BOLD-100 Plus Doxorubicin in Advanced Soft Tissue Sarcomas

A Phase 1b, non-randomized, single-institution trial designed to assess the safety, tolerability and the highest dose with acceptable toxicity (RP2D) of BOLD-100 in combination with doxorubicin in patients diagnosed with advanced soft tissue sarcomas. The trial is divided into two phases: an initial dose-escalation phase for BOLD-100, followed by a dose-expansion phase based on the recommended dose for Phase 2. In the dose-escalation phase, we plan to enroll 12-15 patients, with an additional 17 patients in the dose-expansion phase. Participants will receive BOLD-100 intravenously on Days 1 and 8 of a 21-day cycle, in combination with doxorubicin (75 mg/m², intravenous) administered on Day 1 of each 21-day cycle for up to six cycles. Participants will continue to receive BOLD-100 for as long as the cancer is not getting worse, The maximum cycles of doxorubicin are 6 cycles. Participants will undergo a screening assessment prior to the start treatment to determine eligibility for enrollment. Treatment will commence on Day 1 and will continue until the protocol-defined criteria for treatment withdrawal are met. Disease response will be assessed using CT or MRI scans, starting at 12 weeks after the initiation of treatment and continuing every 12 weeks until withdrawal. Upon treatment discontinuation or study withdrawal, a post-treatment assessment will be conducted at end of treatment and at 30 days of the last BOLD-100 dose, with follow-up visits scheduled every 3 months thereafter.

Inclusion Criteria 1. Written informed consent in accordance with federal, local, and institutional guidelines. 2. Age \> 18 years. 3. Patients must have histologically confirmed locally advanced/unresectable or metastatic soft tissue sarcoma of limited subtype LMS, DDLPS and UPS (including Myxofibrosarcoma-MFS). 4. Patients be systemic treatment naïve, with incurable, advanced or metastatic disease. 5. Patient must have measurable disease as defined by RECIST 1.1. 6. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 7. Adequate hematopoietic function: 1. total white blood cell (WBC) count ≥2000/mm3. 2. absolute neutrophil count (ANC) ≥1500/mm3. 3. platelet count ≥100,000/mm3. 8. Adequate hepatic function: 1. Bilirubin \