Securities code: 688506 Securities abbreviation: Baili Tianheng Announcement No.: 2025-027

Sichuan Baili Tianheng Pharmaceutical Co., Ltd

Voluntary Disclosure About BL-B01D1 (EGFR×HER3 Bispecific Antibody ADC)

For phase III clinical trials in locally advanced or metastatic urothelial carcinoma

Announcement of completion of the enrollment of the first subject

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.

Sichuan Baili Tianheng Pharmaceutical Co., Ltd. (hereinafter referred to as the "Company") independently developed the innovative biologic drug BL-B01D (1 EGFR×HER3 bispecific antibody ADC) for injection in patients with unresectable locally advanced or metastatic urothelial carcinoma who have previously failed platinum-containing chemotherapy and PD-1/PD-L1 inhibitor treatment. The relevant information is hereby announced as follows:

First, the basic situation of drugs

BL-B01D1 is the world's first-in-class, new concept and the only one to enter

EGFR×HER3 bispecific antibody ADC in phase III clinical stage. Recently, BL-B01D1 has been used for prior platinum-containing chemotherapy

and unresectable locally advanced or metastatic urothelial carcinoma that has failed PD-1/PD-L1 inhibitor therapy, and the clinical study has entered the phase III clinical trial stage and completed the enrollment of the first subject.

To date, BL-B01D1 is undergoing more than 30 clinical trials in China and the United States for multiple tumor types

In addition to this newly enrolled clinical trial, BL-B01D1 is also in the stage of subject enrollment in 8 domestic phase III registration clinical trials in non-small cell lung cancer, small cell lung cancer, breast cancer, nasopharyngeal cancer, and esophageal squamous cell carcinoma.

2. Risk Warning

According to the requirements of laws and regulations related to drug registration in China, drugs need to complete relevant clinical trials and pass the review and approval of the State Drug Administration before they can be marketed.

Due to the characteristics of high-tech, high-risk and high value-added pharmaceutical products, drugs from early research, clinical trial approval to production cycle is long and linked, and are easily affected by some uncertain factors, the company will actively promote the above-mentioned research and development projects in accordance with relevant regulations, and strictly follow the relevant regulations to fulfill the information disclosure obligations on the follow-up progress of the project in a timely manner, please make prudent decisions and pay attention to preventing investment risks.

The announcement is hereby made.

Board of Directors of Sichuan Baili Tianheng Pharmaceutical Co., Ltd

April 9, 2025