Inclusion Criteria:

- 18 years old or older

- Histologically or cytologically confirmed diagnosis of metastatic (Stage IV)
adenocarcinoma of the pancreas with measurable or non-measurable disease per Response
Evaluation Criteria in Solid Tumors (RECIST) 1.1

- Performance status score of 0 or 1 according to the Eastern Cooperative Oncology
Group (ECOG) scale

- All prior treatment related toxicities must be Common Terminology Criteria for
Adverse Events (CTCAE) (Version 4.0) ≤ Grade 1 (except alopecia) at the time of
randomization

- Adequate baseline organ function

- Able to swallow and retain orally administered medication and does not have any
clinically significant gastrointestinal abnormalities that may alter absorption such
as malabsorption syndrome or major resection of the stomach or bowels

Exclusion Criteria:

- Prior systemic therapy (i.e., chemotherapy, immunotherapy, hormone therapy, ,
targeted therapy or any investigational anti-cancer drug) for metastatic pancreatic
adenocarcinoma.

(Prior treatment with 5-FU based or gemcitabine administered as a radiation sensitizer
during and up to 4 weeks after radiation therapy is allowed. Prior systemic chemotherapy
in the adjuvant setting is allowed ; however, prior therapy with gemcitabine is allowed
only if tumor recurrence occurred at least 6 months after completing the last dose of
gemcitabine)

- History of another malignancy. Exception: Subjects who have been disease-free for 5
years, or subjects with a history of completely resected non-melanoma skin cancer or
successfully treated in situ carcinoma are eligible. Subjects with second
malignancies that are indolent or definitively treated may be enrolled. Consult GSK
Medical Monitor if unsure whether second malignancies meet requirements specified
above

- Any serious and/or unstable pre-existing medical (aside from malignancy exception
above), psychiatric disorder, or other conditions that could interfere with subject's
safety, obtaining informed consent or compliance to the study procedures, in the
opinion of the Investigator or GSK Medical Monitor

- History of interstitial lung disease or pneumonitis

- History or current evidence / risk of retinal vein occlusion (RVO) or central serous
retinopathy (CSR)

- Symptomatic or untreated leptomeningeal or brain metastases or spinal cord
compression

- History of acute coronary syndromes (including unstable angina), coronary
angioplasty, or stenting within the past 6 months