Clinical and Biological Activity of an Anti-PD-L1 (Atezolizumab) in Operable Localised Soft Tissue Sarcomas Patients to be Treated With Radiotherapy

This multicentric, randomised, Phase II trial will use a pick-the-winner design in order to evaluate the clinical and biological activity of atezolizumab when combined with pre-operative or post-operative radiotherapy in STS patients. Following Inform Consent Form (ICF) signature, eligible patients will be randomised (1:1:1) to receive: * Arm A: Radiotherapy followed by atezolizumab then surgery. * Arm B: Atezolizumab followed by surgery then radiotherapy. * Arm C: Radiotherapy then surgery followed by atezolizumab. The sequence of the study treatments is different among the 3 study arms. However, the dose regimens will be the same: * Atezolizumab will be administered to all patients at the dose of 1200mg, by IV injection, for 2 cycles (Q3W). * Radiotherapy will be administered to all patients at the dose of 2Gy/day, 5 days per week, for a total of 5 weeks and 50Gy. * Surgery will be performed as per institutional practice. Randomisation will be stratified according to histological subtypes as follows: Group 1: Liposarcoma (LPS), Undifferentiated Pleomorphic Sarcoma (UPS), Leiomyosarcoma (LMS), myxofibrosarcoma, angiosarcoma versus Group 2: all translocation sarcoma except Ewing, rhabdomyosarcoma (RMS) and myxoid LPS.

NCT Number	NCT03474094
Lead Sponsor	Centre Leon Berard Collaborators: Roche Pharma AG
Conditions	Sarcoma,Soft Tissue
Enrollment	62 participants
Start Date	2018-08-01
Primary Completion	2026-12-30 (estimated)
Study Completion	2026-12-30 (estimated)
Updated on ClinicalTrials.gov	2026-02-10