Inclusion Criteria:

- Histologically or cytologically confirmed recurrent or metastatic squamous-cell
carcinoma of head and neck (SCCHN), except nasopharyngeal carcinoma

- Disease not amenable to curative treatment (surgery or radiation for curative intent)

- 20 years of age or older

- Progressive disease defined as follows

- after one or two prior chemotherapy regimens including platinum-based
chemotherapy given for palliation

- within 6 months after concurrent chemoradiotherapy (including induction
chemotherapy) delivered as part of primary treatment.

- Life expectancy of at least 12 weeks

- At least one measurable lesion according to the RECIST 1.1 criteria.

- ECOG performance score of 0 ~ 2

- Adequate organ function

- Absolutely Neutrophil Count (ANC) ≥ 1.5 x 109/L, Platelets ≥ 100 x 109/L,
Hemoglobin ≥ 9.0 g/dL

- Serum Creatinine ≤ 1.5 x ULN

- Adequate liver function (total bilirubin ≤ 2.0 x ULN, AST and ALT ≤ 2.0 x ULN or
< 5.0 x ULN if liver metastases are present)

- Availability of tissue samples (archival tissue or rebiopsied tissues) for molecular
analysis (representative paraffin block or unstained sections from tumor diagnostic
specimen are mandatory)

- Patients who have will and ability to comply with the scheduled visits, the treatment
plan, laboratory tests and any other trial procedures

- Patient's informed consent

Exclusion Criteria:

- Nasopharyngeal carcinoma

- More than two prior lines of chemotherapy in the palliative setting.

- Uncontrolled, untreated brain metastasis Patients with controlled and asymptomatic
CNS metastases may participate in this trial. The patient must have completed any
prior treatment for CNS metastases ≥ 28 days (must include radiotherapy and/or
surgery) and, if on corticosteroid therapy, should be receiving a stable low dose
(e.g. dexamethasone 4 mg or equivalent dose of another corticosteroid for at least 14
days before start of study treatment)

- Surgery, chemotherapy or irradiation within 4 weeks of study entry

- Prior treatment with any investigational drug within the preceding 4 weeks

- Concomitant chemotherapy, hormonal therapy or immunotherapy

- Previous or concomitant malignant disease, except adequately treated basal cell
cancer of the skin or cervical cancer in situ, superficial bladder tumors (Ta, Tis &
T1) or any cancer curatively treated > 5 years prior study entry

- Patient who cannot take the oral drug

- Patient is pregnant or nursing (lactating) women, where pregnancy is defined as the
state of a female after conception and until the termination of gestation, confirmed
by a positive hCG laboratory test (> 5 mIU/mL).

- Clinically significant psychological disorders including mood and anxiety disorders
judged by psychiatry physician

- Patient who have not recovered to grade 1 or better from any adverse events (except
alopecia) related to previous antineoplastic therapy before screening procedures are
initiated

- Severe acute or chronic medical condition or laboratory abnormality that may increase
the risk associated with trial participation or investigational product
administration or may interfere with the interpretation of trial results and, in the
judgment of the investigator, would make the patient inappropriate for entry into
this trial.

- Patient has poorly controlled diabetes mellitus (HbA1c> 8 %)

- Patient has history of cardiac dysfunction including history of documented
congestive heart failure (New York Heart Association functional classification
III-IV) and documented cardiomyopathy

- Patient is currently receiving treatment with medication that has a known risk
to prolong the QT interval or inducing Torsades de Pointes. * Active
infection, inflammatory bowel disease

- Inadequate liver function (total bilirubin ≥ 2.0 x ULN, AST and ALT ≥ 2.0 x ULN
or ≥ 5.0 x ULN if liver metastases are present)