Lynparza (Olaparib) Approved in China as Adjuvant Therapy for gBRCA-Mutated, HER2-Negative, High-Risk Early Breast Cancer

Shanghai, China,2025Year 1Month 2Day——Today, MSD (MSD is the trade name of Merck & Co., Inc., located in Rahway, New Jersey, U.S.) announced that the National Medical Products Administration of China has officially approved a new indication for its PARP inhibitor Lynparza® (olaparib), developed in collaboration with AstraZeneca, for the treatment of patients carrying harmful or suspected harmful germline mutations who have received neoadjuvant or adjuvant chemotherapy.BRCAMutation (gBRCAm), adjuvant treatment for adult patients with HER2-negative early high-risk breast cancer. This approval is based on the results of the Phase III OlympiA study.

According to the estimated data from 2022, breast cancer is one of the most common malignant tumor types among women in China, ranking second in terms of incidence in the female cancer spectrum, with approximately 357,200 new cases throughout the year.¹Studies have shown that the frequency of BRCA mutations in breast cancer patients in China is approximately 5.3%.^2-3`, Germline mutations in BRCA1/2 significantly increase the risk of breast and ovarian cancer, and compared with sporadic breast cancer, those with BRCA1/2 mutations develop the disease at an earlier age.`²。

Director of the Cancer Research Institute of Fudan University, Director of the Breast Cancer Research Institute, Chief of the Department of Surgery and Chief of the Breast Surgery Department,OlympiAPrincipal Investigator Professor Zhi-Min Shao"In China, the clinical needs of early high-risk breast cancer patients carrying BRCA mutations are far from being met. Today, we are very pleased to see that olaparib has been approved in China for the treatment of BRCA-mutated, HER2-negative early breast cancer patients, bringing a new treatment option for Chinese breast cancer patients. Olaparib is the first targeted therapy drug approved in China for early breast cancer with BRCA mutations, and this approval is expected to change the treatment landscape for high-risk breast cancer patients."

"Each woman's health is crucial to their families and even society. The approval of this new indication has thrilled us, bringing new hope to patients facing the challenge of breast cancer."Ms. Anna Tian, Senior Vice President of MSD Global and President of MSD ChinaMSD has a broad portfolio of leading products in the field of women's health. We will continue to collaborate with all parties, including industry partners, to enhance the accessibility of innovative drugs and jointly safeguard the health of countless women in China.

Olaparib was first approved in China in August 2018. Before the approval of this new indication, it had been approved for four indications, including epithelial ovarian cancer, fallopian tube cancer, primary peritoneal cancer, and prostate cancer.

AstraZeneca and MSD's Oncology Strategic Collaboration

In July 2017, AstraZeneca and MSD (MSD is the trade name of Merck & Co., Inc., located in Rahway, New Jersey, USA) announced a global strategic collaboration in the field of oncology to jointly conduct clinical development and commercial promotion of certain oncology products, including olaparib, the world’s first PARP inhibitor, across multiple cancer types. The two companies will collaborate on developing combination therapies with these products and other potential new drugs, as well as single-agent treatment regimens. Additionally, both companies will independently develop combination treatment strategies pairing these products with their respective PD-L1 and PD-1 inhibitors.

About MSD

At MSD (the corporate name of Merck & Co., Inc. in the United States and Canada), we unite in pursuit of a shared mission: harnessing the power of leading-edge science to save and improve lives around the world. For over 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We are committed to being a top research-intensive biopharmaceutical company—today, we stand at the forefront of research, delivering innovative solutions to advance the prevention and treatment of diseases in humans and animals. We have built a diverse and inclusive global workforce, conducting our business responsibly every day to ensure a safe, sustainable, and healthy future for all people and communities. For more information, please visitwww.msd.com`, and follow us on X (formerly Twitter), LinkedIn, and YouTube platforms.`

About MSD China

China is a crucial part of MSD's global growth strategy. MSD’s China headquarters is located in Shanghai, with a research and development center in Beijing and manufacturing facilities in Hangzhou, Ningbo, and Tianjin, integrating R&D, manufacturing, and commercial operations. We are fully committed to providing high-quality innovative medicines, vaccines, and services to the people of China, benefiting Chinese society. For more information, please visit MSD China's official website.www.msdchina.com.cn, or subscribe to MSD China's official WeChat account msd_china.

MSD Forward-Looking Statements

MSD is the trade name of Merck & Co., Inc., located in Rahway, New Jersey, USA (hereinafter referred to as "the Company"). This press release contains "forward-looking statements" made under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. The content herein is based on the current views and expectations of the Company’s management and is subject to significant risks and uncertainties. MSD does not guarantee that its products under development will receive the necessary regulatory approvals or achieve commercial success. If underlying assumptions prove inaccurate or risks or uncertainties arise, actual results may differ materially from those anticipated in the forward-looking statements.

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[1] Rongshou Zheng, et al. Analysis of the prevalence of malignant tumors in China in 2022. Chinese Journal of Oncology, 2024, 46(3): 221-231.(1)

[2] Chen Leiyan, Sun Jie, Wan Qiting, et al. Comparison of clinicopathological features of breast cancer with germline mutations in BRCA1 and BRCA2 genes in China[J]. Chinese Journal of Clinical Oncology, 2022, 49(23): 1224-1229.

[3] Sun J, Meng H, Yao L, et al. Germline Mutations in Cancer Susceptibility Genes in a Large Series of Unselected Breast Cancer Patients. Clin Cancer Res. 2017;23(20):6113-6119. doi:10.1158/1078-0432.CCR-16-3227