1952P - Efficacy and safety of utidelone in previously treated patients with advanced or metastatic soft tissue sarcomas (HX-SARC02): A prospective, single-arm, phase II study

Background

Treatment options are limited for patients with advanced or metastatic soft tissue sarcomas (STSs) after failure of anthracycline-based chemotherapy and large-spectrum tyrosine kinase inhibitor. Utidelone, a genetically engineered epothilone analogue, has demonstrated high activity in preclinical and clinical studies against a broad range of tumors. This study aimed to evaluate the efficacy and safety of utidelone in refractory STSs.

Methods

This prospective, single-arm, phase II trial included patients aged 18 years or older with histologically proven advanced and inoperable STSs who had at least received anthracycline-based chemotherapy and large-spectrum tyrosine kinase inhibitor. Patients were treated with intravenously transfused utidelone (30 mg/m², day 1-5, every 21 days) until disease progression or intolerable toxicity. The primary endpoint was the median progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS) and safety.

Results

Between August 19, 2022 and March 1, 2023, a total of 10 patients were enrolled. As of April 16, 2023, all patients could be analyzed. There were 7 patients with leiomyosarcoma, one patient with synovial sarcoma, one patient with dedifferentiated liposarcoma, one patient with myofibroblastic sarcoma. 10 patients are evaluable for response with median cylces of 4 (1-7), 7 of whom are still under treatment. The median number of previous systemic therapies was two. The median PFS has not been reached. The ORR was 10% and DCR was 80%. Most of the common adverse events (AEs) were grade 1 or 2 and were considered manageable and reversible. Grade ≥3 AEs included peripheral neuropathy (1 [10%]), AST increase (1 [10%]) and diarrhoea (1 [10%]). Doses of utidelone were reduced (24 mg/m², on day 1-5) in two patients and discontinued in one patient. No treatment-related deaths occurred.

Conclusions

The present study demonstrated a promising anti-tumour activity of utidelone in patients with advanced or metastatic STSs who were previously treated with and refractory to both anthracycline-based chemotherapy and large-spectrum tyrosine kinase inhibitor.

Clinical trial identification

ChiCTR2200062161.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Beijing Biostar Technologies, Ltd.

Disclosure

All authors have declared no conflicts of interest.