A fifth or final cohort of 10 patients will receive ONYX-015 at the MTD. If the MTD was not determined in cohorts 1-4, patients receive the highest dose administered to cohort 4. Beginning 1-2 days after ONYX-015 infusion, patients receive cisplatin IV over 30-60 minutes once and fluorouracil IV continuously over 4 days. Treatment repeats in 4 weeks in the absence of disease progression or unacceptable toxicity. Cisplatin and fluorouracil IV treatment continues every 3-4 weeks at the discretion of the treating oncologist.