharyngeal carcinoma and as monotherapy in adult patients with recurrent, unresectable or metastatic nasopharyngeal carcinoma that has progressed during or after prior platinum-based therapy.

In terms of international layout, in October 2023, Treplimab was used as the first nasopharyngeal cancer drug in

The United States was approved for listing. In addition, the European Medicines Agency (EMA) and the United Kingdom Medicines and Healthcare Products Agency (MHRA) have accepted the marketing authorisation application (MAA) for the first-line treatment of patients with locally recurrent or metastatic nasopharyngeal carcinoma with teriprozumab plus cisplatin and for the first-line treatment of patients with unresectable locally advanced/recurrent or metastatic esophageal squamous cell carcinoma with paclitaxel and cisplatin, respectively, the Australian Medicines Agency (TGA) and the Singapore Health Sciences Agency (HSA) have accepted applications for marketing authorizations for teriprilimumab plus cisplatin/gemcitabine as first-line treatment for adult patients with metastatic or recurrent locally advanced nasopharyngeal carcinoma and as monotherapy for adult patients with recurrent, unresectable or metastatic nasopharyngeal carcinoma who have progressed during or after prior platinum-containing therapy, respectively.

3. Risk Alert

As pharmaceutical products have the characteristics of high technology, high risk and high added value, and the commercialization of drugs after being approved for marketing is also easily affected by some uncertain factors, investors are advised to make cautious decisions and pay attention to preventing investment risks.

The company will actively promote the above projects, and in strict accordance with the relevant provisions of the follow-up progress of the project to fulfill the obligation of information disclosure. The relevant company information shall be subject to the announcement published in the company's designated disclosure media "China Securities Journal", "Shanghai Securities News", "Securities Times" and the website of the Shanghai Stock Exchange.

It is hereby announced.

SHANGHAI JUNSHI BIOPHARMACEUTICAL TECHNOLOGY CO., LTD

Board of Directors

26 June 2024