Akeso : VOLUNTARY ANNOUNCEMENT - PENPULIMAB (PD-1) OBTAINED BREAKTHROUGH THERAPY DESIGNATION FROM FDA FOR THIRD-LINE TREATMENT OF METASTATIC NASOPHARYNGEAL CARCINOMA

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Akeso, Inc.

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(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 9926)

VOLUNTARY ANNOUNCEMENT

PENPULIMAB (PD-1) OBTAINED BREAKTHROUGH THERAPY DESIGNATION FROM FDA FOR THIRD-LINE TREATMENT OF

METASTATIC NASOPHARYNGEAL CARCINOMA

This announcement is made by Akeso, Inc. (the "Company", together with its subsidiaries, the "Group") on a voluntary basis to inform the shareholders and potential investors of the Company about the latest business advancement of the Group.

The board of directors of the Company (the "Board") is pleased to announce that Penpulimab (τ̵̙) (research and development code name: AK105), an PD-1 monoclonal antibody drug co-developed by the Company with Sino Biopharmaceutical Limited (stock code: 1177.HK) (together with its subsidiaries "Sino Biopharm"), has obtained breakthrough therapy designation from the Food and Drug Administration of the United States ("FDA") for third-line treatment of patients with metastatic nasopharyngeal carcinoma. This is another significant progress Penpulimab made in the United States after receiving the fast track designation and orphan drug designation from the FDA for the third-line treatment of metastatic nasopharyngeal carcinoma. This is also the Company's second oncology drug to receive breakthrough therapy designation.

Breakthrough therapy designation aims to accelerate new drug development. These drugs are designed to treat severe diseases and have shown encouraging results in early clinical studies. This shows that these drugs have a significant improvement in clinical endpoints over existing therapies or when there are unmet medical needs. Drugs with breakthrough therapy designation will receive closer guidance and various forms of support from senior FDA officials during the development process to ensure that patients will be provided with new treatment options in the shortest time.

The success in obtaining breakthrough therapy designation for Penpulimab from the FDA in respect of the third-line treatment of metastatic nasopharyngeal carcinoma will significantly support and accelerate the commercialization plan of Penpulimab in the United States. The Company and Sino Biopharm will work closely with the FDA to swiftly bring Penpulimab to patients with nasopharyngeal carcinoma.

Currently, Penpulimab applied to major indications such as liver cancer, gastric cancer, lung cancer, Hodgkin's lymphoma, nasopharyngeal cancer, etc.

INFORMATION ABOUT PENPULIMAB (τ̵̙)

Penpulimab (AK105, PD-1 monoclonal antibody) is jointly developed and commercialized by a joint venture established by the Company and Chia Tai-Tianqing Pharmaceutical Group Co., Ltd. ("Chia Tai-Tianqing"), a subsidiary of Sino Biopharm. Penpulimab's fragment crystallisable ("Fc") receptor and complement mediated effector are completely removed by mutations of Fc region, it also has a slower antigen binding offrate compared with the PD-1 antibodies that are already launched in foreign market. These features have made Penpulimab more effective in blocking the activity of the PD-1 pathway and evaded the T-cell anti-tumor activity, thus it has the potential to become an anti-PD-1 drug that can achieve better clinical efficacy.

In May 2020, the National Medical Products Administration (NMPA) of the People's Republic of China ("PRC") has accepted the new drug application of Penpulimab monoclonal antibody for the treatment of patients with classical Hodgkin's lymphoma (cHL) that has relapsed or refractory (r/r) after two or more lines of systemic chemotherapy (r/r cHL). The registrational clinical trial for third-line metastatic nasopharyngeal cancer with Penpulimab has also met key endpoints.

INFORMATION ABOUT THE COMPANY

The Company is a biopharmaceutical company dedicated to the research, development, manufacturing and commercialization of new innovative antibody drugs that are affordable to patients worldwide. Since the Company's establishment, the Company has established an end-to-end comprehensive drug development platform (ACE Platform) and system, encompassing fully integrated drug discovery and development functions, including target validation, antibody drug discovery and development, CMC production process development, and GMP compliant scale production. The Company has also successfully developed a bi-specific antibody drug development technology (Tetrabody technology). The Company currently has a pipeline of over 20 innovative drugs for the treatment of major diseases like tumors, autoimmune diseases, inflammation and metabolism diseases, 13 of which have entered clinical stage, including two first-in-class bi-specific antibody drugs (PD-1/CTLA-4 and PD-1/VEGF). The Company's vision is to become a global leading biopharmaceutical company through research and development ("R&D") of high efficacy and breakthrough new drugs that are first-in-class and best-in-class therapies.

INFORMATION ABOUT SINO BIOPHARM

Sino Biopharm is a leading R&D-based pharmaceutical group in the PRC, with business covering the entire industry chain including various pharmaceutical R&D platforms, intelligent production and strong sales system. Its products include various kinds of biopharmaceutical and chemical medicines, and have gained a competitive foothold in various therapeutic categories with promising potentials, including tumors, liver diseases, cardiocerebral diseases, analgesic medicines, respiratory system medicines and orthopedic diseases.

INFORMATION ABOUT CHIA TAI-TIANQING

Chia Tai-Tianqing is an innovative pharmaceutical company with integrated R&D, manufacturing and sales capabilities. It is a renowned R&D and manufacturing base in the PRC targeting drugs on liver diseases and oncology treatment. It is a key high technology enterprise, as well as the highlighted Lianyungang new medical industry base under the State Torch Program. It ranked 16th on the list of the "Top 100 Pharmaceutical Enterprises in China" in 2018, and was the Chinese pharmaceutical enterprise with the best drug pipeline in 2019 (by the China National Pharmaceutical Industry Information Center).

With more than 12,000 employees, Chia Tai-Tianqing's products focus on six core therapeutic areas, including oncology, liver diseases, respiratory diseases, infection, endocrine and cardiocerebral. Apart from liver diseases, Chia Tai-Tianqing has formed its unique product line in the oncology field. "Anlotinib Hydrochloride Capsules", a category 1 new drug, has been proven to treat three major indications including non-small cell lung cancer, small cell lung cancer and soft tissue sarcoma. It was a designated Orphan Drug for treatment of ovarian cancer and soft tissue sarcoma by the Food and Drug Administration of the United States (FDA). Multiple clinical trials are ongoing for other indications.

Chia Tai-Tianqing has over 1,500 R&D staff. It invests 10% to 12% of its annual sales revenue in R&D every year. There are more than 250 projects in its product pipeline.

DEFINITIONS AND GLOSSARY OF TECHNICAL TERMS

PD-1

programmed cell death protein 1, an immune checkpoint receptor expressed on T-cells, B-cells and macrophages. The normal function of PD-1 is to turn off the T-cell mediated immune response as part of the process that discourages a healthy immune system from attacking other pathogenic cells in the body. When PD-1 on the surface of T-cells attaches to certain proteins on the surface of a normal cell or cancer cell, T-cells will turn off its ability to kill the cancer cell

CMC

chemistry, manufacturing, and controls processes in the development, licensure, manufacturing, and ongoing marketing of pharmaceutical products

CTLA-4

cytotoxic T-lymphocyte-associated protein 4, which downregulates T cell immune response to cancer cells

GMP

the Good Manufacturing Practice, which comprise guidelines and regulations from time to time issued pursuant to the Drug Administration Law of the People's Republic of China ( ʕശɛ͏΍ձ਷ᖹۜ၍ଣج' ) as part of quality assurance

Warning under Rule 18A.08(3) of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited: There is no assurance that the Penpulimab (AK105, PD-1 mAb) will ultimately be successfully developed and marketed by the Company. Shareholders and potential investors of the Company are advised to exercise caution when dealing in the shares of the Company.

By Order of the Board

Akeso, Inc.

Dr. XIA Yu

Chairwoman and executive director

Hong Kong, March 30, 2021

As at the date of this announcement, the Board comprises Dr. XIA Yu as chairwoman and executive director, Dr. LI Baiyong, Dr. WANG Zhongmin Maxwell and Mr. XIA Yu (Ph.D.) as executive directors, Mr. XIE Ronggang and Dr. ZHOU Yi as non-executive directors, and Dr. ZENG Junwen, Dr. XU Yan and Mr. TAN Bo as independent non-executive directors.