This study will compare the efficacy and safety of escalating versus standard doses to rash of Tarceva, in combination with gemcitabine, in patients with metastatic pancreatic cancer. During a 4 week run-in period, all patients will receive Tarceva 100mg/day po plus gemcitabine 1000mg/m2 iv on days 1, 8,15 and 22. After 4 weeks, patients who have not developed rash, or only develop grade 1 rash, will be randomized to one of 2 groups. Group

1 will receive a starting dose of Tarceva 150mg po daily, increased in steps of 50mg every 2 weeks up to a maximum of 250mg/day po, until development of grade 2 rash or other dose-limiting toxicity. Group 2 will continue to receive Tarceva 100mg/day po. All patients will continue to receive gemcitabine 1000mg/m2 iv on days 1, 8 and 15 of each 4 week cycle. The anticipated time on study treatment is until disease progression, and the target sample size is 100-500 individuals.