Biostar Pharma has achieved a significant milestone in oncology drug development by dosing the first patients in two Phase II/III multiregional clinical trials of Utidelone Capsule (UTD2) on September 11 and 12, 2025. The trials target locally advanced or metastatic gastric cancer (NCT06841679) and platinum-resistant advanced epithelial ovarian cancer (NCT07044349), representing a major expansion of the company's oral microtubule inhibitor program.
Strong Clinical Foundation in Gastric Cancer
Utidelone has demonstrated compelling efficacy data in gastric cancer through previous clinical studies. In a completed Phase II study of Utidelone Injection (UTD1) combined with PD-1 inhibitor and oxaliplatin for first-line treatment of unresectable locally advanced or recurrent/metastatic HER2-negative gastric cancer, 23 patients completed efficacy evaluation. The results showed 15 patients achieved partial response (PR) and 8 achieved stable disease (SD), resulting in a 65.2% objective response rate (ORR) and 100% clinical benefit rate (CBR). The median progression-free survival (mPFS) reached 6.1 months, with the combination regimen being generally well-tolerated with most treatment-related adverse events being Grade 1-2, reversible, and manageable.
Based on these promising results, Utidelone received Orphan Drug Designation from the U.S. FDA for the treatment of advanced gastric cancer. The longest treatment duration received by a patient was 22 cycles, demonstrating the drug's tolerability profile.
Promising Activity in Ovarian Cancer
Beyond gastric cancer, Utidelone has shown considerable potential in treating ovarian cancer. A US Phase I clinical study of UTD2 as monotherapy for advanced solid tumors included 12 evaluable patients, with notable responses in heavily pretreated ovarian cancer patients. One ovarian cancer patient achieved complete response (CR) after 7 previous lines of therapy, while another achieved PR after 9 lines of therapy. Additionally, a Phase II clinical study of UTD1 as monotherapy for advanced solid tumors evaluated 10 patients in the advanced ovarian cancer cohort, with 1 PR and 3 SD observed.
Advantages of Oral Formulation
Utidelone Capsule offers several advantages over traditional taxanes, which are difficult for oral formulation development. The drug is not susceptible to P-glycoprotein and cannot be pumped out of cancer cells by P-glycoprotein, providing higher oral bioavailability and lower risk of developing cross-resistance. The oral capsule formulation significantly improves administration convenience, patient compliance, decreases treatment costs, and facilitates combination therapy with other oral anti-cancer drugs, making it more suitable for adjuvant or maintenance therapy.
Trial Design and Objectives
Gastric Cancer Study (NCT06841679)
This multi-national, open-label, randomized Phase II/III clinical study evaluates UTD2 combined with standard of care in first-line patients with locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma who are untreated with systemic treatment in the advanced setting. The Phase II portion plans to enroll 78 subjects across China, US, Europe, and Japan, with primary objectives to evaluate safety, efficacy, and pharmacokinetic profile of UTD2 in combination therapy. The Phase III portion plans to enroll 700 subjects across multiple countries/regions, with overall survival (OS) as the primary endpoint and secondary endpoints including PFS, ORR, and safety.
Ovarian Cancer Study (NCT07044349)
This multi-national, open-label, randomized Phase II/III clinical trial evaluates UTD2 for patients with platinum-resistant advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer. The Phase II part plans to enroll approximately 84 subjects to evaluate safety, efficacy, and pharmacokinetic characteristics of UTD2 under different dosing regimens and recommend a dose for Phase III. The Phase III part plans to enroll 480 subjects worldwide to evaluate efficacy and safety of UTD2 compared to investigator's choice of standard treatment, with progression-free survival (PFS) as the primary endpoint and secondary endpoints including OS and ORR.
Mechanism and Broader Development Program
Utidelone is a new-generation genetically engineered microtubule inhibitor with a similar mechanism of action to taxanes while demonstrating multiple advantages, including better anti-tumor activity, broader anti-tumor spectrum, better safety profile with very low hematologic toxicity, effectiveness against multidrug-resistant tumors, reduced propensity for developing drug resistance, capability of crossing the blood-brain barrier, and high oral bioavailability.
Biostar has developed two formulations of Utidelone: injection (UTD1) and capsule (UTD2). UTD1 launched in China in 2021 for treating metastatic breast cancer in patients who progressed after at least one anthracycline- or taxane-containing chemotherapy regimen. Phase III study data showed UTD1 plus capecitabine achieved both PFS and OS benefits versus capecitabine for heavily pretreated metastatic breast cancer patients.
Beyond gastric and ovarian cancers, Biostar is actively planning and advancing multiple clinical studies to expand UTD2's indications, including breast cancer adjuvant intensification therapy, pancreatic cancer, esophageal cancer, and colorectal cancer.
