tTF-NGR Randomized Study - STS

Inclusion Criteria: 1. Patients of all genders (female, male, diverse), with no restriction regarding ethnic or religious background age 18 - 75 years. 2. Patients with advanced or metastatic soft-tissue sarcoma after failure of anthracycline-containing first line therapy (or anthracycline-containing adjuvant therapy within 12 months before entry on study) or with contraindications to these drugs 3. Patients must have histological evidence of high-grade advanced unresectable or metastatic soft tissue sarcoma (grade 2 - 3) according to the FNCLCC grading system. The following tumor types are included: * Dedifferentiated liposarcoma * Myxoid liposarcoma (high grade) * Pleomorphic liposarcoma * Adult fibrosarcoma * Myxofibrosarcoma (high-grade) * Leiomyosarcoma * Rhabdomyosarcoma (alveolar, pleomorphic) * Angiosarcoma * Synovial sarcoma * Undifferentiated sarcoma Tumor types not listed above may be included upon communication with Coordinating Investigator. The following tumor types will not be included: * Gastrointestinal stromal tumors (GIST) * Epitheloid sarcoma * Alveolar soft part sarcoma * Desmoplastic small round cell tumor * Chondrosarcoma * Osteosarcoma * Ewing sarcoma (including CIC-rearranged sarcoma and Sarcoma with BCOR alterations) 4. CD13 positivity with a score of ≥ 1 (20) by central pathology (GDI Münster) 5. Patients must have at least one unidimensionally measurable lesion by computed tomography as defined by RECIST criteria 1.1. Other adequate imaging procedures such as MRI are allowed. This lesion should not have been irradiated during previous treatments 6. Life expectancy of at least 3 months 7. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 2 8. No contraindications for trabectedin (see attachment) 9. Negative serum pregnancy test for females of childbearing potential\* within 14 days of starting treatment 10. Informed consent signed and dated to participate in the study 11. Willingness and ability to comply with the scheduled visits, treatment plan, laboratory tests and other study procedures * Women of childbearing potential (WOCBP) must be using, from the screening to 3 months following the last trabectedin (Arm 1) or the last last study drug (Arm 2) administration, highly effective contraception methods, as defined by the "Recommendations for contraception and pregnancy testing in clinical trials" issued by the Head of Medicine Agencies' Clinical Trial Facilitation Group (www.hma.eu/ctfg.html) and which include, for instance, progesteron-only or combined (estrogen- and progesteron-containing) hormonal contraception associated with inhibition of ovulation, intrauterine devices, intrauterine hormone-releasing systems, bilateral tubal occlusion, vasectomized partner or sexual abstinence. Pregnancy test will be repeated monthly. For men contraception methods should be performed for 5 months after the last application of trabectedin (Arm1) or study drug (Arm 2).Women of childbearing potential are defined as females who have experienced menarche, are not postmenopausal (12 months with no menses without an alternative medical cause) and are not permanently sterilized (e.g., tubal occlusion, hysterectomy, bilateral oophorectomy or bilateral salpingectomy) Exclusion Criteria: 1. curative therapy available 2. clinically significant unrelated illness, which in the judgement of the investigators could compromise the patient's ability to tolerate the IMP or be likely to interfere with the study procedures or results 3. immobilized tumor patients (wheel chair etc.) with increased risk for DVT 4. known hypersensitivity reactions to prior application of E. coli-derived material 5. history of coronary heart disease, stroke, transitent ischemic attacks, pulmonary embolism, or deep vein thrombosis. For reason of mechanism of action of tTF-NGR, exclusion of patients with a history of any of the vascular conditions mentioned is important. Clinical suspicion of coronary heart disease must be further checked e.g. by cardiac MRI or myocardial scintigraphy to exclude coronary heart disease. 6. known hereditary syndromes with elevated thromboembolic risk (FV Leiden and prothrombin mutations (G20210A), hereditary antithrombin, protein C and S deficiency, and antiphospholipid syndrome) after one or more clinical thromboembolic events 7. patients with hereditary vascular disorders (such as Klippel-Trenauny-Weber syndrome) with increased thromboembolic risk. 8. patients with a Khorana score of (Khorana AA, et al. J.Clin. Oncol. 2009, 27, 4839-4847, attached to this protocol) of \> 3 9. elevated Troponin T hs (\> 50 ng/L) or elevated Troponin I hs before entry on study 10. presence of active central nervous system (CNS) disease and/or CNS vascular abnormalities detected by MRI or CT 11. no adequate bone marrow function, absolute neutrophil count (ANC) \< 1.0 x 109/L, platelets \< 50 x 109/L (for trabectedin actually \< 100 x 109/L - to be decided by the investigator on an individual patient basis) and haemoglobin (Hb) \< 8.0 g/dl. 12. chronically impaired renal function or creatinine ≥ 2.0 x upper limit of normal (ULN). 13. inadequate liver function (alanine aminotranserase (ALT), aspartate aminotranserase (AST), alkaline phosphatase (ALP) or total bilirubin ≥ 2.5 x ULN) unless due to liver metastasis (decision by the investigator) 14. fibrinogen \< 150 mg/dL, and/or International Normalized Ratio (INR) \> 1,5 (global coagulation parameters can be discussed with the Coordinating Investigator prior to entry on study) 15. female patients with child-bearing who do not agree to exclusion of potential pregnancy by adequate testing within 48 hours prior to entry on study 16. females of childbearing potential as well as fertile males who do not agree to use a highly effective form of contraception (Pearl Index \< 1) during the study and for 3 months (females) following the last trabectedin (Arm 1) or last study drug (