Phase II Study of Durvalumab(MEDI4736) + Tremelimumab in Pulmonary Sarcomatoid Carcinoma

Inclusion Criteria: * 1\. Recurrent or metastatic HNSCC, regardless of PD-L1 or HPV status 2. Age ≥20 3. ECOG PS 0-1 4. Ineligibility for local therapy (surgery or radiotherapy) 5. Prior palliative chemotherapy including platinum-based chemotherapy. When recurred within 6 months of definitive/neoadjuvant/adjuvant chemo- or chemoradiation, the chemotherapy is considered a line of therapy 6. At least one measurable lesion by RECIST ver 1.1 7. Adequate organ function for treatment * Absolute neutrophil count (ANC) ≥1000 cells/mm3 * Hemoglobin: ≥ 9.0 g/dL * Platelets ≥100,000 cells/mm3 * Estimated creatinine clearance ≥40 mL/min, or serum creatinine \<1.5 x institution upper limit of normal * Bilirubin ≤1.5 x upper limit of normal (ULN) * AST (SGOT) ≤2.5 x ULN (5.0 x ULN if hepatic metastases) * ALT (SGPT) ≤2.5 x ULN (5.0 x ULN if hepatic metastases) 8. 12-Lead electrocardiogram (ECG) with normal tracing or non-clinically significant changes that do not require medical intervention 9. The patient has provided signed informed consent Exclusion Criteria: * 1\. Previous treatment with PD-1 or PDL-1 inhibitors 2. Nasopharyngeal carcinoma 3. Cytotoxic chemotherapy within 3 weeks of study entry; immunotherapy or investigational drug within 5 half-lives of study entry 4. Any major operation or irradiation within 4 weeks of baseline disease assessment. Palliative radiation is allowed 5. Symptomatic brain metastasis 6. Patients with known interstitial lung disease 7. Patients with uncontrolled or significant cardiovascular disease 8. Previous or concurrent malignancy (except for basal or squamous cell skin cancer and/or in situ carcinoma of the cervix, thyroid cancer treated curatively) without evidence of recurrence for at least 3 years prior to study entry. 9\. Pregnant or breast-feeding women 10. Systemic immunosuppressive therapy 11. Active autoimmune disease 12. Patient who have an active systemic fungal and/or known viral infection (for example, human immunodeficiency virus antibodies, hepatitis B surface antigen, or hepatitis C antibodies) (inactive HBV carrier with adequate prophylactic antiviral agent can be enrolled) 13. Body weight \<30kg 14\. Other severe acute or chronic medical condition or laboratory abnormality that may increase the risk associated with trial participation