• Histologically confirmed soft-tissue sarcoma with unknown translocation (including the following histologies but not limited to undifferentiated pleomorphic sarcomas, dedifferentiated liposaromas or leiomyosarcomas). Diagnosis must be reviewed or confirmed by the RRePS Network (Réseau de référence en pathologie des sarcomes et des viscères) as recommended by the French NCI (Institut National du Cancer, Inca).

• Metastatic or unresectable locally advanced disease,

• No previous systemic treatment for advanced/metastatic disease,

• For TLS status: available archived FFPE (Formalin-Fixed Paraffin-Embedded) tumor tissue sample or tumor material newly obtained by biopsy. Except if TLS analysis have been already performed by Biopathological platform at Bergonié Institute, presence or absence of TLS should be confirmed by central review based on FFPE tumor tissue sample (archived or newly obtained by biopsy for research purpose),

• Age ≥ 18 years,

• ECOG ≤ 1,

• Life expectancy \> 3 months,

• Patients must have measurable disease defined as per RECIST v1.1 with at least one lesion that can be measured in at least one dimension as \> 10 mm with spiral CT scan.,

• Patient must comply with the collection of tumor biopsies and biomarkers study. Tumors must be accessible for biopsy,

⁃ Adequate hematological, renal, metabolic and hepatic function

⁃ Female subjects of childbearing potential must have a negative serum pregnancy test within 7 days prior to randomization. Serum or urine pregnancy test must be repeated within 72 hours prior to receiving the first dose of study medication,

⁃ Both women and men must agree to use a highly effective method of contraception throughout the treatment period and for at least two months after discontinuation of treatment for women and four months for men.

⁃ No prior or concurrent malignant disease diagnosed or treated in the last 3 years except for superficial/non-invasive bladder cancer, or basal or squamous cell carcinoma in situ treated with curative intent; b. endoscopically resected GI cancers limited to the mucosal layer without recurrence in \> 1 year,

⁃ Recovery to grade ≤ 1 from any adverse event derived from previous treatment (excluding alopecia and vitiligo of any grade and non-painful peripheral neuropathy grade ≤ 2) according to to NCI-CTCAE, version 5.0,

⁃ Voluntarily signed and dated written informed consent prior to any study specific procedure,

⁃ Patients with a social security in compliance with the French law.