Sihuan Pharmaceutical Holdings Group Ltd. (0460) announced that the National Medical Products Administration of China granted marketing approval for the third indication of its innovative drug Bireociclib Tablets (brand name: Xuanyuening). The newly approved indication allows first-line treatment of hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer in combination with an aromatase inhibitor. This development follows earlier approvals for combined use with fulvestrant and as a single-agent therapy, making Bireociclib the first and only drug in China covering first-, second-, and later-line treatments of HR+/HER2- advanced breast cancer.

According to the announcement, breast cancer remains the most widely diagnosed malignant tumor among women globally. In China, the number of new breast cancer cases rose from 0.32 million in 2018 to 0.37 million in 2024 and is projected to reach 0.44 million by 2032. Approximately 75% of cases in China are HR+/HER2-, of which around 30% are diagnosed at an advanced stage. The market size for CDK4/6 inhibitors is expected to reach 13.00 billion renminbi by 2032.

The approval is supported by findings from the BRIGHT-3 study, a randomized, double-blind Phase III trial conducted in 58 centers across China. Interim analysis showed that, in comparison with a control regimen, Bireociclib combined with letrozole or anastrozole significantly reduced the risk of disease progression or death. The Bireociclib group’s median progression-free survival was not reached at the time of analysis, further indicating its durability in delaying disease progression, while adverse events were reported to be manageable with supportive care or dose adjustments.

Bireociclib is recognized as the first approved CDK2/4/6 inhibitor in China, characterized by a multi-target synergistic mechanism and reduced hematological toxicity compared to conventional CDK4/6 inhibitors. It was initially approved in May 2025 for combination therapy with fulvestrant in HR+/HER2- advanced breast cancer and also approved as monotherapy for patients who had progressed following multiple lines of treatment. The product has been listed in China’s National Reimbursement Drug List since January 1, 2026.

Xuanzhu Biopharmaceutical Co., Ltd., a non-wholly-owned subsidiary of Sihuan Pharmaceutical, independently developed Bireociclib. Xuanzhu Biopharm focuses on major disease areas such as digestive disorders, oncology, and non-alcoholic steatohepatitis. Sihuan Pharmaceutical stated that this latest approval is expected to broaden Bireociclib’s clinical coverage and support the product’s future sales growth.