VOLUNTARY ANNOUNCEMENT - THE PHASE III CLINICAL STUDY OF DARIDOREXANT HYDROCHLORIDE TABLETS IN THE TREATMENT OF INSOMNIA PATIENTS IN CHINA HAS MET THE PRIMARY ENDPOINT

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.Simcere Pharmaceutical Group Limited先声药业集团有限公司 (Incorporated in Hong Kong with limited liability) (Stock code: 2096) VOLUNTARY ANNOUNCEMENT THE PHASE III CLINICAL STUDY OF DARIDOREXANT HYDROCHLORIDE TABLETS IN THE TREATMENT OF INSOMNIA PATIENTS IN CHINA HAS MET THE PRIMARY ENDPOINT This announcement is made by Simcere Pharmaceutical Group Limited (the “Company” together with its subsidiaries the “Group”) on a voluntary basis to inform shareholders and potential investors of the Company about the latest business development of the Group.The board (the “Board”) of directors (the “Directors”) of the Company is pleased to announce that the phase III clinical study of Daridorexant hydrochloride tablets in the treatment of insomnia patients in China (NCT06010693) (the “Study”) has read out the topline results and has met the primary endpoint. The analysis results demonstrated that as compared to placebo Daridorexant hydrochloride tablets can improve various sleep-related indicators significantly such as night-time awakenings of insomnia patients while demonstrating good safety and tolerability at the same time. The detailed results of the Study are expected to be published in academic journals or conferences in the near future.The Group plans to submit a New Drug Application (NDA) for Daridorexant hydrochloride tablets to the National Medical Products Administration (NMPA) of China.– 1 –ABOUT THE STUDY The Study is a multi-center randomized double-blind and placebo-controlled phase III clinical trial and is led by Xuanwu Hospital of the Capital Medical University (首都医科大学 宣武医院) which has enrolled 206 patients at 33 research centers in China. The Study completed the first patient in (FPI) on December 17 2023 and completed the enrollment of all patients on March 15 2024. The success of the Study has verified the efficacy and safety of Daridorexant hydrochloride tablets in insomnia patients in China which is expected to bring new treatment options for patients.ABOUT DARIDOREXANT Daridorexant is a dual orexin receptor antagonist (“DORA”) which blocks the binding of the wake-promoting orexin neuropeptides (orexinA and orexin B) with its receptors. Rather than assisting sleep through sedation Daridorexant only antagonizes the activation of orexin receptors by the orexin neuropeptides and consequently Daridorexant decreases the wake drive allowing sleep to occur without altering the sleep architecture. Phase 3 overseas data of Daridorexant has been reported in The Lancet Neurology: the pivotal studies demonstrated that at the first and third month of treatment compared to placebo Daridorexant significantly improved sleep onset and sleep maintenance and extended the self-reported total sleep time without altering the sleep architecture. In addition the studies also showed that Daridorexant is safe and well-tolerated with no evidence of rebound insomnia withdrawal symptoms or drug abuse which is different from those reported with benzodiazepine receptor agonists.Clinical data on Daridorexant are available for up to 12 months of continuous treatment which can support the long-term medication of Daridorexant. In addition to improving nighttime sleep of adults with chronic insomnia disorder Daridorexant also has a positive impact on the daytime functioning of the patients and is also the only DORA approved by the European Medicines Agency (EMA) that have an impact on daytime functioning. Previously Daridorexant has been approved in the United States Great Britain Italy Germany Switzerland and Canada.On November 15 2022 the Group entered into an exclusive license agreement with Idorsia Pharmaceuticals Ltd. (“Idorsia”) and was granted an exclusive right to develop and commercialize Daridorexant in the Greater China region. On May 20 2024 the Pharmacy and Poisons Board of Hong Kong issued the certificate of drug/product registration to theGroup which allowed two specifications of daridorexant tablets namely “QUVIVIQTABLETS 50MG” and “QUVIVIQ TABLETS 25MG” to be sold offered for sale distributed and possessed in Hong Kong.– 2 –ABOUT IDORSIA Headquartered near Basel Switzerland — a European biotech-hub — Idorsia is specialized in the discovery development and commercialization of small molecules to transform the horizon of therapeutic options. Idorsia has a broad portfolio of innovative drugs in the pipeline an experienced team of professionals covering all disciplines from bench to bedside state-of-the-art facilities and a strong balance sheet — the ideal constellation to translate R&D efforts into business success. Idorsia was listed on the SIX Swiss Exchange (ticker symbol: IDIA) in June 2017.ABOUT THE COMPANY The Company is an innovation and R&D-driven pharmaceutical company and has established a “State Key Laboratory of Neurology and Oncology Drug Development”. The Company focuses on the therapeutic areas of oncology nervous system autoimmune and anti-infection with forward-looking layout of disease areas that may have significant clinicalneeds in the future aiming to achieve the mission of “providing today’s patients withmedicines of the future”. Driven by its in-house R&D efforts and synergistic innovation the Company has established strategic cooperation partnerships with many innovative companies and research institutes.By order of the Board Simcere Pharmaceutical Group Limited Mr. Ren Jinsheng Chairman and Chief Executive Officer Hong Kong May 31 2024 As at the date of this announcement the Board comprises Mr. REN Jinsheng as the Chairman and executive Director Mr. TANG Renhong Mr. WAN Yushan and Ms. WANG Xi as the executive Directors; and Mr. SONG Ruilin Mr. WANG Jianguo Mr. WANG Xinhua and Mr.SUNG Ka Woon as the independent non-executive Directors.–3–