Shanghai Henlius Biotech : VOLUNTARY ANNOUNCEMENT - FIRST PATIENT HAS BEEN DOSED IN A PHASE 1 CLINICAL TRIAL OF ANTI-HER2 DOMAIN II HUMANISED MONOCLONAL ANTIBODY INJECTION (HLX11) FOR METASTATIC BREAST CANCER AND EARLY BREAST CANCER TREATMENT

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Shanghai Henlius Biotech, Inc.

上海復宏漢霖生物技術股份有限公司

(A joint stock company incorporated in the People's Republic of China with limited liability)

(Stock Code: 2696)

VOLUNTARY ANNOUNCEMENT

FIRST PATIENT HAS BEEN DOSED IN A PHASE 1 CLINICAL TRIAL OF

ANTI-HER2 DOMAIN II HUMANISED MONOCLONAL ANTIBODY

INJECTION (HLX11) FOR METASTATIC BREAST CANCER

AND EARLY BREAST CANCER TREATMENT

1. INTRODUCTION
   This announcement is made by Shanghai Henlius Biotech, Inc. (the "Company") on a voluntary basis to inform the shareholders and potential investors of the Company about the latest business development of the Company.
   The board of directors of the Company (the "Board") is pleased to announce that, today, the first patient has been dosed in a Phase 1 clinical trial of anti-HER2 domain II humanised monoclonal antibody injection ("HLX11") developed by the Company (for the treatment of metastatic breast cancer and early breast cancer) in mainland China(excluding Hong Kong, Macau and Taiwan regions, the same as below).
2. DESIGN AND PURPOSE OF THE TRIAL
   This is a randomised, double-blind,single-dose,parallel-controlled,four-arm Phase 1 study aimed to compare the pharmacokinetics, safety and immunogenicity of HLX11 with US-, EU- and CN-sourced pertuzumab("reference drug")administrated intravenously in healthy Chinese male subjects. The primary objective of this study is to compare the pharmacokinetics between HLX11 and the three different sourced reference drugs head-to-head. The secondary objectives are to evaluate the safety, tolerability and immunogenicity of HLX11 and the reference drug and further describe their pharmacokinetic profiles.

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1. ABOUT HLX11
   HLX11 is a biosimilar of pertuzumab (trade name: Perjeta®/帕捷特®) independently
   developed by the Company, which is proposed to be used for the following indications: 1. metastatic breast cancer (in combination with trastuzumab and docetaxel, for the treatment of patients with HER2-positive, metastatic, or unresectable locally recurrent breast cancer who have not received prior anti-HER2 therapy or chemotherapy) and 2. early breast cancer (neoadjuvant therapy in combination with trastuzumab and chemotherapy for the patients with HER2-positive, locally advanced, inflammatory, or early breast cancer (either greater than 2cm in diameter or node positive) as part of a complete treatment regimen for early breast cancer; adjuvant therapy for patients with HER2-positive early breast cancer with high risk of recurrence). In October 2019, the investigational new drug ("IND") application for HLX11 for metastatic breast cancer and early breast cancer treatment was accepted by the National Medical Products Administration (the "NMPA"). In January 2020, the IND application of HLX11 was approved by the NMPA.
   As at the date of this announcement, the anti-HER2 Humanised Monoclonal Antibody sold in mainland China included Herceptin® and Perjeta® of Roche and trastuzumab injection (漢曲 優) of Shanghai Henlius Biopharmaceutical Co., Ltd.* (上海復宏漢霖生物製藥有限公司).

According to IQVIA CHPA's information (IQVIA, a leading provider of professional medical and health information and strategic consultation),in 2009 and first half of 2020,the sales of anti-HER2 Humanised Monoclonal Antibody amounted to approximately RMB4.625 billion and RMB2.161 billion in mainland China.

WARNING STATEMENT WITH REFERENCE TO THE REQUIREMENTS UNDER RULE 18A.05 OF THE RULES GOVERNING THE LISTING OF SECURITIES ON THE STOCK EXCHANGE OF HONG KONG LIMITED: The Company cannot guarantee the successful development and commercialisation of HLX11. Shareholders and potential investors of the Company are advised to exercise caution when dealing in the shares of the Company.

On behalf of the Board

Shanghai Henlius Biotech, Inc.

Qiyu CHEN

Chairman

Hong Kong, 20 September 2020

As at the date of this announcement, the board of directors of the Company comprises Dr. Scott Shi-Kau Liu as the executive director, Mr. Qiyu Chen as the chairman and non-executive director, Mr. Yifang Wu, Ms. Xiaohui Guan, Dr. Aimin Hui and Mr. Zihou Yan as the non-executive directors, and Mr. Tak Young So, Dr. Lik Yuen Chan, Dr. Guoping Zhao and Dr. Ruilin Song as the independent non-executive directors.

• for identification purpose only

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