Utidelone Capsules Combined With Doxorubicin for Advanced Soft Tissue Sarcoma

This trial is an open, multicenter, phase II clinical trial evaluating the efficacy and safety of uterostatin capsules (UTD2) combined with doxorubicin and tislelizumab in the treatment of advanced soft tissue sarcoma. A total of 49 participants are planned to be enrolled. Participants who meet the inclusion criteria will receive UTD2 + doxorubicin + tislelizumab. Doxorubicin will be administered for a maximum of 6 cycles. Participants who have no tumor response or a non-progressive disease (CR, PR, SD) after discontinuation of doxorubicin will receive UTD2 + tislelizumab for maintenance treatment. Maintenance treatment will last for a maximum of 2 years, but tislelizumab monotherapy maintenance treatment will last for a maximum of 1 year.