FAB Accelerates China Approval for Bireociclib Tablets: CDK4/6 Inhibitor Self-Developed by Xuanzhu Biopharma

On May 15, 2025, the latest announcement from the National Medical Products Administration (NMPA) revealed that Xuanzhu Biopharma’s self-developed Class 1 innovative anti-tumor drug, Bireociclib Tablets, has been approved for marketing. It is indicated for adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer:
· As monotherapy for patients who have experienced disease progression after receiving two or more prior endocrine therapies and one chemotherapy in the metastatic setting.

FAB, as China’s leading medical imaging CRO, provided Independent Review Committee (IRC) services for central imaging assessment in the Phase II clinical study of Bireociclib monotherapy for advanced breast cancer.

Source: NMPA

Bireociclib is an oral small-molecule CDK4/6 inhibitor independently developed by Xuanzhu Biopharma. Based on innovative technological design, Bireociclib demonstrates potent enzymatic inhibitory activity against both CDK4 and CDK6, with higher selectivity for CDK4 over CDK6, while also exhibiting significant inhibitory effects on CDK2.

Results from the BRIGHT-1 study (a Phase II trial of Bireociclib monotherapy in later-line treatment) were published in Cancer Communications. This Phase II study evaluated the efficacy and safety of Bireociclib monotherapy in relapsed/refractory HR+/HER2- metastatic breast cancer.

Study results showed significant efficacy for Bireociclib monotherapy:

· Independent Review Committee (IRC)-assessed Objective Response Rate (ORR): 29.8%

· Clinical Benefit Rate (CBR): 42.0%

· Disease Control Rate (DCR): 73.3%

· Median Progression-Free Survival (PFS): 11.0 months

· Median Overall Survival (OS): 29.0 months

The most common treatment-emergent adverse events (TEAEs) included diarrhea, neutropenia, decreased white blood cell count, and vomiting. Most TEAEs resolved after dose interruption or reduction. The overall safety and tolerability profile was favorable, with no new safety signals identified compared to other drugs in the same class.

As a key partner in the Phase II clinical study for Xuanzhu Biopharma, FAB was fully responsible for the critical Independent Central Imaging Review.

During clinical trial operations, FAB leveraged its professional expertise to provide comprehensive support—from image acquisition protocol design and independent review charter development to customized review system implementation. At the critical enrollment stage, FAB delivered baseline eligibility assessment services. Facing tight timelines, the team responded rapidly, completing quality control reviews and providing feedback efficiently, ultimately enabling the enrollment of 131 subjects. Throughout the project, the team maintained frequent communication with the sponsor and study sites, demonstrating professionalism in project initiation, site training, and review timeline management. To meet stringent review deadlines, team members proactively worked extended hours, coordinating expert schedules to ensure timely completion of all assessments. During the on-site NMPA inspection, the team provided precise responses to all queries with thoroughly prepared documentation, achieving an outstanding result of zero findings and earning high recognition from all parties.

With this milestone, FAB’s cumulative approvals have reached a record 38! Notably, Bireociclib is:

· The sixth innovative oncology drug project supported by FAB in the breast cancer field

· China’s first approved CDK4/6 inhibitor for monotherapy in HR+/HER2- advanced breast cancer patients

Currently, FAB has established collaborations with over 100 pharmaceutical companies worldwide, having supported over 320 clinical imaging assessment projects, of which 58 have submitted New Drug Applications (NDAs)—fully demonstrating FAB’s excellence in high-quality, efficient service delivery.

FAB extends sincere congratulations to Xuanzhu Biopharma on this significant achievement. We look forward to partnering with more global innovators to accelerate the development of transformative therapies through high-quality independent imaging evaluation services, bringing new hope to cancer patients worldwide.