BIOSTAR PHARM-B (02563) announced that its wholly-owned U.S. subsidiary, Biostar Pharma, Inc. (US-Biostar), has completed the first patient dosing in a key overseas clinical study: the U.S. pivotal registration trial (NCT06764940) evaluating Utidelone (UTD1) combined with capecitabine for HER2-negative breast cancer brain metastasis (BCBM).

The study adopts a two-stage design, aiming to enroll approximately 120 participants, with the primary endpoint being the central nervous system objective response rate (CNS-ORR). The trial involves nearly 20 leading U.S. research centers, including MD Anderson Cancer Center, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, City of Hope-Duarte, Robert H. Lurie Comprehensive Cancer Center of Northwestern University, University of Colorado Hospital, Augusta University, and University of California Los Angeles.

Utidelone's unique physicochemical properties and insensitivity to P-glycoprotein-mediated efflux enable it to cross the blood-brain barrier (BBB) and combat solid tumor brain metastasis—a distinct advantage over taxanes, another class of microtubule stabilizers.

At the 2025 ASCO conference, a Phase II study of Utidelone combined with bevacizumab and chemotherapy for HER2-negative BCBM (34 patients) reported a CNS-ORR of 67.6%, CNS clinical benefit rate (CNS-CBR) of 88.2%, and median CNS progression-free survival (CNS-PFS) of 15 months. Another Phase II study published in JAMA Oncology (2025) involving 47 patients showed a CNS-ORR of 42.6%, median CNS-PFS of 10.6 months, and median overall survival of 15.1 months. Treatment-related adverse events (TRAEs) in both studies were mostly Grade 1–2, manageable, and reversible.

Utidelone has also received FDA orphan drug designation for BCBM treatment. Approximately 20–50% of advanced breast cancer patients develop brain metastases. Due to the BBB, many breast cancer drugs fail to achieve effective intracranial concentrations, leading to poor prognosis—especially for HER2-negative BCBM patients, whose median PFS is only 2–6 months. Currently, no globally approved therapies exist for HER2-negative BCBM, highlighting an urgent unmet clinical need. Utidelone may offer a breakthrough, providing new treatment options and hope for survival.