By Fineline Cube 
Xuanzhu Biopharmaceutical Co., Ltd. (HKG: 2575) announced that the interim analysis of the Phase III BRIGHT‑3 study demonstrates that bireociclib (trade name Xuan‑Yue‑Ning), when combined with aromatase inhibitors letrozole or anastrozole, provides superior disease control for first‑line treatment of HR⁺/HER2‑ advanced breast cancer.
Key Findings
| End‑Point | Bireociclib + AI | AI Alone |
|---|---|---|
| Progression‑Free Survival (PFS) | 20.6 months | 14.3 months |
| Objective Response Rate (ORR) | 57.4 % | 41.2 % |
| ≥ Grade 3 Hematologic Toxicity | 12.1 % | 28.7 % |
- Significant PFS benefit (+6.3 months) with a modest safety profile.
- Reduced hematologic toxicity compared with established CDK4/6 agents.
- Subgroup analysis confirms benefit across age, performance status, and prior endocrine exposure.
About Bireociclib
- Novel CDK2/4/6 inhibitor with a multi‑target synergistic mechanism that blocks tumor‑cell cycle progression while sparing normal hematopoiesis.
- NMPA‑approved on May 13 2025 for:
- Combination with fulvestrant in endocrine‑therapy‑refractory disease.
- Monotherapy in metastatic disease after ≥2 endocrine therapies + chemotherapy – the first and only CDK4/6 monotherapy approved in China.
- Global development: Phase III BRIGHT‑3 (first‑line HR⁺/HER2⁻), Phase II BIRCH (second‑line), and Phase I/II global trials underway.
Strategic Implications
- Positions Xuanzhu as a leader in CDK4/6 oncology with a differentiated safety profile.
- Opens the monotherapy market in China, potentially expanding global reach.
- Enhances portfolio depth for first‑line endocrine‑plus‑CDK therapy.
Forward‑Looking Statements
This release contains forward‑looking statements that involve risks and uncertainties. Actual results may differ materially.-Fineline Info & Tech