Sihuan Pharmaceutical's Bireociclib Receives NMPA Approval for First-Line HR+/HER2- Advanced Breast Cancer Treatment
Key Insights
China's NMPA has approved Bireociclib (search) (Xuanyuening (search)) in combination with aromatase inhibitors for first-line treatment of HR+/HER2- advanced breast cancer (search), making it the first and only drug in China covering all treatment lines for this indication.
The Phase III BRIGHT-3 trial demonstrated that Bireociclib (search) reduced disease progression or death risk by 47% overall and 64% in liver metastases (search) patients, with median progression-free survival not yet reached in the treatment group.
The approval positions Bireociclib (search) to capture a significant share of China's CDK4/6 (search) inhibitor market, projected to reach RMB 13 billion by 2032, with the drug already included in China's National Reimbursement Drug List effective January 2026.
China's National Medical Products Administration (NMPA) has granted marketing approval for Bireociclib (search) Tablets (Xuanyuening (search)), developed by Xuanzhu Biopharmaceutical Co., Ltd., a subsidiary of Sihuan Pharmaceutical Holdings Group Ltd., for first-line treatment of hormone receptor (search)-positive, human epidermal growth factor receptor 2-negative (HR+/HER2 (search)-) advanced breast cancer (search) in combination with aromatase inhibitors.
This third indication approval establishes Bireociclib (search) as the first and only drug in China to cover first-line, second-line, and later-line treatments for HR+/HER2- advanced breast cancer (search), substantially expanding patient access and enhancing the drug's clinical value and commercial potential.
Clinical Trial Results Drive Approval Decision
The NMPA's approval was based on results from the pivotal Phase III BRIGHT-3 study (NCT05257395), a randomized, double-blind trial conducted across 58 centers in China. The study evaluated Bireociclib (search) combined with letrozole or anastrozole for first-line treatment of HR+/HER2- advanced breast cancer (search).
Interim analysis revealed that median progression-free survival (mPFS) for patients in the Bireociclib (search) group has not yet been reached, significantly outperforming the control group (18.43-19.55 months). The Bireociclib regimen reduced the risk of disease progression or death by 47% overall compared to endocrine therapy plus placebo.
Particularly notable results were observed in patients with liver metastases (search), a population with poor prognosis, where Bireociclib (search) reduced the risk of progression or death by 64%. The objective response rate (ORR) reached 63.5% in the Bireociclib group compared to 42.5% in the control group.
Favorable Safety Profile Supports Clinical Adoption
The safety analysis demonstrated that the most common adverse events, including diarrhea and neutropenia, were predominantly Grade 1-2 and effectively managed. This favorable safety profile, combined with Bireociclib (search)'s unique mechanism as a CDK2/4/6 (search) inhibitor, offers potent anti-tumor activity with significantly reduced hematological toxicity compared to traditional CDK4/6 (search) inhibitors.
Significant Market Opportunity in China
HR+/HER2 (search)- breast cancer (search) represents approximately 75% of all breast cancer cases in China, with about 30% diagnosed at the advanced stage. New breast cancer cases in China rose from 322,200 in 2018 to an estimated 374,700 in 2024, and are projected to reach 435,000 by 2032.
The CDK4/6 (search) inhibitor market for HR+/HER2- advanced breast cancer (search) in China is projected to reach RMB 13 billion by 2032. CDK4/6 inhibitors combined with endocrine therapy have become the standard first-line therapy for this patient population in China.
Reimbursement Status Enhances Commercial Prospects
As of December 2025, Bireociclib (search)'s two previous indications have been included in China's National Reimbursement Drug List, effective January 1, 2026. This inclusion significantly improves patient accessibility and is expected to boost sales volume and market penetration.
Bireociclib (search) was first approved in May 2025 for use with fulvestrant in HR+/HER2 (search)- advanced or metastatic breast cancer (search) patients who have progressed after prior endocrine therapy, and as a monotherapy after two or more lines of endocrine therapies plus one chemotherapy in the metastatic setting. The drug holds the distinction of being the first and only CDK2/4/6 (search) inhibitor in China approved for a monotherapy indication.
Global Market Leadership Position
According to PharmCube statistics, Bireociclib (search) has ranked first in the global CDK2/4/6 (search) inhibitor market, highlighting its competitive advantage and therapeutic potential beyond the Chinese market.
Xuanzhu Biopharmaceutical Co., Ltd. focuses on innovation in major disease areas including oncology, digestion, and non-alcoholic steatohepatitis. The company employs dual R&D platforms covering small molecule chemistry and large molecule biologics, maintaining a deep product pipeline that includes antibody-drug conjugates (ADCs).
Sihuan Pharmaceutical Holdings Group Ltd. (Stock Code: 0460), founded in 2001 and listed in 2010, operates a dual business strategy across medical aesthetics and biopharmaceuticals, supported by robust R&D capabilities, registration expertise, efficient production platforms, and a mature sales system.