Epithelioid Sarcoma Clinical Trials 2026 — Find Recruiting Studies

About Epithelioid Sarcoma

Epithelioid sarcoma is an ultrarare malignant soft tissue tumour defined by loss of SMARCB1 (INI1) expression due to biallelic inactivation of the SMARCB1 tumour suppressor gene, which encodes a core subunit of the SWI/SNF chromatin remodelling complex. Two subtypes are recognised: the classic (distal) type presenting as a slow-growing nodule in the distal extremities of young adults, and the proximal type arising in axial locations with more aggressive behaviour. Loss of EZH2 antagonism resulting from SMARCB1 deficiency renders epithelioid sarcoma uniquely sensitive to EZH2 inhibition — a mechanism exploited by tazemetostat, the first approved therapy for this tumour.

Common Clinical Features

Slow-growing, firm nodule or plaque on the hand, wrist, or forearm (classic type) often initially mistaken for a benign lesion Ulceration of overlying skin, particularly in distal extremity tumours, mimicking a chronic wound Proximal type: deep-seated pelvic, perineal, or axial mass with more rapid growth Regional lymph node metastases, with lymphatic spread rates higher than most sarcomas Bone invasion and periosteal involvement in advanced distal extremity cases Pulmonary metastases as the most common site of distant disease Multifocal local recurrence along fascial planes after resection

Clinical Trial Eligibility Tips

What to know before applying to Epithelioid Sarcoma trials.

Loss of INI1 (SMARCB1) expression by immunohistochemistry is the diagnostic and eligibility criterion for EZH2 inhibitor trials — pathology report must specifically document INI1-negative staining.

Tazemetostat (FDA-approved for this indication) may affect eligibility for combinatorial EZH2 inhibitor trials; document prior exposure to EZH2 inhibitors including dates and response.

Archival tumour tissue for central pathology review is typically required; ensure sufficient FFPE block material is available and arrange transfer of blocks or unstained sections early in the screening process.