3SBio : VOLUNTARY ANNOUNCEMENT - CLINICAL TRIAL APPROVAL FOR ANTI-IL-5 MONOCLONAL ANTIBODY BY THE NATIONAL MEDICAL PRODUCTS ADMINISTRATION

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(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 1530)

VOLUNTARY ANNOUNCEMENT

CLINICAL TRIAL APPROVAL FOR

ANTI-IL-5 MONOCLONAL ANTIBODY BY

THE NATIONAL MEDICAL PRODUCTS ADMINISTRATION

This is a voluntary announcement issued by 3SBio Inc. (the "Company", together with its subsidiaries, the "Group") to provide the shareholders and potential investors of the Company with information on the latest business development of the Group.

The board of directors of the Company (the "Board") is pleased to announce that the clinical trial application for the Group's recombinant anti-interleukin-5(IL-5) humanized monoclonal antibody injection ("610") has been approved by the National Medical Products Administration on 25 February 2020 as a supplemental therapy for the maintenance treatment of severe eosinophilic asthma. The Group is currently actively preparing for the commencement of the clinical trial of such product.

About 610

610 is a humanized monoclonal antibody that specifically targets interleukin-5.IL-5 is a cytokine that mainly plays a pathogenic role in atopic diseases. It can regulate the growth, activation and survival of eosinophils, and can provide an essential signal for the migration of eosinophils from the bone marrow to the lungs and other organs. Eosinophils are considered to play a key role in many diseases caused by inflammation, including asthma. Studies have shown that, as compared to standard treatments, reducing respiratory eosinophilia can effectively relieve asthma symptoms and reduce the frequency of acute exacerbations. 610 binds to IL-5 and blocks the binding of IL-5 to the IL-5 receptor on the surface of eosinophils, thereby inhibiting its biological activity and reducing the level of eosinophils in blood, tissues and sputum to achieve the therapeutic effect of reducing eosinophil-mediated inflammatory response.

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About Asthma

Asthma is a disease with marked heterogeneity, and eosinophilic asthma is a major type of asthma. Research data has shown that the prevalence of asthma in people aged 20 and above in China is 4.2%, with a total number of patients of over 45.7 million, far exceeding previous estimates, and the diagnosis and treatment rates of asthma patients are extremely low1. At present, inhaled glucocorticoids are still the first-line drugs for the treatment of asthma. Although the symptoms of most asthma patients can be controlled through standardized treatment, there are still 5%-10% of patients with repetitive symptoms after drug withdrawal or reduction, and the long-term and heavy use of glucocorticoids can cause systemic adverse reactions. Currently, treatments are also beginning to evolve towards drug combination2.

Along with the development of monoclonal antibody technology, targeting IL-5 has become a key method for the treatment of refractory eosinophilic asthma. It is mainly used for severe asthma patients with uncontrolled symptoms after combined treatment with glucocorticoids and long-acting bronchodilator.

Dr. LOU Jing, the chairman and chief executive officer of the Company, commented, "We are pleased to have received the approval for investigational new drug application for anti-IL-5 monoclonal antibody from the National Medical Products Administration, and we are expecting to speed up the work on the clinical trial of such product in China. 3SBio will continue to look for opportunities and endeavour to explore and develop safer and more effective therapeutic biological agents, so as to meet the urgent medical needs and provide important treatment options for patients with autoimmune diseases."

This is a voluntary announcement issued by the Company. The Company cannot guarantee that 610 will be successfully developed or eventually launched. 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

3SBio Inc.

Dr. LOU Jing

Chairman

Shenyang, the PRC

25 February 2020

1. Prof Kewu Huang, MD, Ting Yang, MD, Prof Jianying Xu, MD, et al. Prevalence, risk factors, and management of asthma in China: a national cross-sectional study. Lancet. June 2019.
2. Jiang Long, Xia Lixia, Lan Fen, et al. Research progress in severe asthma. Journal of Critical Care in Internal Medicine, 2017; 23(5): 424-428.

As at the date of this announcement, the Directors of the Company are Dr. LOU Jing and Ms. SU Dongmei as executive Directors; Mr. HUANG Bin and Mr. TANG Ke as non-executive Directors; and Mr. PU Tianruo, Mr. David Ross PARKINSON and Dr. WONG Lap Yan as independent non-executive Directors.

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