Overview of Soft Tissue Sarcoma Treatment

Soft tissue sarcomas are a heterogeneous group of over 50 histologic subtypes requiring subtype-specific treatment approaches. Doxorubicin remains the standard first-line systemic therapy. Trabectedin and pazopanib provide second-line options. Eribulin has demonstrated benefit in liposarcoma. Tazemetostat (Tazverik) is approved specifically for epithelioid sarcoma as the first EZH2 inhibitor.

Treatment by Setting

First-Line Advanced STS

  • Doxorubicin Β± ifosfamide
  • Gemcitabine + docetaxel (leiomyosarcoma)

Second-Line and Beyond

  • Trabectedin (Yondelis) β€” especially L-sarcomas
  • Pazopanib (Votrient) β€” non-adipocytic STS
  • Eribulin (Halaven) β€” liposarcoma

Subtype-Specific

  • Tazemetostat (Tazverik) β€” epithelioid sarcoma

Epidemiology & Impact

Soft tissue sarcomas comprise over 70 subtypes from mesenchymal tissues with approximately 13,590 cases and 5,200 deaths annually. They account for less than 1% of adult cancers. Common subtypes include UPS, liposarcoma, leiomyosarcoma, and synovial sarcoma. Approximately 60% arise in extremities. Five-year survival is approximately 65%.

Molecular Biology & Biomarkers

Highly subtype-specific. Translocation-driven: synovial sarcoma (SS18-SSX), myxoid liposarcoma (FUS-DDIT3), DFSP (COL1A1-PDGFB). Amplification-driven: well-differentiated liposarcoma (MDM2). Complex karyotype: leiomyosarcoma, UPS. Molecular diversity makes trial design challenging.

Evolving Treatment Landscape

Surgery with wide margins is cornerstone. Doxorubicin-based chemotherapy is first-line for advanced disease. Subtype-specific advances include tazemetostat for INI1-negative epithelioid sarcoma, avapritinib for PDGFRA-mutant GIST, imatinib for DFSP. Immunotherapy shows activity mainly in UPS and alveolar soft part sarcoma.

tazemetostat
FDA Approved 2020 1st Line+ NEW
Approved Indications (US/FDA)
Treatment of adults with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection.
Dosing Schedule
800 mg orally twice daily
Cycle Length
Continuous daily dosing
Combination Therapy
Monotherapy (EZH2 inhibitor)
Manufacturer
Ipsen
Approval Year
2020
Pivotal Trial

Approved Therapies