The purpose of this study is to assess the efficacy and safety of AZD6244 (ARRY-142886)versus capecitabine in patients with advanced or metastatic pancreatic cancer who have failed first-line therapy with gemcitabine. Following baseline assessments, a minimum of 64 patients in approximately 5-6 centers from the US will be treated with either AZD6244 or capecitabine. Treatment will be continued for as long as the patients receive clinical benefit. The status of all patients will be checked (whether they are still taking treatment or not) approximately 3 months after the last patient has entered the study.

Inclusion Criteria:

• Confirmed with pancreatic cancer
• Have failed first line gemcitabine therapy

Exclusion Criteria:

• Previous therapy with EGFR inhibitor, MEK inhibitor or capecitabine.
• Any recent surgery, unhealed surgical incision or severe condition such as uncontrolled cardiac disease or chronic gastrointestinal diseases.