Breaking the “Untreatable”: Biostar Pharma’s UTD1 Achieves First Patient Dosing in U.S. for Pivotal Clinical Trial for Breast Cancer Brain Metastases

SAN FRANCISCO, Dec. 16, 2025 /PRNewswire/ — Biostar Pharma, Inc., the U.S. wholly-owned subsidiary of Beijing Biostar Pharmaceuticals Co., Ltd. (Stock Code: 2563.HK), today announced that the first patient has been dosed for one of its key oversea clinical studies: the U.S. pivotal clinical study (NCT06764940) of Utidelone Injection(UTD1) combined with capecitabine for the treatment of HER2-negative breast cancer brain metastases (BCBM).

The study adopts a two-stage design and plans to enroll approximately 120 subjects. The primary endpoint is the central nervous system objective response rate (CNS-ORR). Nearly 20 top tier clinical institutes across the United States are participating in the trial, including MD Anderson Cancer Center, John Hopkins Sidney Kimmel Comprehensive Cancer Center, City of Hope-Duarte, Robert H. Lurie Comprehensive Cancer Center at 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 prevent or treat brain metastases of solid tumors, setting it apart from taxanes, which are also microtubule stabilizers. A Phase II clinical study of utidelone combined with bevacizumab and chemotherapy for HER2-negative BCBM, which enrolled 34 subjects, was presented orally at the 2025 ASCO Annual Meeting ^[1]. The results showed a CNS-ORR of 67.6%, a central nervous system clinical benefit rate (CNS-CBR) of 88.2%, and a median central nervous system progression-free survival (CNS-PFS) of 15 months. The results of another Phase II clinical study of utidelone combined with bevacizumab for HER2-negative BCBM were published in JAMA Oncology in 2025 ^[2]. 47 subjects were recruited in the study, with a CNS-ORR of 42.6%, a median CNS-PFS of 10.6 months, and a median overall survival of 15.1 months. In both studies, most treatment-related adverse events (TRAEs) were Grade 1-2, controllable, and reversible. The U.S. FDA has also granted Utidelone orphan drug designation for the treatment of breast cancer brain metastases.

Approximately 20-50% of advanced breast cancer patients develop brain metastases ^[3]. Due to the presence of the BBB, many breast cancer treatments were unable to achieve effective concentrations intracranially, leading to generally poor prognoses for BCBM patients, particularly those with HER2-negative BCBM, whose median progression-free survival is only 2-6 months. However, there is currently no clearly effective drug therapy for HER2-negative BCBM, and no drugs worldwide have been approved for this indication, highlighting a significant and urgent unmet medical need. Utidelone has the potential to change this landscape, offering a new treatment option and hope for survival to these patients.

About Biostar

Biostar is an integrated biopharma company focusing on the development of innovative anti-cancer drugs utilizing its synthetic biology R&D platform. The company is listed on the Hong Kong Stock Exchange (HK 2563) in 2024. We are actively selecting reliable global partners through out-licensing or co-development of Utidelone assets. We believe that our strong capabilities of R&D and manufacturing, coupled with our enriched commercial expertise, make us the preferred partner for global biopharmaceutical companies who share our goal of bringing innovative anti-cancer products to patients around the world. For additional information on partnering with Biostar, please contact our business development team at [email protected].