Selinexor in Patients With Advanced Thymic Epithelial Tumor Progressing After Primary Chemotherapy

Inclusion Criteria: * Histologically confirmed advanced TET (thymoma) * Progression after Primary Chemotherapy * No more than two previous lines (Neoadjuvant or chemoradiotherapy will count as one line if disease progression has occurred within 6 months) * Inoperable per local Investigator (Masaoka Stage III or IV) * Progression after treatment with least one platinum containing chemotherapy regimen * Measurable disease (RECIST 1.1) * Age ≥18 years * ECOG PS \<2 * Patients must have recovered from the toxic effects of prior therapy at the time of initiation of the study drug unless toxicity is stable. * A 4 weeks or five half lives interval from any investigational agents or cytotoxic chemotherapy to start of study is required * Signed informed consent * Adequate bone marrow function and organ function: * Hematopoietic function: total white blood cell count (WBC) ≥ 3000/mm³, absolute neutrophil count (ANC) ≥ 1500/mm³, platelet count ≥ 100,000/mm²; Hemoglobin \> 9.0 gm/dL * Hepatic function: bilirubin \< 1.5 times the upper limit of normal (ULN), ALT \< 2.5 times ULN or ALT \< 5.0 times ULN in the presence of liver metastases * Creatinine clearance \> 30 ml/min according to Cockcroft-Gault * Patients of childbearing potential must agree to use adequate birth control during and for 7 months after participation in this study Exclusion Criteria: * No significant medical illness that in the investigator's opinion cannot be adequately controlled with appropriate therapy o…